Aligning differential and subframe
 

Hi guys,

Is there an easy way to align the diff and the subframe to get all the studs to line up with the subframe?

Thanks

I do not know that..
but the bigger question is how to align it with the rest of the car... and I know there is a huge section in one of the two Chassis Manuals..... very important to handling and tire wear....

Oh bugger I thought this was all done and dusted.

Are you trying to get the differential (with the axles fitted) to mate with the subframe?

Exactly it my friend. I though the hard part would be over but getting it to line up has been a challenge.

Oh for the love of $$#%$%#^ !

Have you got four studs fitted to the differential or have the studs come out with the nuts?

With four studs in the differential casing I'm kind of hoping you've got a chance of pushing the studs through the subframe holes.

One stud came off. So you would think it would be simple to align it.

I've jacked the subrame as high as it will go and still can't get them to align. Maybe I need to take a break

If you think you might need a break..... you need a break....
tired or frustrated around cars makes for accidents...

Initially, I had the same problem when I replaced the differential. What worked for me was to tilt the differential, on the jack, where the mount studs all entered the subframe at the same time.

It would not work, with any amount of prying, to start two at a time and try to lift it in place. The spacing of the mount holes is just too tight for this, as you are finding out.

Got it. Did you use 2 jacks at the same time or just muscled it in? any details on that?

Thanks Sam

I used a single jack with a strap and various items to wedge it to obtain the correct angle. With this setup, I raised it delicately into place with one hand on the differential and one on the jack. Once I achieved the simultaneous entrance of the four studs into the subframe, it slipped right into place.

I've always wondered if a transmission jack might be beneficial for this task.

I made a little angle plate that bolts onto the floor jack in place of the pad and then bolts to the two lower bolts securing the door. Just an piece of angle and some welding. Makes any work with the differential real easy including raising the dif into the four top bolt holes. Great for lowering the dif to get the axles to go into the wheel hub as well.

Great info guys.

Thanks!

I had the same issue just putting the Differential itself back in the Subframe. I don't know how many Hours I spent on it but I finally got it in.

I believe once you remove the Differential years of stress cause the Subframe to change shape; making it hard to get the Differential back in.

I don't know how I resisted the idea of enlarging the Holes but I did.

It would be nice if the Studs had pointed ends on them.

I did the job with a Floor Jack and a Sicssors Jack. I think if I had the Transmission Jack I bought recentely the job would have been a little easier.

I wonder what I'm doing that makes it so easy for me... I've never had issues with them.

are you guys dropping the subframe? or just lowering it, and trying to attach the diff with everything still attached?

Lowering the diff while the subframe is still attached.

I'm sure removing the subframe would make things so much easier...

Any progress?

not yet. been tied up.

Plan today is to jack up the hubs and put in the nuts for the shocks, hopefuly that will help, then jackup and manhandle the diff into place.

I've been through this before on the W115/114 and it can be tough even with a perfect subframe. One car I worked on had an accident damaged subframe with a replacement trailing arm and the differential holes were compressed and very tight. The differential had to be pried out.

When the car is on jack stands and the differential is removed the springs push the rear of the subframe toward the trunk floor. If you lower the car to the ground without the differential (don't it will damage the subframe bushings) the rear of the subframe will move toward the ground quite a bit. This seems counter intuitive but that's what happens. Try jacking the trailing arms until the subframe assumes the normal position. Be careful as this tends to lift the car off the jack stands.

If you're trying to install the differential with the rear mount attached to the differential cover (don't it's much harder) it will be impossible without jacking the arms. It can be done with the cover on and the axles in place but it's awkward.

The holes are precision made and very tight. With the differential and subframe out of the car it's still a bit difficult. You really need to bring it up straight. Tying to get one stud in first doesn't work and pushing hard on the diff just pushes the subframe to the trunk floor.

Once you jack the trailing arms you can put a block between the subframe and the trunk floor to help keep it in position and give you something to push against.

There is a reason for that.... and it is also why they should not be enlarged....

I hope it is working out for you - you must be getting close to having the vehicle towed away by the local authorities by now.

Hey Stretch,

I'm down to the wire. I have until monday. I have a SLAP tear and it's difficult to use my left arm. The good news is I do see light at the end of the tunnel.

Last night I was able to bring up the rear shocks, and attach all the hardware. With the help of my son and some neighborhood kids, we managed to jakc up the rear end and fit the flex disk (1 bolt) to the diff. Tonight I'm hoping to complete the rear end.

Alignment doesn't look like it's going to be too bad this time.

Thanks for checking in with me and I'll keep you posted.

I replaced my differential and it was a PITA. I had my car on a lift and I had the differential on a high end trans lift which could manipulate the differential in any direction. Can you get a jack under the differetial ?

Yes I can.

Alright guys. Just had to share my success, and share my knowledge.

First off the easiest way to get the diff off is the jack it up to about the point it would normally ride, support it and then lower it.

TO install it, was a family affair. We had to place a long 2X4 under the diff and jack and support the subframe. My daughter jacked it until the first stud was just touching the subframe, my son used the 2X4 get the second stud to touch, and I grasped and shook the differential until it dropped in the subframe

I hope this information saves countless hours I spend jacking and lowering the differential to get the differential out and back in.

BIG thanks to Stretch and everyone else that walked me through this and kept me sane.

I'm glad it didn't get towed.

Park it somewhere else quick.

Already taken care of. Thanks!