Well my Truck is down so Thank God for FZ6!

[rsmith2072]

My 1999 Z71 Rear End went out yesterday!

I drive my Fz6 everyday anyways and only my Truck once a week just to keep it in shape. But now its all up to my FZ6 to get me to work everyday.

So know i got to pull it apart and see whats wrong.

It started a while back, when i put it in park it would roll just a little. And It started getting worse and worse. Then finally yesterday something broke and now the driveshaft spins but the rear end want engage. So even when in park you can roll the truck.

I will start pulling the rear end apart tomorrow and see what it is. Im thinking that it is the Pinion Gear. Any one with experience or advise would be great. Im a decent mechanic when it comes down to it i just have never had this problem before.

 

[FinalImpact]

Sorry about this turn of events.
I can advise, however we need to move this thread to better location. Anyway, I've done plenty of rear end setups.

If you have to replace the R&P its not entirely friendly on a GM as you'll need a press for most of it and potentially a case spreader.

If you were to say it also "howled on acceleration or deceleration" then I'd say the gears are shot. However, the spider gears are a weak link as is carrier.

PM me and we'll go from there.

 

[FZ09Bandit]

My 1999 Z71 Rear End went out yesterday!

I drive my Fz6 everyday anyways and only my Truck once a week just to keep it in shape. But now its all up to my FZ6 to get me to work everyday.

So know i got to pull it apart and see whats wrong.

It started a while back, when i put it in park it would roll just a little. And It started getting worse and worse. Then finally yesterday something broke and now the driveshaft spins but the rear end want engage. So even when in park you can roll the truck.

I will start pulling the rear end apart tomorrow and see what it is. Im thinking that it is the Pinion Gear. Any one with experience or advise would be great. Im a decent mechanic when it comes down to it i just have never had this problem before.

Drain the grease, pull the cover and look, it may be a spider gear, but most of the time it takes out just about everything, you have 1 of 2 routes, you can either A. Buy a whole other rear end out of a wrecked out (they are everywhere!) or B. you can take the axles out and replace the gears.

But the FIRST thing you need to do is figure out what gear ratio, you can either call Chevy and give them your vin # (fastest) or rotate the big gear around untill you see numbers stamped In it. It has like three sets, but lets say you see an 11 and a 41. 41 divided by 11 is 3.727 or in lamens terms, 3.73 gear ratio, it is imperative you get the same ratios because it will throw your whole 4X4 system out of wack.

Replacing the gears itself isn't very hard at all. Might as well do brake shoes while you have them out.

Is this a 99 square body or 99 new body?

Actually final is right, I just take the axle bearings and have someone with a press do it. Takes 5 minutes and may only cost 10$. But you can always drop a rear with hand tools lol.

 

[rsmith2072]

So i got the driveshaft out and the cover off and this is what i see!

The biggest gear looks ok but everything in the middle is damaged.

There is one gear and some springs just laying on the bottom.

So i guess the next step is to pull the axels so i can get everything out.

The only problem with that is that i had to order a gorilla Lug nut key to remove my lock nuts that Discount tire put on when i got the new tires. It should be in by this weekend.

My Truck is the new body style not the box style.

 

[Ben_H]

The spider pin sheared. Just rebuild it your self should be under $500 in parts to do everything gears bearings seals and ujoints

 

[FinalImpact]

Looks like it has some form of locker in there. You're gonna need a new carrier for certain as well as all the guts inside. Personally I can't imagine the R&P got out of that unscathed and even if they show no actual loss of the gear surface on the heel or toe, they could have been stressed and then break/shear off later destroying everything again....

Bearings, seals, carrier, R&P. Get the axles and out and go from there... Inspect the case for signs of outgoing stress too as a free object like spider gear can break a case!

Good Luck!

 

[FZ09Bandit]

I've seen the bearing break into pieces and completely grenade one. On an excursion, blew about three holes in the case.

Funky thing was, it still drove.

 

[rsmith2072]

Thanks for all the feedback!

As soon as my lug nut key comes in i will get the axels out and give an update. I will also take pictures along the way to share.

The only good thing is that when it broke i was in the driveway at a real slow speed so hopefully it didn't do any damaged to the case.