Hi all, My name is Ben and I am deep in my 50s as far as age goes. When I was young I had 1973 LT and Z/28 Camaros, and also a 1970 Camaro and a 73' Trans-Am. That was all back in the 1980s though. A few days ago I bought a 95' Z/28 with 64K on it's clock. It is a purplish color like some Cudas in the early 70s and it has an automatic transmission. It is all stock, no mods at all. Seems to run fine. I have done all my own work on automobiles all my life, mostly Chevrolet, this is my first Lt1 car and I am nervous about it because it is a bit different and the engine looks hard to get to. Also I am pretty sure the rear axle is making more noise than it should. It is not obnoxious but under mild acceleration the ring and pinion sings a bit and I think I hear some bearing noises at some times to. I have read the axles in these cars are infamous, but I may be over-reacting too. Should the rear axle be 100% silent in operation like the one in my 1992 Caprice Classic seemed to be? I would not be afraid to put a bearing kit in the rear axle for peace of mind. Thanks for any input in advance....

Update, here are some photos of the Z:

 

check fluid level in the rear. with only 64k rear should be ok. that is so long as its not been abused.

 

It might need some posi lube too, does it chatter at all around tight corners?
Low miles like that with an automatic it should be good but things do happen. My '93 Z28 had 222,000 miles when I sold it and I'm pretty sure the rearend was original.It ran smooth and quiet.

 

Thanks for the input guys. I plan on changing all the fluids asap so if that does does-not help, or if I see something bad when the diff. cover is off I will put it up here....

 

Not sure how you would easily check, but I know from personal experience​ here that Richmond racing gears sing, from what I've found in my car at about 36-43mph. They're much tougher gears, but you get running noise as a result of them.

If it's all stock stuff, I can only imagine that it'd be a little low on fluid.

 

If you are having real problems in the rear it should show up as metal flakes in the oil when you drain the rear. If the magnet and fluid look clean then it is more an annoyance then anything else.

I don't know how many rears you have had a part but some metal will still be in there from break in. If you clean everything then drain it again in 3000 miles and there is more metal then you know its heading south.

The whole rear from a LS1 car is a nice upgrade because of the brakes. It has larger disks and if you get one out of a 6 speed it will be 3:42 ratio. So many people are buying LS1/6 speed cars to part them for the engines and transmission complete low miles rears are around at reasonable prices.

 

I am not sure what gears are in the car, it does about 70mph at 2000 rpm. I am more into highway driving than drag-racing so I would rather have 2.73 gears. Last night I bought a set of service manuals for the car off Ebay and also the Kent-Moore tool for pulling wheel-bearings. Next I am going to buy a bearing kit for the carrier and pinion and my plan is to pull everything out of the rear axle and put in new bearings. Hopefully the ring and pinion are re-useable. I would not mind having an extra ring and pinion laying around just in case mine do not look good, so I guess I will have to jack the car up and count the driveshaft revolutions vs. the tire revolutions and see what ratio I do have for sure. I read a GM service manual for Caprice Classics last night and it said of you have a bearing noise coming from the rear axle at low speeds then it is probably the pinion bearings, and if your pinion bearings are going bad then I think it would also make the ring and pinion sing. So I figure I may as well get in there and put in some new bearings and parts so I can have peace of mind and not worry about anything blowing up or a wheel coming off the car when I am going down the interstate at 100mph......

 

You should be able to check your RPO code on the door and find out what gear ratio you have​. You said @ 70mph, you're running 2k RPM. That sounds like what my car used to have before I began modifying everything (A4 Z/28 owner here, stock gears were 2.73). I'm at 3.42 gears now, and I think I'm over 3k just a hair @ 75mph on highway.

 

I think changing fluids may help

 

i would take it to a trustworthy shop to do pinion if your gona do it. pinion is not easy to do even for a experienced mechanic. to easy to mess up the crush bearing/bushing.