Bad low rpm vibration
10-20-2010, 06:14 AM
#1
Bad low rpm vibration Trying to narrow this down, under load and low rpm (only under 2k) I get a real bad vibration from the rear, it's terrible on the highway in 6th gear below 75mph, enough to make the exhaust hit the bottom of the car, stick jumping up and down etc.
I just got the car 2 weeks ago and have only really driven it 3 times, would like to get some pointers on what to look for before I tear it down this weekend. I've never had an issue like this (owned quite a few rwd v8 cars over the years) usually it would be something constant through the whole rpm band.
Thinking it's either:
Siezed u-joints
Chipped tooth (or teeth) on the pinion gear
bent axle?
I know the car was pretty abused and neglected over the years, but I"m trying to bring it back to it's former glory and then some.
Any suggestions would be appreciated.
thanks
I just got the car 2 weeks ago and have only really driven it 3 times, would like to get some pointers on what to look for before I tear it down this weekend. I've never had an issue like this (owned quite a few rwd v8 cars over the years) usually it would be something constant through the whole rpm band.
Thinking it's either:
Siezed u-joints
Chipped tooth (or teeth) on the pinion gear
bent axle?
I know the car was pretty abused and neglected over the years, but I"m trying to bring it back to it's former glory and then some.
Any suggestions would be appreciated.
thanks
10-20-2010, 06:35 AM
#2
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Probably wouldn't hurt to change the u-joints. I doubt a chipped ring gear will give you that kind of vibration. I drove with 3 chipped ring gear teeth for months without knowing it. Bent axle maybe, jack the car up and spin the rear wheels.
Maybe the the previous owner swapped out the factory rubber mounts for polys??
Maybe you have a bent driveshaft??
Chassis mounted torque arm.....gonna let you feel the slightest driveline vibration.
Maybe the the previous owner swapped out the factory rubber mounts for polys??
Maybe you have a bent driveshaft??
Chassis mounted torque arm.....gonna let you feel the slightest driveline vibration.
10-20-2010, 07:11 AM
#3
rear suspension is bone stock (original too at 135k miles) swapped in tubular lca's but vibration is still the same, still has the transmission mounted t/a (soon to be changed to a chassis mounted one).
I'm going to swap u-joints out this weekend, hopefully that's it, but I've had ujoints go and had a constant vibration this is just under low rpm load. It's easy enough to swap at least, so I'll knock those out the weekend.
I'm going to swap u-joints out this weekend, hopefully that's it, but I've had ujoints go and had a constant vibration this is just under low rpm load. It's easy enough to swap at least, so I'll knock those out the weekend.
10-22-2010, 06:09 AM
#5
trans mount is stock, has a bit of play in it though which could also be the culprit. Need to order some parts and get to work on this thing. Should be on a dyno the 6th so I can finally tune this f'd up afr and hopefully pick up a good amount of power. (runs rich enough to shoot flames after a pull lol, definitely in the 11's with some nice black smoke above 4500 rpm ).
