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How do confirm your differential mount bushing needs to be replaced?
Hi. When I was working on pillow ball bushings and had the car jacked at an angle, I had clear oil on the floor. Someone told me it could be the bushing leaking. So I tried to drop the diff without taking it all out. I can’t get all the way down as some others in the forum ... know idea how you change the diff mount bushing without taking the whole diff out!
anyway, I have it mostly out of the frames. (Pics attached). Before I drop the diff I want to be sure I actually need to replace the bushing as it is.
so, how do I confirm they need to be replaced? They look good to me and I have no “clunks” when I drive it.
If it's leaking it needs to be replaced. I don't think you would hear any clunking or anything but you may have more wheel hop and slop in the back end. They may not be so bad that it's super obvious when driving.
You will have to remove the power plant frame to drop the diff to get to the mounts. Once it's out you can let the diff hang by the half shafts and get to the nuts on the top that hold the arm to the diff with the 2 mounts. It's not the most fun thing in the world but it's not terrible to do.
Also, when the diff is hanging/out of the way it's SUPER easy to get to the fuel filter, good excuse to change it.
Ok. I removed the nuts and bolts from the PPF to the diff. My questions are:
1) do I need to also remove the propeller shaft?
2) how do I get the diff off the PPF?
thx!
1. No, but when you start moving the differential around the snub of the drive shaft will move in and out of the transmission extension housing which could be hard on the rear transmission seal. So you might want to go ahead and drop it. That seal is cheap and easy to replace anyway. It’s one of those ‘while you’re in there’ things. It’d suck to have to pull everything off to deal with that seal leaking
2. The 21mm nuts and one 21mm bolt IIRC...at the rear. The whole PPF has to come down so the front nuts have to come off too. You’ll need to support the differential long enough to drop the ppf otherwise the bolts bind.
I think it is possible to do it without removing the PPF, though I may have had to undo the diff end of the prop shaft (I really can't remember it was a long while ago now).
Chances are the bush is cracked on the inside, which you can't see when they are still in place, mine were, both sides looked like this:
I supported my diff on both sides of the suspension to take the weight off the carrier and removed the cross brace at the front of the diff:
The hanger bolts come off easily:
The hanger mounting nuts I think I used a combi ring spanner to remove/replace the nuts, I seem to remember having to buy one of the right size.
If you have a press the bushes pop right out, though I had to improvise the inner press tool (I think it was a 38mm socket):
Then just clean up and paint the hanger the hanger/put the new bushes in and replace
Glad you’re getting it done. You’ve probably already found out that those four nuts on top are on with factory thread-lock and can be tough.
Good call on the fuel filter. I replaced mine with this job too.
Since you dropped the diff you might consider replacing those diff side seals. They’re not expensive. IIRC from the FSM just index the clip on the axles to the 12:00 position going back on. They should just pop back in. I might figure to do a gear oil change too and drain before hoisting it back up.
Since you dropped the diff you might consider replacing those diff side seals. They’re not expensive..
changing the side seals as well per your suggestion. Question, I think I pushed the new one to far in... I’m using a socket as my tool and a rubber hammer. Having a tough time getting it even. Does it matter that it’s not flush? Any recommendations and or tips?
Yep, they should be flush. Try to pull it back out w/o damaging the seal or, better yet, get another. Somewhere there’s a thread I posted about changing them with a caution about the lack if a “seat” for the seal. You just have to be a little careful. My personal method is to use the old seal on top of the new and a small, controllable body hammer with a big flat head. A little oil on the outer edge and start tapping it in slowly increasing force until you see it move...stop when it’s flush.
Thanks @Sgtblue and @DaleClark -- I got one them in flush except one was the one i took out.. it looked ok but after thinking about it last night just ordered a couple new ones to do it right. thanks for the help.
Excellent. May also be worth pulling the rear aluminum cover off the diff and cleaning out any sludge or crap inside. Re-seal with RTV and have it ready to fill back up with fresh gear oil.
Hey! It is a clean 94 SSM FD. I love this car. Not redone, just in good shape. And I try to keep it that way. I bought it from a nice gentlemen in Dallas in 2018 and brought it to Virginia.
Can’t get the drive shaft to go into differential. I hate to force things but do I need to force it? What’s the secret? I also had to take off the tie rod to get the whole wheel moving to even get the shaft in the diff. The FSM makes it look so easy... ugh
I think experience is vary here.
My half shafts always slid right in without too much issue. A good push or a smack on the hub with a 4lb plastic dead-blow hammer and they popped back in. But I know others have struggled. You have the clip on the half-shaft snub clocked to 12:00 O’clock...right?
04-04-20, 04:28 PM
