Super 35 with 27 spline - your opinion?

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eastbloc

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Greetings Jeepers!

I am finally ready for regear of my Dana 30 and Dana 35 combo to 4.56!
However, i ran into a dilemma, my initial idea for having a Detroit Truetrac in the rear went out the window when i discovered that they don't make truetracs for 30 spline super Dana 35 :(
So i though no biggie, why not use chromemoly (or what ever that space age material called) 27 spline? ...... Why not though? .... Why?

I am the kind of Jeeper that rides on 31.6" tires. Maybe in the future i may bump up to 33 inchers... maybe. And i say "maybe" only because i had two instances on a simple trail when i was spinning tires in the air while sitting on pumpkins. My play ground is all over the place, i typically pack a rucksack and drive off into adventure for few days. When i see something that catches my eye, i drive right into it.
I have been in the river and mud puddles chest deep. Plowing through closed roads by the snow blizzards while wearing tank top and flip flops. Colorado mountains. Sand dunes and "deserts" on the west coast. Stuck on top of the fallen tree while thinking why didn't i just drive around. Whats next?!

Based on my experience so far, i have decided that a truetrac in the rear and a selectable locker in the front will be the best option for me.
So far i have gotten through things on stock axles with 3.07 gears, painful but doable. So if i can do all that with a stock Dana 35, which should technically explode from me just touching it, how bad can a super Dana 35 with 27 spline shafts be?

What is everyone's opinion?

And if i do go this rout, who would you advise i go with? At first i was going to go with Revolution Gear, but now i don't know, i only see them making 27 splines for Dana 30.
 
eastbloc said:
Greetings Jeepers!

I am finally ready for regear of my Dana 30 and Dana 35 combo to 4.56!
However, i ran into a dilemma, my initial idea for having a Detroit Truetrac in the rear went out the window when i discovered that they don't make truetracs for 30 spline super Dana 35 :(
So i though no biggie, why not use chromemoly (or what ever that space age material called) 27 spline? ...... Why not though? .... Why?

I am the kind of Jeeper that rides on 31.6" tires. Maybe in the future i may bump up to 33 inchers... maybe. And i say "maybe" only because i had two instances on a simple trail when i was spinning tires in the air while sitting on pumpkins. My play ground is all over the place, i typically pack a rucksack and drive off into adventure for few days. When i see something that catches my eye, i drive right into it.
I have been in the river and mud puddles chest deep. Plowing through closed roads by the snow blizzards while wearing tank top and flip flops. Colorado mountains. Sand dunes and "deserts" on the west coast. Stuck on top of the fallen tree while thinking why didn't i just drive around. Whats next?!

Based on my experience so far, i have decided that a truetrac in the rear and a selectable locker in the front will be the best option for me.
So far i have gotten through things on stock axles with 3.07 gears, painful but doable. So if i can do all that with a stock Dana 35, which should technically explode from me just touching it, how bad can a super Dana 35 with 27 spline shafts be?

What is everyone's opinion?

And if i do go this rout, who would you advise i go with? At first i was going to go with Revolution Gear, but now i don't know, i only see them making 27 splines for Dana 30.
Click to expand...
I got 27 spline axles from Revolution for my Dana 35 about 8 months ago before I went to Moab.
 
If the times you’ve been stuck involve sitting on the differential, a limited slip might not help you there. If one wheel isn’t making any significant ground contact, a limited slip won’t be able to do enough to get you unstuck.

I’ve been in the same situation with another (2wd) vehicle that had a limited slip in the rear. It slid onto the edge of a gravel road, and most of the load was on one rear tire, one front tire, and the rear differential. The vehicle could actually be rocked diagonally because the two opposite tires were in the air with no significant ground contact. The one rear tire with significant ground contact never spun, even with the LS. I ended up having to pay a lot of money for an off-highway tow.

Had I had a selectable locker in that situation, even with the 2wd, I probably could have driven straight out.

That said, limited slips are great for a variety of less extreme conditions, especially snow and ice on road. They will greatly outperform an open differential on sand and mud, and help prevent wheelspin on loose surfaces. And compared to a selectable locker when locked, they operate much more smoothly through turns.
 
Steel City 06 said:
If the times you’ve been stuck involve sitting on the differential, a limited slip might not help you there. If one wheel isn’t making any significant ground contact, a limited slip won’t be able to do enough to get you unstuck.

I’ve been in the same situation with another (2wd) vehicle that had a limited slip in the rear. It slid onto the edge of a gravel road, and most of the load was on one rear tire, one front tire, and the rear differential. The vehicle could actually be rocked diagonally because the two opposite tires were in the air with no significant ground contact. The one rear tire with significant ground contact never spun, even with the LS. I ended up having to pay a lot of money for an off-highway tow.

Had I had a selectable locker in that situation, even with the 2wd, I probably could have driven straight out.

That said, limited slips are great for a variety of less extreme conditions, especially snow and ice on road. They will greatly outperform an open differential on sand and mud, and help prevent wheelspin on loose surfaces. And compared to a selectable locker when locked, they operate much more smoothly through turns.
Click to expand...


There is not a single build that is a perfect all around for everyone, in some situations some configurations will outshine the other. I have been to parts of Russia where no jeep will ever get through, regardless of the mods.
There will always be that "ohh crap" moment.
I am changing my Jeep to make my life easier (not easy), based on the type of the activities i do in it. I cant guess what will i get into next.

I understand limitations of the lsd.
ARB or OX locker will go on the front axle, rear will get lsd.

I think this set up will suit me best, im am also open to counter arguments.
I also ran into dilemma with truetracs not being compatible with 30 spline shafts, so i wanted to know others opinion/experience with 27 spline chromolies.
 
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lowranger said:
I got 27 spline axles from Revolution for my Dana 35 about 8 months ago before I went to Moab.
Click to expand...

Thank you, i looked again and saw them. They list them as 1541H Steel, any metallurgist can dumb it down for me?
I always thought that Chromoly is the kryptonite that turns 35 into super 35.

I see that East Coast Gear Supply is selling their 27 spline chromoly, anyone have experience with them?
 
eastbloc said:
Thank you, i looked again and saw them. They list them as 1541H Steel, any metallurgist can dumb it down for me?
I always thought that Chromoly is the kryptonite that turns 35 into super 35.

I see that East Coast Gear Supply is selling their 27 spline chromoly, anyone have experience with them?
Click to expand...
There are a few posts on this forum from @mrblaine that explain it better, but 1541H is the preferred metal for the Dana 35. The Dana 35, like the Dana 44, is a semi float axle. However, unlike the Dana 44, the roller bearings on the Dana 35 ride directly on the shaft surface as opposed to a separately pressed on inner race.

1541H axles are roughly 10% stronger than stock and are a case hardening alloy. 4140/4340 axles are through hardened, and typically have a softer surface metal than 1541H. They are generally advertised as being 50% or more stronger than stock. The issue is that most 4140/4340 heat treatments do not sufficiently harden the surface for roller bearings, and in some cases, the bearing begins to groove the shaft, resulting in extremely short bearing and shaft life.

Some manufacturers have been able to properly heat treat shafts for roller bearing contact, but from the posts on this forum it seems to be very hit and miss.

I’ll see if I can find a link to one of the posts that shows how an improperly hardened shaft reacts to a roller bearing.

Edit:
Better link:
https://wranglertjforum.com/threads...afts-and-why-4340-is-not-a-good-choice.21950/
Another thread:
https://wranglertjforum.com/threads/omg-another-super-35-question.16552/post-269700
 
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eastbloc said:
I understand limitations of the lsd.
ARB or OX locker will go on the front axle, rear will get lsd.

I think this set up will suit me best, im am also open to counter arguments.
Click to expand...
Ok, you’ve described past activities that run the complete gamut of conditions and suggest you’ll continue to do so & for at least the time being on 31 inch tires, it seems to me you need all the help you can possibly get and to do so there is no substitute for lockers front and rear; if you’re doing this work it doesn’t make sense to leave a big boost in performance on the table by putting an lsd in the rear.
 
Personally I’d stick with 27 spline shafts. If you snap an axle you have a spare instead of having to order another 30 spline axle(and figuring out how to get your Jeep back home)
 
ranger101 said:
Personally I’d stick with 27 spline shafts. If you snap an axle you have a spare instead of having to order another 30 spline axle(and figuring out how to get your Jeep back home)
Click to expand...
Stupid logic. Find out how many broken 30 spline shafts there are before you run with that silliness.
 
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You're running a TT, so 27 spline is your only option. 1541H is what you want, as explained above. If you have the coin and are in there already, there is no downside.
 
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Steel City 06 said:
There are a few posts on this forum from @mrblaine that explain it better, but 1541H is the preferred metal for the Dana 35. The Dana 35, like the Dana 44, is a semi float axle. However, unlike the Dana 44, the roller bearings on the Dana 35 ride directly on the shaft surface as opposed to a separately pressed on inner race.

1541H axles are roughly 10% stronger than stock and are a case hardening alloy. 4140/4340 axles are through hardened, and typically have a softer surface metal than 1541H. They are generally advertised as being 50% or more stronger than stock. The issue is that most 4140/4340 heat treatments do not sufficiently harden the surface for roller bearings, and in some cases, the bearing begins to groove the shaft, resulting in extremely short bearing and shaft life.

Some manufacturers have been able to properly heat treat shafts for roller bearing contact, but from the posts on this forum it seems to be very hit and miss.

I’ll see if I can find a link to one of the posts that shows how an improperly hardened shaft reacts to a roller bearing.

Edit:
Better link:
https://wranglertjforum.com/threads...afts-and-why-4340-is-not-a-good-choice.21950/
Another thread:
https://wranglertjforum.com/threads/omg-another-super-35-question.16552/post-269700
Click to expand...

Big thank you, i was not aware of this.
I think there goes an option for truetrac in the back. Being that 1541H is only 10% stronger (or just as strong as OEM according to some forum posts), that truetrac will probably destroy 27 spline in very short time.
30 spline super with a locker in the back more and more looks to be the only option with this Dana 35.

Once again, big thank you.
 
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eastbloc said:
Big thank you, i was not aware of this.
I think there goes an option for truetrac in the back. Being that 1541H is only 10% stronger (or just as strong as OEM according to some forum posts), that truetrac will probably destroy 27 spline in very short time.
30 spline super with a locker in the back more and more looks to be the only option with this Dana 35.

Once again, big thank you.
Click to expand...
Uh, no. The TT is a worm gear driven limited slip. It is no where near as aggressive and harsh as a locker. Nothing wrong with a locker. Just know that they also come with their own set of quirks.
 
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