I would think on even a pro rock 44 you could run a lightweight 40... of course most of this boils down to what kind of driving you are doing and taking it easy on the throttle offroad. A 37 will be handled very easily from the 44 and especially the 60 in my humble opinion.

 

The semi float 60 will still be prone to rear flange bends just like the 44. With the front 44 you still have ball joints and unit bearings that are smaller than their 60 counterparts.

That said, a light 37 should be fine for most trails. But I would not bounce it hard or hit things too hard.

FWIW we have similar set up on our '18, Teraflex 60/44 combo with a 37" Cooper STT Pro and it's done fine with light to moderate wheeling for several years.

 

I'm running the Teraflex equivalent of that combo (TF44 and CRD60). Running 37's is a non issue IMHO. Running 40's won't break the axle housing(s) per say, but it would put quite a bit of stress on the shafts/gears, and that would be your weak point. Going Full float would be where you could hit 40's much safer if you wheel hard.

 

37's should be fine as long as you're not looking to get featured on madram11's youtube.

 

Overall 37s should be perfectly fine with just some expected accelerated wear of bearings and balljoints. I thought the 5x5 ProRock 60 came with some special rear flange/bearing arrangement that reduced the likelihood of bent flanges?

Too late now but you really missed the boat when you ordered those axles. When ordering those axles and considering 37s a wider width should have specified. By going to 68"-70" wide you could have got away 4.75" backspacing or even greater and reduced a lot of stress on the BJs, bearings, and flanges. To me, full-float 8x6.5 or 5x5.5 would also be the preferred spec even at the cost of new wheels. This makes it a lot easier to get off the trail if there is an axle failure. Some complain about the extra weight but it is all at the axle and helps stability and center of gravity. The extra unsprung weight might be a hinderance on high speed Baja stuff but most of us don't do that with our heavy Jeeps.

I'm converting my "polished turd" D44s to full float but I wish I had known better when I ordered my Tera44R over 4 years ago that wider would have been better; and now Teraflex offers 70" wide axles. Yes most people put 37s on stock width axles but wider is better when starting with new axles. I need 2.75" backspacing to maximize the articulation of my 37s on stock width axles.

 

OP: yes you can run 37s with that set up without any issues. Just don’t jump the Jeep or bomb it though whoops at high speed.

 

Perfect I am not planning any 40s and will run the lightweight 37's, yes full floats would be great but I also didn't want a 60 hanging down upfront without 40s and that wasn't in the cards right now.

 

Update - 1 year later, and I haven't had any problems. I wheeled some pretty difficult trails too. I am very cautious and crawl for the most part. No bouncing.

 

Crap. I wish someone told me long ago that I will bend flanges or otherwise destroy a 44 on 37's, especially the way I wheel. I'm not easy on mine. I don't beat it with the skinny pedal but bouncing off the frame, rails, undercarriage is the norm.
Stock Sport D44 rear with US made Revolution gear chromolly axle shafts, Core 44 front with RCV axles. 37" BFG KM3's. It's been in this configuration for close to 4 years now and I'm always in rock.

 

Crap. I wish someone told me long ago that I will bend flanges or otherwise destroy a 44 on 37's, especially the way I wheel. I'm not easy on mine. I don't beat it with the skinny pedal but bouncing off the frame, rails, undercarriage is the norm.
Stock Sport D44 rear with US made Revolution gear chromolly axle shafts, Core 44 front with RCV axles. 37" BFG KM3's. It's been in this configuration for close to 4 years now and I'm always in rock.

I bent the stock Rubicon rear driver's side axle flange on 35s during a mild day wheeling. I have now had G2 shafts for many years and 37s doing a lot harder wheeling with no bent flanges. It is always luck of the draw but it becomes easier to bend axle flanges the heavier the vehicle and bigger the tires get. At least most times a bent flange is still drivable but annoying. Some people can break an anvil and some people have a lot better luck on drivetrain parts.

 

@Rob50lx are your g2s 35 spline or 32?

 

Mine are the 32 spline G2s.

 

@Rob50lx do you have a 4 door?

 

2-door that weighs as much 5400lbs when loaded up.