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January 23, 2012

DEX410v3 – RR Anti-Squat settings

Filed under: News,Tricks and Tips — Tags: , — Stuart @ 1:29 pm
rr-inserts

The DEX410V3 came equiped with a new design of RR suspension hanger on the back of the buggy.

The new hanger #TD330307 uses moulded inserts #TD330309 to change anti-squat settings, rather than switching the whole hanger.  This means there’s less expensive parts for the racer to purchase and more settings possible.

rrbrace-inserts

Squat is the tendancy of the car to lean back under acceleration – the nose comes up and the rear of the car sits down lower. Anti-Squat as the name suggests is designed to reduce the squatting effect and is achieved by angling the rear suspension arms so the front of the pivot point is higher than the rear.

rrinsert-gerd

The further you ‘lean’ the suspension arms back, the more effective anti-squat you’ll get. Unlike the front of the car which could have quite a lot of angle to the suspension, the rear needs far less angle to operate properly and due to the small angles involved  it’s sometimes hard to really see the changes on the bench.  antisquat-angle

squat

The RR hanger from the DEX410V3 uses plastic inserts to off-set the pivot point of the hinge pin. Three different offset inserts are provided in the kit and off-set by different ammounts.

rrbrace-inserts2 rrbrace-inserts3

rrbrace-pinlocation Above: The ‘3’ insert the correct way up inside the RR hanger. This gives the most anti-squat possible – you can see the hole for the pivot ball is offset to the bottom of the insert.

With the RF hanger in -2 ‘Low Roll Centre’ configuration, these inserts used on the RR hanger give 1, 2 and 3 degrees of anti-squat, when the inserts are the correct way round with the number the correct orientation. Running the insers upside down it’s possible to gain extra setup options.

Note: In low roll centre setup, the ‘3’ insert used upside-down actually gives 0.5 degrees of pro-squat.

dex410-rrbracettt-smallminus-pro

Using the ‘High Roll Centre’ setup with the RF hanger in +2, the settings are not quite as easy to understand since the 1-2-3 inserts don’t give settings that match the number shown. The chart below shows the actual settings using the inserts in both orientations when using the high roll centre.

dex410-rrbracettt-smallplus

The anti-squat settings for both high and low roll centres are shown below – or print the PDF version out for pit box by downloading it HERE

dex410-rrbracettt-large

Anti Squat:
Anti Squat helps to keep the mass transfer of  the car in balance under loading. In general, the more anti squat you run on a car, the more it stiffens up the suspension on loading (On Power). This stiffening reduces the energy lost in the suspension as the mass is transferred, which gives more forward traction on power and increases the level of grip under power.

Over bumps, this stiffening has a slight negative effect, in that it makes the car a little worse (for the same oil/piston setup) over bumps.  It is worth keeping this in mind, as there is a compromise.

In Summary:

Increasing Anti Squat

  1. Increases ‘On Power’ rear traction.
  2. Reduces ‘Off Power’ rear traction (Which can help to make the car ‘pivot’)

Decreasing Anti Squat has the opposite effects.

Roll Centre:

rollcentres

Using the -2 block will lower the roll centre height making the car ‘roll’ more at the rear end, which can help to generate grip on low traction surfaces and will make the car change direction slower than in the +2 position.

When changing to the +2 block, remember to re check your droop setting as it will have changed from the block being in the -2 position.

December 14, 2011

DESC410R TD320141 Rear Bumper Install

Filed under: News,Tricks and Tips — Tags: — Stuart @ 2:15 pm
td320141-title

The DESC410R short course truck comes supplied with a small rear bumper which keeps the weight low and is the best option for fast lap times.   Some racers have asked for a full rear bumper for more heavy contact racing or where the rules state a full bumper is required.  The TD320141 rear bumper set for the DESC410R comes supplied in 4 parts which need to be trimmed from the parts tree.

descrearbumper-parts

The first task to fit the new rear bumper is removing the existing small skid plate bumper from the truck.  7 screws of varying sizes go through this part and it’s a good idea to put these to one side in order so you know where they go when it comes time to install the new skid plate.  The new plate itself is similar to the existing part but has mounting points for the new bumper.

desc410rbumper-exploded descrearbumper-rearplates New skid plate & old

You can assemble each part to the truck one at a time if you like but here we’ll assemble the bumper off the truck and then attach it as one part.

descrearbumper-install1 descrearbumper-install2

The main bumper part screws down to the new skid plate with four M3x12mm button head screws before an upper brace attaches to secure the bumper against the top of the rear bulkhead – again using M3x12mm screws.

descrearbumper-install3_0

descrearbumper-install4 descrearbumper-install5

The DESC410R full rear bumper is made to be light weight but hanging any large item off the back of your car is going to effect handling slightly and so to minimise the weight we’ve designed the bumper to have an optional lower bar at the rear for extra protection, or less weight without it – you choose.  Four M3x12mm screws attach the lower bar and there’s provision for 3rd party mud flaps if you want to go for even more scale looks.

descrearbumper-lowerbar The lower bar on the full bumper can be fitted for extra protection. descrearbumper-lowerbar2

With the bumper fully installed it’s time to adjust the body to fit the new bumper.  The DESC410R full rear bumper set is designed to sit just inside the outer rear quarters of the body shell to protect the corners.clear-bumperTo fit the body you have to cut a recess where the body will sit around the top bar of the bumper.  You can cut this with scissors or better yet a rotary tool with sanding drum as this will create a perfectly rounded recess – you don’t want any sharp corners in here as it could start to tear or deform with rear impacts.

descrearbumper-body1 descrearbumper-body2

See the above images for an example of how the body needs to be adjusted to fit.  Give the bumper some extra room to move around and upwards too – as heavy landings or impacts will flex the bumper so a little extra clearance is a good thing.

Now you can enjoy racing even when people are ramming into your rear bumper – as long as they stay behind it’s all good.

November 29, 2011

Turnbuckle Build Guide

title

Having links pop-off during a heavy crash on the race track is frustrating but understandable – having them pop-off during adjustments however is possibly even more frustrating but it’s something you can prevent.  This guide is to help users build their turnbuckles to minimize the chances of them popping off during adjustments.

unpopped-adjustments Adjust settings without taking the link off

The steering and camber link ball cups on all 10th scale Team Durango vehicles have holes to allow adjustments without popping-off the link and it’s good practice to always use this method when making adjustments.

Every time you pop-off a link it gets a little looser and easier to pop-off next time – which could be during a crash or when making adjustments.  A 2.5mm hex driver can be simply poked through the ball cup to unwind the ball stud and reposition it in the desired location or to add/remove shims.

DEX210 front camber link: front210turnbucklescompared

locking-the-link The reason the links can pop-off during adjustment is due to the turnbuckle having too much friction inside the ball cup.

Left: Locking the link with hex tools will stop it popping off when adjusting.

A quick fix to stop the links popping off during adjustment is to put 2.5mm allen keys / hex drivers in each end of the link – locking the link and stopping it turning and popping off.  This works well for really tight links but isn’t a real long-term solution.

assemblelink To make adjustments easier first grease the threads of the turnbuckle – and then wind it fully in and out of the ball cup a couple of times to free things up. You want the grease the inside of the ball cup where the threads are – so make sure the grease gets inside and isn’t simply wiped-off when assembling the link.

Right: Thread the turnbuckle in and out a couple of times to help future adjustments.

An easy way to build the links is using a 3mm driver shaft placed through the ball cup to hold it in place whilst you turn the turnbuckle (or turn the ball cup whilst holding the turnbuckle). Don’t use anything with a smaller diameter as it might deform the ball cup.  The combination of the greased threads and running the turnbuckle in and out of the ball cup should make future adjustments a lot easier.

geasethreads A small dab of grease on the turnbuckle pre-ream Threaded all the way in

Using the DEX210 as an example – both the front camber and steering links are built with 1 or 2mm of un-threaded turnbuckle inside the ball cup, depending on setup – this makes adjustments hard even with the aforementioned preparation.  On the shortest possible front camber link setting, there’s a substantial length of un-threaded turnbuckle going into the ball cup, making adjustment less easy.

open-rodend The standard HD ball cup has no real accommodation for the un-threaded part of the turnbuckle reaming You can use a reamer to open up the ball cup a little

When building the links you can open them up slightly with a reamer to accommodate the slightly wider un-threaded part of the turnbuckle.  Don’t take out too much – you just want to make it less restrictive around the opening, which shouldn’t have any real impact on the hold of the threads which will be further inside than the reamer will travel.

reamed2 You don’t need to take out lots of material reamed Standard ‘HD’ ball cup left and reamed-out ball cup right.

Something often overlooked is having each end of the link centred so it’s free to move smoothly during normal operation.  If you adjust the links off the car and attach them, chances are the link will be mis-aligned.

Building the links in this way, using grease and winding the settings in and out – along with opening up the end of the ball cup slightly – will help reduce the chance of the link becoming stiff enough that it’ll twist off when adjusting.

LinkTurnAbove: The links should have plenty of room to move smoothly if aligned properly.

Keeping things together and resisting the temptation to simply ‘pop’ off the links when adjusting / maintaining the car will prolong their life and reduce the chances of them coming off in a crash.

June 3, 2011

410 Diff Seal mod

Filed under: News,Tricks and Tips — Tags: , , , , , — Stuart @ 1:57 pm

ttt-410-diffseals-oily The 410 family of vehicles have used the same X-ring diff seals since launch and some users have had less success than others with them.

The washers (TD709001) that sit next to the X-rings and behind the E-clip were updated to a slightly thicker item as a running change to help minimise outdrive movement and keep things nicely sealed but still some users have experienced a slow leak of the diff oils.  The older TD709001 washers were black and the updated items are silver – so you can check to see which you have.

Some of our team drivers have tried other seals to find the best possible performance and some of our drivers have been using DNX408 shock o-ring seals (Part No.TD330099) in the DEX410 differentials for months without problems of leaking.

ttt-410-diffseals-standard Standard X-ring seal ttt-410-diffseals-compared The DNX408 (TD330099) shock seal vs the standard X-ring

The Shock o-rings are smaller than the X-rings but once assembled into the differentials they fill the gaps and seal well. Oil the recess where the o-ring will sit and place the 0-ring in position.

ttt-410-diffseals-assemble1 Lube the recess where the o-ring will sit

ttt-410-diffseals-assemble2 Grease or oil the input shaft

ttt-410-diffseals-assemble4 ttt-410-diffseals-assemble5

If you insert the outdrive / input shaft into position now you’ll probably dislodge the o-ring and getting it fully seated with the outdrive shaft in place can be tricky – you can use the box spanner from the kit, to press down the o-ring whilst the input shaft is in place.

ttt-410-diffseals-install_0 You can use the box driver from the kit to push the o-ring down whilst inserting the outdrive ttt-410-diffseals-oringinstalled2 Done!  –  now for the other side

Reinstall the washer and e-clip and after you’d done both o-rings just follow the rest of the regular differential build – the guides below have some useful tips that relate to building the differentials as well as the gearbox housings.

Items you’ll need for the modification are one pack of TD330099 DNX408 SHOCK SEAL O-RING  – which contains enough to do four differentials.

150wideTTT

You can read some useful differential build information in the DESC410R centre diff article here:
DESC410R Centre Diff Option

Information on tightening the differential case properly to ensure it’s sealed well can be found in the Gearbox Build Guide here:
DESC410R/DEX410 Gearbox Pro-Build

DESC410R 2mm Anti-Roll Bar set screw mod

Filed under: News,Tricks and Tips — Tags: , , , , — Stuart @ 10:42 am

TTT-410-rollbargrubscrew-1The 2mm anti-roll bar is the hardest anti-roll bar option part for the DEX410/R and DESC410R line of vehicles and whilst it was for the most part too hard for the DEX410 buggies it’s an ideal roll bar on the new DESC410R short course truck.

The 2mm bar fills the hole in the alloy anti-roll bar pivot ball (TD330015) and like the smaller bars it’s held in place by a single set screw.

The design of the M3 set screw has a small ‘cone’ shape at the leading edge and on the smaller anti-roll bars this isn’t a problem since the set screw sits deep inside – using the 2mm anti-roll bar however means that this ‘cone’ sits out into the threads so there’s a little less thread for the screw to hold onto whilst tightening. It’s quite easy to overtighten and strip the threads in the anti-roll bar balls when using the 2mm roll bar and standard set screws.

ttt-410-rollbargrubscrew-layout

To get the set screw to have the maximum hold, you can remove the cone by grinding the leading face of the screw so it’s flat – this will allow the set screw to sit further into the alloy ball with more threads engaging.

Above & Below – the ‘flattened’ face set screw allows the threads to contact lower down giving a better hold.

ttt-410-rollbargrubscrew-illustrator

You can use a dremel-style tool with a grinding head to quickly flatten the set screw whilst it’s perched atop an allen key / hex driver.

ttt-410-rollbargrubscrew-ground2 ttt-410-rollbargrubscrew-ground

You still need to use care when tightening the modified set screw and use threadlock to prevent it coming loose – but using this mod should help prevent premature failure when assembling / maintenance.

April 29, 2011

1/10th scale BIG BORE spring charts

Filed under: News,Tricks and Tips — Tags: , , — Stuart @ 4:31 pm

TEAMDURANGO-star180The new big bore dampers for the DEX410, DEX410R and DESC410R are now available in the shops and alongside the shocks we’ve released a range of springs suited to the new larger diameter dampers.

The springs are available in sets for front, hard front and rear. The aptly-named ‘hard front’ spring set is as the name would suggest a harder range of springs than the normal front, and they carry on from that set with 8 new progressively harder spring options.  These ‘hard’ front springs are more suited to the heavier DESC410R for which they were designed – though there’s no reason you can’t fit them to the front of the smaller & lighter buggies, it just wouldn’t be suitable in most conditions.

BigBoreSpringChart-smallBig Bore Spring Chart – Mini Version (PDF)

With so many springs available we’ve created a couple of charts to help racers understand the options – a small chart with just the spring colours and weights, and a more comprehensive version with all the data you’d possibly need.

BigBoreSpringChart-largeBig Bore Spring Chart – Full Version (PDF)

Spring kit part numbers: (all springs are available in pairs also)

#TD230027 – BIG BORE SPRING SET: 45mm LENGTH (8 Pairs)

#TD230028 – BIG BORE SPRING SET: 65mm LENGTH (8 Pairs)

#TD230029 – BIG BORE SPRING SET: HARD 45mm LENGTH (8 Pairs)

April 6, 2011

DESC410R +1 Degree rear hubs

Filed under: News,Tricks and Tips — Tags: — Stuart @ 5:49 pm
ttt_desc410r_toeinhubs_title

ttt_desc410r_toeinhubs_hubs The DESC410R kit comes supplied with some ‘1 degree’ optional rear hubs in the kit, to tune the handling of the truck to suit track conditions and driving style.

The hubs affect TOE-IN values and depending on how you use them, you can gain rear stability or loosen up the rear for more rotation in the corners and greater straight-line speed.

Toe-in on the DESC410R is -3 degrees by default – which is set by the angle of the suspension arms on the inner hinge pin.  -3 degrees is a well established default used on on rear of many manufacturers cars as it’s a good compromise between stability and speed. The optional +1 degree hubs can be confusing as they are marked to ADD degrees the opposite way – in other words, ‘reduce’ toe-in values.

ttt_desc410r_toeinhubs_lineup
TTT_DESC410R_ToeInHubs_toesetting

Toe-in is ‘negative’ toe. Using the ‘R +1’ hub on the right hand side of the car will increase the positive toe at the right hand side of the car by one degree, to two degrees negative toe in total. (-3+1=-2).  Using the R+1 on the left hand side of the car will decrease the toe on the left hand side of the car by one degree to four degrees toe in. (-3-1=-4)

The most common use for optional hubs like these is to create more negative toe-in to aid rear-end stability on loose tracks, so this guide is to help inform racers on which way round the hubs should be used to get the desired setting.

More Toe In – R +1 on the Left,  L +1 on the Right = -4 Degrees Total Toe-In::
Lower top speed
Greater stability at rear
Less Steering

Less Toe In – R +1 on the Right,  L +1 on the Left= -2 Degrees Total Toe-In:
Higer top speed
Less stability at rear
More Steering

DESC410R Centre Diff Option

Filed under: News,Tricks and Tips — Tags: , — Stuart @ 2:42 pm
ttt-desc410r-centrediff-title
TTT-DESC410R-CentreDiff-lockerandparts

The DESC410R Short Course truck comes with a locked centre drive unit which can easily be turned into a centre differential. Purchasing the optional TD210031 ‘Conversion set for centre slipper-diff’ gives you all the parts that you need to replace the ‘locker’ with the diff parts.

ttt-desc410r-centrediff-parts The standard ‘locked’ setup will put all the available power down to all wheels under acceleration (depending on slipper settings) and is the most agressive setup, best suited to smoother tracks with high traction. The centre differential works by limiting the power transmitted to the end with the most load to prevent it breaking traction. Running high powered motors – especially the 550 motors popular in the 4WD SC class, not only puts strain on the transmission but can make the truck hard to drive over rough surfaces or in low traction conditions. The centre diff will help smooth out the power delivery, absorb bumps and jumps to keep the truck headed on desired course.

Building the centre diff on the DESC410R uses the same differential parts as used in the other differentials on the truck – which have been bundled together in the slipper-diff conversion set specifically for the DESC410R.
Building the slipper-diff is similar to the other differentials on the truck. The truck already comes supplied with the X-ring seals which require some lubrication – so if you didn’t already do this when building the car you’ll need to disassemble all the parts and make sure to lube these X-rings and the shaft / drive cup that will ride in them.

ttt-desc410r-centrediff-oilxring Put some diff  oil where the Xring will sit ttt-desc410r-centrediff-eclip

It’s a good idea to test-fit the larger 14 tooth gears on the hexagonal shafts before reassembly as they can be quite tight. Tight or not – you can still fit them by tapping them into place but it will make disassembly more time consuming which is something you’ll need to think about if you’re wanting to regularly swap between running a diff or locked centre.
You can use some fine abrasive paper to take some of the black coating off the hexagons which should be just enough to allow the gears to drop into place.

ttt-desc410r-centrediff-sand You can lightly sand the Hex’s to make assembly/rebuild quicker ttt-desc410r-centrediff-tap Tapping the gears down gently with the box spanner

It’s a good idea to put some diff oil around the output shafts under the gear before pressing it onto the shaft as it can be hard for the oil to work its way back there on its own.  Likewise – if you’re going to run some very thick oil it’s a good idea to partially fill the diff casing with oil before dropping the spider gears into the housing.

ttt-desc410r-centrediff-oilbehind Put some diff oil behind the gears ttt-desc410r-centrediff-fill Some diff oil before dropping the spider gears in

Top-up the oil to just below the top of the spider gears and tighten the diff together using a cross-pattern to ensure the diff casing goes together straight.

The centre differential will help protect the drivetrain from shocks but you still need to use the slipper in combination with the differential.  Testing the slipper in the truck will be hard since the newly installed centre differential components will mask the effect of the slipper – so setting the slipper as suggested in the slipper build guide (http://www.team-durango.com/blog/?cat=3) and testing in the hand is a good method.

Tightening up the screw that secures the slipper-side drive cup can be tricky since you need to clamp both the opposite drive cup and the diff body itself to stop them spinning.  You can use one of the included slipper wrenches in the opposing drivecup to give more leverage and clamp both parts with one hand as you tighten the screw down.

ttt-desc410r-centrediff-full Centre diff filled ttt-desc410r-centrediff-tighten Tightening down the drive cup

Centre Diff Oil Effects:
The centre differential gets a real work out and depending on track conditions, you’ll want to run different oils to get the optimum setting. Generally you’ll use a thicker oil in the centre than you’d use elsewhere and a baseline of around 20K CST is a good starting point. Too light an oil will be obvious as the truck will lean back on hard acceleration and allow the front wheels to spin with the tyres ballooning excessively, meaning the truck is slow to take-off. Running a very heavy oil such as 50K CST will have very little ‘diff’ action and allow for hard acceleration.

Thinner oils are more suited to bumpy and low-traction conditions. Off power there will be more steering whilst on-power there will be less steering. The tendancy for the rear end to wash out under power will also be reduced – so you can be a little less gentle with the throttle, making the car easier to drive.

Thicker oils will feel progressively closer to the locked centre setup. With more drive to the rear wheels there will be more chance for the rear to break traction. Over uneven terrain or slippery surfaces the truck will be more reactive and potentially harder to control – especially if very fast motors are used. On-power steering will be improved.

Because braking is applied to the spur gear, rather than having a mechanical setup as in a 1/8th buggy, oil thickness will also have an effect of braking. A thin oil will prevent the truck from nosing-down too much under braking but could reduce the effectiveness of the brakes too much on high traction surfaces where you’re trying to late-brake into corners.  Like everything, you need to find a balance that suits your driving style and the track you’re running on.

ttt-desc410r-centrediff-packet

March 30, 2011

DESC410R – Slipper Setting

Filed under: Tricks and Tips — Tags: — Stuart @ 8:56 am
ttt-slipper-title

The DESC410R comes equipped with a slipper clutch to protect the drivetrain from high loads and shocks from landing jumps.  With proper build technique the gearboxes should be tough but setting the slipper is a vital part in the process of preparing your vehicle for the punishment of the race track.

TTT-Slipper-parts The DESC410R slipper unit in unassembled form

The slipper works by clamping two fibre-pads, one either side of the spur gear – and by varying the clamping force applied you can change at what point things start to slip.  An ideal setting is one that will allow the vehicle to accelerate quickly whilst minimizing front wheel-lift (wheelies!) and protect the drivetrain from harsh impacts.

ttt-slipper-pads ttt-slipper-padson
ttt-slipper-spring On the DESC410R the slipper is set with a nut clamping down a heavy duty steel spring.  A second nut is used to effectively lock the setting and prevent things from coming loose.

We’ve found a good base setting to be 3mm between the bottom of the first nut and the face of the bearing that sits against the slipper plate.  From this point you can adjust and find a setting that suits your setup and track conditions.

ttt-slipper-measure2 ttt-slipper-measure
ttt-slipper-test You should be able to hold the diff-casing between the fingers of one hand and turn the spur gear with the other.   If it’s very hard to turn then loosen things off – you can always play with the setting in the car to adjust it.  If you tighten things too much you could damage the drivetrain as a result of an ineffective slipper.

Holding the body of the slipper unit in your hand you need to lock the first nut in place so as not to change the setting whilst locking things up.  You can position one of the included wrenches around the lower nut and clamp it with your thumb – then using the second wrench carefully tighten the top nut against the first to lock the two in position.

ttt-slipper-tighten ttt-slipper-nuts

A good test of your slipper is to place the vehicle on a very high traction surface and accelerate hard – you want the slipper to slip for the first few feet instead of the front end elevating.  You should be able to feel & hear when the slipper is doing its job.  It’s best to start loose and tighten up as required rather than risk damaging the drivetrain.

If you choose, you can purchase the centre diff option parts (#TD210031) to run a centre differential to help put the power down on bumpy / loose surfaces.  The centre diff will absorb some impact and help the slipper protect the rest of the drivetrain but don’t assume the centre slipper will protect the drivetrain properly on its own – you still need to use the slipper.  It can be harder to set the slipper and test the setting when using in combination with the centre diff so measuring the setting might be the best way of getting things set right.

March 9, 2011

DESC410R/DEX410 Gearbox Pro-Build.

Filed under: News,Tricks and Tips — Tags: , — Stuart @ 5:10 pm
TeamTechTipsLogo-1

DEX410 / DESC410R Gearbox Build Guide

gearboxtip-01 Getting the gearboxes built correctly on the DESC410R/DEX410 vehicles is critical for long-life and handling the rigors of racing.  The metal gears are strong but nothing can cope with the combination of a poory built drivetrain, extreme power and on-track abuse.  So please take a look at this guide to help protect your drivetrain and keep you on the race track.

With the differential built and filled with oil, attach the crown gear half of the differential and fasten the screws down in a cross fashion.  Back off all the screws a turn or two before repeating the cross pattern tightening again – this is to ensure the crown gear is sat fully in place and aligned correctly.

gearboxtip-crowngear-02 Tighten the gears in a cross pattern. gearboxtip-crowngear-01 After the crown gear is attached – loosen the screws a little and tighten cross-pattern again.

410diffshims

Shimming the differential correctly is an important step and this is the next stage of building the perfect gearbox. The DESC410R/DEX410 come with two types of shim for this purpose, a 0.2mm which is silver in colour and a 0.1mm copper-coloured shim.Firstly you need to know how many shims will get the diff sitting correctly so press down the bearing on the moulded diff-body side so it’s fully in place as we’ll use the crown gear side of the diff to play with shim settings – this is purely because it’s much easier to remove / replace the bearings on this side whilst we find the perfect setting.

Start with one 0.2mm silver shim on the crown gear side and slide the bearing over the top.  Place the diff with shims and bearings installed into the empty differential case and clamp the case tight between your fingers.  Next you need to clamp the outdrives with your other hand, squeezing them inward whilst trying to ‘rock’ the diff side to side in the case.

410diffshimtip02 One silver shim in position. 410diffshimtip01 Test the end-float in the case by trying to shift the diff sideways.
If you can feel a slight movement then you can maybe add a 0.1mm copper coloured shim to the same side, next to the previously installed shim and try again.  If on the other hand your diff is hard to install or feels to be binding then  you can remove / add to find your perfect balance.  The shimming in this guide is for the parts we used – your shimming could be different so be aware.
410diffshimtip04 One silver shim wasn’t enough in this case, so I’ve added a second copper shim. 410diffshimtip03 Silver and copper shims together were the right setting – now it’s time to position them.

410diffshimtip06 Once you’ve found the setting that feels right you need to test against the input pinion gear – this will define where you need to place the shims you’ve just decided upon. Place the input shaft / pinion gear into the gearbox housing along with the diff you’ve just shimmed correctly and clamp the case halves together with the provided screws and spin the input shaft.  With all shims on the crown-gear side (where you should have been test-fitting them) you might find the gears are loud and have excess friction – so next comes choosing which side you place your shims.

You want the crown gear as close to the pinion gear as you can to get a good mesh – but you don’t want it so close that the gearbox is notchy or excessively loud. With the example differential in the photos needing one of each shim, you could leave the 0.2mm silver shim on the crown gear side and place the smaller copper-coloured 0.1mm shim behind the bearing on the opposite side.  This will shift the diff over by 0.1mm and effectively seperate the crown gear and pinion by the same amount.   Re-assemble the gearbox and test as before to check how smooth the gears are – a slight roughness  to the action is fine but if there’s still excessive noise and friction you can continue adjusting the shims to suit.

DiffShimmedAbove:  In the example above, the perfect setting  ended up with one silver shim on the Crown-gear side and one copper shim on the moulded side.

inputshaftWith the differential shimming complete the last point to look at when building your DESC410R/DEX410 is the input shaft itself.  Simply tightening the CVD-shaft onto the input shaft and placing it into the gearbox housing could result in some degree of  movement.  You can check this by clamping the gearbox together very tightly with your fingers or screwing the halves together – then with the unassembled CVD attached to the input shaft, try to rock the shaft vertically up and down (see photo).  The movement, if any, will be slight – but this is amplified inside the gearbox and will result in the teeth of the gears having an improper contact patch which will place excess strain on the gears.
gearboxtip-03 Input shaft with bearings in place. gearboxtip-06 Tighten the grub screw whilst applying pressure to squeeze the two halves together.

To get the perfect setting and eliminate any play in this vital area you need to loosely join the CVD shaft to the input-shaft and place them into one half of the gearbox housing.  Clamp the two metal parts together so you’re pushing the CVD and input shaft together and squeezing the bearings against the plastic divider.  Carefully tighten the grub screw on the CVD part of the assembly whilst applying the pressure and test the input shaft for movement again.

gearboxtip-04 Tighten the gearbox screws TIGHT to help clamp the bearings. gearboxtip-05 With an improper setting the input shaft will be able to rock up  & down slightly – it’s hard to detect with the full driveshaft in place.

TeamTechTipsLogo-3Adjusting the amount of pressure applied during tightening will vary the setting  – when you get it right the shaft should be firmly set and free from any play. If you apply too much pressure you might find the bearings binding slightly, so try again.  The perfect setting should see minimal binding of the bearings but a totally rock-steady shaft.

Your gearbox should now be ready for the track – time to build the other one the same!

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