Dana 44 swap require a new driveshaft?

[dodgeboy]

I got a good deal on a used Dana 44 out of a TJ and I want to swap it into mine. I currently have the stock Dana 35, a 2.5" lift and about a 3/4" t-case drop installed. I know the pinion snout is about 1" longer on the Dana 44. Will I need a new driveshaft when I swap the axle? Or can I get by with the stock shaft?

My jeep had the t-case drop installed when I bought it. I assume it was to fix driveline vibration from the lift and not just preventative. I do not notice any driveline vibration with the current setup.

At some point I may do an SYE, remove the t-case drop and put adjustable control arms on the jeep, but I'd like to avoid spending the money on that right now.

 

[JMT]

You can measure.

It is possible it will work since when you lift it lengthens the distance between yokes, but your drop reduces some of that. Measure.

 

[freedom_in_4low]

You can measure.

It is possible it will work since when you lift it lengthens the distance between yokes, but your drop reduces some of that. Measure.

To add on to that, you need to measure while the axle is bolted into the control arms, but before you install the springs, with the yellow spongey jounce bumpers removed and the axle raised up so the bump stops are making metal to metal contact.

Also, be prepared for the possibility that since the longer snout slightly worsens your drive line angle, it may bring back the vibrations and require you to add some t-case drop.

As you might have guessed, Ive been to this rodeo...

 

[Jerry Bransford]

At the most you might need to have the rear driveshaft shortened very slightly by a driveshaft repair shop. And that does not mean a 4x4 shop or general mechanic who would just send it to a driveshaft repair shop and then mark up the cost.

 

[dodgeboy]

Following up on this... The driveshaft is about 1" too long to fit with the Dana 44. I'm looking at my options now.

 

[freedom_in_4low]

Following up on this... The driveshaft is about 1" too long to fit with the Dana 44. I'm looking at my options now.

As Jerry said, you should be able to have a local drive line shop shorten it pretty affordably. I had one lengthened by 10" and it cost me $90. You could also check the for sale section here and your website of choice to find one someone is selling. I was in the same boat at one point and got a shaft from another member here, who had gotten it from another, and then I sold my old one to somebody.

 

[dodgeboy]

I will probably have it shortened. When I pull the slip yoke out of the transfer case, will the rubber accordion style dust cover slip off of it? Or do I need to cut the clip and replace it?

 

[afitzray97]

Have you confirmed the 44 is the same gear ratio as your front axle? The TJ Sport Dana 44 and LJ 44 was usually a 3.73 ratio. The most common ratio on a Dana 35 was either 4.10 with a 4 cylinder engine or 3.07 with a 6 cylinder. I know there are 3.73 Dana 35's out there so there is a chance your front axle is a match for the swap, but I think it depended on the years and the engine/transmission/option upgrade combinations.

Or if it's a rubicon 44 then it's a 4.10 ratio.

Just wanted to bring this up to double check before you got too far along...

And for that accordion dust cover you can cut the original metal band holding it in place and just replace it with a plastic zip tie when you put it back on.

Just for added info- I did a 44 swap when I lifted mine. The length of the driveshaft was close enough that it would have been usable, but I didn't have a Tcase drop so the driveshaft angle was binding pretty badly.

 

[dodgeboy]

Have you confirmed the 44 is the same gear ratio as your front axle? The TJ Sport Dana 44 and LJ 44 was usually a 3.73 ratio. The most common ratio on a Dana 35 was either 4.10 with a 4 cylinder engine or 3.07 with a 6 cylinder. I know there are 3.73 Dana 35's out there so there is a chance your front axle is a match for the swap, but I think it depended on the years and the engine/transmission/option upgrade combinations.

Or if it's a rubicon 44 then it's a 4.10 ratio.

Just wanted to bring this up to double check before you got too far along...

And for that accordion dust cover you can cut the original metal band holding it in place and just replace it with a plastic zip tie when you put it back on.

Just for added info- I did a 44 swap when I lifted mine. The length of the driveshaft was close enough that it would have been usable, but I didn't have a Tcase drop so the driveshaft angle was binding pretty badly.

Thanks for the guidance and tips! I already knew this was a different ratio (3.73 vs the 3.07 I currently have). I'm planning on removing the front driveshaft to see if 3.73 is "good enough" and then re-gearing the front diff. If 3.73 isn't low enough, I'll re-gear both.

I have a feeling I'm going to get vibrations with the shortened driveshaft and wind up having to do a full SYE. That's something I've been looking at for a bit anyway, so it won't be the end of the world if I have to do it. It'll just mean I wasted the money on the driveshaft, but I'm hoping I can get by on the cheap for this one aspect of the project.

 

[afitzray97]

Yeah try it out for sure, you might get lucky. Would be a good idea to fully cycle the axle before you put the springs in so you can make sure you aren't going beyond the max/min of the slip shaft.

The regear and the SYE conversion were the parts of my project that I had a shop do. In my case I pulled the rear shaft and drove it to the shop in 4wd since the rear binding was too much but I didn't want to pay for a tow truck. My shop was willing to install parts I ordered ahead of time but keep in mind that a lot of shops only want to install things they're selling- mostly just to keep it straight forward for warranty issues. So if you have a shop do the SYE or gears, just be aware that you might want to buy those parts through them. If you're doing it yourself, more power to you, I just personally didn't trust myself to get it right on the first try.

And if the 3.73 works for you, then you could always keep an eye out for an LJ or random TJ to get a 3.73 front axle to swap to avoid dealing with a re-gear and that cost. The junkyards seem really expensive nowadays but facebook and craigslist axles can sometimes be found for decent prices. Also if you do a re-gear double check if 3.73 goes in the same carrier or if you need a new one.