Dana 41 rebuild

Hello Kenny-

Getting a good pattern on a used set of gears would be a 6 on the "pjensen641 scale of difficulty". The link he gives you is a good one to follow, but pay particular attention to the sidebar about setting up used ring and pinion gearsets. Unless you have taken the gearset out of the housing that you are using AND kept all of the shim packs intact so that their measurements can be used in the rebuild, the whole job will be on of trial and error using the guide to get "closer" to an acceptable pattern each time.(This would only occur when you are only changing out the bearings in an axle, and 99 time out of a 100 you could always go back with the same shim setup in that case.)

Several things to remember:

Attempt to match the old wear pattern that exists on the old gear set. Like the guide suggests, paying attention to the coast side of the used gearset will give you a good guide to an acceptable pattern. If you do not use the original pattern that is worn into the drive side of the ring gear, you run the risk of having a noisy setup.

Always use NEW bearings.

When pulling the differential bearings from the carrier be very careful not to damage the bearing with the puller that you have chosen to use.

Remember that small changes in pinion depth (the shims under the inner bearing cup) will make large differences in the pattern.

When setting up the gearing leave the pinion seal out of the setup until you are satisfied with the gear pattern that you have and the pinion preload (the shims between the shoulder on the pinion and the outer pinion bearing cone) is properly set. The seal goes in the very last thing and it will not appreciably change the preload that you have achieved.

Remember that the differential carrier bearings also have to have a preload. You may have to spread the housing slightly to achieve this, but often the side cups can be driven in with a dead blow hammer without the aid of a case spreader. IF YOU ARE USING A CASE SPREADER, DON'T SPREAD THE CASE MORE THAN .015" ( Measured from one side of the case to the other with a dial indicator). DO NOT LEAVE THE SPREADER ON THE CASE FOR AN EXTENDED PERIOD OF TIME.

The gear lash of the finished setup will probably be a little more than a new gearset. Acceptable gear lash on a new set of gears is usually some where in the range of .005" to .008", but a used gearset will probably operate more in the range of .008" to .012". Don't make the mistake of trying to "tighten up" the lash, it is more than likely to cause noise and premature wear.

Last of all, REMAIN PATIENT, because unless you are extremely lucky, its going to take several attempts to get a satisfactory pattern. Even experienced driveline mechanics sometimes have difficulties with a used gearset...it is the nature of the beast...

Good luck, and if you have questions, let us know...pictures of your pattern would probably help...

I'm a novice when it comes to differentials, but I did it successfully after research and some tips here on the forum. You can, too. Here's my thread on this same topic.
https://www.thecj2apage.com/forums/d41-pinion-depth_topic39808.html?KW=D41+pinion+depth

I didn't have the special tool either, but just remember that pinion depth measurements are usually given from the axle (or carrier) centerline to the face or button of the pinion. This measurement can be made with a straight edge across the carrier bearing flats (the flats where the bearing caps go) and a dial caliper. Just remember to add or subtract shims based upon the etching on the button of the pinion. I've noted the pinion depth measurement in the referenced thread.

This is not a hard task, but very tedious and time consuming. Good advice given above by pjensen and SE Kansas, especially about setting up mesh patterns on used gears and the backlash settings. I could not get an "acceptable " pattern according to the examples, but I got close and my rear end is quiet for the first time in years.

My goal, when setting-up used gears, has always been to try to match the wear pattern as closely as possible. It's darn hard to get it just right, because that pattern was worn in with worn bearings. A "textbook" pattern, I would think, would be even harder to achieve.  BW

Bruce W wrote: My goal, when setting-up used gears, has always been to try to match the wear pattern as closely as possible. It's darn hard to get it just right, because that pattern was worn in with worn bearings. A "textbook" pattern, I would think, would be even harder to achieve.  BW

X2