Refreshing rear suspension

Ajsbored94

Regular Member
Joined
Sep 23, 2020
Messages
17
So after ordering the diff bushing, I thought "why stop there?" And proceeded to order the subframe bushings, flex disc, center support bearing, trailing arm bushings and trans mount bushings.

Now, while all of this is being done, what else do you suggest I replace/take a look at?
 

Troy Davis

Newbie
American Zeds
Joined
Sep 25, 2020
Messages
9
Location
Austin, TX
Model of Z
M Roadster
If your car is an M look at the differential subframe mount. Pretty much ripped it out of my car. Big job to rebuild.
 

Jonno Bee

Zorg Legend
British Zeds
The West Country
Joined
May 23, 2014
Messages
243
Location
Exeter
Model of Z
Z3 2.8
Having just done this work on my '98 Zed I would recommend a close look at the brake lines on the trailing arms. One of mine was badly corroded but only obvious when removed from the trailing arm.
Both my rear shocks had no return and the upper mounts were very tired. The rear ARB mounts were also toasted. While you're there have a look at your fuel tank straps, I changed both on mine. Good opportunity to check your hand brake cables, again both on mine had split conduits and were changed.
If you drop the rear beam and trailing arms its likely you'll need to clean and re-protect any rust you find. All well worth doing though! Good luck.
 

t-tony

Zorg Expert (II)
Supporter
British Zeds
#ZedShed
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Dec 31, 2013
Messages
39,864
Location
Torksey Lock,Lincoln, England
Model of Z
Z4 3.0 Auto
So after ordering the diff bushing, I thought "why stop there?" And proceeded to order the subframe bushings, flex disc, center support bearing, trailing arm bushings and trans mount bushings.

Now, while all of this is being done, what else do you suggest I replace/take a look at?
If you do decide to change the fuel tank mounting straps you need to contact Malc @Mazza as he has designed and had made sets of said straps which are better than original.

Tony.
 

Ajsbored94

Regular Member
Joined
Sep 23, 2020
Messages
17
If your car is an M look at the differential subframe mount. Pretty much ripped it out of my car. Big job to rebuild.
I checked the subframe mount/diff mounting bracket and welds to make sure they were not broken while I was under the car. Everything is still good but I believe I will still be getting the trunk reinforced to keep it from happening in the future!
 

Troy Davis

Newbie
American Zeds
Joined
Sep 25, 2020
Messages
9
Location
Austin, TX
Model of Z
M Roadster
I checked the subframe mount/diff mounting bracket and welds to make sure they were not broken while I was under the car. Everything is still good but I believe I will still be getting the trunk reinforced to keep it from happening in the future!
That's a good idea. Much easier to do PM than rebuild
 

Chris Hunter

Dedicated Member
Joined
Jul 26, 2020
Messages
66
Hi I have done the same, rear end refresh. All bushes replaced, brake pipes renewed from under the car floor to calipers, including flex hoses. One of Malc's fuel tank support kits fitted. I found minimal rust, and the boot floor was perfect. However as a pre-emptive measure I have changed my diff rear cover to a twin reared one, hopefully to spread the load.
Chris
 

Troy Davis

Newbie
American Zeds
Joined
Sep 25, 2020
Messages
9
Location
Austin, TX
Model of Z
M Roadster
Hi I have done the same, rear end refresh. All bushes replaced, brake pipes renewed from under the car floor to calipers, including flex hoses. One of Malc's fuel tank support kits fitted. I found minimal rust, and the boot floor was perfect. However as a pre-emptive measure I have changed my diff rear cover to a twin reared one, hopefully to spread the load.
Chris
 

Chris Hunter

Dedicated Member
Joined
Jul 26, 2020
Messages
66
My car is a 3.0i and has a TYP 188 diff, but yours may be different. If you input the last 7 digits of your cars serial number into BMW OEM, and navigate to the parts list for the rear axle it should tell you what diff you have. You will probably find that several other cars with twin eared rear covers use the same diff as yours. Then look on ebay or your local scrappie. It should be noted that the twin eared rear cover requires the removal of the spare wheel carrier.
good luck
Chris
 

Troy Davis

Newbie
American Zeds
Joined
Sep 25, 2020
Messages
9
Location
Austin, TX
Model of Z
M Roadster
Interesting about the twin eared differential cover. Which cover did you use?
 

Troy Davis

Newbie
American Zeds
Joined
Sep 25, 2020
Messages
9
Location
Austin, TX
Model of Z
M Roadster
My car is a 3.0i and has a TYP 188 diff, but yours may be different. If you input the last 7 digits of your cars serial number into BMW OEM, and navigate to the parts list for the rear axle it should tell you what diff you have. You will probably find that several other cars with twin eared rear covers use the same diff as yours. Then look on ebay or your local scrappie. It should be noted that the twin eared rear cover requires the removal of the spare wheel carrier.
good luck
Chris
 

Troy Davis

Newbie
American Zeds
Joined
Sep 25, 2020
Messages
9
Location
Austin, TX
Model of Z
M Roadster
That's right Chris. My car's diff is unique to the M Z3. Your can replace the complete assy with an e46 M3 unit, but don't think any other dual mount covers will work on my diff.
 

Chris Hunter

Dedicated Member
Joined
Jul 26, 2020
Messages
66
Had a slight hiccup with the twin eared diff rear cover. Ordered Febi mounting bushes prior to removing the old ones, only to find the new ones wouldn't fit they were 15 thou too big. It wasn't a big deal, but I had to machine them to the correct size to make them fit. I had assumed they were all the same size. So, If anyone is considering a twin eared diff conversion, measure the diff mounting ears before ordering bushes.
Blue skies
Chris
 
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