Alternator bushings

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JHZR2

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The alternator on my 91 318i is crooked. Tried to get some pictures of this, but it was difficult to get them clear enough to see the angle.

This alternator has a top and bottom set of bushings. I don't have a press. Is there any chance of doing this as DIY?

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Any tricks? I've heard to freeze bushings so they are smaller.

Thanks!
 
If it's like most BMW alternators I've ever dealt with, you should see circlips retaining the inner sleeves in the bushings; pop those off and the bushings should come out. They may be stuck due to age and degradation; either use the bolt as a puller, cut through the bushing with a hacksaw blade, or burn it out with a torch (a last resort, obviously). Use polyurethane replacements.
 
It might just be me, but the top "tensioner" bolt in the bracket looks crooked. Have you tried loosening it and go "down" at the back, "up" in the front, to make the bolt straight across? it would probably sit a lot straighter.
 
Originally Posted By: OVERK1LL
It might just be me, but the top "tensioner" bolt in the bracket looks crooked. Have you tried loosening it and go "down" at the back, "up" in the front, to make the bolt straight across? it would probably sit a lot straighter.


It is indeed crooked, but it always reverts to this position, I believe due to the bushings. I think the bottom bushing is off by a bit, which causes the whole thing to twist when tensioned.
 
There are lots of proper ways to fix this.

Want a ghetto fix? Try hammering nails in the opposite sides around the bushings to fix the angle!
 
Originally Posted By: mechtech2
There are lots of proper ways to fix this.

Want a ghetto fix? Try hammering nails in the opposite sides around the bushings to fix the angle!


I have bushings, no press. Now it is a matter of how to replace them.
 
IIRC these are a two piece bushing like the 80’s models, the difference is the inner sleeve is molded to the rubber in 90’s models and separate on the older ones.
Just push a thin screwdriver down the tube inside and feel for a break in the inner tube indicating 2 separate pieces.
If it is then use an old screwdriver or punch to knock them outwards from inside.

A solid tube needs to be pulled out, you take a piece of threaded rod and a washer just slightly larger then the inner tube but smaller than the bore.
Put the threaded rod through the bushing, put a washer and nut on the end, on the other end take a piece of pipe or deep socket slightly larger than the rubber and long enough to receive the bushing.
Place a washer over the pipe or socket and a nut, snug it down. Put two more nuts at the end of the threaded rod and lock them together, hold this with a wrench to stop the rod from turning while you tighten the nut on the socket, this will draw the bushing out into the pipe or socket.

The easier and faster way is just heat the tube inside front and rear with a propane torch till it gets hot enough to start the rubber burning then push the tube out with a dowel, the rubber can then be collapsed and pushed through. Do this outside, it stinks the high heaven.

To install the new ones even two piece may need to drawn in with threaded rod, just reverse the procedure doing one side then the other. Use some spray silicone on the bushing as it’s going in.
The new bushings are probably 4 pieces, 2 each for the upper and lower. I don’t recall seeing any clips on these but if there is just remove them before removing and reinstall when the new ones are in.

Sorry for making it sound more complex than it really is, once you get your home depot tool made and do one it will only take a couple of minutes.
 
You don't have to have a press, you can move the bushings with a bolt + nut + washers + socket. At most some heat from a propane torch might be needed, if the bushings are badly seized on.
 
Originally Posted By: Trav
IIRC these are a two piece bushing like the 80’s models, the difference is the inner sleeve is molded to the rubber in 90’s models and separate on the older ones.
Just push a thin screwdriver down the tube inside and feel for a break in the inner tube indicating 2 separate pieces.
If it is then use an old screwdriver or punch to knock them outwards from inside.

A solid tube needs to be pulled out, you take a piece of threaded rod and a washer just slightly larger then the inner tube but smaller than the bore.
Put the threaded rod through the bushing, put a washer and nut on the end, on the other end take a piece of pipe or deep socket slightly larger than the rubber and long enough to receive the bushing.
Place a washer over the pipe or socket and a nut, snug it down. Put two more nuts at the end of the threaded rod and lock them together, hold this with a wrench to stop the rod from turning while you tighten the nut on the socket, this will draw the bushing out into the pipe or socket.

The easier and faster way is just heat the tube inside front and rear with a propane torch till it gets hot enough to start the rubber burning then push the tube out with a dowel, the rubber can then be collapsed and pushed through. Do this outside, it stinks the high heaven.

To install the new ones even two piece may need to drawn in with threaded rod, just reverse the procedure doing one side then the other. Use some spray silicone on the bushing as it’s going in.
The new bushings are probably 4 pieces, 2 each for the upper and lower. I don’t recall seeing any clips on these but if there is just remove them before removing and reinstall when the new ones are in.

Sorry for making it sound more complex than it really is, once you get your home depot tool made and do one it will only take a couple of minutes.


OK, Im going to do this tomorrow. Just one question on technique... Mine are the two-piece bushings, no center tube that is separate.

How do I prevent gouging or damaging the body of the part that the bushings go into? Screwdriver at an angle pushing out bushings seems like a prime opportunity to have it slip off and slide through (frustrating and can be dangerous), or gouge the inside of the bore that the bushing sits in.

I assume just go around slow, with the bracket in a vice? Knock the screwdriver with a hammer? Im going to freeze the bushings and then use siliconme as stated. I assume I can lightly hammer them in with a drift?

Thanks again!
 
A couple of internal scrapes won't hurt a thing. You can file or sand them smooth for insertion of the new bushings.
Some sort of lube will help insertion, BTW.
 
2x bushings for the top and bottom each with its own centre moulded in. Correct?
Just clean up any burs if the punch or screwdriver slips with a small round file, dremel etc.
Unless its really corroded they shouldn't be that hard to remove.
A hammer or hard plastic faced hammer is okay when installing but you can use a vice also if you have a large one.

If they are really stuck for removal..
Just hit one with a propane torch in the metal tube not the rubber and heat till the rubber catches fire.
Let burn about 10 sec and put it out, quickly push the metal tube out of the rubber from the other side.
The rubber can be removed easily now.

Just heating the metal tube in the middle of the bushing does not heat the whole unit, it just gets hot enough to start the rubber burning.
 
PITA job but DIY-able. An example of over thinking a non problem. BMW did this a lot. Later E 28 s had solid mounts on 90 amp alternators. When faced with re-doing a 2nd set, I just bolted on a good used one from a 535i
 
Quote:
An example of over thinking a non problem

Cant disagree with that! Classic German over engineering on something that doesn't need it at all. Its genetic and cant be helped.
Check out an older German washing machine sometime if you want to see some absolutely over the top engineering.
Mind boggling does not describe it!
 
Well, I worked this project today.

Pulled the airbox:

IMG_2933.jpg


Worked to get the alternator off:

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Found the bad wire:

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Which lead to these threads:

https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2539590#Post2539590

https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2539754#Post2539754

Which are filled with pics of what I did.

You can see the top set of bushings in these two pictures:

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Surprisingly, they came right out, no problem.

Some pictures of the bushings, you can see that they are pretty worn:

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The bushings went in with a combination of hand-pressing, light tapping with a hammer, and using a threaded rod.

After putting it all back together, it seems to me that it is still slightly crooked, like the pulley on the alternator (which is correctly perpendicular to the alternator body) is not perfectly parallel with the power steering pump pulley right below it.

Dont know what to think. At least I got the wire fixed and new bushings in. Seems that there is a bit of belt noise, but it isnt a continental belt on there, which usually works best on euro cars in my experience.
 
Cant you straighten it out with the though bolt?
Does it have a gear on the front?
back it off slightly and pry the rear of the alternator towards the engine till its straight.
 
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