Differential gear change question

the housing should be the same but your carrier is different!

So I can swap the whole differential (what you're calling the carrier) into the new housing? The bearing seats in the housing aren't different?

I would have went the other way... change the front to 3.76... better gearing and a limited slip in the rear!

Sorry, should have said "differential case", not just differential. The "differential case" is the item that holds the ring gear, pinion mate gears, and side gears. The "axle housing" is the pumpkin shell.

That's still an option, but would require buying another gear set (or even the whole case?) and install kit.

Oops, that should be, "3.73".

True, but changing the R&P in the rear will still require resetting the gears and maybe even the install kit. The front would require a new carrier and R&P. Is the front donor also available from the same source you got the rear?

It was when I bought the rear, but it stupidly didn't occur to me that I would need it to match the ratios, and now it was sold to someone else.

3.73 is one of the "good" ratios. Almost as good as 4.10, which is the "best" stock ratio you can get. My advice is to drive the vehicle some, to see how you like the new gear ratio.

As far as swapping the ring and pinion, it is doable, but setting the pinion depth, pinion bearing preload, ring gear backlash and carrier bearing preload are rightly considered "expert" tasks. If you don't do it right, noises and reduced part life. If you do decide to keep the 3.73, then you will need a 3.73 ring and pinion, a different carrier and probably an install kit. The "carrier" is the part with the spider gears inside.

Earle

The 3.73 is better than the 3.07 for offroading. Why not change the front to match the new rear?

And, you issue isn't the pumkins, it's the carriers. The pumpkin is the outside housing of the differential, the carrier is the part that holds the ring gear. You can swap the 3.07 carrier and ring gear into the pumpkin that now houses the 3.73 carrier and gear.

Yes, you can set the 3.07 carrier into the differential housing. The subordinate parts are the same, so some can be used again if they are in good condition, but some must be replaced.

Gear set and carrier.

I like this idea the best. Drive the 3.73s for a couple of weeks. If you like them, buy more 3.73s for the front.

Frankly, you're looking at the same amount of work to swap the rear gear set back to 3.07 as to swap the front set to 3.73. The 3.73 is a better ratio, and for my money is worth the cost. Since you are convinced you can do the work yourself, then you have no labor cost. But if you had same labor cost, it would be the same to swap the front set or swap the rear set, so labor is a moot point whether you do it or pay to have it done. Your only cost-up to swap the front is that you have to buy parts that you don't already own, but I think the investment is well worth the money.

That's what I'm trying to confirm.

I think the Chrysler manual calls it the "differential case", not the "carrier". The pumpkin they call the "axle housing".

I am inclined to agree with you, but then I hafta buy a bunch more parts.

I'm not convinced this guy understands what is involved in gear set-up (no insult intended Richard). One with that ability would not be asking some of these questions (difference between carriers, housings, and bearings).

You must have misunderstood my questions if you think they suggest a lack of ability.

Usenet is such a wonderful place to ask questions. Not only do you get technical advice, you also get the very core of your being picked apart and analyzed.

There are various cases for various ranges of gear ratios. I was simply asking if the bearing seats and other features in the axle housings are likewise varied and incompatible across gear ratios or ranges of gear ratios, since I have a swap in mind and don't want to tear into the differential to install a gear set that could turn out to be incompatible. This is just an arbitrary fact of the designs that can't be known except by revelation or a costly trial and error.

In short, "Does a case with a 3.07 ring gear directly drop into an axle housing presently holding a case with 3.73 ring gear". Because I am told that these two cases won't accept the other's ring gear.

One has to be wary about advice using various terms for parts, words that differ from the manufacturer's, which are themselves confusing. My questioning of non-standard terminology doesn't mean I don't understand what's going on or what's involved, it just means I want to make sure the advice is correct.

I understand your questions completely, and they have been answered here adequately.

Called carriers in every shop manual and parts house I have dealt with.

IMHO, a mechanic capable of gear setup would know that the bearing sets and housings are the same regardless of gear ratio.

Not rocket science.

Correct. The cutoff is between 3.31 and 3.54 for the DANA 35. The higher the numerical ratio the thicker the ring gear and therefore the mounting flange on the carrier varies to compensate.

Again, no insult intended. All that said, I have yet to attempt setting up my own gears, I have them done by professionals.

Richard,

All the information you need to set up a differential is in the factory service manual.

As an experienced Engineer you have the knowledge to complete the labor and list of specialty required tools is in the back of each manual section and drawing showing the tools in use..

Examples below:

Just get yourself a manual, order the parts, assemble the tools, and get to work...