Rearend/Wheel bearings?

[95LT1.]

I have a 95 Z28 with 146,000 miles on it. It has just startes to make some noice at 40-45 that sounds like tire noise, but I just had the tires balanced and I rotated them with no luck. The noise is a roaring noice that seems to be coming from the rear tires. I checked the rearend fluid and it was good. I did notice that there was a little play in the rear ujoint... Do you think a ujoint can cause this noise? What do I need to check for before I take it to a shop? Please help....

[Joe 1320]

jack up the rear, place securely on jack stands and spin the wheels via the motor. if it were the tires, the noise will have gone away. if it's the rear, you'll still hear the ugliness.

[95LT1.]

I jacked it up with jackstands and with the tires off the ground, the noise was still there. Does this mean the rear is bad? I found a 99 Z28 with 60,000
miles on it. Will the complete rear fit under my 1995?

[Injuneer]

It will "fit", but you will have to change the e-brake actuation cable. The 99 e-brake system is different. You will also need to determine whether the 99 rear has a 3-channel (ABS) sensor system or a 4-channel (ABS + TCS) sensor system, and that is matches your car. The presence of TCS will also affect how many brake hydraulic lines run to the rear.

You also need to determine the rear axle ratio for your car, and the rear axle ratio for the 99 rear. There are 3 different ratios available in the Z28 including 2.73 and 3.23 in the A4 cars, and 3.42 in the M6 cars.

[Wild Willy]

A couple of big 'ifs' here:

If it is just wheel bearings, and if they haven't been too bad for too long, they aren't that hard to replace. If you let them go too far, you may have worn grooves in your axles-

If it is the inner bearings in the diff, you are looking at significantly more money, and an axle swap begins to make sense-

[95LT1.]

Thanks, I am going to change the rear end fluid first and add the GM additive.
Then I will attempt to change out the rear wheel bearings. I just bought the car so I do not know how long it has been making this noise. Any pointers on changing the wheel bearings?

[ConElite]

When I bought my TA, It had only 55K on the ticker, And The Main Carrier bearings where shoot to hell. So I bought a Whole Bearing rebuild kit which included the Axle Bearings, Pinion, and carrier bearings and all the shims for about $114.

[95LT1.]

The 99 Z28 rear end I found has 3.42 gears and does not have traction control.... If I buy this it will be coming out from a 6 speed car and going into my automatic. What problems will I have?

[ConElite]

Should be fine from what I know if. Like Fred Said, If its a unit with no TC and so is your car, Should be fine b/c they will both be 3 channel system.

[Wild Willy]

That is exactly what I did to mine- an easier way to get lower rear-end gears. Make sure that either both or neither car has the 4-channel ABS- the difference being in the 3 channel cars, the ABS reluctor is on the top of the differential, and picks up wheel speed from the ring gear, while the 4-channel has a wheel sensor on each rear wheel-

Those kits are a nice way to freshen everything, if you have a reason to go into the rear, it is the cheapest way to replace all the moving parts. I don't mean to step on any sponsors, and haven't shopped around to see what special deals are out there, but I have always had good luck with rear end parts from Randy's ring and pinion- great service and knowledgable people to ask questions to-

[95LT1.]

I have noticed a new noise. When I turn left I hear a sqeak. Does this mean the wheel bearings? Also I noticed some play in the rear ujoint. I will replace all Friday and hope the rear end is good..... The 99 Z28 rear end I found was sold before I got there so now I found a 95 Formula rear with 3.42 gears. The Pontiac is a 6 speed and my Z28 is a auto. Will this be a problem?