Toyota Celica Supra Forum banner

1 - 20 of 260 Posts

·
Registered
Joined
·
15,002 Posts
Discussion Starter #1 (Edited)
True Trac part number
911A342

Toyota part numbers
90366-35023-77 Inner pinion bearing
90366-30022-77 Outer Pinion Bearing
90368-50006 Carrier bearing (2 required)
90311-38010 Pinion seal
90311-38011 Side seals (2 required)
41182-22011 Cover gasket
41231-22010 Crush sleeve
90179-18001 Pinion nut

Solid pinion spacer if you opt for this instead of the crush sleeve.
https://www.justdifferentials.com/SKCST7-5-p/skcst7.5.htm



First off, you need to make sure you have all the parts necessary to do the conversion. Second, make sure you have a differential with a good ring and pinion. You will need a large bench vise to make this easier.

First drain the fluid from the differential, then clamp the nose of the diff in the bench vise, and remove the nut that is on the nose of the diff. You'll have to use a small punch or screw driver and a hammer to bend the notch out so it will unthread.

Once that is out, slide a long punch/prybar between the differential case and the side output shaft. then smack the punch/prybar with a hammer to pop the output shaft out of the differential. Do this for each side.

Next, remove the 8 bolts holding the cover in place and remove the cover. Now remove the 4 bolts that are holding the center section in place. You'll have to use a long breaker bar or an impact gun as they are tight.

Once they are out, remove the caps, but mark them so you will remember which side they belong to. Also, when pulling the center section out, there is a shim on each side. KEEP THESE!!!! You will need these and may need an assortment of them to get it adjusted right after assembly. Most 4x4 shops can get you a shim pack for a decent price.

Now that the carrier is out, remove the pinion bearing. Remember how everything went together! Take pictures if possible. The outer pinion bearing will slide out from the nose. Now, if replacing the inner pinion bearing, you will want to use a punch and a hammer from the front of the diff and drive the race for the pinion bearing out. If replacing the outer pinion bearing, you will use a punch to push the race out from inside the case.

Next, the differential case needs to be cleaned. You can have it hot tanked at a machine shop, or, do what I did. I put it in a 5 gallon bucket and then poured purple stuff engine degreaser in till it was completely submerged. i let it sit for over an hour then scrubbed it with a stiff bristled brush. there is a black coating on the inside of the diff that will probably not come off. Do not worry about this. After I took it out of the bucket, I then scrubbed it with soap and water to get the degreaser residue off, and to prep it for paint. then i put the ring and pinion gears in to let them soak as well. When painting, make sure to block all the holes for the bolts and also make sure no paint will get inside the diff case.








Now, if you do not have a shop press, you will need to take the True Trac and the carrier bearings to a machine shop to have them pressed onto it. Also take the pinion gear with you to have the old bearing pressed off and the new one on if replacing it. Make sure the shim is left on the pinion gear when they press the new bearing on if these gears came out of the case you are using and you are not changing them. If you are changing gears, you will need a pinion depth shim kit, which can be purchased at most 4x4 shops for Toyota 7.5in differentials. Setting the pinion depth is critical! Once all that is done your almost ready to assemble.






Dave soaked all the bolts and whatnot in carburetor parts cleaner for several minuets to remove all the gunk that was on them. I have found that a sonic cleaner with HOT water and a little bit of Purple Power, or dawn will work as well. Next, you will need a seal/race install kit(Brass punch in a pinch) to drive the new pinion bearing race/s into the diff case. Make sure you do this carefully as it must be perfectly straight, and you do not want to damage the surface that the bearing contacts. .



Once they are in, slide the pinion gear in, then put the new pinion seal in and make sure you slide the parts back onto the pinion shaft in the correct order(remember the pics I said to take?), and make sure you put the new crush sleeve/solid pinion spacer in there and not the old one. Be sure to use the new nut use a new nut. If using a solid pinion spacer, you should be able to measure the length of the OLD crush sleeve to get a starting point for the shims that come with it. You likely will need to add a small amount on top of this thickness to account for wear and tear on the original crush sleeve. Adjust until the preload on the pinion bearings are correct.

Once together, you need to very very slowly tq the nut (if using crush sleeve) until it takes ~3.5-5.2inch lbs for a used bearing or 10.4-16.5inch/lbs for new bearings to turn the pinion gear. If you tq it too much you must pull the nut back off and get a new crush sleeve so be very careful. Too much preload on the pinion bearings will destroy them very quickly! If using the solid spacer setup, once the bolt is tq'ed, check the preload. If it is too low, add another shim. if it is too much, remove a shim. Repeat until it is correct!

For he solid pinion spacer, Marlin Crawler says to hit the nut with the impact. Yotatech says about 90lbs. For Ford 7.5, 8.8, 9in diffs, the tq spec is 125ft/lbs. Your call.

http://www.ratechmfg.com/fordspbs.htm

Next, you will have to use a small flat head screw driver and a punch to bend the little tabs back that lock the bolts that hold the ring gear to the center section. then use an impact gun to remove these bolts. Then you need to use new tabs when bolting the ring gear to the True Trac. The bolts need to be tq'ed to 71ft/lbs, then push the locking tabs up against the nuts as they were before.

Next, insert the True Trac in with the races on each bearing and for starters use the shims you had removed before. The shims are used to adjust end play and the preload on the carrier bearings. The preload should be ~3.5-5.2inch lbs as should the total preload. The backlash should be 0.0051"-0.0071". You may need to install different thickness shims to ge the preload right, and adjust them to move the carrier from left to right or vice versa to make sure the "wipe" pattern is correct. Once the right end play and preload is set install the caps and tq them to 58ft/lbs and recheck that the preload and backlash are still within spec.










Use a new diff cover gasket and coat it lightly with ultra gray rtv sealant. It is best to rub a lil on your fingers and then smear it on the gasket so that there will be no excess to squish out. Then install the diff cover and tq the bolts to 16ft/lbs. Reinstall the axle stubs, and then fill the diff with the proper amount of fluid, and its ready to be installed.

I used standard 75-w90 for the initial break in then switched to Amsoil Extreme duty 75-90 synthetic after maybe 1,000 miles.





Here is a very helpful link.

http://www.cygnusx1.net/supra/library/TSRM_MKII/ra/RA_018.html

http://new.photos.yahoo.com/williamb82/album/576460762348387882

This is why I needed the True Trac.







 

·
Registered
Joined
·
222 Posts
Good stuff. Question on the ring tabs when bolts onto the truetrac, did you get these at the dealer?
 

·
Registered
Joined
·
15,002 Posts
Discussion Starter #3
yes, they are a dealer item. i dont have a part number. ill have to look it up.
william
 

·
Registered
Joined
·
15,002 Posts
Discussion Starter #5
true trac part number
911A342

~325 shipped

toyota part numbers
90366-35023-77 inner pinion bearing
90368-50006 carrier bearing (2 required)
90311-38010 pinion seal
90311-38011 side seals(2 required)
41182-22011 cover gasket
41231-22010 crush sleav
90179-18001 pinion nut

~$150 total

then i bought a 3.727 non-lsd diff from the pick and pull for ~$60 with corecharge and tax. then the purple stuff degreaser and paint ~$20 then the money for the machine shop to install the bearings ~$40 then ~$10 for gear lube so a lil over $600 total.
 

·
Registered
Joined
·
391 Posts
ZZT231,

I need to get bearings for mine, and my brother in law works for a mob that has a toyota dealership, so armed with the part numbers (thanks William) I'll see what I can do for prices

Cheers

Michael B
 

·
Premium Member
Joined
·
1,361 Posts
bbaacchhyy said:
ZZT231,

I need to get bearings for mine, and my brother in law works for a mob that has a toyota dealership, so armed with the part numbers (thanks William) I'll see what I can do for prices

Cheers

Michael B
bbaacchhyy,

Please do! I will buy a backup set as I already done 8,000kms on the diff and it's back in the shop to get a new set of bearings... Thanks William for those part numbers, it makes life soo easy :)

Cheers.
 

·
Registered
Joined
·
15,002 Posts
Discussion Starter #8
i doubt you had the wrong bearings. if you did they wouldnt have fit, i bet they set the preload too tight. that will kill bearings fast.
william
 

·
Registered
Joined
·
15,002 Posts
Discussion Starter #11
it will work fine. i used it when i first put it together. i have som amsoil full synthetic extreame duty gear lube to put in it now. ill prolly change it before finishing the hg and also have some amsoil 80w-90 full synthetic to put in the trans.
 

·
Registered
Joined
·
4,871 Posts
williamb82 said:
ill edit this with the rest of the specs when i get a chance to look them up.

true trac part number
911A342

toyota part numbers
90366-35023-77 inner pinion bearing
90368-50006 carrier bearing (2 required)
90311-38010 pinion seal
90311-38011 side seals(2 required)
41182-22011 cover gasket
41231-22010 crush sleav
90179-18001 pinion nut




first off, you need to make sure you have all the parts neccesary to do the conersion. second, make sure you have a diff with a good ring and
pinion. you will need a large bench vise to make this easier.

first drain the fluid from the diff. then clamp the nose of the diff in the bench vise, and remove the nut that is on the nose of the diff. youll
have to use a small punch or screw driver and a hammer to bend the notch out so it will unthread.

once thats out, slide a long punch betwen the diff case and the side output shaft. then smack the punch with a hammer to pop the output shaft out of the diff. repeat for both sides.

then remove the 8 bolts holding the cover in place and remove the cover. then remove the 4 bolts that are holding the center section in place. you'll have to use a long breaker bar or an impact gun. they are tight.

once they are out, remove the caps but mark them so you will remember what side they go on. also, when pulling the center section out there is a shim on each side. keep these. youll need these and may need an assortment of them to get it adjusted right after assembly.

now that the carrier is out, remove the pinion bearing. remember how everything went together. there is a bearing that will slide out from the nose as well. now, if replacing the pinion bearing, youll want to use a punch and a hammer from the front of the diff and drive the race for the pinion bearing out.

now, the diff case needs to be cleaned. you can have it hot tanked at a machine shop, or, do what i did. i put it in a 5 gallon bucket and then poured purple stuff engine degreaser in till it was completely submerged. i let it sit for over an hour then scrubbed it with a stiff bristled brush. there is a black coating on the inside of the diff that will prolly not come off. dont worry about this. after i took it out of the bucket, i then scrubbed it with soap and water to get the degreaser residue off and to prep it for paint. then i put the ring and pinion gears in to let them soak as well. when painting, make sure to block all the holes for the bolts and also make sure no paint will get inside the diff case.


now, youll need to take the true trac and the carrier bearings to a macine shop to have them pressed onto it. also take the pinion ger with you to have the old bearing pressed off and the new one on if replacing it. make sure the shim is left on the pinion gear when they press the new bearing on. once all that is done your almost ready to assemble.


dave soaked all the bolts and whatnot in carberautor parts cleaner for several min to remove all the gunk that was on them. now, you will need a brass punch to drive the new pinion bearing race into the diff case. make sure you do this carefully as it must be perfectly straight. once it is in, slide the pinion gear in, then put the new pinion seal in and make sure you slide the parts back ont the pinion shaft in the correct order. and make sure you put the new crush sleeve in there and not the old one. also use a new nut.

once together, you need to very very slowly tq the nut till it takes ~3.5-5.2inch lbs for a used bearing or 10.4-16.5inch/lbs for new bearing to turn the pinion gear. if you tq it too much you must pull the nut back off and get a new crush sleeve so be very carefull. too much preload on the pinion bearing will destroy it very quickly.

now, you will have to use a small flat head screw driver and a punch to bend the little tabs back that lock the bolts that hold the ring gear to the center section. then use an impact gun to remove these bolts. then you need to use new tabs when bolting the ring gear to the truetrac.the bolts need to be tqed to 71ft/lbs then push the locking tabs up against the nuts as they were before.

now, insert the true trac in with the races on each bearing and for starters use the shims you had removed before. the shims are used to adjust endplay and the preload on the carrier bearings. the preload should be ~3.5-5.2inch lbs as should the total preload. and the backlash should be 0.0051"-0.0071" once the right endplay and preload is set install the caps and tq them to 58ft/lbs and recheck that the preload and backlash are still within spec. use a new diff cover gasket and coat it lightly with ultragray rtv sealant. its best to rub a lil on your fingers and then smear it on the gasket so that there will be no excess to squish out. then install the diff cover and tq the bolts to 16ft/lbs. then fill the diff with the proper amount of fluid and its ready to be installed.

and here is a very helpful link.

http://www.cygnusx1.net/supra/library/TSRM_MKII/ra/RA_018.html


pics

Nice write-up, William! Writing up a procedure for something precision like this can be kind of mind boggling and time consuming.
 

·
Registered
Joined
·
354 Posts
Are the carrier bearings (90368-50006 carrier bearing (2 required))
for the true-trac larger than the stock MKII diffs ?

If so I assume these are the part numbers for the larger bearings and races ?

I am about to start buying the parts to turn my 4.30 stock LSD into a 3.73 true-trac LSD.

Scott
 

·
Registered
Joined
·
8,104 Posts
Either the stock diff or the True trac has 45mm or 50mm ID bearings. IIRC the true trac is 45mm. That's why you need those bearings. Everything else are stock parts.
 

·
Registered
Joined
·
15,002 Posts
Discussion Starter #15
the od of the races are the same as stock. the id of the bearings fit the true trac. and as i recall the true trac uses the 50mm id bearings where as the stock mkii carrier used the 45mm.
william
 

·
Registered
Joined
·
354 Posts
when I was looking for the true-trac it seems you can get the 4 banger version that has the smaller I.E. stock supra bearings size or you can get the 6 cylinder version with the larger I.D bearings.

Both LSD's are the same price so I might as well go with the larger bearing 6 cyl version.

The 4cyl part number is TT 911A445, found it here:

http://www.ringpinion.com/content/products/default.asp?vid=11&pid=3&aid=&rid=

Scott
 

·
Registered
Joined
·
15,002 Posts
Discussion Starter #17
looks to be a new application it should work as well. however the bearings are the same price for both apps.
 

·
Registered
Joined
·
391 Posts
Just got prices from the local Aussie Toyrota dealer as follows (prices are in Aussie bucks...)

toyota part numbers
90366-35023-77 inner pinion bearing $124.63
90368-50006 carrier bearing (2 required) $77.62
90311-38010 pinion seal $35.97
90311-38011 side seals(2 required) $27.48
41182-22011 cover gasket $15.52
41231-22010 crush sleeve $25.21
90179-18001 pinion nut $8.95

Willaim, how does that compare with the priices that you paid ? I will try and get better prices, but it all adds up to about USD $315 :shock:

Might have to get you to do a group buy !!!!!

Cheers

Michael Bachmann

PS Did you get the email about the auto upgrades ?
 

·
Registered
Joined
·
8,104 Posts
Damn I think I only paid about 150 for all those parts. I'd try and contact Jeff Watson and see if he could mail it to Aus. Not sure what his email is but the phone is 1-800-327-2087, or you could look up the number for Champion Toyota. HTH
 

·
Registered
Joined
·
15,002 Posts
Discussion Starter #20
yeah, i paid ~$150 usd for all the stuff i listed. i didnt buy the outer pinion bearing though. it looked fine otherwise i would have had to order a new one of those as well. jeff watson should be able to ship to aus. i recall someone buying stuff from him and it being shipped overseas before.
william
 
1 - 20 of 260 Posts
Top