Subframe insert install problem

[IN10CT]

Problem installing the subframe inserts? It couldn't be more easy... Well, I started on the passenger side. The trailing 22mm nut came off no problem. The two forward bolts are 13mm however. I grabbed my trusty 3/8 drive socket and in an easy half turn had succeeded in twisting the bolt off!

Rather than move on to the second 13mm bolt, I have replaced the 22mm nut and halted my install. Now I am looking for suggestions. I don't have the equipment to extract the broken bolt so I guess I will have to take a trip down to the shop and get the car up on the hoist. My main question is, how compromised is the rear-end of the car with the one missing bolt?

Second question, I can put my finger right up into the space where the insert will go. Has the bushing completely disintigrated or is this normal?

I am thinking of asking the shop to replace the subframe bushings and thus taking care of the bushing issue and the frozen/broken bolt problem at the same time.

Your guidance and suggestions are eagerly awaited.

[MBXB]

Here's a write-up by the E28 guys. They use a Sawzall to hack the old one out.

http://www.tycksen.com/bmw/tech/subframe/index.php?session=nudY24bh04RndJKvYmZGw3itv2

[632 Regal]

do a search for "subframe bushings", you need a tool to press them back on, dont use soap or anything.

[MBXB]

And another approach from the E32Underground:

http://www.e32underground.com/read.php?TID=453

[Robin-535im]

Problem installing the subframe inserts? It couldn't be more easy... Well, I started on the passenger side. The trailing 22mm nut came off no problem. The two forward bolts are 13mm however. I grabbed my trusty 3/8 drive socket and in an easy half turn had succeeded in twisting the bolt off!

Rather than move on to the second 13mm bolt, I have replaced the 22mm nut and halted my install. Now I am looking for suggestions. I don't have the equipment to extract the broken bolt so I guess I will have to take a trip down to the shop and get the car up on the hoist. My main question is, how compromised is the rear-end of the car with the one missing bolt?

Second question, I can put my finger right up into the space where the insert will go. Has the bushing completely disintigrated or is this normal?

I am thinking of asking the shop to replace the subframe bushings and thus taking care of the bushing issue and the frozen/broken bolt problem at the same time.

Your guidance and suggestions are eagerly awaited.

You'll want to fix the bolt for sure, but easy driving to and from the shop should be okay. Don't sue me if you crash though :) . If I were you, I'd first get the bolt replaced then attempt it again. Compare the cost of having the shop swap the bushings to the cost of the tool rental + shipping, factoring in the fun factor of working on the car (may be a + or a -, depending on how much you like cars!)

The bushings have hollow slots on either side, the look kind of like a capital "theta" in the Greek alphabet. If it were completely shot, you probably would know it after pulling the 22mm off.

You can get an easy-out type kit pretty cheap, maybe rented from the parts store, or any good shop can pull the bolt out for you. Ask real nice and they may do it free.

You will need the subframe tool to do the job; it's hard to fake it unless you build something very similar... takes lots of force to get them in and out. With the tool the job is easy.

On the next bolts, try tightening them until you just break the cold-weld-bond.. don't even have to move the bolt, just tighten it a wee bit until it goes "ping" then it will come out with less chance of torquing off. PB blaster works really well as far as penetrators go, but for that particular bolt you don't have much of a place to spray it.

HTH,

Robin

[dacoyote]

Koala rents the tool.. or at least they used to.. now I cannot find the rental page(Insert Whit)

http://www.koalamotorsport.com

[genphreak]

And another approach from the E32Underground:

http://www.e32underground.com/read.php?TID=453WoW! That's a good approach. Doesn't make things easy if your bolt breaks, but tightening it first and using a penetrant is obviously a must... I'll pin it in here so the loss of the E32underground won't lose this gem!

Posted on: 02-25-05 14:39:08

(http://www.e32underground.com/post.php?action=reply&TID=453&PID=3266&page=1)
Found a clever idea to replace the subframe bushings without the expensive tool, just by using a freezer and heat. Took him less than 1 hour per side.

A disclaimer first that I would not recommend this to the faint at heart, but, it did work for me....

First before you do anything, put the new bushings in the freezer. Pick a side and un-bolt the two 13mm bolts and 22mm nut from the sub-frame bushing plate/housing. I chose the side where the loudest clunking was coming from. (turns out the one piece bushing had worn away into two pieces causing the loud clunk every time I put the car into gear.)

Remove the back seat and locate the recessed hole where the sub-frame stud is pressed into. Then with a 3lb sledge I knocked the bolt out through the hole and pulled it out. (fyi: When you're whacking the bolt, put the nut on so you don't mar the threads.) I then put the car in the air and rough measured the distance the sub-frame was from the body. (unbolted it drops away from the car as it is jacked from the jacking point. The higher you jack the car up, the further away it is from the body) I cut a piece of wood a little smaller than the diameter of the busing and about 4 in long. I placed that in between the body/floorboard and the busing. I took my torch and heated the sub-frame bushing housing to soften the rubber. Place a jack-stand under the sub-frame close to the weld/housing and then slowly lower the car. The weight of the car bushing on the bushing via the wood dowel pressed that thing about half way out. I jacked the car up again and then used a longer dowel, repeated the same thing to get the bushing out the rest of the way. I was blown away it actually worked....

To replace the bushing, I used the dowel again but wedged it between the sub-frame arm and the body so that when the bushing was pressed in it would not stop short from hitting the body of the car. I took the bushing out of the freezer and put in an dilute soap/ice-water bath. I set up a jack-stand with another piece of wood directly underneath the sub-frame busing housing. The wood is larger than the diameter of the bushing. Using the torch again I heated up the sub-frame bushing housing and then took the new (cold) bushing, lined it up with the notches in the housing, set it in a bit and then lowered the car down onto the wood/jack-stand combo and that thing pressed right in. It stopped a little short of home but I just raised the car back up and put a taller piece of wood in and dropped the car back down and the bushing pressed in all the way to it's stop..... Plan and work quickly as I noticed the rubber of the bushing getting a little soft and beginning to bind a bit as the warmth of the housing thawed it out.... I was ok but I can see it being a problem if one were to wait too long.

And that's about it. Button the whole thing up and you're done with that side.

I drove the car and wow... no clunking starting and stopping, going into gear or even over bumps....

Jeff '92 750iL White

:) Nick

[BigKriss]

they are easy to replace, just remove the rear seat and it pulls out.

[632 Regal]

what do you mean "pulls out"? turn it from under the back seat?
they are easy to replace, just remove the rear seat and it pulls out.

[BigKriss]

what do you mean "pulls out"? turn it from under the back seat?
Jeff, a picture is worth a thousand words. I did this a while ago. (http://www.bimmer.info/forum/showthread.php?t=10560&highlight=subframe+bolt)

Ensure the car is on flat ground.

Remove the rear seat
http://img457.imageshack.us/img457/4397/pict01030tu.jpg

Locate the broken subframe bolt
http://img286.imageshack.us/img286/1261/pict01024pl.jpg

Remove by pulling up with your fingers. Reinstall new bolt as appropriate.

http://img273.imageshack.us/img273/5822/pict00994da.jpg