Needed: Wide Trac Center Diff Housing

[cu4whln]

Uh Oh! Doing a LT swap with a 6L80 trans / Dana 300 . . .

Finding my offset Q-Trac rear axle is just not going to work well with my Dana 300 with a centered output. Really don't think I can make a propshaft that will work in 2 planes.. ( ie down AND sideways. )

Soo... anybody have a Dana 44 wide trac axle with a center diff they can part with? Are those common? What years? Will a J 10 axle work?

Want a Dana 44 so I can move the gears over from the original axle. AMC 20 would be a last resort.. unless it has a 3.54 ratio maybe?

The Issue: See the angles? Down, and sideways.

[IMG][/IMG]

[cu4whln]

Hmm.. maybe not. I don't think it will clear the metal coffin tank if located in the center. Dang it.

Driveshaft solution suggestions ??

[wiley-moeracing]

You can run the offset dif, ran one in my race jeep for many years with no issues.

[SnowShoe]

This subject always confuses me....I can't get beyond the thought that the purpose of u-joints is to allow for some misalignment.
What am I missing

[tgreese]

Offset in a single plane seems to work well, but when the offset is in two planes, that can be trouble... apparently.

Coming from the CJ world, that's a looong driveshaft. I would try some high-spec high-angle u-joints before I gave up on the current axle. My J10 could be delivered with either a centered or offset output, and the rear axle is the same. Only difference is it's longer. So some 2-plane action has to be acceptable.

I would call Tom Woods and ask before I gave up on the current axle. Having been around here for a while, I recall that some with the offset axle and centered output are happy, while others search up and down for a centered axle. A few hundred bucks for a high-spec shaft seems worthwhile here.

The J10 axle won't work. It's wider than the WT Cherokee axle (to provide over 4' between the bed wells). A direct centered replacement would be a WT Cherokee axle '74-79 from a Jeep with a manual transmission. An '80-up WT Corporate axle is centered and would also work, but you'd have to regear it. These axles are not like the problematic CJ axles, having 1-piece axles and stronger tubes. Regardless, the ratio also needs to match. Seems like the ratios get taller and taller as time goes by. I would expect 3.31s.

[cu4whln]

You can run the offset dif, ran one in my race jeep for many years with no issues.

Race Jeep:

You had a center output t-case with the offset axle. Any vibration on road at normal speed? And - With a "normal" driveshaft - [ ie 2 ujoints ].

[cu4whln]

Offset in a single plane seems to work well, but when the offset is in two planes, that can be trouble... apparently.

Coming from the CJ world, that's a looong driveshaft. I would try some high-spec high-angle u-joints before I gave up on the current axle. My J10 could be delivered with either a centered or offset output, and the rear axle is the same. Only difference is it's longer. So some 2-plane action has to be acceptable.

I would call Tom Woods and ask before I gave up on the current axle. Having been around here for a while, I recall that some with the offset axle and centered output are happy, while others search up and down for a centered axle. A few hundred bucks for a high-spec shaft seems worthwhile here.

The J10 axle won't work. It's wider than the WT Cherokee axle (to provide over 4' between the bed wells). A direct centered replacement would be a WT Cherokee axle '74-79 from a Jeep with a manual transmission.

I have a CJ as well.. and you're right, this driveshaft is LONG ! Brad measured his centered axle for me and it appears it wont work with my tank.

Calling the experts is a great suggestion... I would rather use my axle if possible.

The working angle is 4.5 degrees up/down. The top plan view angle is around 5 degrees.

I have thought about a driveshaft with a double Carden, or just lengthen the current driveshaft with new u-joints.

Please explain high angle u-joints ?

[cu4whln]

This subject always confuses me....I can't get beyond the thought that the purpose of u-joints is to allow for some misalignment.
What am I missing

I am distinctly confused !!

Just trying to put together a Jeep that wont have propshaft vibrations going down the road.

[wiley-moeracing]

I had a quadratrac transfer case with a centered dana 60 race diff, I ran a cv off the transfer case end, so 3 u joints in the driveline, no vibrations or issues with the u joints at speeds from 1 to 125mph

[cu4whln]

I had a quadratrac transfer case with a centered dana 60 race diff, I ran a cv off the transfer case end, so 3 u joints in the driveline, no vibrations or issues with the u joints at speeds from 1 to 125mph

That's good info! I guess I'll order up the driveshaft tomorrow.

[rang-a-stang]

I don't think there are many factory widetrack D44 centered rear diffs out there. Pretty much all the WT D44 rears I have seen are offset. When QT went away in 1980, Jeep went to centered rear AMC 20's so you could probably find that a little easier but the number of WTs built in 80 and later is nothing compared to the QT years.

I thought I also read the factory 4 speed WTs (center output) also had an offset rear diff during the QT years? No?

There are quite a few stories on this forum where folks ran offset rears and centered xfercase outputs without issue. I think you are good. In the grand scheme of things, it's not off in 2 planes; the angle your U-joint is compensating for just rotated clockwise a bit.

[cu4whln]

I don't think there are many factory widetrack D44 centered rear diffs out there. Pretty much all the WT D44 rears I have seen are offset. When QT went away in 1980, Jeep went to centered rear AMC 20's so you could probably find that a little easier but the number of WTs built in 80 and later is nothing compared to the QT years.

I thought I also read the factory 4 speed WTs (center output) also had an offset rear diff during the QT years? No?

There are quite a few stories on this forum where folks ran offset rears and centered xfercase outputs without issue. I think you are good. In the grand scheme of things, it's not off in 2 planes; the angle your U-joint is compensating for just rotated clockwise a bit.

Thanks Rang . . . That's encouraging.

I wonder is said successes used a "normal" driveshaft or a double Carden set up?

[SnowShoe]

I am distinctly confused !!

Just trying to put together a Jeep that wont have propshaft vibrations going down the road.

I'm not talking about throwing a jeep together ....the key word was SOME misalignment

[Crankyolman]

I've been thinking about this thread for a couple days now and thinking 2 things.


#1- If a centered drive shaft is a problem, is it possible to shift the engine over a little and make the alignment better?


#2- If a centered drive shaft isn't a problem there are plenty of D44s out there that aren't in Jeeps. Dodge used then, I think Ford used them, International too, even Studebaker used them. A tape measure in a junk yard will go a long way. There are also other makers of rear differentials if originality isn't a huge issue, most have data tags telling you the gearing. Back when I was young we did all kinds of swaps like that. Sometimes we had to go to a place called U-joint Specialists to get U-joints that were 2 different sizes but that wasn't a big deal.


#3- Personally I would start by using the offset axle and see if there were any vibration problems before I did anything drastic or expansive.

[bufurd]

The driveshaft does not know the rear is offset, an angle is an angle, it doesn't see it as two angles. If the driveshaft is phased correctly the U-joints can do their job, again it don't care as long as the angles are equal and opposite. The mistake people make is trying to point a tail at a yolk, when usually the opposite is what it wants. U-joints can tolerate a lot of angle (again all it sees is angle, don't care if it's up, down, left, right it just don't matter) as long as the angles are equal and opposite. One thing to remember is equal and opposite under load, the side angle is nothing (pinion points straight ahead, tail points straight back) the pinion will lift changing the angle so that is compensated for by having it angled down a degree or two depending on a few factors. kinda long winded, but wanted to try and make it clear......