Dana 44 with 5.89s

[imahnu]

Hello all!

Anyone run front and rear Dana 44s with 5.89 gears? RGA makes some 5.89s that work with non rubicon locker LP 44s.

Thought is to use the 5.89s with my 4.0L with 42RLE and 35s as many say 5.38s isn’t quite enough for the 35s.

Another concern I have is that the driveshaft speed might be too high with the 5.89s. Could cause some vibration issues or worse.

 

[PNW_LJ]

Hello all!

Anyone run front and rear Dana 44s with 5.89 gears? RGA makes some 5.89s that work with non rubicon locker LP 44s.

Thought is to use the 5.89s with my 4.0L with 42RLE and 35s as many say 5.38s isn’t quite enough for the 35s.

Another concern I have is that the driveshaft speed might be too high with the 5.89s. Could cause some vibration issues or worse.

I made a very similar post just recently and didn’t get any response from folks who have actually tried it.

I did message @mrblaine about it. He explained the strength of the 5.89s is not an issue. He knows the swap is possible but hasn’t tried it himself.

I’m tempted to try it, mainly because I have an LJ so the rear DS vibrations would not be a concern, and front DS vibrations could be solved with a hub kit.

 

[PNW_LJ]

With 5.89s and 35s, at 70mph, the RPMs would still be just below 3k, which is just about perfect IMO.

If 5.89s can work without issue, it may actually make the 42RLE a blessing in disguise - you’re able to gear super low for offroad while maintaining sane highway RPMs.

 

[imahnu]

I made a very similar post just recently and didn’t get any response from folks who have actually tried it.

I did message Blaine about it. He said the strength of the 5.89s is not an issue. He knows the swap is possible but hasn’t tried it himself.

I’m tempted to try it, mainly because I have an LJ so the rear DS vibrations would not be a concern, and front DS vibrations could be solved with a hub kit.

My main concern is the driveshaft speed in the rear at highway speeds. Could be too high.

5.89s actually have more ring and pinion teeth than both the 5.13 and 5.38s.

If you happen to try it out before I do you should definitely post it up to see how it goes. Seems like it’d be the best situation.

 

[PNW_LJ]

My main concern is the driveshaft speed in the rear at highway speeds. Could be too high.

Is a rear axle hub kit an option for you?

5.89s actually have more ring and pinion teeth than both the 5.13 and 5.38s.

If you happen to try it out before I do you should definitely post it up to see how it goes. Seems like it’d be the best situation.

How is that possible for 5.89s to have more tooth contact? Different tooth count?

I will keep you posted. I am still undecided on what axles to go with, but D44s w/ 5.89s aren’t off the table just yet.

 

[imahnu]

Is a rear axle hub kit an option for you?

Not sure what you mean by this? Do you mean front?

How is that possible for 5.89s to have more tooth contact? Different tooth count?

5.89s have 9-53 count both the 5.38 and 5.13 are 8-41/43 if I’m not mistaken. Might not make a huge difference but still interesting as 5.89s should be stronger.

 

[jjvw]

Not sure what you mean by this? Do you mean front?


5.89s have 9-53 count both the 5.38 and 5.13 are 8-41/43 if I’m not mistaken. Might not make a huge difference but still interesting as 5.89s should be stronger.

5.89 being stronger might not be the argument. It's that the lower gear ratio puts the mechanical advantage in favor of the gears and the drivetrain.

 

[imahnu]

5.89 being stronger might not be the argument. It's that the lower gear ratio puts the mechanical advantage in favor of the gears and the drivetrain.

That makes sense and the main reason I want to go to them. Should make it easier on everything especially coming from 4.88s.

@Shawn at Tom Wood's

Any idea if the driveshaft speeds will be too high with 5.89s going say 70-75mph?

 

[Brianj5600]

A canned tune from Flying Ryan would make you forget about 5.89s.

 

[imahnu]

A canned tune from Flying Ryan would make you forget about 5.89s.

Gonna be going through the trouble of regearing and throwing a locker in the front so I’ll have to regear the rear as well. If 5.89s are a better fit than 5.38s then why not go that route and get the tune?

 

[PNW_LJ]

A canned tune from Flying Ryan would make you forget about 5.89s.

I say, gear first, add power second.

 

[Brianj5600]

I thought it already 5.38s. The problem with the factory tune is that it kills power under load. Just changing the timing table makes a big difference. 5.38s and a tune will change your view of the 42rle.

 

[machoheadgames]

I do hope one of you proceeds with 5.89s. It would be great info to add to the forum.

The problem with 5.89s is that in the case of a TJ, it will only work on a set of Rubicon axles AND both factory lockers have to be gotten rid of. So it's a big buy-in cost to the owner. Of course, selling the Rubi lockers could certainly help with the cost of two new lockers.

All that said, the ratio would be just perfect for 35's with the 4-speed. If I stumbled into a 42RLE, that is the route I would go.

 

[PNW_LJ]

I do hope one of you proceeds with 5.89s. It would be great info to add to the forum.

The problem with 5.89s is that in the case of a TJ, it will only work on a set of Rubicon axles AND both factory lockers have to be gotten rid of. So it's a big buy-in cost to the owner. Of course, selling the Rubi lockers could certainly help with the cost of two new lockers.

All that said, the ratio would be just perfect for 35's with the 4-speed. If I stumbled into a 42RLE, that is the route I would go.

Agreed on all points.

I’m in a unique position as a 42RLE owner with TJ 44s axles without lockers, so I might as well try the 5.89s..

 

[imahnu]

The problem with 5.89s is that in the case of a TJ, it will only work on a set of Rubicon axles AND both factory lockers have to be gotten rid of. So it's a big buy-in cost to the owner. Of course, selling the Rubi lockers could certainly help with the cost of two new lockers.

Wanted to clarify but it should work on any LP Dana 44 just can’t have the tj factory rubicon lockers.

I do hope one of you proceeds with 5.89s. It would be great info to add to the forum.

I’ll eventually be getting there. But @PNW_LJ will likely beat me to it.

 

[imahnu]

I thought it already 5.38s. The problem with the factory tune is that it kills power under load. Just changing the timing table makes a big difference. 5.38s and a tune will change your view of the 42rle.

Oh no I’m on 4.88s currently.

 

[machoheadgames]

Wanted to clarify but it should work on any LP Dana 44 just can’t have the tj factory rubicon lockers.

I’ll eventually be getting there. But @PNW_LJ will likely beat me to it.

Correct, just the only really common front 44 LP axles are the ones from the Rubis, which will need the lockers removed. Which is why I'm sure that, at least to my knowledge, nobody has done this yet.

 

[imahnu]

Correct, just the only really common front 44 LP axles are the ones from the Rubis, which will need the lockers removed. Which is why I'm sure that, at least to my knowledge, nobody has done this yet.

Absolutely. Just wanted to make sure someone reading this didn’t think they had to have rubicon axles for it to work.

 

[Shawn at Tom Wood's]

That makes sense and the main reason I want to go to them. Should make it easier on everything especially coming from 4.88s.

@Shawn at Tom Wood's

Any idea if the driveshaft speeds will be too high with 5.89s going say 70-75mph?

From my perspective, yes the shaft will be spinning too fast. Over 4,000 drive shaft RPM, you can find a drive shaft RPM calculator at the bottom of this page. Here's where running low (numerically high) gears at modern highway speeds can become a problem.

1. The industry standard balancing machine only goes to 3,400 RPM. That means that anything above that can't be tested in most drive shaft shops. You enter into uncharted territory and there might be vibrations that show up at those speeds.
2. Centrifugal force of any minor imbalances increases more dramatically at higher RPMs. Every time the speed of the drive shaft doubles the force of an imbalance quadruples. Think exponential but not exactly. More on that here https://wranglertjforum.com/threads/what-gears-do-i-want.51422/post-1168187. Any minor imperfections in the shaft or in the yokes or bearings the shaft attaches to are much more likely to generate vibrations at those 3,500+ RPMs. It's not a guarantee but its much more likely to occur when people are running 5.XX gears.

 

[MikeE024]

A canned tune from Flying Ryan would make you forget about 5.89s.

I do not agree with this statement and I was happy with his stock tune.

The recently installed turbo removes any need for 5.89s, but that's a much bigger commitment.