New vibrations at higher rpms

[Helltime]

I have an 85 325e 5spd and i went to accelerate onto a local highway and I was in the throttle pretty hard, hit 2nd chirped the tires and then continued to the top of 3rd before letting off. I did that last night and the next time i went to accelerate i started getting a pretty noticable vibration from the back of the car above 3k rpm, and it goes away when i shift or let off the gas. What did i break or mess up? When i jack the rear of the car up today are their any obvious signs to look for? Thanks for the help. This is my first bmw (and this one isn't even in very good condition) and i am enjoying it. Can't wait to get a nicer one to autocross!

[Sagaris]

take a look at both your engine mounts and transmission mounts (will need to jack the car up and use a flashlight to see those well enough.) I once had some vibration due to broken transmission mounts.

Also check the center support bearing for the driveshaft. I am sure others will chime in with some better advice, I have really never had issues in this area on any cars.

[Helltime]

take a look at both your engine mounts and transmission mounts (will need to jack the car up and use a flashlight to see those well enough.) I once had some vibration due to broken transmission mounts.

Also check the center support bearing for the driveshaft. I am sure others will chime in with some better advice, I have really never had issues in this area on any cars.

Come to think of it the trans does have a little more movement to it...whether this is the issue or not i should probably get new mounts for it. I will check out the motor mounts next.

Edit: trans and motor mounts don't appear to have any cracks or chunks missing.

[Sagaris]

One thing to keep in mind if you do end up replacing any mounts is to use new lock-nuts or loctite since it is important to have them torqued correctly if you want a vibration-free experience. the torque spec is low, something on the order of ~18-30 ft*lb so that the rubber doesnt get squished/preloaded causing you to lose some of its energy absorbing ability.

Does the vibration happen with revving the engine in neutral or just when driving?

also keep an eye out for torn engine mount points on the subframe. It has happened before

[vpilarrt]

The weight of the engine and transmission can make it had to see any cracks/seperations in the mounts. You need to apply an upward load with a jack or something to really see if they're OK. Check the guibo as well as the driveshaft support (as Sagaris posted).

[Helltime]

I just went for a drive, its most noticable in 1st gear and still there in 2nd, don't notice it much (if any) in 3rd or 4th. Its only when under hard acceleration, i will go get the car in the air now and see if i can figure out whats going on. How do i check the guibo and how do i tell if it is bad?

[Helltime]

My friend says it is the drive shaft and best to replace the guibo too. I checked the trans mounts by carefully jacking up the trans...they are definitely toast. How would i tell if my drive shaft is toast besides buying a new one and hoping for the best?

[Helltime]

I found what i believe to be the problems

[GunMetalGrey]

lol! That will do it!

[Helltime]

lol! That will do it!

After preparing to grab the drive shaft out of the parts car, and getting the trans mounts out of it (the ones in the parts car are perfect!) i put the car in question up on ramps, saw there was a missing bolt and literally laughed out loud.

[Sagaris]

good detective work! post an update and let us know if this resolves things

[Helltime]

good detective work! post an update and let us know if this resolves things

I am going to order new CSB and guibo, hopefully get this going next weekend.

[e30trooper]

fuck that is dirty!

[accident]

Exxon Valdez.

[Helltime]

I am trying to take the drive shaft off the parts car but running into all kinds of issues, any suggestions? I tryed following the bentley manual i have but i can't get the front half off the trans. The CSB is off, guibo bolts are off, the center nut thing between the 2 halfs of the DS is almost separated. i just can't seem to pull it off the studs coming out of the trans, i have gotten close a couple times though.