Dana 20 Vs Dana 300

I believe 26" and 24 " axle shafts would be required to center the input yoke.
Then the engine could set right smack down on vehicle centerline.

 

I have 2 centered 44s from DJs, the one on the garage floor is heading down to Daryl someday. I missed the swap meet in March (got something from my 3 little germ generators)- but I'll get it down there to him at some point.

Anyhow, the DJ 44 is indeed centered. But even with a 2 wheel drive DJ, the original position for the engine is offset to the left a bit, maybe 1" or so off the centerline of the pinion yoke. I figure this is due to the transmission hump and indent on the firewall both being offset to the left to accommodate the driver drop front driveshaft on a 4x4. As near as I can tell, the DJ body is stamped the same as CJ bodies in these two areas. If the engine/transmission was not offset a bit, then they would not line up properly with the tranny hump and firewall indent.

Good thread as the DJ will get a front drive axle someday and I'll face this detail.

 

I ran into a guy says his DJ Dana 44 input yoke position is offset 1" to the right.
Just like the intermediate CJ's.

Not sure what year.... but he says it has Powr Lok and 3.07 gears
Have no DJ experience myself so I'm bewldered on this issue.

I have not been bewildered for a long time now and thought I would try it out once more.... HUH !

Anyway I think I'll shy away from using the Dana 20 transfer case unless I come across a D44 that's truely centered.
IMHO the CJ Dana 44 input is too far to the right for a flatty with its short 80" wheelbase.

 

I'm not so sure that the transfer case output and the axle pinion need to be the same offset (or exactly centered) .
My Jeep example is the Willys wagons/pickups that use the offset/offset dana 18, but have a centered, or nearly centered diff. Admittedly, they have a fairly long driveshaft, but the offset-to-centered driveline doesn't seem to cause any undue vibration problems.
Many years ago. in a wagon, I swapped out a D18 for a D20 from a Commando. I had no issues whatsever.
Am I missing something?
-Donny

 

The length of the driveshaft is why it works in a pickup.
It may be that someone has a swapped in CJ rear also and not know the difference. The giveaway is usually the spring perches that are obviously different between the CJ and DJ and you can usually find evidence of welding and or grinding if a swap has occurred.
Unless you look and pull a tape they can deceive the eye.
I have never found a power lock in a DJ rear axle. They usually have a Trac lok which is actually no different then an open case once it has a few hundred miles on them. At least that has been my experience on the dozen or so of them that I have run. Certainly not an extra or premium add to the price of an axle when looking.

 

Yeah, you're putting way too much thought into this. As long as the t-case is pointing down at the same degree as the pinion is pointing up, and the engine is parallel to the frame, the driveshaft and u-joints won't know the difference between up/down offset or side/side offset, as long it is kept within a few degrees. One inch in an 18" driveshaft won't harm anything.

A degree or two of misalignment is actually good for your ujoints, keeping the needles moving and lubricated.

 

No I don't expect drive line angles need to be perfect, but the closer to straight the better.
Like I say in a short wheelbase flatty the standard engine is 1-1/2" left of centerline and the intermediate CJ axle input is 1" right of centerline.
In my mind that's 2-1/2" of unnecessary offset .

The offset angle is basically amplified in a short wheelbase flatty.
The flatty did not come with a Dana 20 and installng one notable raises the rear propeller shaft at front.
Increasing the angle of the rear propeller shaft into the Dana 44 is both good and bad.
It gets the propeller up out of the kill zone which is good but dramatically increases the cardan cross angles.
IMHO That's where the needless increased propeller angle from being off center comes into play.

Yeah Daryl thats right Jeep quit using Powr Loks when they went to 30 splines.

 

That's another issue I might harp on.
If I'm not mistaken CJ's with factory Dauntless engines were not squared up.
Seems to me the Dauntless engines were offset 1" at engine mounts and transfer case input was offset 1-1/2" .
That's simply not square .

 

What I have read is exactly that.

 

So I went out and actually pulled a tape on both a CJ housing and a DJ housing. Oldtime you were right again. The DJ isn't quite centered either. It appears to be 1/2 of an inch offset to the driver's side. I just never bothered to put that much thought into it because they are what they are.

 

real world test show that I had my texas d300 in my 5 with a d44.....and now i cut it in half and made a cj6 out of it .. I drove that jeep thousands of miles at 60mph and have never felt something was really wrong ... I have never had any problems with joint failure

 

There are at least 3 different DJ Dana 44 rear axle assemblies, all with different axle shaft lengths. There may be more when different wheel bolt patterns are taken into consideration.

Regarding the Dana 300 input gear, there are two used in the Scout 2 "Texas pattern" 300. One is the 20whatever spline count used with automatics and the 6 spline unit used with manual transmissions. The 6 spline tends to be the most difficult to find. I'm working with a guy right now to see if the Scout 300 gears can be installed in a 20 case. He has a complete stock gear set and we're going to play a bit. Yes, the 300 Scout case is different than a 20 case.

 

+1 with a Dana 20 in a SOA 3b on 33s with a 17" driveshaft to a '73(?) center 44. I used to drive it routinely between PA and NH. I had one joint failure due to lube issues in a crappy, cheap joint (descending Mt. Washington auto road) in many many miles. One time I put the shaft back together out of phase, and boy did it let me know. But otherwise I've had no vibration issues or excessive wear on parts.

My current project is a 300 that is tucked up really high, going to a Toyota rear. This one might push the limits.

 

Yeah Nick,
That may be more than I ever wanna know concerning various DJ axles. Ha Ha Ha !
I guess I'm not up to snuff on the 1980 Scout D 300 parts either. Ha Ha on Me !
I'll likely forgo the rare Scout D-300 6 spline unit since the horzontal offset apparently offers no advantage over a D-20.
But yes otherwise the 2.62 could be a nice ratio.

Very Interesting .....let us know how it goes.

Very interesting. That's close to what I have in mind. But I definately will be staying spring under.

Currently I have an intermediate CJ Dana 44 bolted into my 3B frame for mock up.
I'm simply mocking up various drive train combinations at this time to see how they all compare.
Working with a Dauntless powered CJ-3A and trying out a tapered offset Dana 44 vs. flange offset Dana 44 vs. center flanged Dana 44 from an intermediate.
Front axles are Dana 25's vs. Dana 30's.
The various transmissions include T-15 from an intermediate CJ vs modified case Ford T18 vs. modified case Jeep T18.
A lot of it will be playing around with various engine offsets and transmission crossmember positions.

 

I can take pics of/measure my angles if you want. Lemme know.

 

ITLKSEZ, Curious at this point....
Is your D20 in the standard transfer case location or was your transmission crossmember somehow changed ?

 

I can take measurements and let you compare if you want. This is such a mishmash of parts and custom mounts, I don't know how it compares to stock. I made my own adapter to run a T18 behind an F-head, so it's probably going to be a bit longer than what you are running. Plus, I did it 20 years ago and remember nothing.

I'll head down with a tape measure in a bit and see if I can't itritate some yellow jackets. I'm curious too at this point.

 

Let me re-state that I was a stupid kid who knew very little when I threw this thing together, trying to make a deadline to enter a race.

My measurements are all over the place. It's a true testament to how wrong something can be and still work fine.

From inside the driver's side frame rail:
-Up front, to the center of the crank, ~12 1/2"
-To the center of the D20 rear output, ~11 3/4"
-To the center of the (73 or 74 CJ5) D44, ~14"

The center of my D20 output is ~2" up from the bottom of the flat of the frame.

The center of the D44 U joint is ~9" down from bottom of the factory arched crossmember above it.

I couldn't get any good angle readings with the tools I had at hand, but they weren't good.

 

That's all interesting and rather helpfull.
Yes the drive train alignment is kinda all over the place.
And from the looks of it the rollers must get a pretty good workout around the cardan cross journals.