540i rear subframe work

[Billyj]

Wow... The parts price from that 'thebmwminipartstore' is lower than my shop discount from the dealership. Paid like 88 for the belt tensioner. That sight shows 83...

[BleedsBlue]

[Billyj]

By any chance do you have bumpsteer strut spacers installed? Ever felt the need?

[BleedsBlue]

By any chance do you have bumpsteer strut spacers installed? Ever felt the need?

I just did so, at the suggestion of UnrulyGrace after driving my M5 (pretty low on KW V2s). It made a noticeable difference in reducing steering effort/bind, and retaining steering angle over bumps (thus, the "bump steer" term I suppose). I went with AKG's biggest plates.

[Billyj]

Thanks I just came across them and want to try them. Compared to my e39 straight six this e34 is so languid. I'm hoping all the new control arms, bushings and mounts will help..

I believe the actual definition of bumpsteer is steering angle change as a result of suspension compression/extension, isolated from driver input, caused by distance of tie rod centerline from hub center

[Billyj]

Hey guys, quick update. Today we were too busy for me to work on the e34 after work. I did however take some time to poly fill the bushings I ordered the other day.

Most of the bushings didn't have cavities very large so I simply filled what I could and then a bit extra around the edges. For the trailing arm bushings and rear diff mounts there wasn't much empty space, we shall see if it adds any support once it sets just being around the edges (in the case of the trailing arm bushings). The rear diff bushings had two small cavities on each side and see room around the edges.

The most dramatic would be the side subframe bushings, except I have a feeling the bushing is pretty well supported along common load paths. There is metal that extends from the outer sleeve almost all the way into the core. We shall see how this urethane sets. I'm sure it will reduce the room for twisting.
IMG_20170722_123628.jpgIMG_20170722_123642.jpgIMG_20170722_123639.jpg

Also I don't believe I've posted pictures of my bimmers so heres some of those pictures people seems to love
Snapchat-215861311.jpgSnapchat-1793994440.jpg

Happy motoring fellas

[Billyj]

Small update, my e39 is in the process of being totalled out after an Uber driver hit me. As a result work on the e34 is slow to non existent, it's my daily as of now.

I ordered 33311132251 center subframe mount from partstore as well as a set of 6 stainless steel brake hoses from ecs (sale promo was the main reason)

I also happened to order some brake parts, as excited as I am to see the results bleedsblue gets from his brake tests I desperately need to fix my brakes.
4x Zimmerman z coat rotors
2x akebono euro ceramic
A few sets of rotor hold down bolts just because
Some caliper slides just in case.

Rebuilt calipers are like $40 apiece I may order some just for sake of assurance, probably won't, rebuilt is a crap shoot too lolIMG_20170806_191349.jpg

[boostedinaz]

If you are gonna do all this work I highly suggest you pull the entire subframe out. I just did this project on my 540 last year and taking the subframe out was a big bonus. The diff bushings are almost impossible to get in and out with the subframe in the car. I have pics of everything, however, photobucket is lame right now.

[Billyj]

If you are gonna do all this work I highly suggest you pull the entire subframe out. I just did this project on my 540 last year and taking the subframe out was a big bonus. The diff bushings are almost impossible to get in and out with the subframe in the car. I have pics of everything, however, photobucket is lame right now.

So you're telling me I should get a 3.15 lsd and modify it for an extra puck and then swap the whole thing in with a fresh coat of primer and fill of oil while I have the subframe out?

I may be projecting a bit...

All jokes aside I've been going back and forth about dropping the subframe but honestly since I'm doing everything (except center dif bushing) including brake hoses I probably should drop the whole subframe assembly. Your advice seals the deal... Now if only I could convince my boss to let me take a 'day off' to do the thousands of dollars worth of parts replacements I have already stacked up

[katit2]

Can you tell me what is the point of filling up subframe bushings with a silicone?

[Billyj]

It's not silicone, it's polyurethane =D I let it cure much longer than necessary, anything over three days is probably unnecessary, I've waited weeks.
All in all it will most likely help stabilize the side subframe bushings most of all and as I stated above it will be minimal.
Total cost of the one tube that I used was under 20 dollars, figured it was worth a try. I'll post results after I install.

[demetk]

I used 2 part Flexane 80. It will fill every cavity.

[boostedinaz]

Why not just buy polly bushings?

Here is my subframe all done

[Billyj]

Why not just buy polly bushings?

Here is my subframe all done

That is one sexy subframe my friend... Now I want to repaint mine...

And to answer your question, I didn't use poly because I was worried about finding matching durometer/style poly from one company. Also I like to make my life harder, more things to complain about that way

[Billyj]

I received my center subframe bushing (lemforder) today and decided to open a tube of m3 window urethane. This stuff has good penatration and when fully curred is rather firm.IMG_20170817_150150.jpgIMG_20170817_150153.jpgIMG_20170817_151516.jpgIMG_20170817_151526.jpgIMG_20170817_151523.jpg

I may have to remove some material around the aluminum mounting face but this mount had a lot of wiggle room within its shell and now it won't

[m735is]

I used Flexane 60A. The kit was enough for 4 subframe bushes and 2 diff mounts. I still have to install the e23 stuff- it's only been 5 years...

http://www.bimmerboard.com/forums/posts/1076831

[demetk]

I think the 60A is a better choice. I used the 80A and can now hear the diff.