Dynatrac PR60 vs PR80 - ground clearance discussion

highoctane

highoctane

Caught the Bug
I know I know, another PR60/80 thread. Lots on here. I've talked to Offroad Evolution and Dynatrac about the new PR XD60 rear and PR80 rear axles for my upcoming build. The cost difference between the two is less than $400 (as told by the Dynatrac sales rep), so cost is not an issue. Obviously the PR80 is significantly stronger than the PR60. I do not have plans for a Hemi/LS V-8 swap, and if I have engine problems down the road I'll likely just swap in a new/low mileage takeout 3.6. With that said, the XD60 is a high pinion, the PR80 a low pinion. There is a 1" difference in ground clearance between the two. The high pinion should give a better driveline angle and keep the driveshaft higher up out of harms way. The low pinion PR80 is nearly twice as strong. Both have their advantages over the other. Both are practically the same cost. We all know the specs on them.

Which would you go with when thinking about the ground clearance? 1" is the difference between 35" tires and 37" tires, which was a noticeable difference on my last JK. Dynatrac says that the smooth bottom on the PR80 makes it almost immune to snagging on rocks and will just slide right over just about any obstacle I'll encounter. instead of stopping me in my tracks. Has this been the real world experience with the PR80? IS the difference between the two enough to worry about slowing me down on the trail? I love the PR80, but if the extra clearance of the XD60 is a big enough benefit, I'll go that route. Thoughts/opinions? I will be running 40" Nitto Mud Grapplers.
 
Blazindevl

Blazindevl

LOSER
I'm new to this as well and am wondering what's the weight difference between the two? I know that Dynatrac touts weight savings with the xd. If it's substantial then I would think that and the clearance would make it an obvious choice.

I have no experience with this but have to believe at some point you start to hinder performance of the 3.6 by adding 40's and heavier axles and all the bs
 
highoctane

highoctane

Caught the Bug
Blazindevl said:
I'm new to this as well and am wondering what's the weight difference between the two? I know that Dynatrac touts weight savings with the xd. If it's substantial then I would think that and the clearance would make it an obvious choice.

I have no experience with this but have to believe at some point you start to hinder performance of the 3.6 by adding 40's and heavier axles and all the bs
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I'm not too worried about the weight difference since it really isn't a big difference between the two IIRC.
 
Blazindevl

Blazindevl

LOSER
Just did a quick search and it looks like the xd is gonna be a little over 100 lbs lighter. Combine that with the extra inch of clearance and the improvements they made to it in strength, if it were me I'd vote for the xd in your application. Seems to me the pr80 is the standard when upgrading motors and is overkill otherwise but I'm sure that others will chime in...
 
wayoflife

wayoflife

Administrator
Staff member
If you're only option were a ProRock 60 and an 80, I would say go 80 and not give it a second thought. Running a set of 40, I can almost guarantee you that you will break a ring gear sooner than later and that's based on years of experience and seeing it happen on multiple Jeeps. That being said, the new XD60 changes everything and if you're not going to be running a V8, I might seriously consider the XD60 and for the reasons you are already aware of.
 
highoctane

highoctane

Caught the Bug
wayoflife said:
If you're only option were a ProRock 60 and an 80, I would say go 80 and not give it a second thought. Running a set of 40, I can almost guarantee you that you will break a ring gear sooner than later and that's based on years of experience and seeing it happen on multiple Jeeps. That being said, the new XD60 changes everything and if you're not going to be running a V8, I might seriously consider the XD60 and for the reasons you are already aware of.
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Thanks for posting up your experience. I've heard of people breaking the high pinion PR60 gears, but haven't seen first hand. I've seen one, and it was in a 6.4 Hemi JK. On Moby, have you had any issues with the drive shaft being in a low pinion position when compared to the high pinion PR60 on Rubicat? Do you really notice the inch of reduced clearance under the diff on Moby when compared to Rubicat's 60?
 
highoctane

highoctane

Caught the Bug
jeeper52 said:
Did you sell your ud 60's?
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Not yet. I work with a guy that wants them when he returns to the U.S. I'm confident I can sell them for a price that makes me happy. I want to have the Dynatrac axles on order though before I sell my current axles.
 
highoctane

highoctane

Caught the Bug
jeeper52 said:
What are you asking for them? What made you decide to ditch them and go another route?
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My coworker will be paying just over $10k for the set. I don't have the utmost confidence in the 2 pinion version of the Eaton E-Locker, or the relatively thin axle C's. By thin I mean when compared to the Dynatrac axles. People may ask why the hell I bought them. I got a great deal on them, but I've regretted getting them the last few months. Here I am 3 months before I drop the JK off at Offroad Evolution and actually planning on going with the Dynatrac axles. I may only get the front done for now that way the front axle and steering is done, and do the rear this summer myself, but I will have front and rear axles by the time I'm home from work in Aug/Sept.
 
RDE2ROK

RDE2ROK

New member
I had just previously went with a PR D60/ D80 and also struggled with the high pinion 60 vrs the low pinion 80 and went with the 80. I have no regrets! That axle is tough! I drag it across the rocks with no worry. When I go with a Hemi in the future I will not have to worry about axle strength. Don't worry about the weight, the JK is already heavy. A 100 lbs isn't going to make that much difference compared to the strength your getting. Just my :twocents:
 
highoctane

highoctane

Caught the Bug
RDE2ROK said:
I had just previously went with a PR D60/ D80 and also struggled with the high pinion 60 vrs the low pinion 80 and went with the 80. I have no regrets! That axle is tough! I drag it across the rocks with no worry. When I go with a Hemi in the future I will not have to worry about axle strength. Don't worry about the weight, the JK is already heavy. A 100 lbs isn't going to make that much difference compared to the strength your getting. Just my :twocents:
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Did you go with the 1410 or 1480 yoke and rear driveshaft? Safe to say that the design of the PR80 works as advertised and it just slides over the rocks like a skid plate instead of snagging and hanging up on them?
 
jeeper52

jeeper52

LOSER
Yeah if you got the money i dont think you can beat the 60/80 combo. I also paid $10k for my ud 60's i just didn't have the extra money in the budget for the dynatracs. I think the UD 60s will be just fine for me but if i had it over to do again i would go a 14 bolt or sterling rear and a 05+ ford 60 and save a tone of money and have a pretty bullet proof setup. Thats just me though.
 
M

mastrcruse

New member
PR60/80 seems like the way setup for anything you throw at it. I don't think I'll be going with an engine swap so I think I'll stick with the PR60s as my axles goals. I almost was thinking about the XD60 but the response I received about information backing up the increased strength of the XD60 vs. the PR60 didn't seem to give me confidence in the value statement of "more strength". From what I'm reading the strength comes from the internals vs. the housing actually being stronger yet the video seems to detail how strong the new housing is.

My question was in regards to actual strength of the housing and tubing as we see tubing diameter get larger as wall thickness get thinner.

PR60: 3.125 X .5
UD60: 3.5 X .37
XD60: 3.74 X .25

The numbers given to me by Dynatrac was an estimated 12% stronger and 18% lighter from PR to XD
 
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RDE2ROK

RDE2ROK

New member
highoctane said:
Did you go with the 1410 or 1480 yoke and rear driveshaft? Safe to say that the design of the PR80 works as advertised and it just slides over the rocks like a skid plate instead of snagging and hanging up on them?
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I have the 1410, and YES the pumpkin is smooth on the bottom and does drag on the rocks, and I have got on the u-joint/drive shaft a little, but no issues yet. I think it just depends on the terrain your crawling.Just the "Pease of Mind" of 40 spline chromoly shafts, 4" tubes and that big ass R&P! You just don't worry about breaking anything with that powerfull 3.8 motor.:doh:
 
wayoflife

wayoflife

Administrator
Staff member
highoctane said:
Thanks for posting up your experience. I've heard of people breaking the high pinion PR60 gears, but haven't seen first hand. I've seen one, and it was in a 6.4 Hemi JK.
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It's not just on ProRocks but rather, ANY high pinion 60 rear axle. The problem is that in order to be a high pinion, you have to drive on the weak side of the ring gear and over time, it WILL fail if you're pushing 40's and playing hard with them. I have personally seen this happen on multiple high pinion 60s including mine and we were still running a 3.8L at the time. Among other things, the XD60 has a bigger and beefier ring and pinion and being that they are going to be sold for the same price as what the ProRock 60 was selling for (the ProRock 60 will be sold for less now), it's the only thing I would consider for running 40's outside of a ProRock 80.

On Moby, have you had any issues with the drive shaft being in a low pinion position when compared to the high pinion PR60 on Rubicat? Do you really notice the inch of reduced clearance under the diff on Moby when compared to Rubicat's 60?
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First off, you have to remember that it's just the pinion that significantly lower on a ProRock 80. The actual housing itself is just about a pencil thickness lower at the lowest point than an XD60. That being said, we have not experienced any issues in terms of getting hung up on the trail and while we have cleared the weights on the rear drive shaft near the yoke, I can't say for sure that we wouldn't have done the same with an XD60... but, probably not.

Based on my experience running 40's on a JK over the last 7 years, I would NOT run anything less than an XD60 even with a factory 3.6L or 3.8L motor. But hey, that's just me.
 
wayoflife

wayoflife

Administrator
Staff member
mastrcruse said:
From what I'm reading the strength comes from the internals vs. the housing actually being stronger yet the video seems to detail how strong the new housing is.
Click to expand...

For the most part, your understanding is correct and the strength of a 60 comes from the larger and stronger internal components. That being said, a high pinion rear 60 regardless of make WILL have the driving force on the "coast" or weak side of the ring gear. IF you actually play as hard and as often as you think you do, deflection in the housing will put stress on things like the ring gear and over time will cause it to fail. The XD60 is designed to mitigate the short comings of a high pinion 60 by using a BIGGER ring and pinion as well as even stronger internal components AND by having a housing that is more rigid to help prevent any deflection from occurring.
 
highoctane

highoctane

Caught the Bug
wayoflife said:
It's not just on ProRocks but rather, ANY high pinion 60 rear axle. The problem is that in order to be a high pinion, you have to drive on the weak side of the ring gear and over time, it WILL fail if you're pushing 40's and playing hard with them. I have personally seen this happen on multiple high pinion 60s including mine and we were still running a 3.8L at the time. Among other things, the XD60 has a bigger and beefier ring and pinion and being that they are going to be sold for the same price as what the ProRock 60 was selling for (the ProRock 60 will be sold for less now), it's the only thing I would consider for running 40's outside of a ProRock 80.
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Yeah I should've mentioned any high pinion rear axle. Def not a weakness isolated to Dynatrac axles.

wayoflife said:
First off, you have to remember that it's just the pinion that significantly lower on a ProRock 80. The actual housing itself is just about a pencil thickness lower at the lowest point than an XD60. That being said, we have not experienced any issues in terms of getting hung up on the trail and while we have cleared the weights on the rear drive shaft near the yoke, I can't say for sure that we wouldn't have done the same with an XD60... but, probably not.

Based on my experience running 40's on a JK over the last 7 years, I would NOT run anything less than an XD60 even with a factory 3.6L or 3.8L motor. But hey, that's just me.
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I didn't realize it was that small of a difference. I was told the 80 is 1" lower than the PR60, but I also did not take into account the larger ring gear of the XD60. If the difference in ground clearance between the two really is that small, then sounds like the 80 is the way to go if for no other reason than peace of mind. Thanks Eddie.
 
highoctane

highoctane

Caught the Bug
RDE2ROK said:
I have the 1410, and YES the pumpkin is smooth on the bottom and does drag on the rocks, and I have got on the u-joint/drive shaft a little, but no issues yet. I think it just depends on the terrain your crawling.Just the "Pease of Mind" of 40 spline chromoly shafts, 4" tubes and that big ass R&P! You just don't worry about breaking anything with that powerfull 3.8 motor.:doh:
Click to expand...

Ok thanks. I'll likely be doing a lot of the same terrain you wheel since we're only about 2 hrs apart. The rear XD60 does have the 40 spline axle shafts in it too, but obviously a much smaller ring and pinion.
 
wayoflife

wayoflife

Administrator
Staff member
highoctane said:
I didn't realize it was that small of a difference. I was told the 80 is 1" lower than the PR60, but I also did not take into account the larger ring gear of the XD60. If the difference in ground clearance between the two really is that small, then sounds like the 80 is the way to go if for no other reason than peace of mind. Thanks Eddie.
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Here's a video we made about the ProRock 80 back when it was introduced at SEMA a few years back. In it, you'll hear straight from Jim McGean, the owner of Dynatrac tell you how the clearance difference between a ProRock 60 and a ProRock 80 is only about a pencil thickness.


I think the 1" difference you're thinking of is at the yoke. And really, there are benefits to having a higher pinion including clearance and reduced driveline angle but for me, strength and the need for it takes priority. Again, the XD60 does utilize a bigger ring and pinion and that is a BIG improvement over ALL the other high pinion 60's out there.
 
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