[Steven83r]

I recently started hearing a clack clack clack sound when i accelerate at low rpm's at higher rpm's around 3-3500 exhaust drowns out any sound. The other night i was cruising around bored and a street bike and i were slowly cruising side by side messing around i dropped to 2nd from 3rd at around 30mph shifted into 3rd then let off. At the light i took off normal and the sound was really loud now. Could it be the drive shaft? Mods are CAI, shorty headers and bbk o/r h.

Thanks

 

[EagleAutosports]

Does it match with the engine speed? Does it do it when the engine is running or when the car is in motion? Is it like a clang or a thunk? Is it under the car or under the hood?

Either way, you need to stop driving it right now and figure it out before you really tear something up like sling a rod out the side of the block or have the driveshaft come up through the floor.

And what exact car are we talking about?

 

[Steven83r]

Ya it matches engine speed but goes away when i go about 50 mph. its coming from under the car. At idle you cannot hear it or when i rev. also the car is really low the previous owner slammed it i can't even park with out backing up a few times. Speed bumps scrape the bottom of car and run transmission could that of damaged something? I am currently saving to change the springs and raise the car.

 

[Steven83r]

Also if i am cruising at a low speed you cannot hear it. The best description i can think of is when you hear a big truck drive next to you as it accelerates it makes a grinding clanking sound. i dont hear it in reverse either.
Its a 1988 Mustang Gt 5.0 T-Top

 

[Rjennings]

Probably the u joints, just had mine replaced, they were making a clanking noise.. Cost me 96 bucks to get them installed.

 

[EagleAutosports]

Glad it's under the car rather than under the hood, it has to be driveshaft related then. Either the U joints or maybe there's a balance ring on the shaft that's come loose and hitting the bottom of the car. I had that happen, it was around the front U joint but came loose and was around the shaft. When I'd get going and then get on it, it'd beat on the bottom of the car.

 

[Steven83r]

Ok cool thanks for the help guys. Would it be better to replace the U-joints or buy a new aluminum drive shaft completely?

 

[dreger]

I had mine lowered 2 1/2" as you can see in my photo's and ended up putting the stock springs back under it because the 2 1/2" drop caused such a geometry problem that I had lots of noises too. It could be the trans hitting the underside of the transmission tunnel,U joints or a hundred other things.Mine kept eating tranny mounts,when you lower the car you should shorten your drive shaft a percentage of the lowered height depending on the angle of the shaft(I can't remember the formula for this). I didn't do that so when I lowered the car I had too much of the yoke in the tranny and it put load on the entire drive line.I have also heard of the drive shaft hitting the tunnel but I didn't encounter that prob.

Just something to watch. Did you roll the lip of the inner fender? If not you may just have some rubbing there. If it gets louder with weight in the back seat it's probably a geometry prob.

 

[Steven83r]

No the fenders don't rub when i drive or hit dips but do when i try and turn. I don't know what was done to the car as far as suspension goes all i can see are green springs and since he butchered the car i would say he even cut the springs. The ride is horrible car sounds like its going to fall apart every bump i hit. If its not one prob its another looks like ill have to get a new drive shaft for now then go back to restoring it. Thanks again for the help

 

[dreger]

Before you buy stuff just get under there and check for loose or worn parts.Check the tranny mount, look at the undercarriage for signs of rubbing,check U joints. Remember with a stiff ride like that stuff will rattle loose allot so just check it good before you throw money at it. Also check your bell housing and motor mount bolts, E brake cable and crossover.The E brake will make wicked noise if it's dragging on something.

 

[Steven83r]

sounds good i'll see if i can get under there when the sun goes down a little. Live in the desert killer heat and no garage space sucks.