1994 Sierra 1500 Severe Front Tire "Cupping"

[jim_harris3]

Hello GMC Sierra Forum.

REALLY glad to have found you!

I've got a 1994 Z71 4x4 extended cab Sierra that I love. I've had it since 1996.... yep, about 15 years. Driven it from California to Canada and back. Flawless.

The front tires (tread) has severly cupped in the last 2000 miles. (Cupping = every other tread block as you rotate the tire is a different depth than the previous tread block). Some of the differences are pretty extreme, between 1/2 and 3/4 of an inch.

Driver side is worse than the passengers side. Cupping isn't equal across the tire surface either. Driver's side tire is cupping on the outside edge heavily. Passenger's side tire is cupping more towards the center.

I thought it was the front shocks. But I get no broken / worn shock "bounce" as you drive down the road. When someone else drives my truck and I chase them down in another car, the front tires/wheels are perfectly stable - no broken / worn shock "bounce".

Suggestions?

I know I will have to replace the tires.

Currently running: Goodyear MTAs. Stock size.

Truck is totally stock. No lifts, no aftermarket wheels, nothing.

Also - I know a repair for this is coming. Please let me know of a good, inexpensive, trustworthy shop who might do the fix. I've got kids now... and no longer find the time to turn a wrench....

Thanks for the help,

Jim (near Sacramento).

 

[Sal Collaziano]

Bump! This post went into moderation...

 

[happy 2011]

well frist thing is to have the front end checked.... ball joints tie rods and idle/pitment arm, if all that is ok the aligment would be the next place to go. good luck

 

[Z15]

It still might be the shocks along with tire balance...

 

[RuffNeck_Canuck]

Cupping can be avoided by rotating more often

Might be a front end issue, however I seriously don't think thats the problem. I too ran the MTR's on a 2004 Sierra crewcab that was for the most part stock. But when I purchased the tires, the guy installing then asked if i was gonna be wheeling this new truck, which I replied "No" and why ? He said with the more aggressive tire pattern "heavy lugs" and with mostly street driving they would cup. Cupping only occurs on the front steering tires, and is caused when turing the vehicle and the weight shifting to the outside and the lugs start wearing down. The solution would be the rotate them way more than usual tires. I can't remember the exact number he gave me, but I think i went with 2500 - 3000 kms, and that served me well my MTR's lasted pretty much 5 yrs with no troubles. Long story short stick to the dirt side roads or rotate the tires more, but with differences of 1/2 to 3/4 of an inch difference in the cupping I'd say those tires can't be fixed.

 

[jagtoes]

A typical front end problem. Take it to get it aligned and they will find out what components are bad. A 2 wheel alignment will cost around $80-$90 and a 4 wheel alignment is around $150.