5speed won’t stay In gear

[wydopenLb7]

Done allot of reading about other people’s problems and I’ve never heard of this one. Searching didn’t yield anything either.

Coming off a stop light accelerating fairly hard but not excessive and heard a big pop and had no forward drive. Thought I broke a driveshaft at first but everything visible looks fine. Goes into reverse normally but park is like you are in neutral and D-3-2-1 all grind and don’t engage.

Occasionally D will engage but it pops out and grinds as soon as you start to move.

No codes full of fresh fluid

Any help would be appreciated. Was thinking output shaft but then reverse wouldn’t work.

 

[wydopenLb7]

Now it’s not going into reverse either.

Edit: it intermittently goes into reverse. No grinding in reverse. Unplugged harness at trans and no change. Unplugged at tcm and no failsafe. If you put it in 4low it won’t grind and it says you are still in nuetral on edge when you shift. Sometimes it will go into gear but it still pops out once moving.

 

[2004LB7]

Transfer case

 

[wydopenLb7]

Transfer case

That’s what I was thinking. Cheaper than the trans at least.

 

[Chevy1925]

Drain the tcase oil looking for metal before condemning it.

 

[wydopenLb7]

Drain the tcase oil looking for metal before condemning it.

No big shavings but the color isn’t right. Silvery.. I was going to change it this morning ironically but I left the transfer pump at work.

Out of all the things on these trucks the T case is the thing I’ve neglected to learn about the most since I’ve had it and all my old chevys were 2wd. If I broke a gear or the shaft wouldn’t reverse not engage and grind also?

Merchant for a rebuild kit? After a quick search the ones that look like they come with the shaft and gears also come with half the case and arnt cheap. There’s a inexpensive LLY in town with a knock I’m tempted to pick it up for the trans/Tcase and run that tcase while I rebuild mine and build the extra trans.

 

[TheBac]

That fluid doesn't look good at all. Oh well, now you get to learn something new.

 

[Chevy1925]

It’s highly possible the mode fork wore through and broke, then the high low collar can pop out and not catch all the time putting the truck in neutral via the tcase.

That fluid is junk but if you want to be sure, someone needs to put the ass end on jack stand and put it in drive, then you get under there and listen to where all the nasty noise is coming from

 

[wydopenLb7]

Pulled it apart and the shift range fork inserts had shattered. Replacing the fork and hub and all the bearings and seals.

Is that just bad luck? Do guys running big horsepower upgrade their transfer cases or do they hold up to the abuse? Just increased the power about two weeks ago, not sure if it was going to break anyways or if the extra horsepower contributed.

Pervious owner did the pump rub fix about 100k miles ago so I don't think it was incorrect assembly. Haven't been too hard on it since I went to compounds. Haven't used 4wd in months.

Thanks for all the help.

 

[Bdsankey]

Pulled it apart and the shift range fork inserts had shattered. Replacing the fork and hub and all the bearings and seals.

Is that just bad luck? Do guys running big horsepower upgrade their transfer cases or do they hold up to the abuse? Just increased the power about two weeks ago, not sure if it was going to break anyways or if the extra horsepower contributed.

Pervious owner did the pump rub fix about 100k miles ago so I don't think it was incorrect assembly. Haven't been too hard on it since I went to compounds. Haven't used 4wd in months.

Thanks for all the help.

There really aren't "built" transfercases. The fork failing is just luck.

My transfercase that saw 1300whp+ was stock at 360k miles with a pump-rub upgrade is all. The case in my friends truck at 15xx HP is a Kodiak Truck case without their roller bearing mainshaft as they wanted to not remove material from the shaft for his power level (makes sense).

 

[Chevy1925]

Pulled it apart and the shift range fork inserts had shattered. Replacing the fork and hub and all the bearings and seals.

Is that just bad luck? Do guys running big horsepower upgrade their transfer cases or do they hold up to the abuse? Just increased the power about two weeks ago, not sure if it was going to break anyways or if the extra horsepower contributed.

Pervious owner did the pump rub fix about 100k miles ago so I don't think it was incorrect assembly. Haven't been too hard on it since I went to compounds. Haven't used 4wd in months.

Thanks for all the help.

Good to know that’s what it was! It’s just a known wear item, it’s not really a part that fails from horse power

 

[wydopenLb7]

Back on the road..pretty easy job

 

[wydopenLb7]

T case works great but somehow my shift cable won’t stay in the bracket coming off the transmission. When you shift to park the cable slides back and the metal clip gets dislodged. I didn’t disconnect the cable but maybe I snagged the cable when I was taking tcase out?

It’s hard to tell from pictures, is there a separate plastic piece that retains the metal clip that holds the cable in place? I can’t tell if something on my cable broke or if a piece is missing. I searched the ground where I was working and couldn’t find anything.

Edit: think the tabs that hold the clip in broke off. Have a new cable on the way.