90 325i rear end shudders

[akm47]

Hey everyone, I'm new to the forum and BMWs. I recently joined the army and bought a 1990 325i convertible with 120k miles in pretty decent shape here in hawaii. The cars been running great for about 2 months now and just recently I got down on the accelerator from a stop light as I have many times before and the rear of the car shuddered like a tire had gone flat and didn't accelerate as it should. I let off the accelerator and it immediately went away. The car drives normally until I reach a certain acceleration point where I can feel it start to shudder very lightly and then if i press the throttle down more it starts to shudder violently and barely accelerate. It seems to be less forgiving of the throttle the moreI drive it. It feels like something is slipping. Could it possibly be the rear differential?

[muleman]

Hey akm47
I have a 1991 318is (manual gearbox) that exhibited the same condition. You did not mention if you have an automatic or manual. In any event, I would start by getting the car up in the air and having a close inspection of the drive train. Take a look at transmission mounts, as the rubber ages it tends to dry out/crack and weaken over time. Check the "guibo", it is the thick rubber "washer" that isolates vibrations between the transmission output flange and driveshaft. Also check the differential mount, it is a rubber vibration isolation system as well. You will want to check the motor mounts for good measure. I ended up replacing all of the above for good measure
I suspect that the Hawaiin heat has gotten to the rubber mounts.
As you have been geting after it for the past few months (great feeling, eh? ) something may have finally given up. You will also want to check the driveshaft support bearing to ensure it is bolted up tight and not worn out. (no play) Good luck, let us know how you make out. Enjoy that ride, and thanks for your service.
Muleman

Originally Posted by akm47

Hey everyone, I'm new to the forum and BMWs. I recently joined the army and bought a 1990 325i convertible with 120k miles in pretty decent shape here in hawaii. The cars been running great for about 2 months now and just recently I got down on the accelerator from a stop light as I have many times before and the rear of the car shuddered like a tire had gone flat and didn't accelerate as it should. I let off the accelerator and it immediately went away. The car drives normally until I reach a certain acceleration point where I can feel it start to shudder very lightly and then if i press the throttle down more it starts to shudder violently and barely accelerate. It seems to be less forgiving of the throttle the moreI drive it. It feels like something is slipping. Could it possibly be the rear differential?

[akm47]

Yes, it is a 5spd. I'm bringing it to a BMW shop tomorow to get the glovebox repaired and a new blinker knob (broke a few eeks ago ) and while its there Ima have em take a look at the drivetrain and mounts and all. I love the car hopefully its just a mount or guibo and not something more expensive. I'll post what they say is wrong tomorow. Thanks for your reply