Loud Rapid Thud

Aye_plus · Feb 2, 2015

I'm at the point where I'm no longer frustrated with this problem and I'm just tired and want to set this thing on fire.
95 GT, lowered (maybe 2in?) I've been getting this rapid thud coming from what sounds like the pass. side wheel. It almost sound like I'm running on a flat tire. I replaced the hub assembly, the exhaust was hitting the car so I had that bent out of the way and I had the cable stuck to the wall to prevent it from hitting the driveshaft. I also had the DS rebalanced and installed with new ujoints, yet the problem persists. It's a rapid thud and it only happens when I accelerate. I can't hear it when I coast or put the car in neutral. I could use some front struts but I don't have enough for the ones I want, yet. Idk if that could be an issue. Just thinking about it makes me sad and tired..... Thanks for listening

addermk2 · Feb 3, 2015

Pull your different cover and inspect your gears.

Aye_plus · Feb 3, 2015

Even if it sounds like it's coming from the front? I do have some 373s that have been sitting in a box for a while. I've jacked up the rear and ran the car and a light clicking noise came from the gears, I thought it was normal. A buddy of mine says I probably need to replace all rubbers in my cross member but it looks like all I have is the trans mount?

addermk2 · Feb 3, 2015

You never noted front or rear. But when you describe a noise that is there while accelerating but not coasting, I would automatically look towards drivetrain

Aye_plus · Feb 3, 2015

Whoops! I guess I let my emotions get the best of me, sorry. I just noticed that the thud matches the vibration in my shifter. Great!

90lxwhite · Feb 3, 2015

addermk2 said:
You never noted front or rear. But when you describe a noise that is there while accelerating but not coasting, I would automatically look towards drivetrain

Yeah I read this post earlier and he said that the noise sounded like it was coming from the front but when I read it only makes the sound when he's accelerating I immediately thought rear end related. If the noise was coming from the front that'd be something suspension or say hub bearings etc and you'd hear that if you were coasting down a hill. Acceleration wouldn't be a factor if it was coming from the front, it's rear wheel drive.

Aye_plus · Feb 4, 2015

I've read a few other forums and found 2 people in a slightly similar situation and it sounds like the crossmember needs to be tightened up but it already is?! Those threads never came to a conclusion though... I also read that the flywheel might need to be resurfaced? So many things, so little money.

90lxwhite · Feb 5, 2015

Aye_plus said:
So many things, so little money.

Man oh man I know it... I really wouldn't think it'd be the cross memeber if it's an acceleration issue. The flywheel could be plausible though..

Aye_plus · Feb 6, 2015

Well, I've been driving around with my hand on the shifter and I get a lot of vibration. Idk how much is normal but it has a good strong buzz in it. I can also feel the knock, through the shifter, when I hear it. So, maybe. I have been reading about loose flywheels causing similar issues.

jozsefsz · Feb 6, 2015

I'd have guessed u-joints too. Since you had those done I, like others, lean towards a rear-end problem. Maybe even a bad rear wheel bearing, bent axle, bent wheel, or belt separation in the tire. Have you tried rotating tires to see if the problem moves with the wheel? I'd also check pinion bearings, aggressively dropping things messes up your pinion angle and beats the snot out of not just the u-joints but also tailshaft and pinion bearings. A telltale sign would be leaking. I hope they checked that when rebuilding the driveshaft, but it wouldn't surprise me if they didn't (especially if it was off the car). Aside from just checking crossmember tightness, not bad to check the condition of the mounts.

I don't think a flywheel problem would sound cyclical. Vibration yes, but not the wheel-speed noise you describe. Those usually cause difficulties shifting (won't go in gear or slips out of gear) and catastrophic failures.

More questions - does it do it in every gear? The same speed, all speeds?

7991LXnSHO · Feb 7, 2015

Aye_plus said:
I've read a few other forums and found 2 people in a slightly similar situation and it sounds like the crossmember needs to be tightened up but it already is?! Those threads never came to a conclusion though... I also read that the flywheel might need to be resurfaced? So many things, so little money.

Before you tear into the flywheel, I have some easier to access ideas.

Just because the bolts do not move mean they are clamping tightly. One of my Fords had the engine cradle need new bushings and bolts. The bolts were frozen up, the bushings shrunk/worn out and the horrible noise was a pain to find. There was a TSB for another model that led me to check.
Also, check the tranny mount, the output shaft and tail shaft bushing for wear. Those three things will lead to vibration in the shifter and noise. If the tranny is wiggling, it could be clunking against the exhaust or body.

Aye_plus · Jun 11, 2020

Well, it’s been a while and I’ve slowly been replacing misc. like all mounts and front suspension and here is where I am.
With dog bone

View: https://youtu.be/ThrV0MfVcjE

Without

View: https://youtu.be/v4fgWEgZl74

Aye_plus · Jun 12, 2020

Shirley, someone recognizes this sound.

Adieu · Jun 12, 2020

Have you checked the tailshaft in the transmission for play?

Aye_plus · Jun 12, 2020

Ahh, that’s what I was looking for. Yeah, both ends look good. I just removed both tires and rotors and be running another test when I get off work.

Foxslider · Jun 12, 2020

Pull the wheel off, take the drum off and try to wiggle the axle up and down. There should be basically no play. Target being wheel bearing. Its a freebie to eliminate that.

Jacked up with stands on the frame rails or under torque boxes grab the rear end and try to shake it back.and forthshould.be no play also.

General karthief · Jun 12, 2020

Can't tell anything in a video, too many things going on.

Aye_plus · Jun 12, 2020

There’s a tiny bit of play on both axles. Ill try the diff tomorrow.

Aye_plus · Jun 12, 2020

General karthief said:
Can't tell anything in a video, too many things going on.

But the sound, can you hear that vibration?

General karthief · Jun 12, 2020

I can't speak for anybody else but I can't tell what sound is coming from where, video sound comes from speakers and that makes it hard to pinpoint,

Loud Rapid Thud

Aye_plus

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addermk2

Aye_plus

Member

addermk2

Aye_plus

Member

90lxwhite

I'm kind of a She-Man

Aye_plus

Member

90lxwhite

I'm kind of a She-Man

Aye_plus

Member

jozsefsz

7991LXnSHO

wanna catch the space herp

Aye_plus

Member

Aye_plus

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Adieu

Easy there, this ain't a dating site.

Aye_plus

Member

Foxslider

im not that much of a idiot

General karthief

wonder how much it would cost to ship you a pair

Aye_plus

Member

Aye_plus

Member

General karthief

wonder how much it would cost to ship you a pair

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Loud Rapid Thud

Member

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I'm kind of a She-Man

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I'm kind of a She-Man

Member

wanna catch the space herp

Member

Member

Easy there, this ain't a dating site.

Member

im not that much of a idiot

wonder how much it would cost to ship you a pair

Member

Member

wonder how much it would cost to ship you a pair

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