I truely can't make up my mind: PR44 or PR60

OverlanderJK

OverlanderJK

Resident Smartass
3TV said:
PR44 vs PR60? I've done both.

Back in 2010 I installed a 2.5" Teraflex lift, 35s, and a PR44 w/ 5.38 gears in a two door JK. Unfortunately I had a pretty bad front driveline vibration, that after all was said and done, proved to be very difficult to cure. I adjusted the pinion angle more times than I could count, going all the way from obviously too high, to obviously too low, in 1/2 degree increments, with no success. I rebalanced the Tom Wood driveshaft, with no improvement. I had another driveshaft made, with no improvement. Then rebalanced the new driveshaft, with no improvement. I rotated the tires, balanced the tires (twice), and even bought a new set of tires, which didn't help. I changed front axle shafts, which didn't help either. I never did totally fix that driveline vibration, but if I removed the front driveshaft it was gone. About that time I said to myself "self, never again will I spend the money on a new axle, and buy an axle that doesn't have locking hubs".

Fast foward to 2014, and I'm building another two door JK. This time I used a 3" Teraflex lift, 37s, and PR60s with 4.56 gears, and front locking hubs. And this time the Jeep is as smooth as silk. Not only is it smooth, its the smoothest Jeep I've ever owned. There is less driveline vibration than is typically present in even an entirely stock JK. This JK drives wonderfully, and I'm so glad I went with the PR60 this time. I'm sure the 4.56 gears vs 5.38 gears is part of the smoothness, because driveshaft RPM is much less with the 4.56 gears, but being able to unlock the front end on the highway is a huge advantage.

Anyway, just my experiences. Good luck with whatever you choose.
Click to expand...

Your issue was probably had to do with the 5.38's. Why on earth would you do 4.56 with 37's and 60's?
 
dchew

dchew

Caught the Bug
OverlanderJK said:
Your issue was probably had to do with the 5.38's. Why on earth would you do 4.56 with 37's and 60's?
Click to expand...

And 5.38's with 35's? That motor had to be screaming at 40 mph. Maybe the post is backwards? 4.56 with 35's makes some sense but 5.38's with 37's is still high.
 
wayoflife

wayoflife

Administrator
Staff member
3TV said:
What you guys are not realizing is the vastly different overdrive gearing of the auto trans in the 3.8 powered 2010 JK, compared to the auto trans in the 3.6 powered 2014 JK. The auto trans in the 3.8 was so ridiculously over geared that it was impossible to gear it too low with the axles. Even 6:1 gearing wouldn't have been too low. The auto trans in the 3.6 is much more reasonable, and just doesn't need the low gearing that the 3.8 auto did. A lot of people are still trying to build 3.6 powered JKs like they did the 3.8, and are using lower gears than they need. Engine RPM with the 3.8 and 5.38s is about the same as with the 3.6 and 4.56s, if they both have the same size tires. So, yeah, the 37s on the 2014 make it a little taller geared than the 2010 Jeep, but not much.
Click to expand...

Eh, I'm kinda following what you're trying to say but, I've owned a 2007 JKUR, a 2007 JK Sahara a 2009 JKUX, a 2012 JKUR and still own it as well as the first 2007 JKUR. Over the last 8 years, I have run a myriad of gear ratios in all my JK's and at least from my experience, what you're saying is a bit of a stretch.
 
Y

YellowTJ04

New member
I'd use an ox locker instead of arb but I like the mechanical cable actuated no worry of air line issues or electrical issues
 
olram30

olram30

Not That Kind of Engineer
3TV said:
LOL, ok, maybe just a teeny bit of a stretch. I think I made my point, but maybe a little over done. This is JK # 7 for me, and I've run a lot of different set up's as well.
Click to expand...

You've had 7 jk's?
 
wayoflife

wayoflife

Administrator
Staff member
3TV said:
LOL, ok, maybe just a teeny bit of a stretch.
Click to expand...

There's no "teeny" about it. Running the exact same tire size, the engine RPM with the 3.8L and 5.38s is NOWHERE close to being the same as a 3.6L running 4.56.

I think I made my point, but maybe a little over done. This is JK # 7 for me, and I've run a lot of different set up's as well.
Click to expand...

Your 7th JK?? Really??

olram30 said:
You've had 7 jk's?
Click to expand...

Glad I'm not the only one who thinks this is crazy. At least this is a business for me. Can't imagine needing more than one if it weren't.
 
DWiggles

DWiggles

Caught the Bug
So if I cant decide between a PR44 or a PR60, your saying I should buy 12 JKs and run either 5.38 gears with 35s on the PR44? or 4.56 gears with 37s in a PR60?? :thinking: but what if I want to take the top off? I mean 12 tops make up a lot of zippers but I'm still confused... Not to mention the damn muffler bearing and blinker fluid maintenance on 12 different jeeps, hardly have any time left for wheeling... :icon_crazy: maybe I am a newb, but I clicked this thread with the full intention of learning something...
 
Last edited:
sassmouth

sassmouth

Member
DWiggles said:
So if I cant decide between a PR44 or a PR60, your saying I should buy 12 JKs and run either 5.38 gears with 35s on the PR44? or 4.56 gears with 37s in a PR60?? :thinking: but what if I want to take the top off? I mean 12 tops make up a lot of zippers but I'm still confused... Not to mention the damn muffler bearing and blinker fluid maintenance on 12 different jeeps, hardly have any time left for wheeling... :icon_crazy: maybe I am a newb, but I clicked this thread with the full intention of learning something...
Click to expand...

"12 JKs" Now that's funny! :clap2:
 
You must log in or register to reply here.
Top Bottom