Gears from one D30 to another D30

[tgoff]

I bent my old disconnect dana 30 and am going to swap in a non disconnect dana 30. The gears in the new dana 30 are not the same so I am going to swap the gears from the old dana 30 to the new dana 30. What I plan to do is to take the housing and pinion out of my old dsico 30 install it into the new non disco 30. My questions is am I going to have to mess with setting the old gears up in the new housing? Thanks.

 

[xjbubba]

Unfortunately, yes. The distance between the pinion inner bearing surface and the axle center line will probably be different between your old D30 and your new D30. This will probably result in a different pinion depth, if the same shims used in the old diff are used in the new. I'd say put the old stuff into the new housing, using the old shims, check backlash. If OK, get a pattern, and go from there.

 

[ratman572]

If I were in your position, I would seriously keep my eyes peeled and make some phone calls to the local wreckers to try and find one with the right gears, -it would save a ton of trouble, -IMO.

What ratio are you looking for?

The wrecking yards in my area are littered with XJ's, and most are 3.55 gears.

If you're looking for something other than 3.55's, then it will obviously be a little tougher to find. 3.55's definitely seem to be the most prevalant ratio that rolled off the line.

 

[IslanderXJ]

Adam said he would probably help you after spring break, you may have to compensate him of course.

 

[Mechanic_Dave]

I actually deal with selling gears up here in Canada. With Dana you need to be careful that they are the right gears. Dana has a nasty habit of changing up specs all the time in axles that are the same ratio and sizing. When you find some gears, make a call to a good local shop that carries Dana and give them the numbers off of the crown gear as well as you housing build number, found on the axle tube on the cover side. I deal with these 10x a day, and there are so many variances to watch for. You would almost be better off finding the ratio you need in a complete housing.

 

[tgoff]

I looked at the local yards here and no 4 cyl XJ's were around so I am pretty much stuck to doing it this way I was just checking to be sure that this was required. Its my daily driver so I can't really wait really long for one to come up.

Unfortunately, yes. The distance between the pinion inner bearing surface and the axle center line will probably be different between your old D30 and your new D30. This will probably result in a different pinion depth, if the same shims used in the old diff are used in the new. I'd say put the old stuff into the new housing, using the old shims, check backlash. If OK, get a pattern, and go from there.

So it would be better/easier to swap the gears into the new housing? Thanks for the suggestion.

 

[xjbubba]

Of course, finding a new housing with the gears you need would obviate the need to set up gears. I've never set up used gears, in a modern diff, but I've read it's difficult to get the pattern optimal, which could result in a noisy front. Since it's the front, it may not matter.
I'd install all new bearings, etc., while your at it. Check the pattern and back lash of the old set-up before disassembly. Try to set the backlash the same in the new set up, if the old is within specs.

 

[tgoff]

When swapping gears can I reuse both the pinion and differential shims? Also providing that they are in good shape could I also be safe reusing all the bearings? This would help because I would not have to purchase the new shims and bearing plus I wouldn't have to install them as well. Basically a swap of carriers and pinions without removing any bearings. Then reusing a combination of shims from both differentials to get it set up right. Basically reuse everything except pinion and axle seals. Will this work? Thanks.

 

[xjbubba]

You may get by using the old bearings, since it's a front diff. But pinion depth is an adjustment that accommodates the manufacturing variances of the individual housing to the manufacturing variances to the specific ring and pinion set used in that housing. You'll probably have to adjust pinion depth, which requires varying the shims under the inner pinion bearing race. I've normally damaged these shims upon removal, to the point that I could not accurately measure there thickness. The backlash adjustment, if needed, requires removing the bearings from the carrier; again, I've not had good luck removing these bearings without damage to both the bearings and the shims, which are located under the bearings. Also, depending on what year of D30 you have, the outside pinion bearing preload (critical) may be determined using a "crush sleeve", as opposed to shims. These generally are not reusable, thus you'd need to buy another one.
I'd suggest you get a Dana manual for your diff and study the set-up procedure before you start this project.
If you just install the old pinion and carrier into the new housing, you'll probably end up with noisy gears. They may last a long time in a front application where you have a disconnect axle.
When I was in high school--read no money--I got away swapping out just the ring gear in the rear of my old Ford. It was a little noisy, but who cared? Any way, except under emergency conditions, a job worth doing, is a job worth doing right.

 

[tgoff]

I have the factory service manual so I have been looking at that but of course it has you replacing everything. I was wondering how much I could reuse. Also would NAPA carry pinion and differential shims for the D30. The Dana 30 I am going to be working with is 86 disconnect gears into a 92 non disconnect. Thanks.