Well first let me start by saying this all happened about a month ago when I first bought the car, so I probably should have asked then, but it just recently came back to memory.

When I took my car in to Pep Boys for a basic check up (my guy is friends with the Mechanic there), they found that the car had a very damaged U-Joint, and to make things worse the previous owner had raced the car with the damaged U-Joint causing it to flop around and cause some damage under the car.

I had the U-Joint replaced, and the mechanic said everything else should be fine. But that there was something that should be fixed before "racing it". He said it was some kind of bar possibly, but I can't remember what. In fact, he didn't sound too sure of himself either.

So my question is, what could have been damaged by a loose U-Joint?

Oh, and the mechanic said it was something that would most likely give if the car put down too much torque.

Thanks if anyone can help me out.

 

I would guess the torque arm. But, it sounds to me he's like he's probably feeding you full of S***. First lesson is never trust a mechanic that works at pep boys.......they're tire changers. JMHO

 

Get a second opinion if you are worried about it, or get some undercarriage pictures and post them here. The torque arm is the only bar that runs parallel with the driveshaft so I would imagine that is what he is talking about.

 

A joint failure would only do that unless it let go all together. Allowing the drive shaft to flop around. Drive shaft failures are quite common on cars that race with stock shafts.

What he was probably referring to is a drive shaft loop which holds the shaft from flopping around beating the bottom of the car or digging into the pavement.

They are common for race cars



It goes in place of the lateral stabilizer bar under the mid section of the car.

 

were you having noise from the rear of the car? usually a bad u-joint will give you some funny clunking noises, when you get on or off the gas.

a driveshaft loop is a good investment, expecially with a stick car.


aaron

 

In very low speeds (about 15mph or less) and very high speeds according to the old owner (100+mph). After looking in my Chilton book, I'm thinking it was the torque arm. But would a damaged U-Joint be able to tear up a torque arm that bad?

 

a bad ujoint will cause the car to vibrate.if the car had a ujoint fail,i.e. brake in two, then the driveshaft might have hit the torque arm.a bent torque arm is no good for racing.it could be anything though.have your buddy throw it on the lift at pep boys and shake it down and take some pics.

 

Like others have said unless the u-joint completely let go and allowed the driveshaft to flop around I can't see the torque arm getting damaged. Also make sure you get quality u-joints not pep boys brand. Those won't last long with how most of us drive our cars.

If you want to see what a real messed up torque arm looks like just check this out



That's the result of a rear end locking and rolling forward underneath the car. Also destroyed my u-joints.

 

he might be talking about the trans or reasr end yoke. if they were damaged they should be replaced. a loose or bad u-joint cannot cause the shaft to hit anythiong else. get a second opinion. i own a repair shop and i don't mean to badmouth but some of the midas,pep boys and larger chains recruit on pay not on experience. my brother is head tech at local midas and hate to say but he is an idiot.

 

if the ujoint was to break, then the driveshaft could hit the torque arm.another way the driveshaft can come into contact with the bottom of the car is if the car has had a failed trans mount, but it usualy just hits the top of the tunnel.its almost impossable to guess what could be wrong with your car, if anything.

 

That is just plain nasty.

 

They checked the yoke, and said it could be replaced but would be fine as is. The U-Joint never completely broke, but was one VERY lose.

I just went and took a look at it, he is talking about the Torque Arm. Also, my Torque arm is painted red, so it mite not be the stock arm. Whats the best way to tell?

I'll try to get the car lifted up and snap some pictures.

 

Usually an aftermarket arm is much thicker and has a bolder, stronger look I guess you can say. The presense of a Spohn, BMR, or UMIPerformance sticker would be a dead giveaway too.