Dana 44 Rear Diff...

I am assuming that Dana made several different types of differentials over the years. I have either a locker or a limited slip type 44 on the rear of my jeep and a regular old run-of-the-mill Dana 25 on the front. Is there some way of telling what type of diff is in the rear short of pulling the cover? I found a metal tag on the diff, but I can't read it. Too old. There is a big ol' "44" stamped on the diff housing, however. Please advise... Thanks!!!

 

With the age of our JEEPs, there is no telling what is original and what has been changed over the years. Your signature shows you have a '62, but I don't know if 4:27 gears were standard until '63 or '64 when they went with the D27 front diff. I'm guessing things are not original under your JEEP. The easiest way to distinguish a D25 from a D27 is the presence of a vent on the front cover on the D25.
As far as the rear D44, they are all pretty much the same from the mid-'50s though around 1970 when they went to a 1-piece flanged axle. The early models had left and right hand threaded wheel studs, but I'm not sure when they standardized to all right hand threads-maybe around '63?
As far as I know, a Powr-Lok is the limited slip option from the factory, but there is no telling (until you open the rear cover) what might be lurking back there. Unfortunately, I have seen a couple Lincoln Lockers back there (crudely welded spider gears).
It might be a good idea to crack that rear cover to at least change the gear oil, and to find out your ratio, which will be stamped on your ring gear, and answer what type diff you actually have. There is no other sure way to determine this.
-Donny

 

If you pull the tag off and polish it up on the bench it may become legible.

 

Pull off the differential cover. Its easy, you get to change the gear oil, check condition of gears and see exactally whats in there. How do you know its not half full of water?

 

Yep, take a look. Buy a gasket and look inside.

The Dana 44 for your Jeep should have tapered axles with nuts on the end. The hub is separate from the axle shaft. Except for the '70-71 with flanged (1-piece) axles, all the ECJs have this axle.

But look inside... Jeep offered the open differential or Powerlock LSD, with a couple of ratios.

 

This... It's the only way you can be sure, and you need to see the internal condition anyway.

 

To all,

From the research I have done, the 4.27:1 gears were actually available in late '62. My jeep was manufactured in late November and definitely has 4:27 gears in it. Pulling the covers on both diff's sounds like a good idea anyway from the input you all have given me. I had just drained both the front and rear diff's and added new oil. That is why I am trying to avoid pulling the covers, but it appears that may be the best thing to do anyway. I will order the gaskets and do this. I know the front diff is just a standard D25, but it's the rear end that is a mystery at this point. Both diff's seem to be in good shape -- no noise, no binding, nothing out of the ordinary at all.

Tim, I don't know if have tapered axles with nuts. One thing I do have, though, is a couple of grease zerks located on the ends of the axle housing. facing rearward, right next to the backing plate for the brake shoes. I didn't know they were there until a couple of days ago. What is being lubricated by these? Anyone know?

As usual, thanks for the help...

 

I'll try, but it looks pretty well shot to me...

 

November of 1962 should be 5.38 or 4.27 ratio:
http://cj3b.info/Photos/Tech/ServiceBulletins/SB601AxleRatio.JPG

Grease them very sparingly as in one pump per wheel bearing.
Otherwise too much grease will risk blowing out the axle shaft seals.

 

There should be a cupped ring around the axle that can be seen with the rear brake drum off. Its held in place with the brake backing plate. That cupped ring helps to "catch" the overflow grease when the rear bearing is lubed too much through that zerk you found.
You do have a two-piece tapered axle in the rear. There is a large nut hiding under that small dustcap at the center of the hub.
-Donny

 

Thanks. Now, the obvious question, since I am not familiar with Jeep rear end anatomy, what choices were there for different rear ends and is this a good one to have? What is actually meant by a "two-piece tapered axle"? Thanks...

 

Before the jeep was moved off the jackstands, I pulled the plugs on the front and rear diff's and drained out whatever the PO had in there and put fresh lube in both, using the additive for limited slip in the rear diff. Didn't see anything weird in the lube that was drained -- no metal, no water, looked good.

 

Except Powr Lok there were no axle optrions prior to November 1962.
The Power Lok became a rear axle option in late 1956.
Front Powr Lok was not available as an option before the early 1960's.

After November of 1962 4.27 became the standard ratio and 5.38 remained as an option.
Those are the only two ratios that were ever used on 4 cylinder CJ's prior to 1972.
So its 5.38 ratio only from 1945 through 1962 on 4 cylinder CJ. No differential gearing options for CJ's.
Early in the 1963 model year (11/62) 4.27 differential ratio became the standard along with the T90 C transmission.

Tapered rear axle shaft implies that the outer end of axle shaft is tapered and keyed to accept the wheel hub.

 

The D44 in your Jeep should be fine to use, as long as it is in good condition. Your signature indicates you are still running an f134 engine, and have 31" tires. Generally, the 2-piece tapered axle is more than strong enough for the torque of the f134, and 31" tire should still be OK. I wouldn't recommend anything taller than 31"s though.
Many of our old Jeeps have the Dauntless V6, or even small block Chevy engines, and still have no issues with breaking the axles. I ran a V8 Buick for the better part of 20 years and never broke the same axle/ratio axle you have. As long as you don't really abuse things back there, you should have no problem breaking axles.
-Donny

 

You really need to remove the covers to properly drain the diffs. I also wipe the inside, bottom to remove any sediment. If you're up on jackstands you can slowly rotate a wheel to inspect the gear teeth for chips or any abnormality.

 

heck if your not wanting to drain the diff oil because you just put new fluid in there just get a really clean pan, clean the axle REALLY good and drain into the pan and reuse it. i've done it in a pinch (cuz i'm dutch). but i don't recommend it all the time. but to do it right just drain and fill then be done with it. this way you know for sure what is in there with both the oil and diff.

 

Could strain it through cheese-cloth or equivalent.