Orion 4:1 t-case jumps out of gear

[Alan Kiecker]

My Orion 4:1 t-case doesn't like to stay in low range. This seems to be a pretty common problem.

Is there a solution? Can this be fixed?

How big of an effort would it be to back the Orion out and return to the stock t-case?

 

[rlong]

It is a known issue with a likely fix, so much so there is a sticky at top of forum. ORION

Good luck!

 

[cstav86]

In the same boat with a recent build so none of the older issues apply. Just pulled the driveshaft to ensure the output shaft nut is torqued properly. Going to run it without the shift boot as well. Need a solid downhill to test it.

 

[White Stripe]

My theory is that it's the spline design on the shaft in which the shift coller slides are machined incorrectly. They should have a slight taper. Eventually I will pull mine apart and dremel down the splines by hand.

 

[Alan Kiecker]

In the same boat with a recent build so none of the older issues apply. Just pulled the driveshaft to ensure the output shaft nut is torqued properly. Going to run it without the shift boot as well. Need a solid downhill to test it.

Let us know how it goes!

 

[cstav86]

You may want to check out this thread: O R I O N - https://forum.ih8mud.com/threads/o-r-i-o-n.139377/page-49
Some interesting options to fix the problem.

 

[peesalot]

White Stripe, I have thought about that but then the dog teeth are even narrower ? Many Orions have no issues of popping out, it is not 1 common issue amongst all.

 

[White Stripe]

White Stripe, I have thought about that but then the dog teeth are even narrower ? Many Orions have no issues of popping out, it is not 1 common issue amongst all.

Afaik slightly angled teeth are common on dog teeth. It would be very slight and i doubt would loose enough strength to matter in my opinion. As far as common, i dont know i only have my experience

 

[65swb45]

My theory is that it's the spline design on the shaft in which the shift coller slides are machined incorrectly. They should have a slight taper. Eventually I will pull mine apart and dremel down the splines by hand.

So you're thinking that the output shaft is PULLING the shift collar off the gear, rather than the gear PUSHING the collar away? Interesting I have always thought that since the output shaft is preload shimmed to a very exact tolerance, while the gear suffers from the get-go with a tolerance limited by the bushing's need to be oiled, that it was the gear pushing the collar off.

 

[White Stripe]

So you're thinking that the output shaft is PULLING the shift collar off the gear, rather than the gear PUSHING the collar away? Interesting I have always thought that since the output shaft is preload shimmed to a very exact tolerance, while the gear suffers from the get-go with a tolerance limited by the bushing's need to be oiled, that it was the gear pushing the collar off.

I haven't had my tcase apart in a while. I believe it's possible that since none of the splines are tapered that it makes it more prone to pop out of gear. This is a thought that's been in my head for a while but I don't remember all the reasons i want to look into that possibility. Which spline exactly needs to be tapered I'm not sure. I would have to look at it again, and I could be wrong in all this. It's fairly far down on my to-do list. I will see if I can find some pics of the inside of a fj40 case to post.

 

[White Stripe]

So basically my thought was to taper the splines of 36204 and the splines of 36203. That will help(I think) sleeve 36235 to always want to keep itself pulling into whichever way it's shifted naturally. The other option could be to have the shaft splines modified like this modified stak shaft is: So I figured out why my STaK front output pops out of gear. - https://www.pirate4x4.com/threads/so-i-figured-out-why-my-stak-front-output-pops-out-of-gear.882110/
I don't know how you would do that though.