XJ rear D44 pattern check

Thoughts? 16-18 in-lbs at the pinion, .006-.007 backlash with setup bearings

And just for reference, here it was earlier in the night, before I added .005" to the pinion depth. Backlash was the same .006-.007", but preload was a little tighter around 22 in/lbs.

Heel toe pattern looks good. Backlash sounds good. .007-.008 is what I shoot for. But everything looks good. Did you mark a couple different spots around the ring grear and spin 3 times to compare different spots ?

Yup, looks good!

Yup, marked 3 spots an spun it 3-4 times by the ring gear while someone held the yoke. 95% of the teeth look exactly like what's in the first pics. This is my first time rebuilding a rear, so I definitely wanna get it right. I've read lots of conflicting reports about Dana's loosening up over time, so it's better to have backlash at the tighter end, while other people say they hardly ever wear in at all. I was always taught a little tighter is better than a little looser

I think your pattern looks good, and i don't think you'll be able to get it any better.

The only two things we can't tell from your pictures that are important are:

1. Is your pinion nut torqued all the way down when taking these measurements? And make sure to use a NEW nut when you go to finally install everything.
2. Do you have enough shims on the carrier to make it fit extremely tightly in the housing? You should have no side-to-side movement of the carrier when it's in the housing, and it should be difficult to install/remove (i had to use a deadblow hammer)--ideally you'd have a housing spreader, but most people don't

In response to the above^
-The pinion nut was toequed to 200ft/lbs
-The carrier had the same amount of shims that it originally had.

HOWEVER... The previous installer went a little ghetto, and instead of putting all the shims between the bearings and the carrier, there was one .030" shim outside of the bearing on the RGS. I'm guessing this was his method of snugging it all up, but it still doesnt make a lot of sense to me.

With the original shim (total) count, the carrier was a tight fit, and did required a knock or two from the deadblow. But with two prybars it still popped out no problem. I didn't like this. So upon final install, I added .0025" (My kit had .0125 shims) to each side before sending it home. This made the carrier MUCH more snug in the case.

Here is my final pattern, run through 3 times in each direction.
-Preload at 34in/lbs with new bearings, seal, and nut installed. Torqued to 200ft/lbs. Before putting on the seal and new nut, it measured 25 with the old nut and new bearings.
-backlash DEAD on at .007". I measured it in 5 different places and it was consistent.

Drive


Coast

That's a good setup, run it! Good job. Remember to do a proper break in if you want a long life from it. Also if its not too late, put a strong magnet on the inside of the diff cover to catch wear material.

Thanks John! I know you've done a million setups so that is very reassuring. I have some small rare earth magnets I'm going to put inside and check after the first 500 miles.

Any tips or favorite procedures for breaking them in?

DanMan2k06 said:

Thanks John! I know you've done a million setups so that is very reassuring. I have some small rare earth magnets I'm going to put inside and check after the first 500 miles.

Any tips or favorite procedures for breaking them in?

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The idea is just to make sure they don't get hot. I suggest driving normally for about 20-30 miles and stop at a do it yourself carwash and cool the diff with the sprayer and then drive normally for a couple of days never going farther than about 30-50 miles at a time.At 500 miles you should be broken in. If you have magnets in the diff cover you do not need to change the oil at 500 miles but it wouldn't hurt anything.

Perfect. My morning commute is about 18 miles, all back roads and stop lights. Ill stick to that for two tanks and it should be golden. In regards to the fluid change, the oil is free (don't snitch) and Im always on a lift so it takes no more than 10 minutes