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Strength of 5.13's in Rubi D44

5K views 88 replies 28 participants last post by  Jsawduste 
#1 ·
Has anybody had / or heard of any issues with running 5.13:1 gears in Rubicon D44 axles?

I am thinking about regearing to 5.13's, but I am concerned they may not be so strong due to the size of the gear and thus the smaller size of the teeth....and we all know it's all about the size of your toys :naughty:

Any comments / input would be appreciated.
 
#2 ·
I'm kind of curious as to what kind of wheeling you're doing with the tire size in your avatar that you need 5.13's in a rig that already has a 4:1 case?

Anyway, yes - the teeth are staring to get small at that point, but do you have the power to break them? I run 5.13's, but that's in a 60/70 combo. I think I might lean towards more power and less gear with smaller axles so something else breaks, like a lockout or a u-joint.
 
#3 ·
I'm currently running 35's but I have just picked up a set of 37's :rock:

I am still running the 4.10 gears and really find the rig bogs down on the freeway, thus it will be even worse with the 37's. Maybe 4.88's would be enough but the 5.13 will get me almost exactly back to the stock rpm's in 5th gear with the 37's.
 
#6 ·
Don't know if you need a gear that low or not but I run 5.13's in my front 44 (waggy) and I'm not worried about the ring and Pinion. I'm pretty sure I'll dump some u-joints or lockouts before the R&P goes. What I'm not sure in your case is how the Rubicon thick cut 5.13's compare to the standard cut 5.13's Running the numbers in a gear calc. says 4.88's would put you back to stock.
http://www.4lo.com/calc/geartire.htm
 
#7 ·
I would run the 5.13 with the 37s.

But I would definitely upgrade your axle shafts and get some beefy U-Joints too.

Try posting this over on rubiconownersforum too. ROF is another great offroad forum.
 
#13 ·
I'm running 4.56's in my D44s and I'm using 38" tires.

Still goes 70ish on the highway (and its an 85 CJ, yours probably would have more power). 4.88's would be the lowest I would go.
 
#15 · (Edited)
I would have gone lower, like to 5.89's if they were available for the ford 8.8. But then again, I don't have you 4:1 t-case....

I know these aren't 5.13's but just to give you an idea of the guys I wheel with are running

4:88's with 4cyl non rubi 38.5" TSL front BoggerRear Wheeled HARD all day Waggy 44s front and rear. - No breakage that day. Jonathan's not broken a R&P yet but has spit out losts of u-jounts



4.88's with 4.0L non Rubi, 38.5" TSL's Stak monster box. Wheeled hard all weekend - No Differential Breakage. Scott's has fragged one R&P set.

 
#20 ·
Running 5.13`s with a 4.8 stroker and NV4500/Atlas on 37`s.

Havent broken anything but am in process of upgrading to HP60`s F/R.

But having said that. I would have changed to 5.38`s in a heartbeat.

Vote is for 5.38`s IF you plan on running 37`s or bigger. 5.13`s for 35`s.

Get chromo shafts/inners and outers. Buy the best U joints you can afford.
 
#31 · (Edited)
Unless your running (or plan on running) 38+" tires... a 60 is a giant waste of weight.

In the midwest, with alloy wheels and lighter tires (Irok) you can even make a 44 survive on 39.5's with alloy shafts.

I dunno when this go 60 or go home mentality started in the Midwest... but it's seriously becoming a epidemic.

I saw a lot of D44's in our group at the Badlands surviving ledges and undercut rocks with no gear or shaft breakage.

I have personally done full throttle front wheel drive burnouts on pavement, with 36's, with no shaft issues. I did take out a hub while doing this once (draging a locked up rear), but drive flanges easily solve hub problems.
 
#32 · (Edited)
In the midwest, with alloy wheels and lighter tires (Irok) you can even make a 44 survive on 39.5's with alloy shafts.
Well said. :thumb:

IMHO ... if you still plan on driving back and forth to the trails, then I'd go with the 4.88's. If you decide that you're going to start trailering within the next year or so ... 5.13's.


edit: add chromo's in there somewhere...
 
#42 ·
blackjack and i are the minority. i spent all the money on a 44 and still broke it. 2 sets of chromo shafts 1 superjoint and 6 hubs,in 7 months. i will put my new 14 bolt and 60 to the test and feal good about the skinny peddle.like what was stated not everyone needs it, but there is a minority that needs the bigger stuff. i like to try everything and not give up until i make it.
 
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