Rear thumping
 

As I got on the highway today to come home, I noticed an unusual sound coming from the rear of the car. It only happened when you had your foot on the gas and accelerated. It sounded like a thumping sound. Could I just be low on diff. fluid?

I just took it for a drive and it seems greater from 35MPH and after, increasing upon more acceleration.

Any suggestions? I really need help.

Try checking your driveshaft.

Could that be loose? I read somewhere it could be the hubs?

The noise isn't coming from the middle of the car, only the rear.

Could possibly be bad bushings back there too, a friend's STi does that and some bushings are shot.

Its only above 35mph or so

It's been my experience with vehicles that a "thumping" noise under load from the back of the car is normaly the driveshaft. It's really easy to spot if it is by pulling up on a curb and looking underneath for a wear spot above the driveshaft.

or the subframe/diff bushings, I don't know about the lexus' and their bushings, but I know S-chassis nissans' do it all the time

i had driver side axle bolts backing out and it did this, i came home one night heard a klink sound looked under my car to find an axle bold laying on the ground jacked the car up found that another one had fell out and that every one of them was loose and about to come out

also dont these cars have carier bearings i havent been under mine in a while to check

This is a prime example for proof that I overlook the small things.

I let my neighbor have my car the other day so he could put snow tires on the back for me. He owns a tire store/repair place in town and we have become pretty good friends--(I buy the tires from him at cost and he puts them on FO FREE). One of his guys must have not tightened the lugs up enough, so they were spinning freely.

I tightened them with my t-bar and the car is fine.

Talk about a scary moment. I thought I was in for a big expense. :D

This gives me an excuse to change my axle fluid though.

When was the last time your transmission mount was replaced?

Good find. You may want to check and see if they didn't damage your wheel studs.

WOW. Not cool. Been a mechanic for 7 years and never left a wheel loose ever... you are lucky you didnt wreck your car

Yeah I laughed when I jiggled the lugs last night.

Dave bought me lunch and a box of Warsteiner as an apology...so its okay.

haha