Whammy's Journal Thread

[Whammy]

Today I had to bring the car to the mechanic. The car is having some drivetrain flexing issues where I can feel the rear and and the driveshaft move. I think I've heard the driveshaft hit the tunnel wall when going over a bump. Also, I have a new coolant leak I wasn't aware of. Hoping the shop will take care of everything.

[Vas]

Today I had to bring the car to the mechanic. The car is having some drivetrain flexing issues where I can feel the rear and and the driveshaft move. I think I've heard the driveshaft hit the tunnel wall when going over a bump. Also, I have a new coolant leak I wasn't aware of. Hoping the shop will take care of everything.

Most likely the center support bearing on the driveshaft is bad. That would be my guess.

[slater]

Most likely the center support bearing on the driveshaft is bad. That would be my guess.

feeling the rear end moving around is likely gonna be more than a CSB. hoping it's not rear floor-related...

[Whammy]

Most likely the center support bearing on the driveshaft is bad. That would be my guess.

Me too.

feeling the rear end moving around is likely gonna be more than a CSB. hoping it's not rear floor-related...

My guess is that it is a combination of the CSB and the subframe bushings. I was under the car on Monday and looked at the rear. I do not see any cracks at all in the subframe floor. While the subframe bushings are hard to inspect, they do look a bit worn for 177k.

[slater]

My guess is that it is a combination of the CSB and the subframe bushings. I was under the car on Monday and looked at the rear. I do not see any cracks at all in the subframe floor. While the subframe bushings are hard to inspect, they do look a bit worn for 177k.

the CSB would have to be a really sorry state to make a banging noise. that said, a full exhaust-out inspection on a hoist is going to reveal a lot. have you replaced any bushings in the rear suspension? if not, i'm going to assume that the RTABs and outer RCABs are toast, as they should be well dead by 177K miles. the subframe mounts do wear but i was surprised by how good mine looked at 140K miles when i replaced them.

definitely check the rear floor thorough. the left rear mount and kink in the floor just inboard of the mount, as well as the left rear wheel well where the vertical sheet metal meets the floor and the first critical areas to inspect. then the right front mount, but the damage it usually not seen until the subframe is lowered. also, you can't really see fine cracks or popped spot welds without fully dropping the subframe and cleaning the rear floor. if you're dropping the subframe to replace mounts, there isn't a better time to do this.

[Whammy]

the CSB would have to be a really sorry state to make a banging noise. that said, a full exhaust-out inspection on a hoist is going to reveal a lot. have you replaced any bushings in the rear suspension? if not, i'm going to assume that the RTABs and outer RCABs are toast, as they should be well dead by 177K miles. the subframe mounts do wear but i was surprised by how good mine looked at 140K miles when i replaced them.

definitely check the rear floor thorough. the left rear mount and kink in the floor just inboard of the mount, as well as the left rear wheel well where the vertical sheet metal meets the floor and the first critical areas to inspect. then the right front mount, but the damage it usually not seen until the subframe is lowered. also, you can't really see fine cracks or popped spot welds without fully dropping the subframe and cleaning the rear floor. if you're dropping the subframe to replace mounts, there isn't a better time to do this.

So, the shop tightened up the shock mounts and re-torqued the subframe bolts. Noise from the rear end seems better and not as loose. After driving the car this week, I still notice the driveshaft vibrating. At times it is extremely noticable, other times it is subtle. The shop owner, a friend, doesn't want to start chasing things and wants to wait until the problem gets consisent and worse.

I've done the RTABs, but not the RCABs.

[Whammy]

[slater]

bummer.

however, your username makes sense now.

[slater]

So, the shop tightened up the shock mounts and re-torqued the subframe bolts. Noise from the rear end seems better and not as loose. After driving the car this week, I still notice the driveshaft vibrating. At times it is extremely noticable, other times it is subtle. The shop owner, a friend, doesn't want to start chasing things and wants to wait until the problem gets consisent and worse.

sorry to say this, but it sounds like time to find another shop... clearly they're not interested in finding or fixing the issue, friend or not. bummer.

[BMWCurves]

Self inflicted?