Is there a guide for T-Case rebuilds?

[chance9888]

Hey all,

I'm rebuilding one of my transfer cases, and I'm going to swap it onto the truck. I recall there being a photo album online, or something that showed how to rebuild a[n NP 200] T-Case.

I can't seem to find it, but does anybody know of one?

[gmharris]

Try this one: http://blog.gieselman.com/post/NP200...e-Rebuild.aspx

[Charles Talbert]

Glad to help you Spencer, give me a call, we have 2 t/case builds going at the shop next week. I can answer any questions that you might have.

[JStinson]

Gear driven?

I'm looking at those pictures. Is the NP200 a gear driven unit like the NP205? I know the 203 is chain driven.

205s, I've heard are the ultimate bomb proof tcase. Largely because they're gear driven, making them tougher than the 203 and 208s. How tough is the 200 in our beloved older model powerwagons?

For that matter, how do the axles compare? Are they on par with D44s? D60s?

This is information I'd REALLY like to learn. Thoughts?

[Clint Dixon]

I'm looking at those pictures. Is the NP200 a gear driven unit like the NP205? I know the 203 is chain driven.

205s, I've heard are the ultimate bomb proof tcase. Largely because they're gear driven, making them tougher than the 203 and 208s. How tough is the 200 in our beloved older model powerwagons?

For that matter, how do the axles compare? Are they on par with D44s? D60s?

This is information I'd REALLY like to learn. Thoughts?

The answers to these questions are probably going to be different from each person and somewhat subjective based upon their own experience. Comparing the Chrysler Corporate axles to Dana/Spicer units is kind of like comparing apples to oranges. The following is just my 2 cents:

I feel that the Chrysler Corporate axle is an overall physically stronger assembly compared to the Dana 44 or 60. It is composed of formed and welded pieces creating natural gusseting, rather than a separate center section with separate tubes inserted and welded into it. As far as axle shaft diameter and spline count, you can probably find Dana 60 pieces that are stronger. The Chrysler 3rd member has four pinions, a backer block on the ring gear, and a very good bearing design on the pinion gear. The Chrysler also uses constant velocity universal joints. I would put the Chrysler a step above a Dana 60 and a couple steps below a Dana 70. The Chrysler is easier to work on and to correctly set up the gear tooth contact pattern.

As far as the transfer case, I would say the NP200 NP 201, and NP 205 are all equal as far as strength. All are gear driven. The NP200 is simpler in internal construction but operates hotter because of constantly moving parts even when in 2wd.

[JStinson]

The answers to these questions are probably going to be different from each person and somewhat subjective based upon their own experience. Comparing the Chrysler Corporate axles to Dana/Spicer units is kind of like comparing apples to oranges. The following is just my 2 cents:

I feel that the Chrysler Corporate axle is an overall physically stronger assembly compared to the Dana 44 or 60. It is composed of formed and welded pieces creating natural gusseting, rather than a separate center section with separate tubes inserted and welded into it. As far as axle shaft diameter and spline count, you can probably find Dana 60 pieces that are stronger. The Chrysler 3rd member has four pinions, a backer block on the ring gear, and a very good bearing design on the pinion gear. The Chrysler also uses constant velocity universal joints. I would put the Chrysler a step above a Dana 60 and a couple steps below a Dana 70. The Chrysler is easier to work on and to correctly set up the gear tooth contact pattern.

As far as the transfer case, I would say the NP200 NP 201, and NP 205 are all equal as far as strength. All are gear driven. The NP200 is simpler in internal construction but operates hotter because of constantly moving parts even when in 2wd.

I always assume that no news is good news. I never hear M37 owners complain about weak axles. It's not that I haven't read about breakage, but it's just not a topic that comes up frequently. I've hit some brutal stuff with mine, and have followed WA Watson's trail rides. By the way his machine is set up, I can't imagine the axles have an easy life.

The reason I'm interested in this comparison is because I have a friend that's into the chevy builds. In his world, D60s and Corporate 14 bolts are gods among men. I know WA was interested in a D60 swap, and my chevy buddy suggested I do the same. Since I have no interest in paying a jillion dollars to get a D60 shortened to fit under an M37, I've always wanted to know how the Chrysler units compare.

In terms of strength, how much could be gained by replacing a set of Chrysler M37 axles with a set of D60s or a 14 bolt rear and a D60 front?

Thanks for the feedback Clint. Anyone else?

[Charles Talbert]

We have built many Chrysler, Dana 60, and Dana 70 diffs. My pick is the Chrysler; as far as axle shaft breakage, we have found that where this issue has been the plague; most often a simple reason can be explained. I've found that axle breakage doesn't seem to be a big deal if all units within the system are well built and tight to spec. If you have a differential with worn spider gear thrust washers, side gear thrust washers, worn gear teeth, etc; all the loose motion within that is created by this is a major contributor to shaft snapping. If you can picture this; with all this loose motion in play, every time you let out on the clutch, all this looseness must reach its limits of movement before power is transfered to the wheels. Unless you are driving like you plan to run over an egg and not break it, this loose motion will create a sudden snap within the system; that sudden slap winds up getting transmitted right to the axle shafts, breaking same because of sudden slapping. I've seen foote shafts snap just as quickly as the originals when this issue is in play. The secret to success is of course don't be an abusive driver, and tight drive train components throughout. An abusive driver will tear up any drive train you put under him; the same as any well set up system will stand the pressure applied by a good driver.

Many persons who have experienced M37 axle shaft issues have blamed the shafts as being inferior; when most often a worn out drive train that needs to be rebuilt is the major cause of it all.

Loose motion in the transfer case and all the way through the entire system contributes to this issue. If you have KNOWN tight, (set up to spec) drive components in place, and a good driver at the controls; issues will be minimal; however if you don't the story can have a very different ending.

One other thing, all systems have limitations as to how much torque they can stand. Again a good driver can have a lot to do with how much a system will take even from a higher horsepower engine. Some seem to think that a vitually stock system should stand up to a big V8 in severe off road and rock crawling environments. This is not realistic and the common sense factor should kick in telling you that if your end use plans are this, forget stock and build a custom system capable of taking the treatment you plan to dish out.

[OLD DODGE]

In terms of strength, how much could be gained by replacing a set of Chrysler M37 axles with a set of D60s or a 14 bolt rear and a D60 front?

Here is a physical comparison of the axle shafts you would find in a Dana 60 equipped W200 vs the ones in the R-65M axle in the WM300.


............................W200.................. .................WM300
............................Dana 60................................R-65M
............................5500 lbs Capacity...................6500 lbs Capacity
---------------------------------------------------------------------
Material.................Med. Carbon Steel.................Chrome Alloy Steel
Dia. At Center........ 1.18 ................................... 1.25
Dia. Over Splines ....1.31 ................................... 1.37
No. of Splines ........ 16 ..................................... 16


The Chrysler axle housing gives an additional 1/4 inch ground clearance over the Dana 60.

[Gordon Maney]

Here is a physical comparison of the axle shafts you would find in a Dana 60 equipped W200 vs the ones in the R-65M axle in the WM300.


............................W200.................. .................WM300
............................Dana 60................................R-65M
............................5500 lbs Capacity...................6500 lbs Capacity
---------------------------------------------------------------------
Material.................Med. Carbon Steel.................Chrome Alloy Steel
Dia. At Center........ 1.18 ................................... 1.25
Dia. Over Splines ....1.31 ................................... 1.37
No. of Splines ........ 16 ..................................... 16


The Chrysler axle housing gives an additional 1/4 inch ground clearance over the Dana 60.

Very illuminating.