Dana 44 Differential

[Rusty XJ]

I paid someone to set up the 4.56 gears and Detroit locker in my Dana 44 and finally got the thing in and ready to go. When I drove it I hear a binding metal to metal noise from the rear and it jerks when I pull out. It also makes a humming noise down the road. Anyone have any suggestions on what to look for aside from maybe the pinion depth wasn't set up correctly?

[Rick_Bear]

I'm not a gearing expert by any means but it sounds like the pinion depth it off.
Was it done professionally...?

[Rusty XJ]

Done at Napa machine shop on the side.

[CJ8Ted]

Pull the cover and look, but you might not be able to see the problem. It could be a number of things, I'm thinking backlash or bearing preload.

Let us know what you find.

Ted

60% backlash, 30% bearing preload, 10% 

[hillbilly]

just an iffie but is there gear oil in it/enough?

[Rusty XJ]

Yeah Hillbilly. I drove it about 5 miles thinking my clutch was the issue since my clutch wasn't the best when I parked it. But then I started thinking more towards the differential and was like,' Ugh did I put fluid in that?" I pulled over and pulled the fill plug off and it was spot on still. I also noticed that the Detroit gearless locker was a little too well mannered around corners, like it was an open diff still. I had a co worker listen to it while I pulled out in the parking lot today and it was coming from the rear according to him. Tomorrow the brakes are coming off to eliminate those from the equation since I coverted it to disc. If it still binds without them the cover is coming off. I talked to the guy at Napa and he said he'll come take a look at it when I officially eleminate the possibility of it being a brake issue.

[airframer]

Um if you can hear your rear axle making noise while you drive that is not a good thing. I also have a dana 44, I locked it and it made no extra noise I guess I could say, also when I regeared it(I did it myself) I went to 4.56. There is a break in period but i never had any binding and you said it jerks when you pull it outta gear? You do have A LOT more power so the pedal is more sensitive, my jeep does jerk if I go around a corner and mash the gas or if I take off to fast. Did they give you a warranty with the job?

[Davew]

If you have a hum or whine the ring and pinion are not set correctly , could be pinion depth or backlash. A pattern needs to be done to see how they are meshing . The jerking you feel probably isn't from the axle, could be that you need to adjust to the new axle ratio.

[Rusty XJ]

I don't know exactly where it's from but I'm 100% it's not something that's normal. It's like it binds for a second then it takes off, usually does a small burnout. I'm not so sure that the humming is coming from the rear now. Seems like that's just the tires and my ebrake cable was rubbing the driveshaft. I put the cable back up where it belongs and the binding still exists, I thought the cable coulda been the issue. The driveshaft seems to be at a good angle and doesn't seem to be too long or too short, u joints only have a few hundred miles on them. The brakes are free of binding as well as the e-brakes. The issue seems to go away when I have it on a lift and drive it. So whatever it is only happens with a load on the ground. The pinion turns about 45 degrees before the tires start to move, I'm not sure that seems right. I pulled the cover off and it had a few little metal sparkles but I assume that's normal for new gears in the break in process.

[airframer]

You should see some metal flakes at first because gears have a protective coating from the factory, as far as your driveshaft goes you can turn the pinion a little before it hits the ring gear and that combined with your locker engaging could allow it to turn a little. Id still get it checked better safe than sorry.

[CJ8Ted]

You should see some metal flakes at first because gears have a protective coating from the factory,

What is this protective coating you speek of?

Ted "radiator bearing"

[airframer]

When I was doing research I found thsat they are coated with a type of corrosion preventative so they don't rust during the time the are on the shelf.

[Blacksahara1]

Does it make the noise and burnout when you're starting out in a straight line, or turning?  If turning, sounds somewhat normal to a detroit.  I drove a YJ with a detroit in the rear and it made a similar noise as you describe.  Take a short vid or sound clip and link to it.

[Rusty XJ]

It makes the moaning/binding noise when I pull out and sometimes around turns. I tried pulling out in 2nd and it does it in 2nd as well. I just stalled trying to pull out in 3rd. I pulled the cover off and I'm not totally sure what it is i'm looking at as far as the locker goes but it seems to turn a whole lot before it engages the axles. The gears appear to be set up properly according to the guy who put them in. But he is unfirmiliar with Detroit lockers just as I am. He's used to open diffs and spools. The two halves of the locker aren't tight against the center pin and the tires aren't locked together. Also when I turn the pinion, the two little orange springs in there have a lot of side to side movement. I got the locker and carrier used and the guy who set the gears up never touched them, no real need to take the locker out of the carrier to put gears in. Anyone have experience with how the lockers work?

[Blacksahara1]

Call the mfg, they should be able to help diagnose.  When I had issues with my ARB their tech support was the best....very knowledgeable, and all wheelers.  Hopefully Detroit is similar with their support.

Most you describe, except for the squealing tires, sounds normal to the function of a mechanical locker.  Do the tires squeal when starting out under all conditions (straight, turns, little throttle, heavy throttle)?  Have you taken it off pavement and done some slow hard turns to see how the locker performs?  Inner wheel should turn faster, and should stay locked on low traction surfaces.