Rebuilding 2.25 stealth diffs - substitutes and all
Posted: Wed Mar 14, 2018 6:46 am
Howdy yall
as the tide wipes out our conversations daily, I thought it was time to capture all these in a topic.
The issue: rebuilding stealth diffs has gotten expensive and parts ref aren't that clear. Let's list all tips and tricks here as they develop
for a full-blast rebuild, you theoretically need the following AE refs:
- diff rings: #6579 - $2 - https://www.amainhobbies.com/team-associated-differential-drive-rings-b44-asc6579/p16636
- T-nuts + cover + bolt: #6575 - $6 - https://www.amainhobbies.com/team-associated-differential-thrust-bolt-bearing-cover-locking-tnut-asc6575/p8001
- Thrust washers: #6573 - $8- note that these now come with an extra bolt. https://www.amainhobbies.com/team-associated-differential-thrust-washers-and-bolt-asc6573/p7999
- Main Balls x12 (3/32"): #6581- $12 - https://www.amainhobbies.com/team-associated-3-32-carbide-diff-balls-14-asc6581/p5227
- Thrust Balls x6 (5/64"): #6574 - $2 - https://www.amainhobbies.com/team-associated-5-64-precision-differential-thrust-ball-6-asc6574/p8000
That's to say pretty much everything but the diff spring (which doesn't really wear out), outdrives, and main gear.
That'll set you back $30
Some of these prices have increased like crazy lately. Not only did 6575 used to include the T-nut + Thrust washers, but it was $2 not too long ago (vs. $13 today if you add 6575 and 6573's prices...). I mean, like a decade ago, not 25 years ago. See package I kept in stock, picture from yesterday's diff rebuild session:
@GoMachV suggested using the TC3 diff rebuilt kit #3926 - $14
https://www.amainhobbies.com/team-associated-differential-rebuild-kit-asc3926/p32580
That compares vs. $17 for thrust assembly +diffrings+Tnut - you get an extra bolt and spring, but frankly these don't wear out ...
The picture on AE's site shows the long T-nut for #3926, as the TC3 outrives were asymetrical (remember, conical gear ):
@DaveM confirmed that #3926 has both long and short T-nuts, so it's perfect for rebuilding a Stealth diff
(which, again, shows that the single T-nut pack at $6 is stupidly overpriced... )
Alternative solution, again from @GoMachV : Associated 9351, B2/B3/T4 diff rebuild kit.
https://www.amainhobbies.com/team-associated-differential-rebuild-kit-rc10b3-t3-asc9351/p58119
Watchout: these are the wrong diff rings... An extra set of #6579's is $2
Spare Thrust washers:
I have a few NIP MIP $2-a-pack 9151's at home... They are for the B4. Yesterday, I pulled out some used B4 diff parts I had, and proceeded to check whether they would fit in the original stealth outdrives. First, they look VERY similar (2.25:1 parts on left, 2.6:1 parts on right).
And the answer is: same part, fits like a glove.
Which means, one can tap into the more modern B4/SC10 diff parts supply to rebuild the original stealth diff
Hence, these parts can be used:
- Thrust: Remember the bolt doesn't wear out, really...
- MIP 9151 (available for $3 still, in some places)
- ASC 9274 $4.50 - washers + bolt (grrrr) https://www.amainhobbies.com/team-associated-differential-thrust-screw-washer-set-asc9274/p130504
- Any of the Protek/Shelle/Avid $8 to $10 combos that also provide you with a caged set of ceramic balls, too
- T-nuts: not many alternatives here
- MIP 15010 $10 is a lovely machined piece, but not cheap https://www.amainhobbies.com/mip-aluminum-0.250-bore-machined-tnut-mip15010/p450995
- Custom works $5.50 seems to be repackaged AE stuff https://www.amainhobbies.com/custom-works-differential-thrust-bolt-cover-tnut-csw4361/p640924
Serpent has a great looking (cheap) T-nut / externally adjustable and (expensive) sealed bolt a(a la losi) from their SRX2 but I'm sure these are metric. Maybe they would work in the stealth outdrives - anyone tried?
https://www.amainhobbies.com/serpent-ball-differential-bolt-2-ser500172/p269204
https://www.amainhobbies.com/serpent-spyder-differential-tnut-2-ser500187/p269219
Spare Balls:
The hot combo is carbide main balls, ceramic thrust balls. Ceramic main balls are too demanding on the diff rings and lube quality, performance is higher but so is wear and the tuning window is much narrower. For shelfer where the diff isn't stressed
steel balls all around are perfectly fine For my rebuilds, I use:
- Steel - eitther the below, or sometimes I also buy bulk from non RC sellers.
- 3/32": Yokomo 505 (x24!) $2 https://www.amainhobbies.com/yokomo-3-32-differential-ball-24-yokzd-505/p242512
- 5/64": AE 6574 $2 (the original ref...) https://www.amainhobbies.com/team-associated-5-64-precision-differential-thrust-ball-6-asc6574/p8000
- Carbide 3/32" and ceramic 5/64" for runners: I buy bulk only... LHS prices are not acceptable I think, for the added value they provide. Not worth it.
Next section - lubes - TBC.
as the tide wipes out our conversations daily, I thought it was time to capture all these in a topic.
The issue: rebuilding stealth diffs has gotten expensive and parts ref aren't that clear. Let's list all tips and tricks here as they develop
for a full-blast rebuild, you theoretically need the following AE refs:
- diff rings: #6579 - $2 - https://www.amainhobbies.com/team-associated-differential-drive-rings-b44-asc6579/p16636
- T-nuts + cover + bolt: #6575 - $6 - https://www.amainhobbies.com/team-associated-differential-thrust-bolt-bearing-cover-locking-tnut-asc6575/p8001
- Thrust washers: #6573 - $8- note that these now come with an extra bolt. https://www.amainhobbies.com/team-associated-differential-thrust-washers-and-bolt-asc6573/p7999
- Main Balls x12 (3/32"): #6581- $12 - https://www.amainhobbies.com/team-associated-3-32-carbide-diff-balls-14-asc6581/p5227
- Thrust Balls x6 (5/64"): #6574 - $2 - https://www.amainhobbies.com/team-associated-5-64-precision-differential-thrust-ball-6-asc6574/p8000
That's to say pretty much everything but the diff spring (which doesn't really wear out), outdrives, and main gear.
That'll set you back $30
Some of these prices have increased like crazy lately. Not only did 6575 used to include the T-nut + Thrust washers, but it was $2 not too long ago (vs. $13 today if you add 6575 and 6573's prices...). I mean, like a decade ago, not 25 years ago. See package I kept in stock, picture from yesterday's diff rebuild session:@GoMachV suggested using the TC3 diff rebuilt kit #3926 - $14
https://www.amainhobbies.com/team-associated-differential-rebuild-kit-asc3926/p32580
That compares vs. $17 for thrust assembly +diffrings+Tnut - you get an extra bolt and spring, but frankly these don't wear out ...
The picture on AE's site shows the long T-nut for #3926, as the TC3 outrives were asymetrical (remember, conical gear
):@DaveM confirmed that #3926 has both long and short T-nuts, so it's perfect for rebuilding a Stealth diff
(which, again, shows that the single T-nut pack at $6 is stupidly overpriced...
)Alternative solution, again from @GoMachV : Associated 9351, B2/B3/T4 diff rebuild kit.
https://www.amainhobbies.com/team-associated-differential-rebuild-kit-rc10b3-t3-asc9351/p58119
Watchout: these are the wrong diff rings... An extra set of #6579's is $2
Spare Thrust washers:
I have a few NIP MIP $2-a-pack 9151's at home... They are for the B4. Yesterday, I pulled out some used B4 diff parts I had, and proceeded to check whether they would fit in the original stealth outdrives. First, they look VERY similar (2.25:1 parts on left, 2.6:1 parts on right).
Which means, one can tap into the more modern B4/SC10 diff parts supply to rebuild the original stealth diff
Hence, these parts can be used:
- Thrust: Remember the bolt doesn't wear out, really...
- MIP 9151 (available for $3 still, in some places)
- ASC 9274 $4.50 - washers + bolt (grrrr) https://www.amainhobbies.com/team-associated-differential-thrust-screw-washer-set-asc9274/p130504
- Any of the Protek/Shelle/Avid $8 to $10 combos that also provide you with a caged set of ceramic balls, too
- T-nuts: not many alternatives here
- MIP 15010 $10 is a lovely machined piece, but not cheap https://www.amainhobbies.com/mip-aluminum-0.250-bore-machined-tnut-mip15010/p450995
- Custom works $5.50 seems to be repackaged AE stuff https://www.amainhobbies.com/custom-works-differential-thrust-bolt-cover-tnut-csw4361/p640924
Serpent has a great looking (cheap) T-nut / externally adjustable and (expensive) sealed bolt a(a la losi) from their SRX2 but I'm sure these are metric. Maybe they would work in the stealth outdrives - anyone tried?
https://www.amainhobbies.com/serpent-ball-differential-bolt-2-ser500172/p269204
https://www.amainhobbies.com/serpent-spyder-differential-tnut-2-ser500187/p269219
Spare Balls:
The hot combo is carbide main balls, ceramic thrust balls. Ceramic main balls are too demanding on the diff rings and lube quality, performance is higher but so is wear and the tuning window is much narrower. For shelfer where the diff isn't stressed
steel balls all around are perfectly fine For my rebuilds, I use:- Steel - eitther the below, or sometimes I also buy bulk from non RC sellers.
- 3/32": Yokomo 505 (x24!) $2 https://www.amainhobbies.com/yokomo-3-32-differential-ball-24-yokzd-505/p242512
- 5/64": AE 6574 $2 (the original ref...) https://www.amainhobbies.com/team-associated-5-64-precision-differential-thrust-ball-6-asc6574/p8000
- Carbide 3/32" and ceramic 5/64" for runners: I buy bulk only... LHS prices are not acceptable I think, for the added value they provide. Not worth it.
Next section - lubes - TBC.
Fixed now