srv3fender

Ok i have a 1998 silverado z71 with a lift and 35's, whenever im on dry pavement and i turn on the 4 wheel drive and start to go the right rear wheel will stop for just a split second about ever 10 ft, when i put the truck in reverse and back up the left rear wheel does it and not the right. offroad i dont have this problem. The rear differential looks a little wet like the fluid is low, had the rear end rebuilt about 2 years ago, but dont know for sure what gears were put in, the guy says he think from memory he ordered 3.73s. Any help would be greatly appreciated. I would not normal care about this problem but im trying to sell the truck and i found a buyer and he doesnt wanna buy the truck until this issue is solved. <!-- google_ad_section_end -->

therewolf

Hi srv3fender,

Welcome to the Chevy Forums.

The Z71 comes complete with a G80 LSD rear axle.(AKA POSI-REAR)

The benefit is you have three-wheel traction in dirt in 4WD. Both your rear wheels, and, if memory serves, your driver front wheel. This is great off road, and gives you a great advantage over a high percentage of stock 4WD trucks in the dirt.

Unfortunately, the locking rear can be a little miserable in tight turns on hard pavement. What you are experiencing is "axle hop" or posi axle bind. Since your rear axles are locked, there's very little play between the wheels, and when one wheel goes farther than the other, such as in a hard turn, the wheel going the lesser distance doesn't "slip" the way a standard non-posi rear axle does on hard pavement. With no other way to compensate, the stationary wheel, which is being forced to be stationary but wants to go the same distance as the wheel in the wide turn, breaks traction and spins, or "hops" to compensate.

2wd-K5

if this hop is happening in only strait lines, i would say your axles have diferent gear ratios, if rear is binding the rear has lower gears

srv3fender

this is happening when driving straight and only when 4wd is engaged

2wd-K5

i would say there is a difference in the gear ratios then, only use the 4wd when in slippery conditions untill it is taken care of

therewolf

Kindly allow me to apologize. Your original post made it sound like you were having these difficulties in turns. What RPO code do you have for your gear ratio?

Since your 4WD shifter only controls your transfer case(up forward), and has no control over your rear axle, this sounds like 2wd-K5 is right.

Check your Service Parts Identification sticker inside your glovebox, and see if you can determine your pickup's factory gear ratio.

Gearing Ratio RPOs:

GU5==323s
GU6==342s
GT4==373s
GT5==410s
GT8==410s

It almost goes without saying that you've been very lucky so far. Generally mismatched gears, or running your 4WD too long on hard dry pavement results in an axle bind which blows your transfer case.

99ChevyZ71

How do you know what these codes mean? Where do you find out what all those part codes mean?

therewolf

Ha ha ha! I KNOW THIS BECAUSE I AM THE GENIUS OF THE UNIVERSE!

Seriously, google RPO codes. It takes some research, but with some tenacity and effort, you can find the meaning of almost any code.

There's even a couple of guys here at CF who will take your VIN, and translate your truck's RPOs for you. Aside from ice, there's not much cooler than that.

99ChevyZ71

Awesome, who would these people be?

99ChevyZ71

http://www.rpocodes.com/