Hello all

I own a 2006 GMC Z71 4x4 crew cab with rear drum brakes. It has 16k miles. I just took it in today with severe rear brake pulsation especially when slowing from freeway speeds. The dealer says the drums are egg shaped. Can anyone tell me why this happened? The truck is normally driven on the freeway without loads and only tow my boat twice a month for a 5 mile round trip. I don't drive mountain roads. This is just after I had the steering shaft replaced. Needless to say I'm not too happy with the truck.

 

They have problems with the rear drums getting out of round, they will need to be turned. But I have not had to return a set after they have been machined.

 

Thanks Grumpy for the info. My chief concern is that the pulsating will return. I drive my truck like a car with mostly freeway miles. This is nuts.

 

If you have aftermarket wheels on vehcle make sure the two metal retainers are
removed, or it will cause a horrible teeth chattering pulsation in the rear, test drive
after removing clips and reinstalling wheels and it should be gone.

 

Have you left your parking brake on before? If you drive around with the p brake on you can warp your drums.

 

Thanks for the ideas guys. I still have the stock wheels and haven't had the parking brake on except when it's parked. According to GM Owners.com a bunch of people are having drum problems. I can't believe they went to drum brakes from disc. Then the dealer did me a huge favor turning the drums under warranty. Next time (and there will be a next time according to the service writer) the cost is on me.

 

bigbadwolf Ive got 20's on my truck and theres two retainer clips on the drums...those should be removed???

 

Probably should remove the clips, unless they are OEM 20's.

I, too, am pissed off about them going back to drums, and that's one of the things keeping me from buying a newer truck. I've had some bad experiences with drum brakes and all the damn springs in them.

 

if they are aftermarket 20's yeah better off removing the retainers, if they are GM 20's it wont affect them

 

Ok, explain. If I am not mistaken, wolf you work at a dealer, right? well I do also, and I am just wondering if you would mind explaining the clip deal. I can see where the clip could cause a little distortion between wheel and drum, but why would it only affect aftermarket wheels??? Just curious