Quote:
Originally Posted by Yozh
I kept the dogbone. It's a heavy piece, but BMW describes it as a vibration damper and I did not want to experiment. The rear bushing we could not press out. It moved 0.25" each way but otherwise stuck. We ran out of time. Advise to others, please have proper bushing press to do this. But I think a challenge with the rear bushing is the welded subframe that bushing gets stuck in a gap between the two pieces.
Sukutash, I have solid aluminum subframe bushings and I have barely any whine. Only on deceleration a tiny faint sound that I could hear sometime.
|
In regard to this rear bushing, the bore is not a continuous cylinder. It is two inward protruding barrels but a small gap that doesn't let the cylinder be continuous at close to center of it's axial length. I thought my pushing washer was getting hung up on one of those internal lips. Hope that makes sense. I broke my threaded rod 3 times before I realized something fundamentally important. I used a 3-1/2" hole saw as a receiver cup. I used a 1/2"-13 thread rod with several step sized washers and the wonderful bearing in HP Autosport's bushing press setup. That holesaw turned out to not be deep enough. So, the bushing was hitting the bottom of the holesaw and then couldn't move anymore. So, the threaded rod would tension load up further and then break.
Before I realized the bottom out problem, I thought I 1) had a lube problem on the threads 2) too much friction on the threads 3) I had another bullshit theory but I have forgotten it.
I cut another rod and luckily the h/w store makes you buy a 3 foot piece of threaded rod. As I took 4 tries to nail it. I used the much deeper cup from the HP Autosport kit but had to use my 1/2" threaded rod with it. It EASILY came out once I had the proper depth to push OEM one all the way out. It was only about 1/2 way out with the earlier iterations.
For those that aren't informed, Harold at HP Auto rents out this bushing tool kit for $69 + shipping +$300 deposit. I bent the threaded rod in it fighting the rear subframe bushing (not the rear diff bushing). Long story short, one piece poly bushings for the rear subframe are damn near impossible. I had to cut mine and slide in each half from top and bottom. I whined and got help over on the suspension/brakes/chassis forum. thanks to several over there for your help. Harold was cool and only deducted $15 for the damaged threaded rod. The threaded piece in the kit is much more robust than the 1/2" one I got from h/w store. This thing is more like an 11/16" and is a hardened alloy/toughened mutha.
Yozh, I'm surprised that fancy bushing puller kit you have access to couldn't do it. You put M3 bushings at front of diff, right? Not sure you had that down in thread here versus texts to me.
I have no whine that my old man ears can hear. Whatever was going on has disappeared. Of course I have polys instead of aluminum S/F bushings though. I agree the coupling from the diff to subrame is more important. I also think the dogbone plays a role in damping the noise. Nice discussion and thanks for sharing from other alternate configs.