Rear differential repair

How-to's and repair secrets for your 4WD can be found here. Have a question? Ask it in here!
Post Reply
steen
Newbie
Posts: 16
Joined: Mon Dec 13, 2010 9:39 pm
My tercel:: 1986 SR5 no mods

Rear differential repair

Post by steen »

OK, the 78,000 mile Tercel I bought for 2400 has a bad rear end - high pitched grind/whine where the drive shaft enters the rear differential. How complicated/expensive is this repair? I have another Tercel with 200,000 miles but no whine, switch the rear ends or engine into the 200,000 miler?
User avatar
Petros
Highest Ranking Member
Posts: 11930
Joined: Sun Jan 28, 2007 6:31 pm
My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Rear differential repair

Post by Petros »

Not too difficult. Make sure the noise is coming from the diff (not too common), and not a wheel bearing (common), or the u-joints, or center drive shaft bearing (also common).

The rear diffs are fairly robust, if they were mistreated or ran dry they can have issues of course. The '83-84 has a different rear end ratio than the '85-88, so make sure your replacement is from the correct year. Same is true with the front diff in the trans, it must match the rear end ratio. More than a few have gotten Tercels where someone replaced a trans from the wrong year, and ended up trashing the rear diff because it did not match the front diff ratio, so make sure that was not the fate of yours.

To change the rear diff is easy if you keep it all together on the center carrier, or third member. Jack up the rear and drain the diff. Remove the rear brake backing plates (after you remove the rear drums) and pull the left and right axles out about 3 inches (hang the axles with a bungee cord so you do not damage the rear wheel seals). The seals are just inside the bearing seat in the axle housing, or expect to replace them. You do not have to remove the brakes or shoes, but it helps to unbolt the brake line support bracket behind the shock, this is to allow you some wiggle room for the brake backing plates. Unbolt the drive shaft, and than remove the 8 or 10, 12mm nuts off the carrier and pry out the diff assembly. Than you clean out the housing with solvent (might have metal particles in the housing that caused the whine), than install the new diff assembly, replace the rear axles and drive shaft, and refill the diff with gear oil. Use either a new gasket or lots of form-a-gasket sealer.

when the rear axles are out and hanging from the bungees, rotate the wheel bearings by hand, they should be smooth and quiet when you spin them. If not replace the bad bearings.

What year are your two Tercels? If your other one is in fair or better shape it would be a shame to make it not drivable because of the differential, unless it is a rust bucket or wrecked. I would not use it as a parts car unless it is just not worth fixing. I can find you either a 4.1 or 3.73 rear diff assembly locally for under $100 if you just need a diff. where are you located?
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
User avatar
ARCHINSTL
Goldie Forever
Posts: 6369
Joined: Sat Apr 30, 2005 1:52 pm
My tercel:: Goldie is a 1986 SR5 attualmente con Weber/also owned the first T4WD in STL in late '82
Location: Kirkwood, a 'burb of St. Louis

Re: Rear differential repair

Post by ARCHINSTL »

While you have the backing plates off - good idea to check these:
Petros thread: http://www.tercel4wd.com/forums/viewtop ... ake#p22409
My thread, with photo: http://www.tercel4wd.com/forums/viewtop ... ear#p42553
Tom M.
T4WD augury?
"Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"
"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
Mark Twain
steen
Newbie
Posts: 16
Joined: Mon Dec 13, 2010 9:39 pm
My tercel:: 1986 SR5 no mods

Re: Rear differential repair

Post by steen »

Not a wheel bearing, unfortunately confirmed by two seperate mechanics. I think we're just going to go for the rebuild, probably the wheel bearings as well just to not do it again for a long time, hopefully. Could this make the car get crappy mileage as well?
takza
Highest Ranking Member
Posts: 4414
Joined: Fri Apr 02, 2004 4:28 am
Location: Tibetan plateau

Re: Rear differential repair

Post by takza »

I'd find a low mileage rear end from another wagon before I'd go for a rebuild....lower mileage factory part bound to be better?
Give a boy a gun-give a biatch a cell phone-and pretty soon you almost got yourself a police state.

Orwell said: War is peace! Freedom is slavery. Ignorance is strength...

Image
User avatar
dlb
Highest Ranking Member
Posts: 7305
Joined: Mon Jul 06, 2009 9:03 pm
My tercel:: '87 sr5, '83 dlx parts car
Location: bc, canada

Re: Rear differential repair

Post by dlb »

takza wrote:I'd find a low mileage rear end from another wagon before I'd go for a rebuild....lower mileage factory part bound to be better?
ditto.
steen
Newbie
Posts: 16
Joined: Mon Dec 13, 2010 9:39 pm
My tercel:: 1986 SR5 no mods

Re: Rear differential repair

Post by steen »

I am located in northern New Mexico and would love to find a low mileage rear end if you know of one, thanks Steen
steen
Newbie
Posts: 16
Joined: Mon Dec 13, 2010 9:39 pm
My tercel:: 1986 SR5 no mods

Re: Rear differential repair

Post by steen »

Pinion gear? Best place to look for a good used rear end? (HaHa, no jokes please)
takza
Highest Ranking Member
Posts: 4414
Joined: Fri Apr 02, 2004 4:28 am
Location: Tibetan plateau

Re: Rear differential repair

Post by takza »

Look here for prices and availability?

http://www.car-part.com/ now need a VIN

Probably need to buy locally due to the weight?

By used I mean somewhere under 200K miles.
Give a boy a gun-give a biatch a cell phone-and pretty soon you almost got yourself a police state.

Orwell said: War is peace! Freedom is slavery. Ignorance is strength...

Image
steen
Newbie
Posts: 16
Joined: Mon Dec 13, 2010 9:39 pm
My tercel:: 1986 SR5 no mods

Re: Rear differential repair

Post by steen »

Thanks for that site, there are two in 'Burque that will save me some shipping.
Post Reply