Cadillac Repair: Rear differential sticking/slippage?, mass air flow sensor, mass air flow

Question
I have a 1996 Fleetwood Cadillac. ( By the way thanks for your help on locating the "Mass Air Flow sensor". It (the MAFS)went out the day following your response, and the car would'nt start. I removed it and had to order a replacement. It cranked right up after installing the new one). Knowing where to find it
As far as the rear slippage or sticking feeling; It only happens when I attempt to slow down and then accelerate shortly afterwards, as you would when you slow down and complete a right turn. It has also occurred in stop and go traffic such as an expressway/interstate back-up. I've had the car for two years and it has been occuring ever since I acquired the vehicle. I originally thought it was a transmission problem, but the transmission was replaced the first month I had it. I described the problem to the service person that replaced the transmission(could not duplicate the slip/stick problem when I returned to the service shop), who stated that the problem I was experiencing was in the "rear differential". Servicing, according to the mechanic will clear the problem. Where on the 1996 Fleetwood can I find the location to complete this servicing (provided I am capable) and what lubricant and specifications should be used.

Answer
Hi Bennie, Glad to hear that I gave you the right advise and it helped you fix your car. Sounds like you could have a limited slip differential. What that means is inside the differential there is a clutch pack that slips and allows the rear wheels to turn at differant speeds when going around the corner. There is a special additive that needs to be installed with the gear lube or the noise will occurr. The auto parts store should have the additive or you can get it from the Caddy dealer. Serviceing is a piece of cake. All you need to do is get the car up on stands and place a drainpan under the differential. Then by removing 10 bolts the cover should come off, maybe with the help of a screwdriver placed between the cover and the diff. and prying out. Then on the RH side there is a plug that needs to be removed with a 3/8" extension on a ratchet and 4.2 pints of 80W90 gear lube filled in there with a hose on the end of the bottle after the cover is installed. The fluid can have a rather strong odor so wear some old clothes. Bill