Rear Diff
 

I am getting a lot of noise from my rear diff when i turn corners, especially right turns. However it only makes a noise when its hot after a long trip. Tried adding more Ltd slip additive and also over filling the the diff but to no avail. Any suggestions ????????
Im using Castrol 80-90, tried Amsoil, Casrol Syn, and Penzoil. All were the same. Maybe i just worry to much ???? Any info would sure be appreciated. Thanks

Might not have enough additive in it. You want at least 7-8 oz of additive in it. I'd drain, add 8 oz of additive first, then fill to fill hole with gear oil.

If you live in a hot climate area you might try to run the 80-140. That's what I use in California.

I've tried 6 oz. of additive, maybe a bit more. You say two full containers of the dealer additive. Sounds like a lot, but if it works?

sorry to hi-jack, but... while we are on the subject...
What is capacity on the rear diff ? I need some fresh juice.
janb

8 oz of any LSD additive/friction modifyer. Can be had from any parts store, don't pay high dollar at the dealer for it. Dumpster, plus if you drain/refill again, you'll have the diff cover off and you can inspect the r&p and clutches etc. See if you have shims in the oil, check for damage. Add the additive first. For an open diff, non limited slip/posi, no additive necessary. Fill is probly less than 3 quarts. Never a bad idea to have some on hand in case of a pinion seal leak from when you wanted to run synthetic:rolleyes: :p ;) .

I thought you couldnt fill to the hole because it could leak into the brakes:confused:

There are seals on the drums that keep the oil from getting on the brakes, and you want oil to go down the axle tubes, thats how your wheel bearings get lubed!!!

The best bet is to drain the diff, and check the magnet inthe cover to see if there is any metal particles on it. at least then if there is a bearing going out you might catch it in time, before you waste a rear end. it will only cost you the new fluids to check.

I changed my fluid the other day and found two things. The carrier bearings had spun into the housing. I pulled it apart to fix that and found that the side and spider gears and breaking up. So a Detroit Locker is on order for a replacement for the Power Lock.
It's worth the cost of the oil to look inside now and then.

Sometimes it does, sometimes it doesn't. The FSM says 3/8" below the fill hole is the proper level.

Thank guru[tapdshut] I mean Dave.

Michael

Yea i have seen some small metal fillings on the magnet but nothing that looks really bad. How can you check the clutches with only taking the cover off. It does seem like the clutches are the problem.

my rear diff was making a noise and this is how i fixxed it................................................ .................................................. .................................................. ................................sold the truck![laugh] really i did.

Check to see how much slack there is. Turn the driveshaft back and forth, the wheels should react at the same time as the ring gear. If not, the cluches are worn out. There is a series of pics in my gallery from when I rebuilt my Powr-Lok, mine were toasted but they never made. I thought I had an open diff until I pulled the cover off. :o