Thudding noise by my foot when I accelerate

[koshe]

I have a 69 Charger with a 440. When I accelerate I hear and feel this thuddung sound under my feet on drivers side. I was told that my leaf springs were flexing. I installed new ones. New shocks all around. Noise still there. The motor mounts seem fine. The exhaust seems to have clearance. It does not occur over bumps. It just feels like something is hitting the floor. What have I missed???

[koshe]

I has the trans rebuilt, and the transmission mount bushingnwas just fine...

[74Charger]

i assume it is under hard acceleration?  Could the sound be coming from the rear and what you hear is the pinion snubber hitting the body?

[koshe]

It could be. It does not have to be heavy acceleration. Would not the new leaf springs help? It seems like to happens way to easy.

[OttawaCharger]

Is it just one thud until you let off or does it keep thudding?

[koshe]

only when I accelerate.

[mikepmcs]

I think Ottawa is asking if the noise is continuous like thud thud thud thud thud thud while you have the pedal depressed .....or does it just do it one time and not again until the next time you romp on it from a stop or whatever.

You said the motor mount seems fine.  That one has me wondering right there   how did you check it??

My 55 Chebbie had a bad motor mount(driver side of course) and it was very difficult to see.  But when I took it out it fell apart in my hand.  Had I stomped on it my engine most likely would have come through the hood.


I'm still leaning towards motor mount or tranny mount.

I just keep seeing in my mind, you hitting the gas, the motor rising up and the bellhousing smacking against the underside of your car.

good luck, keep us posted.

v/r
Mike

[74Charger]

Have you checked your u-joints and carrier bearing?

[koshe]

It does not seem to happen over bumps. Well, here is how I check my engine mounts...I watched the engine and tried to rock it while in gear with the brake on. I did not here it or see the engine move. It could be a mount.  Whats the right way to check it? I looks like a pain top replace......

I have no idea the condition of the carrier bearing.

Thanks!!!!

[mikepmcs]

Also to check your u joints, as that is a possibility as well, get the weight off the car, put in neutral and see if there is movement in the driveshaft, meaning excessive play up down left right.  U joints can also become rusty and bind too.


Take a crowbar and try to lift the driver side of the motor or move it with that to check the motor mounts as well.  That might be a better indication. You can't really put the same load on your car the way you described because of the difference of the car standing still and transfer of power to the rear wheels to make your car move IMHO.


v/r
Mike

[koshe]

How much play should their be?

[mikepmcs]

none on the u joint/driveshaft if that is what you are asking.  Driveshaft is a balanced part of your drivetrain.

v/r
Mike

[koshe]

The u-joints were checked when the trans was out. I was wondering about play in the motor mount

[mikepmcs]

oh, sorry.  You'll be able to tell if it's separated because the motor will lift up off the part that mounts to the car.  Of course there is some movement because of the material in the mount but if it's broken it it should be easy to tell.  Hopefully some others will come on here to offer more advice on this as these are just my experiences and I'm no expert.


v/r
Mike

[HITMAN 149]

just turn up the radio real loud!!!!!!!!!!! see... problem fixed!!!!!!
no fee for the first time!!!! 
sorry but i just couldn't resist!!!!!

[74Charger]

You should be able to crawl under there and inspect them.  And see if they are broke.  We just changed some in my friends dodge motorhome with a 440 in it this last weekend.  Getting it ready for MATS.  We had access to a lift though.  Which made it a little easier.  For some reason the driver side was alot easier to get to than the passenger side.  Because of the location of the mount. 
We unbolted the nuts.  Jacked up the motor slightly.  With a little prying they came out.  Getting them out and in was a different story on the one side.  We ended up sticking the nut on and cutting the bolt on both sides a little to get it to slide back in there.  It was way too long anyways.  Just make sure to have the nut on before cutting it so as to have the threads line up.  I am sure your cars hould be close to the same.

[68chrgrwife]

I have a 69 Charger with a 440. When I accelerate I hear and feel this thuddung sound under my feet on drivers side. I was told that my leaf springs were flexing. I installed new ones. New shocks all around. Noise still there. The motor mounts seem fine. The exhaust seems to have clearance. It does not occur over bumps. It just feels like something is hitting the floor. What have I missed???

is it your foot hitting the floor???  Sorry had to do it....

[koshe]

It is probably the drivers side. The exhaust is louder than the radio!!!

[smasherofall]

if its under the feet area, maybe kickdown linkage is loose or hitting when the engine is torqued. It's really close........

[Back N Black]

A good visual inspection of the floor in that area should show a wear mark or a shiny spot if something is hitting the floor?

[Heck2G14]

I've got the same thing.  Mines the exhaust, U got header?  Check flanges and any underbody scrapes around driveshaft and exhaust.

[bull]

I was going to suggest it might be the muffler thumping against the bottom of the car.

[Ghoste]

I had a woodpecker in the back once that only happened under acceleration.  I couldn't find it until the tailpipe finally wore a little paint off the shock.  It could be any number of things but as mentioned, I'd start looking for things that move under torque and look for shiny spots-grime or paint worn away.
Check that all your front end components are tight too.

[rob9593]

I was going to suggest it might be the muffler thumping against the bottom of the car.

I had a similar sound on mine, was the left header hitting the cross member when the motor torqued to the left....poly trans mount was fine, solid motor mounts fixed it...

[BigBlackDodge]

Exhaust pipe near the torsion bar perhaps?

BBD

[koshe]

I replaced the drivers side engine mount because I thought it rocked to much. Same issue. Maybe the exhaust just was not made to accommodate that. Motor still rocks a fair bit. Is there normally a fair bit of rock with these?