Stock supra differential shimming

[Cp2295]

Picked up a used 3.90 lsd diff for cheap but it is missing the carrier shims for some reason.. want to do a full rebuild on it and do a crush sleeve eliminator. Anyways I’m having a real tough time finding shims for this diff and now I’m seeing pics of how the mk4 diff is shimmed so don’t know what to think of it. Does this diff get shimmed like any other diff or does it use those weird shims with the bolt holes like a mk4 diff? Where can I find these shims, apparently Toyota discontinued them. Thanks in advance


Sent from my iPhone using Tapatalk

 

[Zazzn]

talk to wier performace. He has them all.

Just had him reshim with his kit nice and tight.

mk4 is never shimmed, it's torsen.

 

[Piratetip]

Toyota did not discontinue them.

I buy them regularly for the multiple rebuilds I perform.

The full list of shims available and their part number.
Designation T=x.xx is the thickness of the shim in millimeters.
http://www.cygnusx1.net/Supra/Library/EPC/291410/part.aspx?S=41334C

TSRM Procedure for installing these carrier shims.
You set carrier preload and ring gear backlash simultaneously using these 2 carrier shims.
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=RA&P=35

Without a starting point for where this differential was set from the factory it will be difficult to get it on the 1st, 2nd or 3rd try through trial and error.
Also these shims cost ~$6 each so it becomes expensive.

I can get you close, but you will probably need to buy at least 4 of these shims to get it perfect.

As a starting point I would recommend getting these 2 first, based on all the tear-downs I have performed these were the most common across all differentials.
90201-52014 - T=2.97
90201-52016 - T=3.03

See where this gets you on carrier preload and backlash.
Follow the TSRM to a T.
Calculate out exactly which shims will get you perfect (Also outlined in the TSRM)
Buy 2 more shims from Toyota once you determine exactly the ones you need.

 

[Cp2295]

talk to wier performace. He has them all.

Just had him reshim with his kit nice and tight.

mk4 is never shimmed, it's torsen.

I’m talking about the shims on the outside of the diff. To set the backlash/carrier preload.


Sent from my iPhone using Tapatalk

 

[Cp2295]

Toyota did not discontinue them.

I buy them regularly for the multiple rebuilds I perform.

The full list of shims available and their part number.
Designation T=x.xx is the thickness of the shim in millimeters.
http://www.cygnusx1.net/Supra/Library/EPC/291410/part.aspx?S=41334C

TSRM Procedure for installing these carrier shims.
You set carrier preload and ring gear backlash simultaneously using these 2 carrier shims.
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=RA&P=35

Without a starting point for where this differential was set from the factory it will be difficult to get it on the 1st, 2nd or 3rd try through trial and error.
Also these shims cost ~$6 each so it becomes expensive.

I can get you close, but you will probably need to buy at least 4 of these shims to get it perfect.

As a starting point I would recommend getting these 2 first, based on all the tear-downs I have performed these were the most common across all differentials.
90201-52014 - T=2.97
90201-52016 - T=3.03

See where this gets you on carrier preload and backlash.
Follow the TSRM to a T.
Calculate out exactly which shims will get you perfect (Also outlined in the TSRM)
Buy 2 more shims from Toyota once you determine exactly the ones you need.

Cool, I appreciate it. Just curious do you know the outside and inside diameter of the shims? I was thinking maybe I could find a shim kit for another diff that might work, something a little more common


Sent from my iPhone using Tapatalk

 

[Piratetip]

Cool, I appreciate it. Just curious do you know the outside and inside diameter of the shims? I was thinking maybe I could find a shim kit for another diff that might work, something a little more common


Sent from my iPhone using Tapatalk

I will take the measurements later today and give them to you.
Though I am not aware of any other differentials that use this size shim.
Would be much easier to just source the right part from Toyota.

These parts are readily available, just need to order them.

 

[Jeff Lange]

In North America, there are a few other cars that use the same size/style of shims, notably, the MX83 Cressida, IS300, IS250 RWD (and AWD from 2009+), BRZ/FR-S/86, 2006 GS300.

Additionally used in some trucks such as the FJ Cruiser, 4Runner, and Land Cruiser 100/LX470.

That said, the A70 does seem to use thicker shims than others, but regardless, they should still be available if you need them. Alternatively, speak with a local driveline shop and see what they have, often times the aftermarket will have thinner shims that you can stack in different orders to get the thickness you need.

Jeff

 

[Piratetip]

Good ol' Jeff to the rescue!
Great info.

Just have to be careful stacking shims with this style carrier.
Go too thin and they might fold or shift on you since the carrier has to be pressed down into the case.
Wouldn't recommend using a shim < .020" for this location.

 

[Jeff Lange]

Good ol' Jeff to the rescue!
Great info.

Just have to be careful stacking shims with this style carrier.
Go too thin and they might fold or shift on you since the carrier has to be pressed down into the case.
Wouldn't recommend using a shim < .020" for this location.

I concur, avoid thin shims unless you absolutely have to (and in that case, try to get it between a thicker shim).

Jeff

 

[Cp2295]

Yeah I totally agree with you guys, I prefer to use thicker shims in any diff rebuild I do. Too bad the guy I bought it from lost the shims, I asked what the deal was with the carrier being so sloppy and where the shims were and his reply was great, “oh the axle stubs need to be hammered in all the way.” Yeah, whatever you say lol [emoji23]. Anyways, I will have to try and measure the shims I need and will probably end up getting the ones you recommended Piratetip. Finding bearings for this thing is nearly impossible from a local parts store. Just gonna have to get some of those online too.


Sent from my iPhone using Tapatalk

 

[Piratetip]

Uh yeah...
Bearings from Toyota are not cheap for these differentials either.
That's where I get mine.

Tip. Don't buy any parts for this diff from a local parts store.
They will be of zero help, and if they find a part they think might fit... it probably wont.

The only exception, they might* carry the pinion or side shaft seals.

 

[Cp2295]

Uh yeah...
Bearings from Toyota are not cheap for these differentials either.
That's where I get mine.

Tip. Don't buy any parts for this diff from a local parts store.
They will be of zero help, and if they find a part they think might fit... it probably wont.

The only exception, they might* carry the pinion or side shaft seals.

Yeah, I figured that out pretty quickly.. at any rate I’d be more inclined to get OEM Toyota seals, they aren’t too bad. Bearings are like $50 a piece! Oh well, I only paid $100 for the diff so I’m not out too much! Could probably reuse the bearings but they got a little pitting on them so probably better off not chancing it behind the 1j lol


Sent from my iPhone using Tapatalk

 

[Piratetip]

Yeah best to just replace all the worn parts.
You aren't going to want to take it apart later after you find the diff is noisy.

 

[Cp2295]

Yeah best to just replace all the worn parts.
You aren't going to want to take it apart later after you find the diff is noisy.

Or worse and get gear deflection and shred the ring and pinion... that would be no good! Also, I want the posi to grab good but not chatter. So would shimming it to a breakaway of 100 ft lbs be good, and put that heavier spring from weir in and then add a few oz of friction modifier?


Sent from my iPhone using Tapatalk

 

[Piratetip]

Yeah that's what I do for 98% of the rebuilds I perform.
There are 2 steps up available from that stage 1, but if you want no chatter stay with stage 1.

Good to break in the diff with conventional gear oil (Ford) and the friction modifier.
Do a drain and refill after ~500 to 1000 miles, you can stay with conventional oil or switch to a synthetic like red line.

 

[Piratetip]

Oh yeah shim measurements:
OD - 81.8mm
ID - 46mm