Subframe mount replacement: WARNING, GRAPHIC IMAGES!

[Tomguy]

This isn't for the weak of heart! If you are a rubbermentalist, rubber conservationist, a member of PETR (People for the Ethical Treatment of Rubber), or a Vynyltarian, this thread may disturb you with its graphic pictures of extreme rubber abuse. NOT for the weak of heart!

Picture #1: With my front end jacked up (both wheels off the ground), you can see the poor condition of the mount is quite evident: It's no longer in one piece. (this is the passenger side, it was in a little better condition than the driver's side). The forces of the subframe shifting around due to these poor bushings caused the subframe stabilizer arm to snap, as shown in Picture #2, just like Mike Tangas's had. FYI: I did not need to disconnect my parking brake, brake lines, or what Mike refers to as "Leaf Springs" - the subframe's secondary method of being attatched to the frame - as Mike did in his article. I also did not need to loosen the hex bolts on the motor mount, unbolt the top of the left side engine shock absorber, or the fan shroud. I believe this is because my subframe mounts as well as my engine mounts were/are beyond shot (my engine mounts are next to be changed, they're just as bad as the subframes - my engine shocks do nothing, the mounts are so flat).

Picture #3 shows the poor condition of the mount from the underside: It's obvious that this mount is nothing more than decoration at this point in its life. (Note that my car's frame isn't rusted that badly for a car living in the rust belt for 33 years, with frequent wintertime salt exposure - it's mostly cosmetic rust).

Picture #4 shows what the new subframe mount looks like installed. I cleaned the area out, wire-brushed it, vacuumed it, wiped it clean with denatured alcohol, and gave it a fresh coat of paint, to prevent further rust. It also looks a LOT better!

Picture #5 shows the 2 subframe mounts - the pass side I destroyed trying to get out before I realized that blowtorches burn rubber and "Unstick" it from the subframe - and the driver's side I reassembled after removing and pushed down on to give an idea how flat it was. Note: It was only about 50lbs of pressure that did that much crushing of it! New mount shown for comparison.


The result? My car now handles MUCH better, obviously! Even my idle is smoother now. The front end sits about 2-3" higher. With a small camber adjustment and alignment I did myself, the difference is amazing, road noise is less, and it's so responsive at 80MPH+, that I could slalom around dimes!

[kpb]

DUDE! I will shortly be vacating all the crap out of one-half of my garage to perform this exact replacement. Your info is quite valuable as a supplement to Mike T's DIY expository. Thank you so much. Hopefully, In the next week or two I shall too have completed this subframe process.

[joshhol]

Good job. I cant wait to try out the 300D with its new subframe mounts and complete new everything else in the front end. Next, I badly need to replace the mounts on the fintail with shocks all around. I believe I'll throw in a set of rear subframe mounts on the fintail as I am doing on the 300D along with differential mount. Don't know what other rubber bits I can replace on the swing axle at this time, but will locate and destroy targeted items.

BTW, how did you shrink pictures down to upload them? I assume you're using a digital cam there. . . (duh)

[psfred]

Swing axle rear end has bushing at both ends of the control arms, at the diff mount, and at the locator mount for the diff bracket. Check the condition of the pivot bushings, too -- should be no sideways play to speak of. Grease while under there...

Peter

[MikeTangas]

When doing the front end it is good insurance to replace the original rubber brake hoses. Even if they look good externally they can be seriously deteriorated internally. Best part is they are cheap.

Good job on replacing the sub-mounts. Not overly difficult with great returns. And to think I thought my mounts were bad...wow, you really needed them!

[JMela]

Way to teach that rubber a lesson it'll never forget. Another good project in terms of handling improvement is the stabilizer bar bushings. That's been my favorite in terms of the handling improvement/ $$$ ratio.

Motor mounts take about 15 minutes to swap out, so you're home free on that one. Actually, I might have a spare set sitting around in my garage, email me if you need'em.

[cbdo]

Haven't been in a 108 in decades, but it's still my fave of all the cars the family's had. The combination of that "slalom around dimes" feel with the sensation of riding in a rolling bank vault is why, and nobody's ever done it as well as MB.