Subframe bushings - replacing old poly with new poly

[Beej '86 325es]

So I've been doing E30's for a while, and my 12 year old Powerflex bushings are tired. They need to be replaced, along with my diff bushing before the next track season.

All I can find online is DIYs to replace the old rubber ones with polyurethane, which is of course a very daunting task. Since mine are already polyurethane, they should be much easier to remove.

My question is, do I need to drop the whole subframe, trailing arms, diff, etc to do this job if they just slip out? I'd hate to get into disconnecting brake lines, etc. I'm starting to get older and less willing to do these involved jobs on the floor of my garage.

Thanks!

[reelizmpro]

Depends if you are doing the trailing arm bushings as well. If so, drop everything. If not, you can do the subframe bushings on the car. You may even be able to get the trailing arm bushings as well with a little clearance.

[Beej '86 325es]

Exactly what I was hoping, maybe I'll give it a go - thanks, Barry

The trailing arm bushings are pretty new and should be ok.

[reelizmpro]

I know there are special tools that allow the bushings to be changed on the car but since you have poly already you should be able to get them out without too much trouble. It's really not that big of a deal to undo the parking brake lines from the cabin and undo the 2 brake lines though if you need to drop the entire subframe. Do you think the polyflex bushings have broken down? I was under the impression poly would last virtually the life of the car.

[Beej '86 325es]

Ha! I would have thought the same thing. The Powerflex bushings are a little softer than most of them out there, maybe that's why have worn quickly. These things were installed in 2002 on my previous E30 chassis, before we swapped it all over to the new chassis.

Another thought is that I always put my jackstands under the subframe, and it sits like that all winter. That may be putting too much pressure on them, crushing the upper part of the bushing. ...maybe I need to go with solid bushings this time, since it's more-or-less a track car anyway.

[FrostedE30]

I plan on refreshing my subframe bushings also replacing trailing arm bushings, but I don't know if I should replace them with oem rubber or poly, this is a daily driver, but also plan on tracking it as well. As for brands for poly bushings do you guys have recommendations on which brand? I've been looking at Garagistic's poly bushing what are your thoughts on that?