View Full Version : Plagued with Drive Shaft Issues

February 16th, 2020, 10:46 PM
Not really carnage per se, rather some interesting front drive shaft issues I've been plagued with the last couple weeks. Such is life on a straight axle swap :wrench:

From no front drive shaft and 2 wheeling it during summer months the past couple summers, I was more than ready to dive head first back in the 4x4 game when I had Bill's Englewood Driveshaft make me a custom two-piece shaft and slip yoke. My first run with it was Feb. 8 up Switzerland with no issues. Ran over to Ironclads/Bunce and my issues began just after the first rock pile going up Ironclads. The shaft didn't have enough travel and separated a few times during suspension cycles when bouncing around.


Dropped it off with Bill after work that Monday and he had it back to me by Friday


Just in time to go run Sevenmile the following day. Not having to worry about the two piece shaft separating again I was ready for more fun! :tisktisk:


Credit to Jim for this awesome picture!

The fun unfortunately ended here.. My hypothesis is that the deep water crossing caused water to go into shaft and shortly after making it out, froze, and "fused" my two piece slip shaft together. During suspension cycles and still having a slip yoke on the t-case side it was pulled off.



So... my goal this week is to try and tap the output shaft so that I can bolt the yoke onto it. Hopefully that will fix my front drive shaft issues for the time being. Eventually I'll open the case up and swap the output shafts for proper fixed yokes.

February 17th, 2020, 01:08 AM
Tossing out some mental ramblings...

Could you place a compression spring on the driveshaft slip yoke? It would put extension pressure to the DS to help push/keep the TCase end in place. I agree - a limp-along until the TCase output can be changed. How difficult might the drill-n-tap method be?

Drill thoughts... Take the easily removable portion of the driveshaft and drill that first - in a convenient place (not on vehicle) and use the two pre-drilled holes as a guide when you drill the vehicle mounted TCase output? Drill 1/2-way, rotate 180 deg and drill from the other side. Each TCase to DS hole would align properly even though some mis-alignment might happen mid-TCase shaft.

Would a new snap ring or a beefier snap ring on the TCase output be enough to solve the issue?

February 17th, 2020, 09:36 AM
Compression spring is a good idea, it'd have to be a big one though, like garage door spring size cut to length. I was just digging around in the selection of springs Jax has to offer a few weeks ago and don't recall them having anything close to the size I would need to do that however.

The end of the t-case output shaft is already tapered inwards so I think I stand a good shot at getting it tapped. If not... I'm half considering a few tack welds to keep it on there. My thought process is... I'll need to drop $$$ on the SYE and the current shaft/yoke are trash anyways.. so what do I have to lose? Worst case.. I blow a u-joint, break the yoke or output shaft. I can pull the front shaft and 2 wheel myself off the trail and install a proper fixed yoke. In the mean time I'll throw that $$$ towards other parts. Like chains, which should be here this week :2thumbup:

Also, the snap was a new one. Which is also shot after this weekend :lmao:

The splines on the yoke got hit hard over the weekend:


February 17th, 2020, 09:41 AM
Hmm - a deviation on your drill and pin comment that came around when you mentioned welding. Drill a hole in your removable yoke - 1/4" or larger. Then tack weld into that hole onto the TCase output. Hopefully only one as when you need to work on the TCase you'll need to drill out that tack weld to separate the parts (though the TCase would be out of the vehicle at that point and on a workbench for easy drilling).

I just ordered my second set of chains last night - $180 to the door.

February 17th, 2020, 09:48 AM
Hmm - a deviation on your drill and pin comment that came around when you mentioned welding. Drill a hole in your removable yoke - 1/4" or larger. Then tack weld into that hole onto the TCase output. Hopefully only one as when you need to work on the TCase you'll need to drill out that tack weld to separate the parts (though the TCase would be out of the vehicle at that point and on a workbench for easy drilling).

That's actually a better idea! Much less chance of melting the seal, which was my only real concern. Maybe I'll go that route! Eventually I'll fix it properly, for the time being I just want to kick that can down the road.

February 17th, 2020, 10:20 AM
More mental ramblings (I like this idea best)... Instead of welding one tack weld, go set screw - it'd be easily removable (and installable). Put a set screw into one side of the yoke to press / lock INTO a divot on the TCase output shaft.

Take the yoke off. Drill one hole through one side. Stick it onto the TCase output and use the same drill bit to drill into the output shaft but only enough to create a divot for a set screw to press into. Remove the yoke and tap the yoke's hole for the set screw. Leave the yoke off of the TCase output and, if needed, drill a larger divot into the TCase output shaft (to better fit the set screw). The result is a field serviceable / easily removable and installable yoke by simply loosening the set screw (use a set screw and not a bolt for better weight / out of balance issues - I believe your front DS spins full time / no front lockout hubs).

Yes, you'd need to pay attention to aligning the set screw to the divot but that'd be trivial.

February 17th, 2020, 10:28 AM
I hear the outer 1/8" or so of the output shaft is hardened and no chance at getting through it without proper carbide bits $$$. I'd say this is the case looking at the splines on the t-case shaft that don't have a mark on them compared to the splines on my yoke.

I do have a part-time front shaft with the center axle disconnect.

February 17th, 2020, 11:25 AM
You might not _need_ to have a divot for a set screw to push into - possibly just the force (with some lock-tite) would be good enough.

A grinding wheel (Dremel or angle grinder) would likely make a suitable divot easily enough without a costly bit. (I'd still try the drill bit and see what happens)

February 17th, 2020, 11:29 AM
I'd take the whole rig down to Bill's Englewood Driveshaft and ask them what the best fix would be.

February 17th, 2020, 12:28 PM
I'd take the whole rig down to Bill's Englewood Driveshaft and ask them what the best fix would be.

This one isn't on Bill. The best fix would be to convert my t-case to a fixed yoke output. That's a $500 kit though :lmao:. I'm going to try a hack-n-tap which will allow me to bolt my slip yoke onto the output shaft and not have to worry about it slipping off.

February 17th, 2020, 01:02 PM
I understand it's not their responsibility, was just saying they would likely help you with a solution since you bought the shaft from them.

February 17th, 2020, 10:01 PM
As I tried to explain over text messages, I would not weld (tack or otherwise). I would cut the output shaft down with a cut off wheel about an 1/4" if there is room to do so. This would eliminate the issues you are having with the hardened end of the shaft. Then drill and tap the center, creating your own hack and tap. But only if you have to room/clearance to do so. Otherwise, you will run a perfectly good output.

What days do you work? Maybe I can free up some time on an off day for you to throw it up on the lift to help.

February 17th, 2020, 10:36 PM
I like that perspective - If there's room, it could be the long term solution over a limp-along solution.

I enjoy offering ideas and will give a thumbs-up to the better mousetrap.

The StRanger
February 17th, 2020, 10:48 PM
I agree with Aaron.
Take about an inch outa the tail shaft & yoke, then drill &pin the yoke.
you start welding a on a heat treated shaft and your askin for it to snap on the trail.
and thatís a bad weekend.

February 18th, 2020, 08:27 AM
I did attempt to drill/tap the output shaft last night, unfortunately it only marred the surface at best. New plan this evening will be to use an angle grinder and cut the end of the shaft in hopes of being able to drill/tap the softer metal. I'm attempting the "wise" options that will keep it serviceable before resorting to hitting it with a welder.

Thanks for offering help Aaron, I believe I'll be able to get it with the tools I do have.

February 21st, 2020, 09:48 PM
There are some folks out there (probably several on this forum) that can eyeball such things, but I would not trust myself to drill a straight hole in the end of a shaft freehand. Especially a shaft that I had to cut the end off with an angle grinder. Looks like some folks sell drill guides for this kind of thing.


It would be interesting to figure out if one of these match the OD of your shaft. 35 or 40 bucks isn't too bad compared to trying to remedy a crooked hole. Or better yet, find someone with a lathe and a propensity to do favors for beer. Even an aluminum guide would work for one hole and would be quick and easy to turn.

I suppose if you removed and disassembled the T-case and drilled the shaft on a drillpress it would be easier to get straight, but that makes for a bit more work.

What thread are you planning to tap? I suppose keeping the bolt head small enough to fit in the yoke is important here. I'd expect a fine thread to go in a little easier that a coarse thread.

February 21st, 2020, 10:21 PM
I wound up tack welding it. The shaft is part time. I'll run it until it fails me, pull it and then do front/rear SYE and have a rear drive shaft made up.