Notorious

I've had some odd movement from the rear of my car for some time.
It is most noticable when starting from a stop light at certain intersections... I
m guessing due to better traction on certion sections of asphalt.
Anyways, I was onder the car looking around a week ago and noticed my right (passenger side) rear differential mount is broken.

My shop manual calls this part a 'differential cushion'.
It also has detailed instructions on how to remove and install it, using a couple of special Toyota tools.

I've searched here and on SF, but no one has ever written anything about having to replace this part. Here are my questions:

1) Has anyone ever done this? Any tips?
2) I plan on replacing both of the rear differential mounts. Should I spring for the front bushings on the differential also?
3) Is the job doable without the Toyota tools, especially the special alignment tool?
4) The shop manual says you completely remove the diff before replacing these. I think it can be done just by lowering the diff, leaving it still attached to the driveshaft (supported by a jack, of course). Opinions?
5) is there a high likelihood of encountering other major failures on the car by driving it with this broken mount? It will probably be a couple of weeks before I can fix it....

Thanks,

Marcus

UpInTheLex

iTrader: (5)

Take pictures!!! Show us whats wrong! You noticed it is broken, we want to see what it looks like! Snap us a pic or two!

Everyone sooner or later is going to have this exact same problem. We give you advice you fix yours, yours is better you ride on... Then the next one pops up, the next one pops up, on it goes... Lets document your progress so we can say hey, here's how notorious did it, follow his lead.

By reading your post, you seem to already know exactly what to do here... You just gotta do it! Also 6 more bolts the driveshaft is off and the diff is out on the ground. Just remove the whole thing. It'll make things easier.

Also How many miles do you have? What year is the car? Is it a 300 or 400? What kind/duty driving do you do?

Have you considered replacing the diff(entire pumpkin) with one from a turbo supra? You could solve your worn mount problem and get LSD at the same time...

Notorious

UITL,

Thanks for the reply.
Yeah, I know what's wrong, just kinda surprised no one else has had this issue.

I've got a 93 SC300 with a 1JZ swap, factory 5-speed (w/ rps clutch and 'max' pressure plate), already have the supra TT auto LSD. The motor's pretty stout (greddy single mount w/ PT61 DBB single turbo, HKS FMIC, 3" full exhaust, 4" intake, on Mines ECu w/ HKS EVC5 and SAFC neo, 550cc, walbro, etc., etc.) and the suspension is decent (JDM Supra Bilsteins). When I bought the car, the swap was already done and the rubber in the main failing bushings (LCAs, sways, etc) was already replaced. Motor probably has about 60K and car has well over 100K, I think [have dash cluster from anouther SC in because all needle work on it... original cluster is in garage]. Car is my DD, but I've been working on mastering oversteer in it as well.

Unless I'm mistaken, I've got to drop the half shafts too (in addition to the driveshaft)... so I've got a number of critical (?) bolts to be worried about...
Heck, I'll probably drop them all so I can get to the mounts easier.
I'll do all 4 mounts while I'm down there so I don't have to go back any time soon. I'll do the fuel filter too while I've got the *** end up in the air too... and I'll do the supra subframe mounts so I can use this Supra TT sway I've got hanging around in my garage.... and upgrade to TRDs or Titans some day.

UpInTheLex

iTrader: (5)

With all that power I'm not surprised that their toast.

You don't have to pull the half shafts from the hubs. Just unbolt from the diff.

Let us know how the subframe mounts go.. theres another guy on here who wants to do the same thing.

Take some piccies!

SC400DAVE

I would not drive my car knowing about this. If you think about it is critical that the diff be properly mounted and aligned. If it is not then you are putting a lot of strain on the gears and drive train. This is going to cause premature catastrophic failure sooner than later.

UpInTheLex

iTrader: (5)

There are Universal joints in the driveshaft which reduce the forces due to side loading of the output shaft of the transmission. Although it's a problem that needs to remedied soon, I don't think it's "critical".

SC400DAVE

I scrapped 3 diffs on a vehicle I had before they figured out the diff was not lined up right. Is it going to happen the next time he drives the car? Probably not, but like I said if it was my car, I would not even chance it based on experience.

UpInTheLex

iTrader: (5)

Was it a DD or a racecar? What kind of car was it? What diff was it?
I'm curious... Elaborate for me Dave...

Notorious

Ordered the rear diff mounts from Chapion today (using SF discount).
Not cheap, but I have no choice.
I also picked up a fuel filter... no idea when the filter was last changed in this car.

Toyota/Lexus does not sell the front bushings for the diff any more... thought I read something about some other company who did, but I can't recall who it was.... any ideas?

SC400DAVE

DeeDeeDee

SC400DAVE

I would check with Toyota on Supra mounts. They gotta still make them, or check with our member aliga, he resells parts too. Let us know what happens. I think this is a first for CL. Thanks and good luck!

JspecSC3

iTrader: (4)

Ive changed out a blown diff on an SC300 before. I wouldnt recommend lowering the diff while hooked to the axles. You might stretch and rip the CV boot and then you will have set yourself back another couple hours to replace those. You basically remove the entire drive shaft. Remove all the large allen head bolts that secure the axles to the diff. You then remove the two allen bolts behind the diff. Then you put the jack under the diff so it doesnt drop while you remove the two big diff mount bolts.

While the diff is out I would definetly inspect for any leaks around the seal. If there is then reseal and refill the diff. Differentials are probably the most neglected part of the drivetrain on a rear wheel drive vehicle. To see if your gears are still in good condition you can unscrew the drain magnetic drain bolt located on the side. If you see any metallic particles then I highly recommend a drain and fill if it isnt too late. Have fun!

Notorious

Jspec,

Thanks for sharing your experience.
Yeah, I'll just follow all of the shop manual instructions, which include disconnecting the drive shaft as well as the axles.
I'll check the diff, but I expect it's in good shape as I had a brand new mk4 supra TT LSD unit put in last year and used Amsoil fluid.
I assume that removing the axles will necessitate a fluid change? or is it safe to just balance the pumpkin and reinstall as soon as the new mounts are in?
Don't want to be penny sie and pound foolish, but that Amsoil fluid is supposed to last like 100,000 miles....

Thanks again,
Marcus

Notorious

Oops.. meant penny WISE, pound foolish.

JspecSC3

iTrader: (4)

There is no spline end going from the axle to the diff. so you wont lose any of that precious AMSoil. which by the way is really good stuff. You just remove those allen bolts and you're good.