driveshaft ?'s

[gloucester Q]

with all the talk about driveshafts going on recently: i've got some omnipresent vibration that new rubber, new tires, and 2 alignments haven't solved, so i'm turning my attention to the driveshaft...

is there a way to be sure it's the driveshaft causing the vibrations before replacing it?

it seems a rather hefty part. is the best way to order it from scottsdale and pay shipping? anybody got any estimates before i start checking?

it seems that a couple people are making do with used driveshafts. any advice here?

any general comments about the whole thing would be greatly welcomed, probably won't get to this until jan/feb of the new year, but wanted to start thinking about it/planning for it. happy holidays to all. randy

[Q_SHIP]

Check the U joints. Im not to sure if they are replaceable or not.

You might also want to just have your driveshaft balanced again. That might take care of it.

[squeefoo]

If you search on transmission mount vibration, I think you'll find out a lot, many different symptoms. Could also be motor mounts, but more likely the trans mount. Usually happens above 40 MPH though... that's where mine did it.

Sometimes a rotor will cause that too.

[redmanfx]

with all the talk about driveshafts going on recently: i've got some omnipresent vibration that new rubber, new tires, and 2 alignments haven't solved, so i'm turning my attention to the driveshaft...

is there a way to be sure it's the driveshaft causing the vibrations before replacing it?

it seems a rather hefty part. is the best way to order it from scottsdale and pay shipping? anybody got any estimates before i start checking?

it seems that a couple people are making do with used driveshafts. any advice here?

any general comments about the whole thing would be greatly welcomed, probably won't get to this until jan/feb of the new year, but wanted to start thinking about it/planning for it. happy holidays to all. randy

I have a couple of questions for you:

How many miles does your transmission & driveshaft have on it? Is your vibration constent or just at lower or higher rpms?

If your transmission has 125K on it or even 100k, it would be something to check along with the transmission mount. You can have this checked by a mechanic first for just a couple of bucks, if they charge you that much.

If the drive shaft is old then changing it could help, but if your transmission caused the problem in the first place then your wasting your money. This can also be checked by a trusted mechanic.

In my research I found a few cases where the driveshaft was changed without changing the transmission and the vibration was fixed. I would not just change it without getting it checked first however.

A brand new drive shaft from Joe is around 850.00 with no return core credit. Call and talk to him to get some input.

Remanned driveshafts are anywhere from 250.00 to 500.00, with a few giving credit back for a returned core. Powertrain Industries in Garden grove, CA is a good source of remanned driveshafts(325.00). They provide many auto dealers and mechanics across the country with remanned driveshafts, so just go to the source. 714-901-3611 is their number.

In my case, I had vibrations when the car was cold and it felt like I was going over a rough rode. Not severe vibrations, but enough to notice. After the car warmed up the vibration subsided. My transmission was old-old-old and so was my driveshaft. Both were the originals. MY 92Q had massive mileage, so it was a no brainer for me. Both had to be replaced and I bought a new transmission mount from Joe for 85.00 as well. After that was done my vibrations were gone.

You can also check the motor mounts.

Please have it checked before you replace anything.

red

[91QAZ]

I agree with sqee and red. I replaced my transmission mount just today and based on a limited test drive, at least half of my vibrations are gone. I'm HOPING that new wheels/tires later this week will take care of it. Also heard some people suggest changing exhaust hangers, but I've not done this yet - I need to do more research on what this is...

[gloucester Q]

thanks all, that's an excellent start. i've got a crack mechanic in town and will ask him to investigate. to answer some specific questions, i have a pretty low mileage q, 80k on a 93. i have been meaning forever to get down to the q dealer and get a print out of its entire service history. i saw it once years ago and it looked pretty good, but at the time i didn't know what i was looking for and didn't keep it, so i don't know for sure what's original and what isn't. the vibrations are all over the rpm and vehicle speed map, although once i'm at cruising speed, 75 or so, they're not as noticeable as 25-55 driving. thanks again all. randy

[96Qowner]

If your vibration subsides at 75 Mph, I do NOT think it's a transmission mount. It was the exact opposite for me. I had my worst vibration peak at 75 Mph before replacing it, and mine correlated to 2200-2300 Rpm, worse in 4th than 3rd.

[Edit] Would some of the techs chime in about engine harmonics and their effects on drivetrain vibration; ie, which Rpms correspond to which likely problems?
Modified by 96Qowner at 9:20 AM 12/29/2004

[texasoil]

you can 'map' the engine driven vibration harmonics for your particular car real easy. Just put it in Park or Neutral and slowly ramp up the engine speed. there are several 'sensitive' speeds and the exact RPM varies with the condition of the rubber hangers and mounts on your car. Note: If you have a rough running engine--that will telegraph through the car also. transmission mount sagged will alow contact with the crossmember and excite the car body right at rear mout of the front seats. 1150 and 2350-2400 seems to be two RPM's that get that one going in most cars. 1200RPM can also be exhaust system hangers hard and stiff. (also get a 2400 RPM from exhaust) Note you can 'soften' exhaust hangers by drilling 1/4" holes in the rubber at 90 degree angles to each other at least 1" apart. A loose engine belt can cause a number of vibration patterns as will the A/C compressor sometimes. With the peak vibrations RPMs noted without moving, then drive the car and see what road speed acts up. You can 'remove' engine RPM causes by changing gears so engine RPM is not at a vibration node--meaning any running vibration is definitely driveline, tires, wheels. To my knowledge, the Q45 doesn't seem to have any torsional vibration modes that are detectible.

[96Qowner]

Ran across this old discussion on tire/wheel/rotor harmonics from Feb 2004:

http://nicoclub.com/zerothread?id=51949
Modified by 96Qowner at 10:25 AM 1/5/2005