Is my driveshaft going bad?

[Shifty556]

I have driven my vr-4 like an absolute baby since the day I bought it. I did a speed run and kinda chickened out at 130mph about 2 weeks ago. Other than that, I really baby the car.

A friend of mine drove it yesterday and I noticed something. When going from 0% to 90-100% throttle quickly (like a quick tap to the floor and immediately letting off to 0% throttle again) I heard a clicking noise under the car.

I sat in the back seat and had him do it again. Could this be the rear differential or the driveshaft causing this noise? I had never noticed this before since I never drive in that fashion. This doesn't happen when I press the brake to the floor and release, only the throttle. Any help would be much appreciated.

[lawdogg]

Can you describe the clicking? Do you hear it or feel it? Can you feel it through the gas pedal?

[Shifty556]

Cannot feel it through the pedal. After quickly releasing the throttle from high% to zero, I hear a series of 3-4 clicks. Seem to be coming from the bottom of the car, near middle or rear. Sometimes happens when slamming on the throttle from a roll. i.e., rolling at 40 mph in 4th gear, release throttle and drop the tach down to 2000rpm then slam throttle again...I get the clicks.

Had the car for about 5 weeks now and I really baby it due to 2nd gear. I don't grind it at all hardly. Maybe like 6 times since I bought it, really. And, since I baby it, I have never made the car do this myself. It took another driver to discover it. I suppose maybe that's good....? I know something is wrong, though.

[daddy]

Could be motor mounts.

[dbrVR4]

I had a similar problem when I first started driving my VR4 - clicking under hard acceleration. After numerous looks underneath at numerous shops, what I figured out was that the fuel door was knocking. Check yours out!

[Shifty556]

I did some more testing on the way home from work. It seems that even gentle "tick-tacking" on the throttle at a roll....like quickly going between 0% - 10% - 0% - 10% makes a little racket too. I did check the fuel door and it wasn't that. Thanks for the tip though!

[etecnifibre]

My money is on motor mounts or carrier bearings.

[Shifty556]

I gather I can check the motor mounts myself. Carrier bearings, not so sure.

Would you recommend taking to a shop?

[Let-luse]

Typical symptoms for carrier bearings going bad would be a "thump" when releasing the throttle suddenly under high load conditions (higher gears) and pressing the throttle again. It's a loud thump like something has just knocked the car from behind.

It's one thump because when you're under throttle it's the engine/transmission that is moving the driveshaft and when you release the throttle it's the wheels that are moving it so when the carrier bearings are shot they have a slack that makes the DS knock them on the transition. It's one thump every time you release/press the throttle under load.

Checking the carrier bearings is pretty simple, jack the car and put it on stands (always put the car on stands when you're working underneath) then crawl underneath and try wiggling your driveshaft close to each CB. Check for excessive play (there's shouldn't be much). Also check the rubber inside the CBs to see if it's thorn or cracked.

But I highly doubt that it's the DS. I would think motor mounts or rear suspension .

Anyways, if the car is not otherwise feeling weird, I'd leave it alone for the moment and wait to see if the noise gets worse. These cars are getting old so expect some noises (transmission, differential, suspension...).

Good luck!

Reda/

[etecnifibre]

Originally Posted by Shifty556

I gather I can check the motor mounts myself. Carrier bearings, not so sure.

Would you recommend taking to a shop?

Basically the opposite. Checking the carrier bearings is easy. Just do what let-luse said.

Motor mounts are a different story. I'd say in most cases, they would have to be removed to see the full extent of the damage. I was getting a substantial clunk under the conditions you describe, so I figured at least do my front and rear mounts. I decided to do all 4 and was surprised to find the driver's side one was the worst of all. And it sits right there, on top, in plain view.