35 Spline D44 Vs SF60?

Braxtonsag

Member
I’m trying to decide which route I want to go in the rear. My options right now are a SF prorock 60 or converting the rear over to a 35 spline carrier and shafts. I always see people saying that the sf60 isn’t worth the money and that’s why this is even a predicament. I am currently running 38s, my jeep is reletively lightweight, and I’m soft on the gas. The current setup I have had 0 issues with my oem dana 44, but I’d feel a lot better with some more beef in the back.

With all that being said, full floaters are pretty much out of the question. I don’t have the budget to replace front and rear both, plus buy new wheels and driveshafts. I just got a prorock 44 at the beginning of the year and want to build the rear to be just as good.
 

fiend

Caught the Bug
Not sure what more “beef in back” you’re looking for. Main reasons to go with a 60 would be to run 40s and 5.38s. Sounds like you’re not planning either of those. A reason to go with a FF60 is to eliminate bent flange risk. SF60 doesn’t do that. SF60 axle shafts will be thicker and stronger then 44 shafts, but I haven’t heard that shaft breakage is much of an issue with 44s. Unless you’re dropping in a V8, which I assume you’re not. Bottom line, I personally see little benefit to going SF60. I would save the money and put it toward chromoly axle shafts, as well as a big brake kit if you don’t already have that.


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Masjkf84

Caught the Bug
I have the sf60 rear and pr44 front as well with no complaints at all. Like you full float and all the other parts weren’t in the cards at the time.

Saying that... I went wheeling once 3-4 years ago to Moab and haven’t done a damn thing since so I’m not the best to tell you about strength. It gets me to work really damn well though and I fear no Midwest pothole.
 

wjtstudios

Hooked
I’ve run a Fusion 60 SF Rear for two years running 37s on them. Yes it is stronger, and yes you will still bend a flange every now and then if you play hard enough. You will loose a bit of clearance at the rear diff too. I can say that I have never bent a flange to a point where it “wagon wheels” or is not drivable. The Yukon shafts have held up very well and they are lifetime warranted against bent flanges. Is it worth it, I really don’t know but I had a lot more confidence getting after it on the rocks. Like you I wasn’t ready for full floats when I did it, but now I am in the next year or so. If I do decide to dive in, I’ll have a 60/44 hybrid front and 60SF rear up for sale sometime in the spring/summer, but I can’t make any promises yet.


2015 JKUR AEV JK350
1985 CJ8 Scrambler
 

Ddays

Hooked
IMHO absolutely DO NOT waste your money on a SF rear. In my case, I've bent 4 flanges on my PR60 FF that II bought 5 years ago because I wanted a bullet-proof rear end.
I've wagon-wheeled two of them and the other two just drove me goddam bonkers with the chirping. If you want to go to a 60 rear end, go all the way and do a FF.
 

cozdude

Guy with a Red 2-Door
Build the rear 44. That’s what I did and it hasn’t let me down. That being said I’m still running 30 spline rear cause then I can carry the stock rear shafts with me for if I bend one of my Revolution shaft flanges
 

Braxtonsag

Member
Not sure what more “beef in back” you’re looking for. Main reasons to go with a 60 would be to run 40s and 5.38s. Sounds like you’re not planning either of those. A reason to go with a FF60 is to eliminate bent flange risk. SF60 doesn’t do that. SF60 axle shafts will be thicker and stronger then 44 shafts, but I haven’t heard that shaft breakage is much of an issue with 44s. Unless you’re dropping in a V8, which I assume you’re not. Bottom line, I personally see little benefit to going SF60. I would save the money and put it toward chromoly axle shafts, as well as a big brake kit if you don’t already have that.


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I’ve played with the idea of running a 40. The 38s have done well and I haven’t had a single issue, but just thinking 40s would probably be too much for oem 30 spline. Before anyone asks why, my wife hates getting her ass beat offroad, so the easier the jeep can walk up and over things as small as a fist sized rock the better. I think with my habits of a soft foot and not forcing the jeep to do something it doesn’t want to do I could get away with the 44 R&P, but that’s another reason I asked about the sf60, in case I need to eliminate that from the equation.
 

jorgelrod

Hooked
I’ve played with the idea of running a 40. The 38s have done well and I haven’t had a single issue, but just thinking 40s would probably be too much for oem 30 spline. Before anyone asks why, my wife hates getting her ass beat offroad, so the easier the jeep can walk up and over things as small as a fist sized rock the better. I think with my habits of a soft foot and not forcing the jeep to do something it doesn’t want to do I could get away with the 44 R&P, but that’s another reason I asked about the sf60, in case I need to eliminate that from the equation.

If you see Eddies video of him running 40’s on a 35 spline 44, he grenaded his ring and pinion, not his shafts which is most likely what will happen even with a light foot under the right conditions...


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KevinG

Caught the Bug
I’ve played with the idea of running a 40. The 38s have done well and I haven’t had a single issue, but just thinking 40s would probably be too much for oem 30 spline. Before anyone asks why, my wife hates getting her ass beat offroad, so the easier the jeep can walk up and over things as small as a fist sized rock the better. I think with my habits of a soft foot and not forcing the jeep to do something it doesn’t want to do I could get away with the 44 R&P, but that’s another reason I asked about the sf60, in case I need to eliminate that from the equation.


I think the big thing with running a 40, even with a light foot, would be the size of the pinion and width of the axle. The video of moby on 40s at Dusy has been posted so many times that we have all seen it too much, but there's a pretty good lesson in there and mileage and trails are really well documented.
Just to give you another data point, I have a Sahara, so the 35 spline upgrade was easy when I regeared. For the last 10k miles I have been running 37 13.50 R17 Toyo MT's (10 ply) on Machetes. Not what I would call a light combo. The 40k miles before I was running 37 12.50 Toyo RTs. Trails aren't super hard up here, but there is a lot of slick mossy rock so "slip and grab" is kind of the terrain. Axle's held up really well. Hope this helps. :thumb:
 

KevinG

Caught the Bug
If you see Eddies video of him running 40’s on a 35 spline 44, he grenaded his ring and pinion, not his shafts which is most likely what will happen even with a light foot under the right conditions...


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Well played, sir. :beer: I need to type faster.....
 

Braxtonsag

Member
If you see Eddies video of him running 40’s on a 35 spline 44, he grenaded his ring and pinion, not his shafts which is most likely what will happen even with a light foot under the right conditions...


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Yeah Iv seen it and taken it into consideration for a really long time actually. The reality is I almost never get on trails that hard. I’m able to go play out west once a year. Another thing I’ve taken into consideration with that is that Eddie has stated moby weighs around 7000lbs. That’s a TON of weight for an axle to deal with. Now my jk isn’t anorexic but last I had it on the scale it weighed 4520 and that was with heavier wheels, tires, and bumper than it has now.

I’m not really saying that’s a huge difference, but it’s still 2500lbs less.

Another thing is he was running 5.38s if I remember right, I’m currently on 4.88s and would probably only jump up to 5.13 if I felt like it absolutely needed it. I hated my 4.88s on 37s. It felt way over geared and I was cruising above 3k on the highway. The 4.88s seem perfect with the 38s right now so I couldn’t imagine bumping above 5.13 for 40s.

If I do end up breaking a r&p, I have a brand new one on the shelf with master kit from when I bought the pro rock so itl be a lesson learned. The general consensus here is to stay away from the sf 60 though. Might just leave it alone until it gives me an issue and go from there.
 
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KevinG

Caught the Bug
I think (not 100% sure so take it for what it is), that you are thinking of what moby weighs now. I am totally going to guess out of my ass, but I think the V8 adds at least 300 to 400 lbs. I have no idea how much more a PR60 front and a PR80 weighs, but it's going to be a significant difference. I think the PR44 is more than 50lbs heavier than a stock 44, so I am guessing just the 60 is probably closer to 100 lbs. The 80 has to weigh quite a bit more than a rear 44. etc. etc. etc. All of that aside, the unsprung weight is compounded when moving and the footprint is way bigger. Plus, you need to get everything pushed way out further or else you aren't going to be able to turn it. Spacers on 40's?
If you're hell bent on running 40's, go for it! Like I said, I would love to do it, but watching the end of that video, it doesn't look like much fun to have to rip out my diff's intestines and crawl out of wherever in front wheel drive like a honda. I end up on the trail a lot by myself and chances are if I tried it I would be by myself.
You mentioned that part of the reason that you are thinking about them is for a nicer ride over fist sized boulders, right? What do you air down to?
 

desertrunner

Active Member
I'm in agreement with all the stuff posted above but I'll throw in my 2 cents. I went through the same thing when I upgraded my axles. I ultimately went with the trail leader package. Part of my decision was based on not planning on bigger than 37s for a while and going 4.88s due to R&P considerations. At the time it was also nice to keep the stock rear driveshaft (ended up buying a 1350 later anyways but it was money saving for initial purchase). As mentioned above the the only real benefit you get with the SF60 is the R&P size which is confidence when going with 5.13 or bigger. Still can bend flanges same as a 35 spline upgrade. 5.13s in my opinion is kinda the tipping point for a 44 you can definitely grenade a set of gears with that combo in a 44 depending on how you drive. So I wouldn't completely say a SF60 is a waste of money if you are looking for added confidence in your R&P, especially if your wanting to go 40s. Obviously the best option for full confidence in the rear is FF but based on what you have described I think you will be fine with a 35 spline upgrade on the 44.

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Ddays

Hooked
Something else to consider is to run the FF60 rear in a 5x5.5 wheel pattern and use adapters or do a Spyntec hub conversion up front. Teraflex also makes an 8x6.5 front hub conversion kit
 

jorgelrod

Hooked
Something else to consider is to run the FF60 rear in a 5x5.5 wheel pattern and use adapters or do a Spyntec hub conversion up front. Teraflex also makes an 8x6.5 front hub conversion kit

I won't lie, I've seriously considered these, mostly because I'm not sure how much I might get from trying to sell my PR44 to start over.


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Ddays

Hooked
I won't lie, I've seriously considered these, mostly because I'm not sure how much I might get from trying to sell my PR44 to start over.


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Couple members here have run the Spyntec hubs with good success and I really like the option of having lockout hubs. I'm going with the Teraflex 8x6.5 kit ( I know, I know :rolleyes2:) based on advice from Fusion and Bubba - both recommended the Teraflex kit over the Spyntec.
If my PR44 front shits the bed with this combo ( I think it will be just fine with 37's) I'll spring for the 60 front. But honestly, with the FF60 rear and the PR44 up front, I should be set.

Edit: Another consideration that sways me to the TF kit is if I would eventually go to a 60 front, I would already have the 8x6.5 wheels. To the best of my knowledge, I don't think anyone offers a front 60 with a 5x5.5 bolt pattern. I only want to buy one more set of wheels. My shed & garage are starting to look like a wheel & tire shop :crazyeyes:
 
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fiend

Caught the Bug
Couple members here have run the Spyntec hubs with good success and I really like the option of having lockout hubs. I'm going with the Teraflex 8x6.5 kit ( I know, I know :rolleyes2:) based on advice from Fusion and Bubba - both recommended the Teraflex kit over the Spyntec.
If my PR44 front shits the bed with this combo ( I think it will be just fine with 37's) I'll spring for the 60 front. But honestly, with the FF60 rear and the PR44 up front, I should be set.

Edit: Another consideration that sways me to the TF kit is if I would eventually go to a 60 front, I would already have the 8x6.5 wheels. To the best of my knowledge, I don't think anyone offers a front 60 with a 5x5.5 bolt pattern. I only want to buy one more set of wheels. My shed & garage are starting to look like a wheel & tire shop :crazyeyes:

You just have to come back and tell us how great everything Teraflex is.

What FF are you going with? CRD60? That’d match the front. [emoji6]


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