rear diff rebuild or used purchase?

[KVF]

It appears that my 373 lsd is in need of replacement or repair (1988 325is). I'm getting a vibration/growling that appears to be coming from the passenger side output flange if I'm anywhere above 20mph AND accelerating (any degree of acceleration). New ds (complete w/csb & guibo), new rear wheel bearings, new cv axles, and fresh subframe & trailing arms bushings. The unit still locks up well and doesn't appear to have any other issues, but I'm assuming that will change in the near future.

My question is how difficult & expensive is it to rebuild the unit VS replacing it? Pros cons? As much as I've searched I haven't found much information on rebuilding, yet I'm leery of going straight for a junk yard unit, as I may simply get the same problem I already have. Educate me rev!!

Thanks in advance for any help.

[lateracer]

I called around a few shops in the San Diego area to check prices for having my convertible's open 4.10 rebuilt. Best I got was "probably around $400."

I just scored a 3.73 from Autobahn, a local BMW dismantler, for about half that ( link ). Because this is a common problem with high mileage E30's, reputable parts yards will only sell lower mileage diffs (under 100K). Not sure what shipping would be, but it's cheaper than the rebuild.

[KVF]

Thanks for the reply.

As luck would have it, Mossman is local and came through with a 373lsd for a decent price. He even accommodated me with a test ride in his S52 and dropped the diff off to me, just five minutes from my home.

As fate would have it, the diff was apparently not my problem as I still get the same stupid rumble/vibration if I'm above 20-25 with my foot anywhere into the accelerator.

[jlevie]

A vibration/noise that is worse with generous use of the throttle at in the lowest gears is most likely to be the drive shaft or half shafts. I realize you have replaced those, but they could still be the problem.

[Aus E30]

^ funny enough when I accelerate through second (320i Auto) I get a vibration from the rear..so possible driveshaft/half shaft? hmm... -.-

[KVF]

A vibration/noise that is worse with generous use of the throttle at in the lowest gears is most likely to be the drive shaft or half shafts. I realize you have replaced those, but they could still be the problem.

As it turns out my issue was the newly installed guibo. Apparently Bavauto wasn't the place I should have purchased a guibo. I installed it (correctly) about 800 miles ago, with the new driveshaft, centering sleeve, & CSB. I crawled under the car the other day, just to double check everything, and I finally looked up at the guibo. The thing was cracked all over the place, had chunks missing, and was squishy as all hell! The CSB looked and felt good, so I reinstalled the old guibo, which had been replaced because it was slightly cracked (200k of use)... Now I only get vibration if I'm above 70mph, so I'm sure the guibo was the issue. I have a new OEM guibo on the way and I'll re-check the driveshaft, CSB, & centering sleeve prior to install, just to be safe.

More E30 fortune came my way when my drivers side shock mount completely failed last night. The rubber completely broke away from the metal plate and was allowing the shock to just bob up and down at will. It was installed about the same time as the guibo, AND was another bavauto purchase. I'm not sure if they have some older E30 stuff that's just been sitting and dry rotting, but I'll need to call them today, as this is completely unacceptable. I've had great experiences with them in the past, so I'm hopeful that they will do the right thing here.

[eldercaddy]

It appears that my 373 lsd is in need of replacement or repair (1988 325is). I'm getting a vibration/growling that appears to be coming from the passenger side output flange if I'm anywhere above 20mph AND accelerating (any degree of acceleration). New ds (complete w/csb & guibo), new rear wheel bearings, new cv axles, and fresh subframe & trailing arms bushings. The unit still locks up well and doesn't appear to have any other issues, but I'm assuming that will change in the near future.

My question is how difficult & expensive is it to rebuilt engines the unit VS replacing it? Pros cons? As much as I've searched I haven't found much information on rebuilding, yet I'm leery of going straight for a junk yard unit, as I may simply get the same problem I already have. Educate me rev!!

Thanks in advance for any help.

I will suggest to you to buy a used VS instead of rebuilding it because it cost a lot of money and time. If you are not agree with my suggestion then it's your decision. I'm just suggesting. :)