Rear suspension Overhual problems

[NickMav]

Alright so today I dropped my subframe with trailing arms and my diff. Whole rear basically. I changed out the subframe bushings and trailing arms bushings with Revshift replacements. Now getting them out was a bitch I basically just set them on fire let them heat up and hammerd out the old rubber ones. The new ones went in pretty easy on the subframe that is. When I got to the trailing arms things got ugly. After 2 hours or so I finally got all 4 in, I dont know why they were so hard to get in. I tried many different methods and found using a cclamp and pressing one side in at a time with the pin in it and then aligning the other one with a center piece and pressing that on with the cclamp. Only id say 2 out of the 4 gave me this trouble. Alright so I have them all pressed it. The one was a little messed up but eventually it all fell together. Now where it bolts onto the tabs on the subframe I got it all lined up and put the bolts and nuts through. I torqued them down to 45lbs. The tabs bent a little bit on the left arm and if I try to move it up and down its very stiff while the other arm is not easy but not fairly hard. Im probably going to take out the bolts tomorrow rebend the arms and see if i can get the bushings to sit better. Did anyone have any problems with this? I Dont know why its being so stubbern when the right arm went in almost perfect and the left is just giving me headachs Any help would be appreciated




How they should sit, others are bent slighty


How I got the bushings out



New Diff! 3.73 LSD instead of 4.10 welded

[Vivek]

My IE's were pretty stiff. They're gonna move with the car's weight on it no matter what. I wouldn't worry about it.

[AndrewBird]

^^^What he said. as long as they do move, you should be fine. They are likely stiff due to manufacturing variances in both the bushings and the subframe. It wouldn't take much to make them tight.

You did use lots of silicone grease when installing them right? It isn't needed on the subframe bushing as they don't pivot, but if you didn't use grease on the trailing arm bushings, they are going to squeak a LOT.

[dashboardmonkey]

+1 on the grease. If you didn't....get the pins out and grease them with a good synthetic grease. Petroleum type grease will eat the poly material.

When I installed my AKG trailing arm bushings I did not grease them. They squeak like hell.

[NickMav]

Thanks guys, got the pins out and greased everything up. Hopefully the one trailing arm bushing that looks a little funky wont cause any problems and it will settle soon. Ill have pictures up later but I have another questsion. Do you guys know the torque specs for the subframe bushings? The 2 that bolt up to the body through the rear seats. I have them at 60lbs now and i have the trailing arm bolts that connect to the subframe at 45lbs. I keep finding mixed numbers for these specs and i checked on a lot of websites and even ondemand5 and couldnt really get a straight answer. Thanks

[Chuck C]

BMW's torque spec book says 101 ft. lbs. on the crossmember bolts--M14x1.5--and 48 ft. lbs. on the trailing arm bolts, which should be tightened with the car in the normal position. Looks like you're going from a small case diff to a medium case--any issues bolting the halfshafts to the diff flanges?

[NickMav]

BMW's torque spec book says 101 ft. lbs. on the crossmember bolts--M14x1.5--and 48 ft. lbs. on the trailing arm bolts, which should be tightened with the car in the normal position. Looks like you're going from a small case diff to a medium case--any issues bolting the halfshafts to the diff flanges?

Thankyou, i have the trailing arms at 45 so i should be good. I deffinitely need to tighten then subframe bolts though. Yes i went from a 4.10 open diff to a 3.73 lsd

[Northern]

I've been having similar issues installing my rtabs, but I found that the rtab bolt with some washers works well to slip the bushings in, although one will still not go in all the way.

[NickMav]

Trailing Arm Bushing (Here the bushing wasnt going in correctly and I was tired of messing with it so just put it all together. After a day or two of driving the bushing is now sitting how it should along with all of the other ones. Pretty happy with the way they came out at first I thought I was butchering everything. (No proper Bushing Tools))


Size Difference


Test Fitting


Subframe Bushing and Trailing Arm Bushing (Here I did not use the top metal washer that came off with the old ones. I wasnt sure if you had to or not and I did not. Well see what happens, hopefully it will be ok.


As of Now(Car rides wayyyy different, the rear has little to no roll at all and is stiff as fuck. It handles way better and i really like the outcome. However I went from a small case to a medium case and you can tell the weight and size difference right away. I thought I was screwed as it wasnt going to fit or the axels would not work. The axels bolted right up with no problems and everything went together smoothly. At ride height position that i am at. handr race springs and blienstien sports the axel angle is almost 180degrees across. Im pretty sure thats bad on the bearings inside of the axel but well see what happens. If something blows ill be getting the 325i axels.

[Vivek]

By not using the top washer on the subframe bushings, won't the part that it connects to damage the bushings when it all flexes?

[NickMav]

By not using the top washer on the subframe bushings, won't the part that it connects to damage the bushings when it all flexes?

I would think it would but the metal pin goes into the top of the body almost 1/2 inch so I think more stress is on the pin itself then the bushing. Im not to worried about it but if something comes up i know why and im most likely going to take it somewhere and get them redone instead of doing them myself in my driveway. It was fun and all but this is my daily and i was borrowing someones car for a little while. Also if anyone knows what this could be, whenever i shift sometimes theres like a metal clunk coming from the rear (espically in stop and go where i have to let off the clutch in first) It happend before i changed the bushings and it also happend on my old e36. Im thinking it has to do with the driveshaft and the differential. Any help would be great. Thanks

[jlevie]

The washer that goes between to top of the bushing and the body is a load spreader. Without it the subframe bushings won't last long.

The clunk when loading or unloading the drive train could be from a bad drive shaft, but that normally produces other, worse, symptoms. The odds are better for the clunk to be from excessive wear in the differential.

[NickMav]

The washer that goes between to top of the bushing and the body is a load spreader. Without it the subframe bushings won't last long.

The clunk when loading or unloading the drive train could be from a bad drive shaft, but that normally produces other, worse, symptoms. The odds are better for the clunk to be from excessive wear in the differential.

alright thanks, ill see how the bushings go if need be ill get them replaced and just pay someone to do it at a bmw shop. Doing it in a driveway in cold weather was not fun haha