Noisy rear diff

[jackb]

Pull the R/A. Keep up on stands under frame.. Take the R/A to a reputable Jeep shop and have them evaluate your problem.

[evilhawk]

I think I may end up having to wait before I can try the figure 8 thing. Its supposed to snow today where I have the car stored... I heard blizzard conditions. I wish I had time to try it last night, but I ran out of daylight and the charging system isnt working in the car yet. In the mean time, Im ordering the correct diff gasket.

On another note, I know a couple places where I might find another rear end. I know of a scrap yard that has a few GT Hawks and Lark types.

[karterfred88]

I would try the figure eight thing first, can't hurt it any more than it might be already. Yes, there are new clutch style posi units that will fit and work with 19 spline axles in the old Dana 44, but hold onto your wallet! If it doesn't loosen up and you don't want to spend big bucks you might try finding a Jeep 4x4 shop that will go in and try to O/H it, most of the parts are out there and there might be some other things the rear end needs that can be taken care of at the same time. The "other rear end" option can also work, but again, if it's used you may face other problems, and if adapting one, even more headaches and cost. You might try taking that cover off and looking before deciding, making sure there are no chipped gears or massive looseness from wear. Good luck!!

[evilhawk]

I got the chance to work on my Hawk again yesterday. The plan was to pull the diff cover off to see if there was any obvious damage to the rear end, but I ended up buying the wrong gasket so I left the cover on and refilled with oil (80-90w limited slip) and friction modifier. I drove the car around and it seemed a lot better at first, but when I took the final left turn onto the street where my storage garage is, the rear stayed locked in around the corner. The car shook so hard I thought the rear end was falling out. I think it sat too long with little to no oil in the rear and the clutches are now sticky. I am wondering if I do figure 8s in a parking lot if the clutches will start working correctly after a while or if it would just damage things? Are there still posi units available for these old 44s? The other option is to find a different rear end.

[BILT4ME]

My 1971 Scout has posi on the rear and plain diff. on the front. When I started to feel the Scout slip a bit on ice I pulled it into 4 WD and it gripped the road nicely, even on curves.

I only had one time when I had everything locked in and was driving on a sheet of ice (100% coverage) on a street. A downhill right-hand curve. As I came around the corner, I continued to slowly spin to the right and I could not steer (because all 4 wheels turned the same speed). I was headed straight for a light pole head-on. I locked the brakes, stuck it in reverse, and punched it and dumped the clutch. I stopped about 8" from the pole.

After that, I would only lock in one hub in order to maintain steering if I was in critical highway conditions and only run in 2WD until I felt I needed the little boost of control in 4WD.

It's amazing at the confidence you have in going places when you have front and rear limited slip! I pushed that truck through 8 ft snow drifts and water standing in plowed fields. (not at the same time......)

[TWChamp]

My 1971 Scout has posi on the rear and plain diff. on the front. When I started to feel the Scout slip a bit on ice I pulled it into 4 WD and it gripped the road nicely, even on curves.

[BILT4ME]

I installed one in the truck. It had its pros and cons. I could pull anything and go as far as I wanted and then some. Steering on slick surfaces was interesting. If I was in the mud, I had to "burp" the throttle in order to steer by rocking the steering and suspension. If it was snow or ice on the road, I would drive with it NOT in 4WD, or would do it with only one hub locked in. I pulled loaded semi trucks out of the ditch with that one. I miss it! (69 Chevy, 350 bored 0.060 over, ported, polished, balanced, 4 speed w/ granny low, 4.11 gears, with LS in front and rear.)

"The very first time my pickup with a LS in the front diff came loose,"

I thought limited slip didn't come on the front of vehicles because it would be hard to steer on ice and snow. My 1971 Scout only has L/S on the rear.

[Hawkowner]

The 70s GM positi adative had whale oil The instructions were to add the oil and drive to a parking lot and do figure 8 eights. Saw it work every time. As far as I know the replacement adative does the same.

[evilhawk]

I think I let off the throttle when going around the corner. Also, I think I have way too much friction modifier in it. Ill drain and pop the cover off and have a look inside when I get a chance. Do you guys know how much modifier is required? I think someone mentioned a 4oz bottle with limited slip 75-90w.

[TWChamp]

"The very first time my pickup with a LS in the front diff came loose,"

I thought limited slip didn't come on the front of vehicles because it would be hard to steer on ice and snow. My 1971 Scout only has L/S on the rear.

[BILT4ME]

Were you totally off the throttle when going around the corner? If so, the "bang" is when the gears/plates/cones release to allow the axles to turn different speeds.

Next time, go into the corner and accelerate. You should NOT hear banging, but the chirping of tires.

If you find an intersection where someone's sprinklers are soaking the roadway, you can check it by decelerating through it and by accelerating through it. The water on the road will allow the tries to slip a little more.

The very first time my pickup with a LS in the front diff came loose, it sounded like someone hit it with a sledgehammer. I thought I broke an axle shaft. No, that's they noise they make when they're tight. The more you drive it, it will loosen up a bit and you will get used to the noise. Only run enough friction modifier that it requires. Running twice as much will actually burn the clutches and junk it because it will release and slip too much and cause heat, and burn the clutch plates/cones.

If you want it to be quiet, change it out to an open diff and send the original one to me........

[evilhawk]

So I did add modifier and it seemed to help at first, but then the car started to bang around corners pretty loud again after a short ride, so I drained out the fluid and refilled with a 4oz bottle of modifier and 75w 90 limited slip oil and drove it again. It was still banging pretty loud so I added more modifier and went for another drive. This time it banged so hard when taking a left turn that it shook the car and it felt like the rear end was coming out! So I limped it home and crawled underneath, but didnt see anything out of the ordinary. So now the diff cover is coming off so I can inspect the gears. I am expecting to see damage. I dont know the history of my car, but I know it had a rough life so I wouldn't be surprised if the rear end is trashed.

[BILT4ME]

On a non-Studebaker vehicle, I found that the Eaton limited slip diff I had was noisier and would tend to pop in and out harder if I did NOT have the friction modifier in it. The friction modifier allowed it to open and close more easily and thus, quieter.

If it were me, I would use the off-the-shelf GL-5 and add the friction modifier. There may be others that disagree, but I run 4x4's with big tires and limited slips and that's what works for me (unless it's a Detroit Locker....)

[studegary]

I always recommend adding a small bottle of GM limited slip additive to a change of Twin Traction lubricant.

[StudeRich]

I've never had a problem if I used oil that said for limited slip./Cut/

It does not matter what "they say" on the bottle or what Brand it is, what matters is the GL rating, I run the other way from ANY that have multiple GL Specs, I have seen GL-4, GL-5 all on the same Label!

GL-5 is the ONE that can be used for modern Limited Slip Units, but for older designs it is best to play safe and Add an additive like Jeep recommends for their Dana Axles.