Transfer case not engaging rear drive shaft

[Aj637]

I recently broke my rear differential on the way to work. Luckily, I made it there without losing my tire in 4H with power to the front wheels only. I'm thinking my transfer case is shot as the rear drive shaft doesn't spin at all regardless of what I'm in (2H, 4H, 4L). The rear drive shaft spins freely by hand, even when I have the shifter in gear, ie 1st gear, 2nd gear etc)...any ideas?

 

[LJBean]

Looks like the loose spider gears may have seized the pinion gear causing your t- case main shaft to fail? It's amazing you still have drive to the front axle. If you have a slip yolk, maybe it sheared the splines? I've never heard of it happening, but may be a best case scenario.

 

[Aj637]

Yeah, you're absolutely right about the pinion being seized. Everything was stock and I didn't have a SYE. It that's the case of the t-case main shaft, is that something worth just rebuilding/replacing? I'd probably have to remove and open up the t-case anyways to find out huh...thanks for your input.

 

[hear]

if the rear driveshaft isn’t spinning you’re staring headlong into opening the t-case either way. It’s really not a bad job. Do the SYE while you’re at it.

 

[Aj637]

if the rear driveshaft isn’t spinning you’re staring headlong into opening the t-case either way. It’s really not a bad job. Do the SYE while you’re at it.

Sounds good. I'll pull off the t-case and go from there. Maybe Super 35?

 

[Aj637]

I pulled the speed sensor...

 

[Aj637]

I pulled the speed sensor...
View attachment 513499

I ordered the SYE kit...is that the shaft that the kit replaces?

 

[OldBuzzard]

Yes, that SYE shaft replaces the one that's broken.

But you may have other problems in there. You have to take most of the TC apart to install the SYE, so you'll be able to check everything out.

 

[Aj637]

Yes, that SYE shaft replaces the one that's broken.

But you may have other problems in there. You have to take most of the TC apart to install the SYE, so you'll be able to check everything out.

I'm in the process of removing the TC. I have four skid plate bolts that are just spinning so I'll have to cut them off.

 

[hear]

Please post pics of the inside of the t-case, I want to see that output shaft. Or what's left of it, anyway.

 

[LJBean]

As long as the case is intact, you will likely be able to get it refreshed. As @OldBuzzard noted, you may have other issues due to shrapnel from the grenaded shaft. Plan on getting a rebuild kit and refresh the bearings and seals while you're at it., and take a close look at the planetary to make sure any metal chunks and shavings are cleaned out.

 

[Aj637]

Ok, will do. May take a couple days or so.

 

[Aj637]

Just the shaft was broken in the TC...I replaced it with the SYE Kit. Replaced the rear differential and the TJ is back in business! Thanks for all the help.

 

[Gilaguy23]

Foot slipped off the clutch eh

 

[Aj637]

Foot slipped off the clutch eh

The spider gear retaining pin broke on the highway going on a slight hill, then got lodged between pinion and gear...seized the read drive shaft.

 

[Rubiconned]

Look at the bright side. At least it was inspiration for you to join the forum and to create an avatar

 

[Gilaguy23]

A mess for sure. Ive never seen a cross pin break. It could have always been worst, you and the TJ are in one piece still.

 

[freedom_in_4low]

 

[macleanflood]

Junkyard Digs (YouTube channel) had a cross pin sticking out of a rear diff cover.

-Mac

 

[OldBuzzard]

I've seen two cross pin shafts fail, one sticking out of the diff cover like Mac's photo above.

One was on my friend's '67 Camaro, and the other was on my '68 Camaro a year later, on the same street within 50 yards of the same spot (irrelevant, but slightly interesting).

I recently found this on a Yukon blog:

Q: My cross-pin shaft is scored and the spider gears wore into it. What happened?

A: When a differential is traveling in a straight line, the spider gears remain motionless in the carrier. It is not until one tire turns faster or slower than the other that the spider gears rotate on the cross pin shaft. This most commonly happens when turning a corner. However, other situations cause the spider gears to spin much more rapidly, such as getting stuck in the mud or snow. When this happens, the spider gears can rotate on the cross pin shaft so quickly that it slings all the differential oil away from it, giving way to metal-on-metal wear. This causes the cross pin shaft and the gear to get so hot that they melt each other, sometimes to the point where they weld themselves together. Damage such as this can not only destroy the spider gear set, but compromise the carrier and ring and pinion set.

Hah! 48 years later, I finally discovered why our cross pin shafts failed. Open diffs and lots of extended power-wheel burnouts.