What is the biggest tire you would run on a dana 27?

I have 427 gears with a possible swap to 538. I will also be running a lock right locker.

 

I've been running 33's on my 1960 Dana 25 w/ Powrlock all over, including trails like the Rubicon. No probs, except when one time it tried backing up a steep hill to turn around with the wheels turned sharply (broke axle). So don't do that and you'll be fine.

 

More then height, width of the tire can put a lot of stress on the axle parts. Replacing the spindle bolts with studs can go a long way toward giving some extra strength.

 

I actually read about this in a book last night and it said a 31, but I have ran 33's for 7 or 8 years with no problems.

 

jeep performance 4x4 hand book vol 2, was skimming threw it while waiting on the wife in the book store. So guess it could be someones opinion.

 

Dana 25 and 33X12.5’s here and I’ve busted parts left and right. About the only thing I haven’t broken at one time or another is an axle shaft.
The list includes:
1 ring and pinion set
2 sets of spider / side gears
1 drive shaft when the spider gears scattered the first time
1 knuckle when the spindle separated from it
a couple of manual lock out hubs
Uh, that’s about all I can think of at the moment.

Some advice, if you care to learn from my mistakes:
1. The knuckle stud conversion is a must particularly since you plan to run bigger tires.
2. Replacing the stock spider / side gears is a good idea but in my opinion a Power Lok is a better plan since it replaces the stock case and single spider gear shaft with four spider gears and a cross shaft. It still provides a traction improvement over an open differential but does allow one side to slip a little of the other side is in a bind.
3. The 4.27:1 gears will be stronger than the 5.38:1’s. That is because the pinion gear has to be so much smaller to get that gear ratio that it makes the 5.38’s a weaker set.
4. Learn to back out of the throttle at the slightest hint of front end wheel hop. Every set of spider gears I’ve gone through was because I hopped the front end on the throttle, trying to get with horsepower what I couldn’t get with traction.
5. One more thing that will help, remove the lock out “pill” between the shifters on your transfer case. This will allow you to use Lo range independent of 4WD. I actually do most of my wheeling now in 2Lo and only engage the front end when necessary. I feel this helps take stress out of the front when it isn’t needed.
6. Keep in mind I’m running a heavy, high strung V-8 over an axle that was designed for a four cylinder. Your mileage may vary.

So there you go, hopefully this helps you and your early Dana front axle live a long happy life together.

 

33" max and you'll still brake axles if you wheel it.

 

7.00 x 16

 

Mine either.
I ran 33's for years with a warmed up 231 and heavy right foot and the 25 survived quite well. When it eventually did start having issues due to MY aggessive driving only then did I upgrade to a 44 front. Only issues I had were breaking spider gears and that was only once, other than bending a housing when racing, but that doesn't count as trail driving.

 

Agreed... Been running 33's with 4.88's since 1991. Fire roads, desert, rocks, beach and some mud... It's all good!

 

Exactly. Dana 60’s can be broken with a thrasher for a driver.
Every part I’ve broken has been directly relatable to inadequate throttle to brain ratio and I’ll readily admit that.

 

Thanks guys, I ran 33s on this jeep for years. Never was a issue. I would love to put some 35s on it but I figured I would be inviting trouble.

 

When I had my flatty with the 231 on 33's I'd snap at least one front a year. Those ten spline axles just won't hold up to the Rubicon and Fordyce and I was being careful because I knew how fragile they were. A buddy ran 35's with a 10 spline 27 and 19 spline 44 and broke 3 axles within and hour going into Barrett hour and he was taking it pretty easy. needless to say we turned around and I drug him back out from the rock garden

 

Ran 31's for years on a 27 and the only problem I had, similar to one of the above posts, was blowing the spider gears backing up to turn around.

 

I run 35"s but im pretty easy on it. The only thing iv broken is driveshafts