Help, Driveshaft rubbing problems!!!

[e9nine]

Interesting that the medium case would alter the positioning. Dan - do you remember the d.shaft being this close to the gas tank from the beginning or it's been too long? Sorry I haven't gotten to taking pics yet :rolleyes:

[M42boy]

Interesting that the medium case would alter the positioning. Dan - do you remember the d.shaft being this close to the gas tank from the beginning or it's been too long? Sorry I haven't gotten to taking pics yet :rolleyes:

I don't remember anything pre-medium case installation.  When I took the shaft out this last time (after the 4.10 med case was in there) I noticed it looked really close, but don't think it was actually rubbing.  

There was very little room there before, but now that the place that rebuilt the prop shaft put a counterwieght there, it's causing an issue as that sticks up enough to hit against the gas tank bracket.  

If you get a chance to take some pictures of that area, let me know.  Maybe we can meet up this weekend for a beer and I can jack up the back end of your car and take a look at things in there.  

My neighbor has a 325is with a LSD, so I'm gonna go take a look at his ride as well.  Somethings not adding up right.

[bmwman91]

Are your subframe mounts shot?  It could be sitting in the wrong position if the rubber in them has torn badly.

The metal circle.  That was probably put on when they were balancing the shaft...leave it alone.

Rubbing on the gas tank is a SERIOUS hazard.  Do not drive it until you remedy this, especially since it looks a bit rusted.

[D. Clay]

If it is the different differential cases, I would go with the suggestion above to put a couple washers between the differential and the subframe(very flat and smooth to maximize contact area.) Also might shim the CSB the same amount.
Doing any of that stuff to the fuel tank is way crazy.

[M42boy]

Well, went down and took a close look at my neighbor's 325iS this weekend.  Took some pics of his driveshaft/gas tank area as well as the rear subframe.  I'm convinced my rear bushings aren't pressed in all the way, causing the rear subframe to ride higher and hence everything else is off.

See pics below:
1) is of the driveshaft (as you can see, it has PLENTY of room between it and the bottom of the gas tank)
2) Is a closeup of one of the rear bushings as it sits mounted.
3) Rear bushing (different angle)

Any comments?  This looks correct to me.  





A slightly different angle...



What do y'all think?  Am I on the right track?

[bmwman91]

The bushings are definitely in all the way.  The lower lip of it is pressed against the subframe.  The locating bracket is not suposed to go all the way up there, so you look good in that respect.

[M42boy]

Maybe I was unclear...   The last three pictures are of my neighbor's car.  I think his bushings are mounted correctly.  My bushings aren't in all the way (from the way it looks to me).  I'll take pictures of my bushings when I have a chance as comparison.

But, it was when I was under my neighbor's car when it immediately became clear to me that this was the differentiating factor.  I think I've found the problem.  

Unfortunately the solution is a royal PITA.    

Basically, I'm looking at taking the whole rear end of the car completely apart again and putting it all back together... AGAIN.  

Since I have to do all this, I want to yank the good gas tank out of my parts car and swap out the two...  but this all takes a decent bit of time, something I have little of right now.  I'm hoping that someday...  someday...   maybe I'll actually be able to drive this car instead of looking at it up on jackstands.  

[D. Clay]

I did this in my driveway. My wife said." I guess it makes a difference if it's a BMW up on blocks but not much!"
http://www.m42club.com/forums/showthread.php?t=565
You'll have to paste the link because my url inserter isn't working.

[M42boy]

Okay...   I took a sabatical from my car for a few weeks but determined to get it off the jackstands and out of the garage...  more as I may be buying something else and need the room.

Anyways, I'll post a better picture of my rear subframe and bushing later tonight.  Problem is my bushing isn't pressed in all the way and the subframe is riding up higher than it should be, causing the driveshaft to have clearance issues.

Seems like an easy solution on paper, but the reality of yanking the rear subframe out of the car, disconnecting brakes, axle, diff, etc... all doesn't excite me too much (hence why the car has been sitting).  

So, my question to all of you is...

Is there any way to get these bushings pressed in all the way with the subframe on the car??   D Clay, your shadetree mechanic expertise, tools and procedures will be of immense value to me here!!!!

Someone help me figure out how to get the subframe pressed onto these bushings all the way without having to pull it all apart again and put it back into a press.  Any help/advice, therapy sessions all greatly appreciated.  :rolleyes:

[D. Clay]

Remove the piece that bolts to the rocker panel. Put a 2.5" galvanized cap on the bottom of the bushing and try to get a puller on the subframe from the bottom. Use the puller to push the bushing in. I'm not sure if you can find the room to get the puller in there.
Pic #1 shows the puller. #2 shows a 2.5" cap on the bottom of the bushing. Put the gear puller on from the bottom instead of the top. Use a lot of lube on the bushing. If there's no room, you may be able to remove the mount bolts on each side from inside the car. Use all-thread with a nut on it to knock the bushings out of the body. The differential mount will hold it in the car with a jack under the differential. Pull one side down for more room.
If the bushings break in their mount holes you'll have to replace them anyway. If you pull one side down with the other still in the body hole it will cack the bushing. There's always the "quick and dirty" - put 2 big washers between the differential and the subframe.
 

[bmwman91]

Voted: most awesome home brew bushing tool EVER.