85 monte carlo rear wheel seals?

I just bought an 85 monte carlo SS and the guy told me it needs new rear wheel seals. I'm not quite sure what that is or how to replace them. I am mechanically inclined and can surely do it if i know what i'm looking for. Also, i am told it will need gear fluid for the differential and im not sure how to put that in it or how to know if i have enough in it. any help would be greatly appreciated. thank you

3 Answers

  • 8 years ago
    Favorite Answer

    Jack rear end up off the ground enough so you can get under it, both in front of and behind the differential.

    Take off rear wheels. Take off the drums. If you don't see evidence of leakage, put the drums and wheels back on, and don't touch it. Trust me. Seals are not preventive maintenance.

    If you have to go further. Get a big pan, put it under the differential. A 1 gallon milk jug with the cap on it, with one side cut open with razor knife will work. Undo all the bolts on the diff housing. Start loosening up top, then move to the bottom. Completely remove bottom bolts. With top bolts very loose, use sharp screwdriver and pry around the lower edges of the diff cover until it brakes free and starts to leak fluid. Might need two milk jugs, don't think it holds 4qts though.

    Once it stops spewing fluid mostly, remove the remaining bolts. Look at the carrier, which is what the ring gear is bolted to. Inspect ALL gear teeth for wear. Any abnormal wear, you are looking at more of a rebuild. For standard (open, not posi) differential: Rotate gear until you see the head of a small bolt (5/16" wrench flats?) that faces to the passenger side of the car. Remove that bolt. It should be threaded for about 1/4", then smooth, with a rounded end. If all you get is a threaded portion, the rear is toast, forget disassembly. Put it back together and drive until it breaks. If you get the pin/screw out, rotate carrier until you can get the big pin that runs through the center (its called the pinion shaft) pushed far enough out of the way so that you can see the ends of the axles. With the pin out of the way, push one axle IN towards the carrier. Remove the C-clip on the end of that axle. Repeat other side. Pull axles out. Replace seal. Lube seal with gear oil before inserting axle. Insert axle making sure not to tear the seal with axleshaft.

    Reassembly reverse order. Once all buttoned up, move to front passenger side of differential. Find the plug that takes a 3/8" square drive. CLEAN THE SQUARE DRIVE PORTION COMPLETELY OUT OR IT WILL STRIP. Using an extension on your ratchet, remove the plug. Inject fluid into differential until it starts to dribble out the hole. Note that if the back end of the car is up too high, it will be too much fluid. Ideal to have car level front and rear, but thats pretty tough. Proper fluid level is at the bottom of that fill hole, with the vehicle level front to rear, and side to side.

    BTW, your car has a 7.5" 10 bolt unless it was swapped for the ultra-rare 8.5" 10 bolt, if you get a gasket or any other parts.

    Source(s): Own an '85 Cutlass with 8.5" 10 bolt. Done PLENTY of carrier/gear swaps on GM C-clip rear axles.
  • ?
    Lv 4
    4 years ago

    previous due 80s have been the final produced MCs that have been rear wheel force. I also have a 2004 Monte Carlo Intimidator and that's certainly front wheel force. i'd have a complicated time pulling doughnuts interior the parking zone. And to the 1st responder, NO, no longer all autos are rear wheel force. autos could have 4-, all wheel-, or front wheel force. it easily relies upon on makes, fashions and each now and then changes (i.e. Gravedigger)

  • monte
    Lv 6
    8 years ago

    monkey boy has it right. I'll add this is the time to also check the rear brake shoes or change them if the seal has let gear lube make a mess of them. After all is clean, also check the rear wheel cylinders for leaks and the backing plate for any excessive wear.

    Source(s): Did this to an 81 Grand Prix back when.
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