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MKII Supra Built LSD Differential.

30K views 81 replies 28 participants last post by  piratetip 
#1 · (Edited)
Hey All!

I don't spend a lot of time here but wanted to share a nice MKII rebuild I performed.
Typically I spend most of my time rebuilding MKIII differentials and shipping them all over the country as well as overseas.
I mostly spend my time on SupraMania under the same username.

This is the 1st individual that has requested a MKII differential from me. (Not for sale)
I just wanted to share the condition of this MKII diff, as its one of the lowest mileage / cleanest I have ever come across.
Even as received it was super clean, thought it was worth showing.

I can't say I have seen many diff's with ~30k miles. This has to be some sort of anomaly!
Even the rear aluminum cover is in its original die cast finish. (no sandblasting needed)

I swapped gear ratios for this one to 4.10. (Had 4.30)
Upgraded the LSD with the Weir kit.
Also switched to the solid pinion spacer.

Esentially the same upgrades I usually do for the MKIII's.

Also took some comparison measurements side by side with the MKIII, just for curiosity sake.
Side shafts/LSD Plates/LSD Construction ect..
Its interesting to see some of the same design attributes that were carried over to the MKIII from the MKII.
Also pretty clear the improvements implemented and weaknesses that were corrected with the newer MKIII.
The MKIV is a whole different level beyond this, but will get to that at some point.

Photos for your enjoyment :D
















Check out the factory machining marks still on that side gear!





Comparison of the LSD plate stack to the MKIII.

 
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17
#3 ·
Impressive props for sharing!! MKE = Milwaukee??

Lots of us including me need LSD's rebuilt, what services can you provide?
 
#4 ·
Yes I am in Milwaukee.

Prices depend on what someone wants done.
Different gearing / different LSD carrier / LSD upgrades / solid pinion spacer / ect..
Feel free to PM me for prices..
 
#5 ·
Copy Thanks!!
 
#9 ·
How much for the solid pinion spacer and do you have one in stock? Only thing my Truetrac diff needs. Would like to change it when I install the "large" pinion flange.
 
#13 ·
Looks good! I'll be building an exact duplicate of that for myself soon for my mk2. I have all the bits, just need to find the time to put it together lol

Hey, speaking of the diff evolution, what did Toyota do for setting the pinion backlash on the mk3? I noticed Weir doesn't sell a solid pinion spacer kit for it, I assume Toyota basically did something along those lines from the factory? The crush sleeve was a dumb idea.
 
#14 · (Edited)
Good deal SupraFiend.
Yeah recommend upgrading everything.
The LSD especially is weak in the MKII from what I have observed. Lots of gains there to be had.

MKIII has multiple (30) different thickness side carrier plates to set backlash as well as carrier preload (at the same time).
Similar to the MKII but the plates are a different design as well as different ID and OD.
You have to make the measurements and calculate the 2 plates that will set preload and backlash correctly. (R&P backlash and carrier bearing preload)
The plates are $5 a pop from Toyota so you want to ensure you calculate exactly which to order, otherwise it starts to get expensive quick.

The MKIII has a crush sleeve from the factory as well.
Weir does have a solid pinion spacer for the MKIII, it is down the page a bit.
The solid pinion spacer of course sets the pinion bearing preload.
The shim behind the pinion head sets the depth of the pattern on the face of the ring teeth.

Toyota used solid pinion spacers on older differentials from the factory, but they moved away from them in the early 80s I believe.
Probably due to easier setup from the factory. Quicker manufacturing.
 
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#16 ·
Yes the LSD design is much much different.

The last photo shows the size and quantity of the LSD clutch pack between the MKII and MKIII.
I have other photos I could post up comparing the MKII LSD design to the MKIII.
 
#17 ·
What we need is Weir or someone to make solid spacers to replace the now NLA crush sleeves for the rear control arm bearings.
 
#19 ·
#20 ·
Oh interesting.

The rear wheel bearings set the preload with a crush sleeve.

From that thread it looks like they figured out a 7.5" solid pinion spacer might work.

Though I see no mention of the min OD that will still fit over the hub.
Hard to say if a 30mm solid spacer will fit without modification over the hub.

Even if you used a solid spacer when doing new rear wheel bearings I don't expect many shops willing to put in the time to install correctly.
They would need to dissassemble and re-assemble at least a couple times to get the correct shim stack and measure preload.
Setting up a solid spacer correctly is quite time consuming, but once you get it...man is it good. :D
 
#22 ·
Yes, but most of us would tackle this ourselves.
 
#21 ·
Did a bit of reading.
Another easier method might be to use the 7.5" differential pinion crush sleeve.

If someone has one lying around to measure the ID and OD and compare with that thread. (And overall length)

I believe the overall length isn't much over the rear wheel bearing crush sleeve.
Looks like 2.188" overall length (used) crush sleeve.
PN: 41231-22010

I don't have one lying around or I would measure it.
Looks like it would only need to be crushed 0.020" more.

From SilverMK2's measurements:
Overall Length 55.05mm

Small End 34.5 OD 30.5 ID
Big End 39.45 OD 35.6 ID

Max diameter around the bead 46.4
 
#25 · (Edited)
#26 ·
Ah so you are getting a feel for how many times I have to take apart these diff's to get the settings just right :D

0.20 mm / 0.007" shims is are not small enough increments IMO to properly setup anything.

I have to work in increments of 0.002 - 0.001" or 0.05 - 0.02 mm when I approach the final steps to set up diff's.

I had an RC nitro car waaaay back, but my parts were nothing like what you are showing.
That is once nice looking billet aluminum housing there.
What type of engine/motor does it use?
 
#27 ·
This one is MUCH easier to set up,sitting in my chair and drinking beers,listening to the Scorpions on Pandora! I made a jig to hold it.

The cases are split vertically! The ring slides from the end,instead of horizontally.
.2 mm shims are what I have to use and it takes a LOT of time. I did the ring gear end play first and go onto the pinion depth. You see in the photo,I have a way to go!
It's a diff out of a Kyosho 1/8th scale buggy,but the cases are all CNC machined to fit my E Maxx.

The LSD part is inside the plastic diff case and has 4 pinion gears that is filled with 10,000 weight silicone to do the "posi" action. It's a 4 WD truck,so the diffs have different weight silicone fluid. 5K in the rear.
This my FIRST time setting up a gear differential! My other trucks have ball diffs.


I was a suspension guy,not a drive train guy.
These were set up tight,because they will loosen up and then I'll need to change the diff fluid again after 10 hours of "play".
My Maxx is custom with 5S power and and a 1515 Neu motor @ 1650 KV.
It wheelies on one rear tire.

It's pretty fast>
<a href="https://imgur.com/eMH595u"><img src="https://i.imgur.com/eMH595u.mp4" title="source: imgur.com" /></a>
<a href="https://imgur.com/eMH595u"><img src="https://i.imgur.com/eMH595u.mp4" title="source: imgur.com" /></a>

If it wasn't fun,I wouldn't spend this much money on a TOY.
 
#29 ·
Thanks. I'm still learning HOW to post links.:salute:
My 5 forums are different as to what link to choose.
BB code makes the images take up WAY too much space.
There was sound with that video at one time.
 
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