Gear Ratio tag? D27/D44

[mhubacek]

I spent some time cleaning up my differentials to get some ID number's off of them. After I did some reading on them, I identified them as Dana 25/27 front, and Dana 44 rear. How can I tell between a Civilian dana 25 and a dana 27? On my rear Dana 44 the gear ratio tag states, 43/8. Anybody know what that means? Is there a formula I can use to find the gear ratio without pulling covers and counting teeth? The ID#'s I got are as follows:
Front, 17038 and rear, 18419. My front axle is a closed knuckle axle. What would you recommend as a direct swap with open knuckles? My turning radius right now is not very good, and when I put 33X12.50's on it It will be worse! I want to keep my rear Dana 44 for awhile, until it breaks or I come accross a really good deal. Too many other things to replace right now!

 

[mhubacek]

According to another site if in fact these are the original stock axles they should be Front: D27 (full-floating)from 66'-71' and rear: Dana 44 -2 (semi-floating) from 50'-70'. (for a 68' CJ) So, to paraphrase my thread I'm looking for a way to get open knuckle's up front while keeping my same stock rear axle, and decifering my gear ratio. A fraction (43/8) makes know sense to me.

 

[Old Dog]

the gear oil probally has not been changed in 41 years, so why not pull the cover and count teeth to be sure.

 

[mhubacek]

I hear you on that one, I'm sure it's been a long time. I did get I close look at the gear oil though, it's now all over my garage floor! From what I've been trying to gather old dog, if I use the tag I could divide 43 by 8? Making 5.37? I will definately count the teeth as well.
Thanks

 

[BajaEdition]

I would assume that you have a 4 banger cj. two reasons that is a 5.38 gear ratio. Killer. second is you did not say it was a v6.
ok so here goes, that is a d 27 front, a very nice axle if you want to keep it. The do not break unless abused and will not be bothered by 33 inch tires, I run on in my 70 CJ6 . now you will have to look at something, does the rear axle have dust caps in the center, If so it is a 2 piece rear axle, nothing wrong with that. If not it is a flanged axle, those are a lot better than the 2 piece however currently there is no one making replacement axles for it.
One thing you have to realize is that you have an offset rear pumpkin and will need to run that unless you change out your Transfer Case . However the d18 t case you have is a great case. you can use the pto port on it for either a pto or an oversdrive. Nice.
If it is a 2 piece, you can get a full floater kit for it with modern shafts from Herm the Overdrive guy in Washington, I think he is in the links here, A full floating rear axle and you will have quite the axle and also be the envy of a lot of guys. the front axle you can get upgraded shafts for fron Herm also.
If you want to swap out the front for a less maintenence one, open knuckles, you will be able to swap a 72 or later Dana 30 from a cj into it. I would check with my local jeep builder about gear availibility first.
Here is a warning about the early narrow d30s, they are not making stock shafts for them at the moment and only chrome moly ones are availible, 700 clams for just the inner shafts. I know I just built one for my 67 CJ5 .
Anyway unless you plan on rock crawling that driveline is not a bad one at all, If you do plan on hard wheeling I would be more worried about the rear axle before the front. One more point, you have 9 inch brakes on the d 27, you can get the 11 inch brakes from a later jeep and swap them out in a few hours and really improve your braking.

 

[crscrkcj]

Very good points in response. I also have a M27 and M44 setup in my 68 CJ5 . Both are in very good condition and I don't plan on replacing any time soon. My tags have both gear ratios and tooth count numbers such as 4.27 and 44-11. Guess they changed the way they numbered the tags fairly often.

 

[mhubacek]

Thanks baja edition and crscrkcj for your responses. I currently have a sbc conversion in the cj. It's a 305 v8, Spicer D18 Transfer Case , and T90C tranny. I've been warned that this combo will not hold up well on the trails for long, but it's what it came with, so I'll probably go with it until something breaks! I"m currently rebuilding a ramsey PTO winch, but I might try and trade it on craigslist for a Warn Overdrive . Thanks for the info on the axles. I did not notice any dust covers on the Dana 44 , but I'll take a closer look. I read that 11" brake swap on earlycj5.com, and I've put that on my long list of things to do!
One of the sites I got onto stated that my jeep came stock with Semi-floating Dana 44 ?