Subframe Bushings

[jbd5015]

I ordered some new subframe bushings for when i do the diff swap

I figure itll be a bit easier to swap the diff with the subframe on the ground. Im also replacing the trailing arm bushings and the dogbones. I also want to bleed the brakes, so if im doing all that, why not drop the subframe and replace the bushings?

My question is, how hard are these suckers to get out? I couldnt find any procedures in the Bentley about it. Do they just slide out or do i need a BFH? Ive got a 4lb sledge, ill also have access to heat, but probably no air tools. i should be able to get bigger hammers as well if needed. Just want to know what im going to need for this job.

-Jeff

[CW6er]

Here is a little light reading, there will be a test after: :D :cool

Trailing Arm Bushings:

The trailing arm bushings can go in backwards, here is the right way around:
https://store.nexternal.com/ireland/images/E30RearCamberToeKit.jpg

Check out these threads about removing the rear Trailing Arm Bushings. it's not as easy as it looks (read all of the posts):
http://bigcoupe.com/phpBB2/viewtopic.php?t=9393&
http://bigcoupe.com/phpBB2/viewtopic.php?t=9604&[/URL]
________________

Rear Subframe Bushings:

RR the Subframe bushings using the "tool" on the car, you have to knock the splined center bolt up and out to use it. The bolt doesn't always cooperate:
http://bigcoupe.com/phpBB2/viewtopic.php?t=9068&highlight=subframe+bush%2A

Then there is the Sawzall method, first some comments and tips:
http://bigcoupe.com/phpBB2/viewtopic.php?t=9340&highlight=subframe+bush%2A (http://bigcoupe.com/phpBB2/viewtopic.php?t=9604&postdays=0&postorder=asc&highlight=ton+press&start=15)

A discussion with tips on the method:
[URL]http://bigcoupe.com/phpBB2/viewtopic.php?t=5051&highlight=subframe+bush%2A

The method itself:
http://e34.org/forums/posts/263870/

A recap of the different methods:
http://bigcoupe.com/phpBB2/viewtopic.php?t=3981

_________________

While you are at it, and have the subframe dropped, "you might as well":

http://bigcoupe.com/phpBB2/viewtopic.php?t=6997&
https://store.nexternal.com/ireland/images/E30RearCamberToeKit.jpg

http://countlessbargains.com/BMW/Subframe_Mod/Kit_9.JPG

[dm635]

I've read these are the toughest bushings to punch out. And that trailing arms have been ruined. Pinching the locating points closer together.

[jbd5015]

Well thats not very comforting now is it?

Fortunately, I plan on pulling it all out to begin with. Hopefully that will make my life easier.

I also have access to a press (have to check on how big), oxy-acetylene torch, and a bunch of random nuts/bolts/all thread/chain/cables etc.

I wanted to do the camber kit, but its just not in the cards. Apparently I've got enough trouble to deal with!

I wonder if heating the trailing arm bushings would help soften any 'seizes' that it may have.

Thanks for those links, ill be reading through them a few more times and hopefully getting some contacts for a few of the guys!

-Jeff

[Badgas]

On the sub frame bussing replacement;
I was able to fabricate a tool similar to the one shown and it worked very well. Not really hard if you can get it welded up for free. Washers and threaded rod came from the hardware supply.

The tricks that worked for me.
1. Soak the bushing retaining bolt with penetrating fluid overnight. Using a sacrificial nut on the lower end, beating it up and out with a long handled sledge.
2. Heat the housing to soften the rubber to while extracting the old bushings.

[DaHose]

The subframe bushings pushed out rather easily with the right die, but it must have cutouts so it doesn't damage the alignment "bumps" that portrude inside the tubing. Putting the new bushings in was also pretty easy.

Removing trailing arm bushings should NOT be attempted by anyone who has less than a 60 ton press and the proper, hardened dies. It is an absolute NIGHTMARE!!!!

Jose

[HayekFan]

I was going to do mine when I did my diff but realized it was going to be a pretty big PITA. I would have gone ahead and done it just for the principle of it except that the bushings seemed to be in good shape, which surprised me given the car's age and history.

What are the signs that these bushings are bad? Do they get brittle and crack, or mushy and pliant, or do they just rot? If they're bad, is it usually obvious from looking/poking at them?

[DaHose]

All of the above. They crack and they get brittle. In my case, the two "ribs" of rubber that connect the center to the outer were almost completely sheared on the passenger side bushing. The driver side WAS completely sheared and flopping around. The result was that the rear end felt WAY squirrelly under various conditions.

Jose

[Flash635]

I wanted to do the camber kit, but its just not in the cards. Apparently I've got enough trouble to deal with!
-Jeff

You could do the poor man's version.
Slot the holes like as if you were going to fit the camber kit then bolt up the suspension fairly tightly but not final tight with strong washers under the nut and bolt head.

Do the wheel alignment with a hammer then tighten the bolts and weld the washer in place..

[dm635]

I'm refering to the trailing arm bushings, not sub frame.

[jbd5015]

I just got the bushings in the event they are toast. Im pretty sure the subframe bushings are done, but not sure about the trailing arm bushings. They could be alright for all I know. Unfortunately I wont be able to see until i get the car off the ground.

Would heat aid in releasing the trailing arm bushings?

-Jeff

[HayekFan]

All of the above. They crack and they get brittle. In my case, the two "ribs" of rubber that connect the center to the outer were almost completely sheared on the passenger side bushing. The driver side WAS completely sheared and flopping around. The result was that the rear end felt WAY squirrelly under various conditions.

Jose

Okay, thanks. The ribs were good and the rubber in general seemed healthy. Makes me wonder if they were replaced at some point.

[Bentsdl]

The trailing arm bushings of the E12 and E28 based sixes are quite the same right? I did mine a couple month's ago and didn't have lot's of trouble. I fabricated something like this: http://www.firstfives.org/faq/trailing_arm_bushing/trailing_arm_bushing_faq.html
Cost under 10$ and had all four changed in 3 hours, and that's with the trailing arms still under the car. (didn't want to undo the half-shafts and brake lines:D) It should be a looooot easier witht the subframe and trailing arms removed.

http://www.firstfives.org/faq/trailing_arm_bushing/tool_on_arm.jpg
http://www.firstfives.org/faq/trailing_arm_bushing/bushing_removed.jpg
http://www.firstfives.org/faq/trailing_arm_bushing/images/1.jpg

Pulling new ones in:
http://www.firstfives.org/faq/trailing_arm_bushing/trailing_arm_bushing_faq_image018.jpg

[jbd5015]

we've got a bunch of dies built for the press downstairs that is rated for 50 tons maximum. Ive give it a shot without heat and if they move im going to go ahead and get them out.

Jose, do you think that yours were so hard to get out because of the damage to them? Perhaps the failures caused different pressures on the bushing housings to make them seize? You used a 60 ton press, did you use 60 tons of pressure?

-Jeff

[DaHose]

E12 and E28 control arms are NOT NOT NOT the same. The E12 bushings would come right out, easy peasy. I have a spare set of E12 bushings I ordered in error, if anyone wants to buy a cheap set.

The worst of the bushings I pushed out of my M6 (E28) control arms required about 40 tons before it moved. Your 50 ought to be enough. It scares the piss out of you because everything in the room jumps and there is a seriously disturbing cracking noise. You can expect them to crack and creek some more, before they finally push free. Pushing in the new ones will be surprisingly easy compared to the removal. I believe the reason they are so damn hard to remove is that they get ignored. Eventually the vibration and rusting between the surfaces of the bushing and control arm cause SERIOUS galling and it's as if the two pieces have fused together. The bushing rubber is so dense that they probably just really last a long time and the galling is just a byproduct of how long they last. Good luck getting those out easier than it was for me.

Jose

[CW6er]

You used a 60 ton press, did you use 60 tons of pressure?

Opps, I got the wrong link in my post above, here is Da_Hose's description of removing the busings and how much force it took:

http://bigcoupe.com/phpBB2/viewtopic.php?t=9604&postdays=0&postorder=asc&highlight=ton+press&start=15

[jbd5015]

Thats what i was figuring about the bushings, they just get seized up after being ignored for so long.

At least Ill have new bushings to compare these old ones to. If they are reasonable, ill just put it off a little longer, i cant really risk not having a vehicle for a while if i screw up a trailing arm!

-Jeff

[Trevor M]

The trailing arm bushings of the E12 and E28 based sixes are quite the same right? I did mine a couple month's ago and didn't have lot's of trouble. I fabricated something like this: http://www.firstfives.org/faq/trailing_arm_bushing/trailing_arm_bushing_faq.html
Cost under 10$ and had all four changed in 3 hours, and that's with the trailing arms still under the car. (didn't want to undo the half-shafts and brake lines:D) It should be a looooot easier witht the subframe and trailing arms removed.

http://www.firstfives.org/faq/trailing_arm_bushing/tool_on_arm.jpg
http://www.firstfives.org/faq/trailing_arm_bushing/bushing_removed.jpg

Pulling new ones in:
http://www.firstfives.org/faq/trailing_arm_bushing/trailing_arm_bushing_faq_image018.jpg


Hey! Those are my pictures...lol :cool

[Bentsdl]

Hey! Those are my pictures...lol :cool

Aha, now I know who to thank for that outstanding how-to! It was very useful when I replaced mine!

Thanks!

[PRJKTGRMN]

I did this last summer jeff let me simplify if for you...

1 lots of pb blaster
2. A bfh
3. A torch
4. A large burly man...to go with the bfh
5. And a lot of swearing

[jbd5015]

Did you do the work with the subframe in the car? And was it just the subframe bushings?

-Jeff

[PRJKTGRMN]

Did you do the work with the subframe in the car? And was it just the subframe bushings?

-Jeff



We took out the subframe, replaced the dog bones and pretty much everything else on there. We also cleaned up the rust and put on some fresh undercoating so it looks all nice n pretty. See my build thread, there are lots of pix too of our progess. I'd post a link but I am on my mobile!