Will the 36's fit? Or is it pushing the limits?

[Achmed]

Yeah, I wheeled 37's on a 30 spline HP30 until this past weekend when I went down to 35's. You must be REALLY hard on the drivetrain if you are breaking that many axles. I have been wheeling on 35's and 37's for a while now and do not break shafts and I wheel moderately aggressive and mainly on rocks.

 

[cal]

I go out and wheel to have fun. As long as my jeep is capable of getting me home again, its all good. I do drive it home from every run though, save one where my alt failed halfway home.


I've seen guys who "wheel hard". I just don't fit in that class - but we may define hard differently, too.

 

[Mdub]

It doesnt change the point about a 27 spline 8.25, 4.10's and 36's.

Boooo ! !!!1

 

[Achmed]

I've seen guys who "wheel hard". I just don't fit in that class - but we may define hard differently, too.

I call this moderately aggressive and I dont break shafts. Yes, I bounce mildly, but know when to call it quits.

 

[cal]

I call this moderately aggressive and I dont break shafts. Yes, I bounce mildly, but know when to call it quits.

I may be a little more aggressive than that, but I try not to bounce too.

 

[Achmed]

What kind of traction aid(s) do you run?

 

[Supermanxj]

I

What rear bumper is that????
Josh

 

[Achmed]

C-Rok

 

[cal]

From beginning to end:

35/open 30/open 32's
8.25/no-slip 30/open 32's
8.25/no-slip 30/open 35's
44/detroit 30/open 35's
44/detroit 30/super30 inners and outers 35's
44/detroit 35 spline 30/super 30 inners and outers 35's

 

[wicked_xj]

3 hop stop

 

[Mudderoy]

The axle breaks at the splines, or you pull the shaft out for whatever reasons and the splines are twisted 20+ degrees.

The point was more, if 30 spline 4340 shafts go with 35's .. 27 spline 1541h (there are no chromoly 8.25 axles) shafts are not going to hold up to 36's very well, even with very very light use.

Well I was thinking it was the material that the axle was made of and not the spline count. I mean if it is twisting off seems like the splines are doing their job. I haven't had this happen to me "yet" so I was trying to learn something.

 

[89xj]

Dude, 4.10s with 36s is EXACTLY the same as 3.07s with 27s (stock config). And as far as rocks go, I've done plenty of 'em. I've never needed more gears. Sometimes I'd like to have more but not at the expense of a top speed on road of 50mph.

dude, what calculator are you using?

 

[igotanxj]

Not everybody continually bounces on the rocks until shafts break.

I don't think you guys understand how extreme the terrain can be in the tahoe/rubicon area. There are HUGE boulders everywhere and while we may think that 35s or 36s are big tires for XJ's theres guys up there with some serious rigs running around. I spent the first 20 years of my life in Sacramento and I remember that there are a lot of serious off-roaders in the area. So maybe cal is harder on his drivetrain than you guys, it doesnt mean he is abusive towards it.

 

[Achmed]

But he just said he doesnt bounce, which is "generally" what snaps shafts.

 

[cal]

Its been my experiance more break just from getting a little wheelspin and hooking up again than bouncing; maybe not in percentages but in volume.

Thats not keeping it to the floor until you go, just getting a little spin and grabbing.

*shrug*

 

[Achmed]

Well..............................atleast you are not a garage queen.

 

[cal]

haha. I should be, my jeep doesn't keep the rain out or the warm air in.

 

[Mdub]

dude, what calculator are you using?

It's pretty easy math. You take the ratio of your tires and compare that to the ratio of your gears. Like this:

Stock the rig came with 27" tires and 3.07 gears.

I have 36" tires and 4.10 gears.

36"/27" = 1.333

4.10/3.07 = 1.335

I am a rocket scientist, but this ain't rocket science. :lecture:


For more info on gearing and tire combos you can reference: http://www.grimmjeeper.com/gears.html

 

[MoparManiac]

I can see how the math would work but not everything is a simple 1 variable equation. Theres a lot of other factors...

Increased drag, rolling resistance, weight, blah blah.

Here's a question though, do you guys feel the $1500 for the Super 30 kit was worth it?

I plan to eventually hit 35s and want to plan long term, so I'm deciding if its worth it or not.

 

[vetteboy]

Its been my experiance more break just from getting a little wheelspin and hooking up again than bouncing; maybe not in percentages but in volume.

Thats not keeping it to the floor until you go, just getting a little spin and grabbing.

*shrug*

Seems like every time I break stuff, I'm not spinning the tires at all.

'Course, 185:1 low range will do that to ya. Gotta keep a good eye out for things that are bound up.

On 33's I broke Spicer 297's pretty often. Locked up front and usually trying to crawl up something with the wheels turned. I went through a bunch of u-joints and shafts with that setup.

Now on 39.5s I break bigger, more expensive things. Two 4340 35-spline stubs, stock 30-spline stub, 35-spline drive flange, 30-spline drive flange, 35-spline detroit side gear, Spicer Life Series 332x joint...fun stuff. A lot of this though is crawling over terrain that makes 39's look little.

BTW - the flaw in the 4.10 argument is that 3.07s sucked as a stock ratio too. That was a horrible decision by Jeep.