40s and semi float 60
 

Who out there is running 40s on a semi float PR60 or similar on the rear of their JKU? If you are, have you bent any flanges/axle shafts or had problems with axle seals? Looking for answers from guys that wheel them fairly often. Trying to decide whether to buy a PR60 semi float or just stay with 37s. Can't justify spending 8-9K on an axle (for just the rear :crazyeyes: ). I don't wheel enough to spend that kind of money to go from my 37s to 40s. I wheel around 5-6 times a year and I am usually fairly easy on the skinny pedal (I will try steep hill climbs and large rocks/ruts/ledges etc, but no high speed and when the tires start spinning or hopping I know to let off). If I'm going to be changing shafts fairly often then I'll just stay with 37s and enjoy it. Any input appreciated. I know the front axle and driveshafts have to be addressed, this thread is just for the rear axle. Thanks.

...I know there is the option of the new Dana Spicer 60s also. Any input on them as well but I would like to stick with Dynatrac.

I'm also looking at the value of the new Mopar/spicer 60's. Full float rear for $4,000 or less seems like a bargain for the guys that don't wheel every weekend. Some places are offering discounts off retail too, so I'd look hard at the mopar 60 before a semi float dynatrac d60.

You'll bend flanges with 37's. For sure

Yeah it's a great value. I just wish they offered it in a 5.13 gear ratio.

Been wheeling on 32 spline chromoly shafts in my stock Dana44 housing on 37s for about a year and a half now with no issues. Not doubting you, I just need more info/proof to help me not make a bad decision LOL.

You really have to consider a lot here. I priced out everything to go to full float mopar 60's with new wheels and 40's. It came out to about 17k. Then subtracted the value of my current axles, wheels and tires and figure my out of pocket expense to be around 10k. With trail ready bead locks. Semi float you could retain your current wheels so you're just paying for the new axle. If you've been fine on a 44 for a year and a half you'll probably be fine on a semi float 60. If you don't wheel that much or that hard do you really need 40's?

Just to add one more thought to this, a 44 on 37's has 3/4" less ground clearance than a 60 on 40's. Is $10k worth that 3/4" clearance? Whenever I think about this I put my thumb and first finger 3/4" apart and then imagine the stack of $100's being a lot higher than that distance, lol

I know there are other considerations, but unless you are going to run 42" or 44" tires, semi float 60 kind of seems like a lateral move compared with the 44 on 37's.

You weight will be the main issue. For a two door you might get away with a semi float if you are light. No way would I run one on a JKU. I know a guy out here that had a semi float rock jock and broke the rear axle and lost it on the way home from wheeling one day. The whole wheel and end hub assembly came off the jeep. 40's on a daily driver really makes little sense as the added width makes it harder to part (watch for mirrors on small sport cars), your mpg drops, you don't have enough motor unless you are supercharged, and then there is the cost at $600 per tire. But it is your jeep and if you run 40's on a semi float don't be surprised if you do in fact bend flanges or break wheel studs.

Agreed here.... Go full float or forever hold your peace.

I have Currie Rockjock full float 35 spline and 40's. I wheel hard and often. Friends with Semi float break but my full floater never breaks or bends. It works excellent and the D60 has some different options for suspension that give it far more travel than the D44. I bent and broke front and rear D44, front tried sleeves, tried upgraded tubes all broke cracked with 37. With the full float Rockjock I am never in fear of breaking and can go out to trail knowing that I will be able to drive home.