Wolfie1 X-MAXX

[wolfie1]

The rear diff issues have reared their ugly head again, so it has got me into really trying to get to the bottom of it for once and for all. My thought are the pinion bearing thats causing the issues, most likely like everyone else you see a cheap bearing kit on ali and think price is right, mine. So what im thinking is when the power is on the pinion pushes back against the bearing and and causes sideward force on it causing it to deform and thus causing the pinion to only engage 1/4 of the way against the crown gear and then the teeth are wearing/chipping and letting it slip. I have bought 3 rather expensive bearings like £12 each bearings, 1 for the pinion to run on and 1 for each end of the centre diff.

 

i then cut a piece of an old centre driveshaft and made it fit absolutely perfectly (6.19mm) between the back of the pinion and the bearing on the centre diff

it fits in like this

my theory is by doing this as well as using really good quality deep groove bearings i am also spreading the load against all 3 bearings and thus stopping them failing, will it work who knows but the theory is sound i think

i liked the look of this newly designed diff carrier as the race which the bearing runs on is hardened steel so should have a longer service life, i did try it in the centre as it is a bit more chunky than the standard design but it does not fit even though its advertised for this use as well

Edited May 23, 2024 by wolfie1

[Stormbringer]

Really hope that finally sorts it for you mate 

[wolfie1]

24 minutes ago, Stormbringer said:

Really hope that finally sorts it for you mate 

Thanks, heres hoping. I did also order an alloy top bulkhead but it doesnt fit with the brand of alloy diff covers i have, so am waiting for the same brand diff cover to arrive so that can be installed

[Kpowell911]

21 hours ago, wolfie1 said:

The rear diff issues have reared their ugly head again, so it has got me into really trying to get to the bottom of it for once and for all. My thought are the pinion bearing thats causing the issues, most likely like everyone else you see a cheap bearing kit on ali and think price is right, mine. So what im thinking is when the power is on the pinion pushes back against the bearing and and causes sideward force on it causing it to deform and thus causing the pinion to only engage 1/4 of the way against the crown gear and then the teeth are wearing/chipping and letting it slip. I have bought 3 rather expensive bearings like £12 each bearings, 1 for the pinion to run on and 1 for each end of the centre diff.

 

i then cut a piece of an old centre driveshaft and made it fit absolutely perfectly (6.19mm) between the back of the pinion and the bearing on the centre diff

it fits in like this

my theory is by doing this as well as using really good quality deep groove bearings i am also spreading the load against all 3 bearings and thus stopping them failing, will it work who knows but the theory is sound i think

i liked the look of this newly designed diff carrier as the race which the bearing runs on is hardened steel so should have a longer service life, i did try it in the centre as it is a bit more chunky than the standard design but it does not fit even though its advertised for this use as well

Have you shimmed the diff? How good are your plastic bulkheads (condition wise)?

[wolfie1]

1 hour ago, Kpowell911 said:

Have you shimmed the diff? How good are your plastic bulkheads (condition wise)?

Yea diff is shimmed with 2 .1mm shimms, (it was shimmed last time too),i found a .3 was too much. It was a brand new rear bulkhead last time i rebuilt it with about 16 sets of packs through it, i have rebuilt it with another new bulkhead this time around again, i have never had a car which likes eating diffs so much!

[Tug]

It's a Traxxarse, they eat diffs for fun. 

[Kpowell911]

1 hour ago, wolfie1 said:

Yea diff is shimmed with 2 .1mm shimms, (it was shimmed last time too),i found a .3 was too much. It was a brand new rear bulkhead last time i rebuilt it with about 16 sets of packs through it, i have rebuilt it with another new bulkhead this time around again, i have never had a car which likes eating diffs so much!

Its mental because Im on my 5th Xmaxx and 1st XRT. 2 of my XMaxx’s had 56XX motors, and Ill be honest, Ive never even saw an Xmaxx diff as Ive had no issues? =/
 

 

[wolfie1]

42 minutes ago, Kpowell911 said:

Its mental because Im on my 5th Xmaxx and 1st XRT. 2 of my XMaxx’s had 56XX motors, and Ill be honest, Ive never even saw an Xmaxx diff as Ive had no issues? =/
 

 

And i have replaced everything more than once already!

[MrMcG]

Really enjoyed reading this. 

 

They are phenomenal pieces of kit, definetly my favourite basher the only other car that comes close is the old Losi LST2.

 

Feel inspired to do one about my X-Maxx now 😄

 

Great thread buddy

[wolfie1]

10 hours ago, MrMcG said:

Really enjoyed reading this. 

 

They are phenomenal pieces of kit, definetly my favourite basher the only other car that comes close is the old Losi LST2.

 

Feel inspired to do one about my X-Maxx now 😄

 

Great thread buddy

Go for it, i would enjoy reading yours too.

i thought i would start my own dedicated thread to see the evolution from when i first got it shiny new to whatever it turns out to be in its lifetime, its actually quite nice for myself to look back on too and reminisce 

[wolfie1]

12 hours ago, Tug said:

It's a Traxxarse, they eat diffs for fun. 

I have a few other traxxas models, a trx4, slayer and a tmaxx and have never killed a diff in any of them, they only other models i have killed diffs on is a savage xl but upgraded them too sintered ones about 15 years ago and have been good ever since, (this is the only other car where i have actually broken teeth though) a quantum flux but it was the diff alloy casing that wore away and i broke a drive cup where the pin goes through inside the diff on my blackout.

The thing that gets me though is after reading online it seems to go 1 of 2 ways either like kpowell and have never broken a diff or like me and am always replacing them, the only constant is me as i have replaced everything on the rear end driveline within the bulkhead, i dont think im especially hard on it as when i go out its usually in a grass field and run 5 pairs of pack through it and dont do huge jumps, i do wonder if its the more powerful motor thats causing it through the extra torque, but hopefully i have addressed that with my latest idea, either that or i will destroy the teeth in the centre diff with the extra drive shaft piece i added getting hot and then expands and pushes everything together too much! I can only try i suppose

[wolfie1]

Went out to test what i had done, got to the end of the first set of packs and the new diff is slipping again, came home and took it apart, removed all the shims including the spacer bit i made, put it all back together and just running it in my garden its not slipping, i need to do a more thorough test to know but all i had to do was give it power and it would slip and now its not so its looking positive

 

edit- it was a fail new hardened steel diff is destroyed, im just not sure where to go with this now, new bearing has destroyed itself too, maybe no shims?

Edited May 26, 2024 by wolfie1

[Tug]

On 25/05/2024 at 11:07, wolfie1 said:

I have a few other traxxas models, a trx4, slayer and a tmaxx and have never killed a diff in any of them, they only other models i have killed diffs on is a savage xl but upgraded them too sintered ones about 15 years ago and have been good ever since, (this is the only other car where i have actually broken teeth though) a quantum flux but it was the diff alloy casing that wore away and i broke a drive cup where the pin goes through inside the diff on my blackout.

The thing that gets me though is after reading online it seems to go 1 of 2 ways either like kpowell and have never broken a diff or like me and am always replacing them, the only constant is me as i have replaced everything on the rear end driveline within the bulkhead, i dont think im especially hard on it as when i go out its usually in a grass field and run 5 pairs of pack through it and dont do huge jumps, i do wonder if its the more powerful motor thats causing it through the extra torque, but hopefully i have addressed that with my latest idea, either that or i will destroy the teeth in the centre diff with the extra drive shaft piece i added getting hot and then expands and pushes everything together too much! I can only try i suppose

 

The only Traxxas I've owned that didn't eat diffs was the Slash 4x4, but the diffs were the right size for the Slash. In my E-Maxx, Revo and Summit, the diffs were the same as the Slash diffs and would fail all too often. 

 

Sintered is not an upgrade, it's a downgrade. Did you mean hardened?

[wolfie1]

12 minutes ago, Tug said:

 

The only Traxxas I've owned that didn't eat diffs was the Slash 4x4, but the diffs were the right size for the Slash. In my E-Maxx, Revo and Summit, the diffs were the same as the Slash diffs and would fail all too often. 

 

Sintered is not an upgrade, it's a downgrade. Did you mean hardened?

Maybe it was hardened, it was many years ago i changed them, i do remember them being £30 each though

[wolfie1]

Today took the xmaxx out and thought i would try something with the latest diff rebuild, used a standard diff which normally lasts about 5 minutes and i got through a whole set of packs and no diff slipping, so no ground down teeth! After the last time it went i was thinking what in common there was each time as when i first got the truck diffs were lasting, only thing i came up with was shimming the diff, so i didnt bother this time!, Now when i was doing this i was adding a 0.1 or 2 shims to get rid of the slop in the mesh and made sure it wasnt binding, will need to run a few more packs tomorrow as run out of time today as i was helping a friend fit a pick up hitch on his vintage tractor

[Stormbringer]

Good luck with it tomorrow mate 

[Tadas]

On 01/06/2024 at 20:47, wolfie1 said:

Today took the xmaxx out and thought i would try something with the latest diff rebuild, used a standard diff which normally lasts about 5 minutes and i got through a whole set of packs and no diff slipping, so no ground down teeth! After the last time it went i was thinking what in common there was each time as when i first got the truck diffs were lasting, only thing i came up with was shimming the diff, so i didnt bother this time!, Now when i was doing this i was adding a 0.1 or 2 shims to get rid of the slop in the mesh and made sure it wasnt binding, will need to run a few more packs tomorrow as run out of time today as i was helping a friend fit a pick up hitch on his vintage tractor

Interesting that you have so much probs with diffs... In last 2 years iv replaced diff only one time. Is your center diff locked or has some give? Do you jump or stop/start aggressive a lot? Its a big truck, something will always brake if you drive aggressively 🙂

 

[wolfie1]

22 hours ago, Tadas said:

Interesting that you have so much probs with diffs... In last 2 years iv replaced diff only one time. Is your center diff locked or has some give? Do you jump or stop/start aggressive a lot? Its a big truck, something will always brake if you drive aggressively 🙂

 

No none of that stuff to excess and it does have the centre diff, although now that i havent shimmed anything nothing has destroyed itself as yet, so fingers crossed, i did have a tyre shred on me on Saturday, it was like it exploded! It was quite cool to watch, my friends sister got it on video!

Edited June 16, 2024 by wolfie1

[wolfie1]

Had my car out on saturday and i had a back tyre explode on me!

 

[Stormbringer]

Ouch mate ,have you spares ?

[wolfie1]

5 minutes ago, Stormbringer said:

Ouch mate ,have you spares ?

Not a tyre, tbh it was the last thing i ever expected to happen especially being belted tyres, have ordered a new pair

[wolfie1]

So this was the bit of tyre that came off

[Kpowell911]

On 16/06/2024 at 18:02, wolfie1 said:

Had my car out on saturday and i had a back tyre explode on me!

 

This is why I wheelie as little as possible! Bizarre that the rear one went first. Were these the ‘belted’ Louise ones (I forget what Louise called belted tyres)

[wolfie1]

1 hour ago, Kpowell911 said:

This is why I wheelie as little as possible! Bizarre that the rear one went first. Were these the ‘belted’ Louise ones (I forget what Louise called belted tyres)

Yea thats the ones louise belted tyres, never noticed no damage on tyre beforehand as i had just properly cleaned the car as i had it to a vintage rally as you can see, put some on display in the model tent and had the trx4 and trailer driving around the place putting a smile on folks faces, that got so many photos over the weekend

[Stormbringer]

Nice collection of models mate