So I go to pick up my jeep after having 5:13 gears put in and get on the highway to head back home and BAM!! Jeep was tacking 3000 rpm going 70 in 6th gear. Transfer case is cracked wide open down the canter. It sheared the rear pinion gear so my DS is dangling. Front DS is still intact. WTH happened here?! Some info: stock DS's and fixed CA's. Other info in my signature. I'm guessing the gearing was too much? Should have gone with 4:56 or 4:88 maybe? Jeep does and will be driven on highway. Any help is appreciated.

 

oh man, i'm sorry to hear about your break but glad to know you are okay. your gearing should have nothing to do with this break especially being that it occured in the rear. i see that you have a 2007 jk - more than likely, your drive shaft was on its way out and finally seized up.

 

Sorry to hear about that, I'm gonna subscribe to find out what happened.

Thanks WOL for jumping in so quickly with your post, when I first read about this, I began to worry (slightly) as my Jeep goes into ORE tomorrow for Gears (5.13), Gussets and Sleeves. Now you got me thinking about my DS

 

this would be the first non-rubicon t-case i have heard of breaking but not the first factory drive shaft causing it. in spite of what some would try to suggest, EVERY drive shaft has lots of moving parts that can seize up and fail and when it does, this is what happens.

 

Is there a lot of reports on the jks having t case failures?

 

From a former Cincinnatian to an current Cincinnatian that really sucks man. If I had a spare T-Case I'd send it your way. Was it the factory shaft that ate it and caused the blown case? Do you have a lift? Was the old shaft spitting grease then stoped when it ran out? How do the gears look when you pull the diff cover? Shot or salvageable. Sorry for the 100 questions, just trying to further understand the failure.

 

like anything with lots of moving parts, drive shafts and their joints need to be maintained on a regular basis. on an aftermarket shaft, this would mean greasing and or replacing u-joints which is for the most part, cheap and easy to do with parts that can be found at most any napa store. maintain your shaft and you will be fine. unfortunately, the factory shafts use an exotic rzeppa joint that is NOT serviceable and not replaceable.

 

on a forum like this where most everyone is modifying their jeeps, you will see what looks like a lot of failures but and most of which i feel are a result of install error and or lack of proper maintenance. but, in the bigger scheme of things, i think it would still be fair to say no, there are not a lot or reports of this happening.

in his original post, the OP points out that this is a stock rear drive shaft. he has an 3.5" aev lift and, although he said that it sheared the "pinion gear", i can only assume he meant to say "pinion flange".

 

That sucks! I think the consensus is that 4" of lift you are running would be borderline for the stock rear driveshaft of an unlimited (3.5" lift and .5" spacer). So as WOL said you would be looking at the driveshaft to see what has happened to it. Please report back once you have examined it because I would like to know what caused this.

I'm nervous running 3" of lift on stock shafts. I'll be watching them extra closely now though!

 

That sucks. Hopefully you get back on road soon at a decent price