HARDENED STEEL Differential gears at lower prices (to go with your aluminum diff cup)

[noir 522]

Yes we all know that TruckMasters from Germany sells Aluminum diff cups for approx $155 a pair. But their hardened steel diff gears are even more ($180)
Surfing the erevo boards I realised that the differential ring and pinion gear are the same for both the erevo and the summit
(traxxas part number 5379X Ring gear, differential/pinion gear differential).





And also the internal spider gears for the erevo and summit are the same
(Traxxas part number 5382X Gear set, Differential set (output gears (2)/spider gears (2)/ spider gear shaft/ diff carrier support)




I took apart both, an old erevo diff and a newer summit locking diff that I had sitting around and yes all the parts (spider gears, pinion, ring are interchangable - I switched them to test)


Knowing that the erevo has a larger aftermarket following than the summit I have found two companies that sell Hard steel diff parts for the erevo (summit)

RRP Robinson Racing Parts - but they only sell the hard steel main pinion and ring gear - APPROX $40 each diff




http://www.ebay.com/itm/ROBINSON-RAC...-/221039387664

and GPM - they sell the entire Hard Steel internal diff gear set APPROX $20 per diff



http://www.rcmart.com/strv1200-hard-...th=595_739_603


I know that RRP parts are top quality but I dont know much about GPM hard steel parts (although their aluminum parts look nice)

and of course there are the truck masters set for a little over $170 for 2 complete sets



http://www.truckmonster.de/shop/k003u006s001.htm


** of course you would still need the aluminum diff cups and some proper shimming, but there is money to be saved.

Anyone know of other companies that sell hardened steel diff gears for the EREVO?

[reod12x2]

one part is the inlongated output shaft for the lock plate
only thing for the down side or diffrence between the diffs(spool)

[bwill11]

I was going to ask if truckmaster prices are "justified" Is it really worth investing approx. $300 in the diffs of my Summit? I can buy a few complete replacments or rebuild the ones a have quite a few times. I know down time isn't fun, can a shimmed diff in a factory stock Summit last just as well? Sorry if i'm highjacking.

[satyrisci]

HAHAHAHAHAHA dont buy those.

These are $8 a set



https://www.google.com/shopping/prod...ed=0CG0Q8wIwBA

[satyrisci]

A factory built stock diff is about $35

http://www.ebay.com/itm/Traxxas-Summ...244#vi-content

http://compare.ebay.com/like/1409155...Types&var=sbar

http://compare.ebay.com/like/1210647...Types&var=sbar

[noir 522]

Or you can upgrade to aftermerket for the same $35

GPM Hardened steel diff gears: not quite $8 ($35) but they are made of HARDENED steel .



strv1202 is the complete set
strv1200 is just the pinion and spider gears only

[Edstoys]

Hot Racing makes a Black Alum. Differential cup for the E-Revo, that can be bought threw Hobby Etc. for $18.88
http://www.hobbyetc.com/item.cgi?part_id=34517
Not the hardened gears but its a part that helps with the stock gears.

[JoelRobbo]

Hot Racing makes a Black Alum. Differential cup for the E-Revo, that can be bought threw Hobby Etc. for $18.88
http://www.hobbyetc.com/item.cgi?part_id=34517
Not the hardened gears but its a part that helps with the stock gears.

Will these fit the summit? And what is the benefit?

[ignis]

For the love of God, why can't someone just make better diffs for E-Revo? It seems like every Traxxas vehicle except for Revo has decent aftermarket diff options

[noir 522]

For the love of God, why can't someone just make better diffs for E-Revo? It seems like every Traxxas vehicle except for Revo has decent aftermarket diff options

Actually erevo has the strongest diff of the traxxas line up. The slash and xo-1 diffs are direct copies of the erevo. Erevo diffs are made stronger with the I bar and diff cups but the summits locking components deter after market companies from making parts for us summit owners. Not enough of us to make a decent profit I guess.

[pavmentsurfer]

Ive never hurt a diff in my summit. My ERBE ive stripped one, but ive never done one in my summit. I drive it like its designed to be driven, not like a race truck. IMO, the ERBE needs stronger diffs, but the ones in the summit are fine if you drive it like a summit is meant to be driven. If you drive it like an ERBE, yup... needs stronger diffs.

[ignis]

Georg from Truckmonster says:

as I know the parts (cups and gears) are different and will not fit [the E-Revo]

[jamann]

Cups are different gears are the same
As a matter of fact,a bunch of others use the exact same spiders so if you need spiders a bunch of different kits will work.different part #'s.
output gears are no good but the spiders are.
We can only use one from "our"
Kit anyways.handy for me when you don't have a big selection of places to buy parts from



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[ignis]

How come the output gears are no good? I've double checked E-Revo and Summit parts explosions, and both cars use the same spider, ring and output gears - 5382X and 5379X. Assuming Truckmonster parts a direct replacement to stockers, they should fit right in on a Revo...

[noir 522]

That was my bad. One output gear on the summit is slightly longer and has two holes compared to the stock erevo ( shorter with one hole) so yes that part needs to be swapped for the stock part.

[ignis]

As far as I can tell, Truckmonster make 3 different output gears:



The one on the left is definitely a Summit gear, but the two on the right look just like E-Revo output gears...

[Jimmie Neutron]

The one in the center is the pinion.

[ignis]

The one in the center is the pinion.

Well, yes, but my point is that it looks identical to 5379X used in E-Revo. And the gear on the right is 5382X output gear. So both should work in the E-Revo diff.

[noir 522]

Hard erevo pinion

Summit stock pinion

[noir 522]

Once I get home I will take some actual first hand pictures

[ignis]

Hard erevo pinion

Yes, that's the gear in the middle of the picture linked in post #16

[Northern Adventurer]

I do not believe the revo output gear will fit properlly in the summit pinion gear. Not sure if both revo gears together will work either in a summit either.

Please let us know if it worked.

[ignis]

I do not believe the revo output gear will fit properlly in the summit pinion gear. Not sure if both revo gears together will work either in a summit either.

Why wouldn't it fit, if both Revo and Summit use identical parts (except for the parts responsible for locking functionality of the Summit diff)?

[noir 522]

OK heres the low down

The main pinion gear used from the GPM Hardened steel gear sets (strv1200 or strv1200), which is originally designed for the e/revo will not fit (will not be long enough actually). Remember the summit has the differential housing elongated on one side to accomodate for the differential locking components, therefore that pinion gear needed a longer shaft to pass completely through.





But all the spider gears, main ring gear and ther other two pinion shafted gears appears to be the same.

I have yet to complete the installation so I will update with any other oddities.

PS by the looks that $80 Truckmaster kit has the correctly sized longer pinion shaft.

[Northern Adventurer]

Was affraid of that... hopefully those hardened spider gears last. I hate busting diffs lol

[Northern Adventurer]

Noir - how are those diff cups holding up for u? Were they worth the cake? Eating same amount or spider gears or less?

[jamann]

Mine are holding up much better.
Broke all four screws holding the ring gear on that caused some issues. But got them out and rebuilt

Are they worth the money?
To me yes I have rebuilt a couple in my time lol



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[Northern Adventurer]

Wow, quite a collection of diff parts.

How much were the cups with shipping and all?

If you were willing to spend the $ for the Truckmaster cups, why did you not get their gears too?

[Jimmie Neutron]

Cups were available way before the gears.

[WhereitsAT]

From reading around it seems like the truckmonster alum cups are awesome. Does anyone think otherwise or have had a bad experience of them? Do they blow up stock traxxas gears still, perhaps at a lower rate of failure than with the stock cups? I'd just like to get some "reviews" and tips and tricks regarding these as info is a bit scarce. Success stories too please.

Also, if stock gears still get eaten in the alum diff cups, has anyone tried the hardened gears from any of these companies? Which configurations have been tried, and did the improve the rate of failure? Worth the money? I'm looking for a "best" option, and perhaps a cheaper good option for me and others to follow.

I'm trying to get some folks to answer all of this in one thread for the future use of the Summit community. Please contribute if you have info, and thank you in advance

[jamann]

I was the second person to try them
First guy was on here at one point.
I paid a bit more than everyone else(I did get replacement cups after I did the testing and suggested a few changes
http://youtu.be/JWroN0fVW-U


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[rizz0d]

Mine are holding up much better.
Broke all four screws holding the ring gear on that caused some issues. But got them out and rebuilt

so now we need beefier diff cup screws sheesh, when does it end?

[Jimmie Neutron]

If I remember correctly, they were sent with stainless screws... while they may be pretty, they are a lot weaker than the stock 12.9 hardness screws that are Traxxas stock.

[jamann]

What I would really like is if they were just a bit bigger.I used locktite but suspect they may have backed off a bit.
That allows the mesh to change and crunch crunch crunch or worse allows the ring gear to rotate a bit under loads
The screws don't stand a chance for very long.those were the traxxas screws.If they loosened off ,with the amount of torque being delivered not to much can take that kind of force.made sure everything was clean this time
Threads and all we shall see


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[noir 522]

So the traxxas screws are more durable, yet Jamman was still able to break 4 of them? Scary thought, having to remove broken screws out of such an expensive piece. I think I will stick with the traxxas screws. Hey jammam did you use shims? If so where and how many? I have already copied your marine grease idea figured I might as well follow in the footsteps of experience.

[jamann]

I believe I used 6mm a .2 and a .1 on the locker side.and a .1 on the ring gear side.it took a few dry fits to get it to feel right.i just wanted to take up a bit of slack in there.i have eatin a few gears but I believe it was my ring gear issue
Good news is it doesn't hurt the cup any
I got lucky getting the screws out.
Treated it like surgery putting it back together this time clean no contamination of the locktite....hopefully
I do run in some tough spots and my truck has some serious miles on it


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