Tercel differential rebuild questions

[Esaus]

Hi!

Im going to check my rear differential due to noises related to deceleration and when the car is in 2wd. Im not getting noises in 4WD and when driving with load.
I have a few questions to those with more experience with these units. Im going to replace the oil seal while im at it and check the pinion bearings for wear. Might aswell order new ones since im having it apart and it takes a couple of weeks to get parts from the states sometimes.

Im wondering what bearings i should order for the differential?

Rockauto has rear inner listed, but not rear outer? Is it the same bearing for both the pinion gear inner and outer bearing? Some are listed as rear 4wd.
Some have 6.2inch ring gear listed on them. I don't know which to get.

Mine is registered as a 86 model year. 4WD manual. In a old register paper it has 8509 listed as first registered, but still 86 model year. Model code T02405.

Is there a good way to read the diff numbers to see which one I have and what parts i need?

Ive read somewhere they had a change in gear ratios at some point. Does it affect the bearings?

Im going to check lash and everything while its out and adjust as needed. I havent heard any other bearing noises from the rear so im not worried about the axle bearings.

[Paul]

Sorry I don't have bearing info for you. I would order them if needed after seeing what's inside. Before you dig too deep tho, you might disconnect the driveshaft and make sure the universal joint is OK. While disconnected, you could turn the pinion shaft and see how it feels. Ideally, you would check this with the diff out, per Xirneh's guide. The ratio change is described in item #9 of the FAQ in the General section. Good luck... I hope you find something easy.

[dlb]

Esaus, what are the noises you hear on deceleration when in 2wd?

I honestly can't recall anyone here having a rear diff go bad on them. The closest I can think of to that is mixing gear ratios when replacing the trans but that doesn't sound like your issue. Did it have a leak and run out of gear oil?

[Esaus]

Found a source on https://partsouq.com/ where diagrams are listed with parts.

Bearing for rear pinion drive front: 9036830069 replaced by 9036830002.
Some googling i found a source for the bearing using a genuine toyota part. Im going to see if i can order it to sweden. Another site had 2 weeks shipping from japan.

Bearing for rear pinion drive rear: 9036625047 koyo bearing available Koyo, BEARING HI-CAP57152N partno: 57152N25KC54N, BEARING HI-CAP57152 partno: HICAP57152.

SPACER, REAR DIFFERENTIAL DRIVE PINION BEARING: 4123112020 not avail

It does list the 9036625047 as a pinion bearing front aswell so it hits at it might be the same bearing for the both.
Can anyone confirm this?

[Esaus]

Esaus, what are the noises you hear on deceleration when in 2wd?

I honestly can't recall anyone here having a rear diff go bad on them. The closest I can think of to that is mixing gear ratios when replacing the trans but that doesn't sound like your issue. Did it have a leak and run out of gear oil?

Ive checked the universal joints and they are ok. The noise is a whirring noise that isnt loud. It mostly comes when decelerating in 4WD or all the time if im driving in 2wd when the rear axle is simply spinning on its own.

Found this video which describes it as a loose pinion nut
https://www.youtube.com/watch?v=CvmZ1xN ... =TomMorton

[Esaus]

Thoughts about the spacer: If its compressed too much? And a shim kit isnt found. Cant i just add another small shim in front of the spacer to increase it and then apply the torque to recompress it? Wouldn't it have the same function?

I asked a site that sold ae86 shim kits from another forum post and they said they wont fit a tercel rear axle.

[Esaus]

Sorry I don't have bearing info for you. I would order them if needed after seeing what's inside. Before you dig too deep tho, you might disconnect the driveshaft and make sure the universal joint is OK. While disconnected, you could turn the pinion shaft and see how it feels. Ideally, you would check this with the diff out, per Xirneh's guide. The ratio change is described in item #9 of the FAQ in the General section. Good luck... I hope you find something easy.

Ive felt the pinion when the drive shaft was out with the rear axles in place and I thought it might have had too much play. I havent really had rwd cars other than a 1960s buick and that car had more play without noises but thats a 60 year old car so.

[dlb]

Found this video which describes it as a loose pinion nut
https://www.youtube.com/watch?v=CvmZ1xN ... =TomMorton

Wow, neat video. I've never heard or seen anything like that before. If this is indeed the same problem as you are having, I wonder what caused it to happen. Like I mentioned, these rear diffs are pretty bulletproof.

[NWMO]

I’ve not been into one of these differentials. However, my son and I worked on his 76’ Maverick rear diff which (unlike the Tercel) requires removing the pinion nut to remove/renew the oil seal. We marked the nut before removing it, reused the “crush” washer and torqued back to spec, 125 ft-lbs as I recall. We’ve not had issues. I believe the professionals use a marking grease of some type and actually evaluate the pinion/ring interface by “reading” the marking oil on the teeth. I’m getting to be an older man and still so much to learn!

[Esaus]

Found this video which describes it as a loose pinion nut
https://www.youtube.com/watch?v=CvmZ1xN ... =TomMorton

Wow, neat video. I've never heard or seen anything like that before. If this is indeed the same problem as you are having, I wonder what caused it to happen. Like I mentioned, these rear diffs are pretty bulletproof.

I suspect either a worn bearing or that the oil seal might have been replaced at some point and the nut not torqued correctly. i have 75w-90 oil in there too if it attributes to the noise. I have ordered 80w-90 for it. The seal has been weeping oil, the diff is moist but doesnt drip. When i replaced the oil, the level was abit low but not by alot. It has been like that for atleast 10 years. The car has only driven 170000 km.

[xirdneh]

Rebuilding a diff is complicated
Having someone do it is expensive
It’s better to find a replacement
Used one

[marlinh]

Noise on deceleration in 2WD indicates worn front diff pinion and gear, not rear diff. You can remove the front cover of the diff and look at the wear pattern on the teeth. That's been my experience in the past.

[Esaus]

The noise is definetly coming from the rear. There is no mistaking where its coming from. I had the front diff cover off when i replaced seals on the transmission. Didnt look worn when I checked. Either way im going to check the rear when the seal comes. Im going to inspect the bearings on the pinion and check whatever i can.

[Phatcat]

Hey,

The best Toyota diff guy I know of is a man named “Zuk” at Toyota gear installs. He does work on all diffs for older pickups and 4Runners, but I’d be willing to bother him in this instance with a call, if it were me.. Zuk is a bit of a genius with the Toyota diffs and very reputable. He may just help a guy out and do a Tercel build for you. Or at the very least, worth picking his brain for 10 minutes to see what why and if he knows anything above what you do.

[Esaus]

Hey,

The best Toyota diff guy I know of is a man named “Zuk” at Toyota gear installs. He does work on all diffs for older pickups and 4Runners, but I’d be willing to bother him in this instance with a call, if it were me.. Zuk is a bit of a genius with the Toyota diffs and very reputable. He may just help a guy out and do a Tercel build for you. Or at the very least, worth picking his brain for 10 minutes to see what why and if he knows anything above what you do.

I might give him an email. I havent had the time to take the rear diff apart yet. Im currently doing work on my 88 corolla 4wd. Waiting for parts that never arrive. I live in sweden so sending a diff to USA isnt an option.