M35A2 5th Gear Issues

[electraman]

Hello, I am having problem with my 5th gear. Since I am new to this kind of truck, I need some help. When I shift in to 5th gear, It jumps out of gear, If I try to hold it gear it fources itself back out... Any ideas? All other gears and clutch work fine and sifts smoothly.

Thanks

 

[Katahdin]

Is it a sprag t-case? The linkage might need adjustment.

 

[electraman]

Thanks for the help! I'm not sure what I have, I have only owned this truck for a week. could you tell me what to look for? I hope that it is only an ajustment. Its a 71 Kiaser with an Herc. motor.

 

[Westech]

Is it a sprag t-case? The linkage might need adjustment.

That is not going to make 5th gear act like that..... sounds like a internal Transmission problem.

 

[Flyingvan911]

There are two ways to engage the front axle. A Sprag transfer case does it automaticly when it senses the rear tires slipping. An airshift transfer case has a switch toward the bottom side of the dash in the middle. It will say "In" and "Out." It will also have a light on it.

Sprags can be a pain if they are out of adjustment. That's all I know about them. My deuce has an airshift. It is nice being able to decide for myself if the front axle is engaged or not and it is less of a mechanical headache.

 

[jasonjc]

5th grear rides on a bushing with lip on one end. These can get damage then the grear moves too far. You need to pull the top cover and take a look. The sooner the better only will make thing wosre if you leave it.

 

[electraman]

Thanks Flyingvan, I do have on the dash a switch that i can shift the front axel in and out, does have a light on it too, I was told it was power by air

 

[Flyingvan911]

It is air operated. Just press the clutch in and flip the switch to "in". Same thing to disengage it. It is syncronized and you can engage the front axle at any speed. I try to engage mine at a low speed or at a stop. I just feel better doing it that way. Most of the time you'll be going slow anyway when you are in a situation to need the front axle. The steering wheel will jerk some when you steer with the front axle engaged. If you expect it you can compensate. Some times it will resist turning and other times it will help you. When it helps, hold on so it doesn't turn more than you want.

 

[schwenk industries]

Do you have the TMs if not i will post it anyway because the old site is down. (TM 9-2520-246-34P Direct Support and General Support Maintenance Transmissions, Transfers, PTO's) it is only for the trans ect. Hope it helps

 

[electraman]

Thank you everyone! Looks like I have some work this weekend...Schwenk Industries, thanks for the manual!

 

[gringeltaube]

New to manual transmissions also....
Just in case..... take a look inside and examine the little dogs on the synchro where they engage 5th gear. Compare with the pics below (showing a new part vs. the same presenting extreme wear). 5th gear condition can be better checked after removing/ disassembly of mainshaft. (you already got the TM or...?)

Worn dogs and generalized wear combined are the most common cause for a transmission jumping out of gear!
Both referred parts in your's could be worn out to that point where the only cure is replacing them... (-> $$$) All other gears and parts could be in a similar condition even if they still are functioning "smoothly"....?

Hopefully not but it could be time to think about a whole replacement tranny.

Try to shoot some close-ups from what you find!
Good luck!

G.