I blew the rear diff coming home from Death Valley. It's in the hospital getting fixed as we speak. I know that if I blew it once, I’ll blow it again. So I’m looking at the possibility of going to Dana 60’s. With that decision I also need to decide if I’m going to leave the door open to 40’s. I’ve been doing the research and am finding out that a 2dr with 40’s is a very exclusive group. Planman is the only one that I’ve found that is even close to the build that I’m looking at.

To complicate matters I recently installed GenRight’s Aux fuel tank which limits the space for a Dana 60. I’ve taken measurements and Curries RockJock will not fit. The Currie representative said that RockJock’s measure 6-6.5” from the center of the tube to the back of the cover. Dynatrac says that they are 5” from center of tube to back of cover. The ProRock should fit, but it is tight. I’ll be going down to Off Road Evolution next week so that Mel and the guys can eye ball it and tell me if it fits. They’ve seen more Dana 60’s than anyone in the area.

This next step in my JK’s evolution is a pricey one. The direction that I think I want to go is either:
• Dynatrac ProRock 44 Front, Dynatrac Trail 60 series w/ProRock upgrade for the rear. Front 14” coilovers.
• Dynatrac Pro 60 w/ ProRock upgrade front, Trail 60 series w/ProRock upgrade for the rear. Front 14” coilovers.

The choices that I need to make are:
• 37’s, 38’s or 40’s- I really like the Toyo MT’s and would like to stay with them. The MT/R’s are also an option, but reviews say that they don’t seem to balance very well and are just OK in the snow/ice.
- 37’s – I like the 37’s, I’ve been able to take them everywhere that I’ve wanted to go, so far at least. They also look great on my current 17” spyderlocks.
- 38’s – Would require an 18 or 20” wheel. It would keep the look that I currently have and it would get me to a 15.5” wide tire that WayofLife says is most helpful to him for traction. At 106 lbs. their almost the same weight as 40’s.
- 40’s- Definitely bad-ass, but their huge. Is there really an advantage to these over a 37 or 38” tire with the short wheel base of a 2dr??

• Wheels – I really like the spyderlocks that I have now.
- Spyderlocks only come in 3.5” backspacing, great for the 65.5” axles, but a little too wide for the 68.5’s
- Walker-Evans, I can get them in 4 or 4.5” backspacing. It would make for a slightly narrower track with the 68.5” wide axle. Would the 1-2” make that big of a difference? The cost, Ouch!

• Gearing- 5.13 or 5.38
- Pretty much decided on 5.38’s. I really like my current 5.13’s for highway driving, but on the mountain roads I can feel the loss of power.

• Track width: I want to stay as narrow as possible without major rubbing issues and without limiting my turning radius.
- 65.5” (stock JK) – If I stay with 37’s I can stick with this width. It would require that I keep my Dana 44 front axle or upgrade to a Prorock 44. I would still run the risk of grenading my front axle and Diff. Trail Bud and others have already had this experience. This option saves me a ton of money as I'd keep my current wheels and tires.
- 68.5” – I would have to go to this width for the option of using wider tires. Ouch, this is wide. 2 door wheel base is 95.4”. That makes the jeep almost square. Probably provide better stability on off camber stuff though. This axle may be wide enough to run outboard coilovers that several companies are working on.

My biggest conflict when doing research on this decision is the difference between the 2 door and 4 door models.

I would really appreciate your opinions on this decision.

 

FYI a TeraFlex CRD60R measures 5" from center of axle tube to the face of a Tera diff cover.

 

Thanks TeraFlex, More options that's what I like. I'll look at the CRD60R as well.

 

No problem, also TeraFlex CRD60's are a dual bolt pattern (5 on 5" or 5 on 5.5").

 

I went to TOYO 40's on my 2-door a few weeks ago. I will use them for "special occasions" & run my 37's normally. My set up is 12" coilovers in front & evolever in rear. with SOLID d60's / 5.13 gears. I also added the Rubicrawler to help turn the 40's. I am higher with the 40's on but also a lot wider between added backspacing and the wider wheels I am now pushing 89" out to out, but no rubbing even at full stuff.

 

x2 what planman wrote. However, because my rig is dual purpose trail ride/daily driver, I spent a lot of money up front on what I felt were going to be the most reliable parts for the offroad environment, and would also work comfortably for daily street usage.
I did major upgrades on the axle components (many will say unnecessary) for the peace of mind I can have while wheeling in rocks with 40" tires. Fortunately many guys on the forum had done a lot of the homework already, which help with my decisions.
The JK on Dana 60's, 40" MTR's with coilovers EASILY goes places that my friends with 37"s and conventional coil on axle suspensions have difficulty finding lines through. It's almost unfair.
On the street, the JK handles like a badass lifted sports car, minus the power to weight issues, but suprisingly very streetable and with a compliant ride.

Build your rig right with smart, quality parts choices and the jeep can be capable in both environments. But again, as planman wrote, a used full tube chassis rock buggy is a great option for a lot less money and it is designed to take a serious amount of abuse with none of the worries about being your dedicated driver around town.

 

If you need help man talk to one of US guys on the Forum that run 40+ tires. If you PM me, I'll tell you everything you'll need or want to budget for... Been there done that.

 

Thank You for the offer of help. I understand the mods that get done to run 40's. Just trying to decide if it's worth it to go that big on a 2dr.

I ordered the D60's today. I went with the 68.5" width. I'll go with the TR beadlocks with 4.5BS to help stay a narrow as possible. I'll also probably go with the 38x13.5 tires over the 40x15.5's in order to stay a little narrower.

Axles are 4-6 weeks out, so as long as I can get the wheels and tires, I should be good to go for EJS.

 

What D60's did you get? And Im runnin 40x13.5 tires... a 2dr on 40's looks huge... Do it.

 

I went with the Dynatrac 60's due to the ability to option them out just the way I wanted them. Size wise they should work with my GenRight Aux fuel tank. May need some love to clearance on the tank though.

Here's the simplified build list.

EVO 12" double throwdown coilovers front, King shocks rear.
Dynatrac Trail 60 w/ PR rear - ARB, 5.38
Dynatrac ProRock 60 front w/ ARB, 5.38, 35 spline, CTM U-joints, stub hub, Dynoloc HD's, high steer.
EVO custom steering.
8" PSC ram w/ skid. - D60 use the bigger ram, so I have to change out mine.
TR beadlocks 5 on 5.5 4.5BS
ARB compressor
Modification to 1350 coast DS's
Tires will either be 38x13.5 or 40x15.5, I'm leaning to the 38's