Engine/Transmission (1998.5 - 2002) 6-speed broken. Now what?

[JesseJ]

So I was driving down the highway headed back home on Sat. and rolled into the throttle, it freewheeled like it popped out of gear. Slowed down and stopped, started going again, all my gears seem to be fine. Got into 6th gear and it was all normal. When I give it throttle though, it's like it just pops into neutral. If I babied it, it would hold 6th gear but any power and it would just spin. Don't know if anyone has come across this problem before, the best I can figure out is that the teeth are pretty much stripped out and it will only hold if you don't give it any throttle. The nearest place I can work on it is 2 hrs. away, don't know if I should risk doing any more damage driving it there or if the damage is already done. Anyone had this happen before? Any help?

 

[blacksheepdiesel]

It works fine in all gears but 6th? It could be the clutch disc also.

If it is the transmission call Blumenthal's in Oklahoma City.
The Blumenthal Companies - Transmissions, Engines, Drivelines and all Powertrain Products

Godspeed,
Trent

 

[JesseJ]

Well I thought it might be the clutch but like I said, I got on it in 4th and 5th and it was fine. I should mentioned when it spins free in 6th under power it does make a horrible metal grinding sound, not like a clutch slipping.

 

[FosterW]

the shift forks inside the transmission slip over sliding clutches. there is one fork for two different gears. So when you shift it moves the shift fork and sliding clutch and engauges it with a constant mesh gear. 5th and 6th are on the same sliding clutch. So the teeth on 6th gear that the sliding clutch engages with may be too far worn from grinding and whatnot. Soo worn that even when it is in gear there isnt enough metal surface for the sliding clutch to grab onto so it slips out.



thats what I think is happening.

 

[JesseJ]

Well, you're the second person who has mentioned that same kind of scenario and it does make sense. I never had problems with it shifting into 6th and never had it grind on me going into 6th either, that's what makes it so odd to me.

 

[FosterW]

yeah that is the problem. . It could be something simple like a detent ball and/or spring. These make for a positive shift into gear and also keeps it in gear. I know my 5600 will not stay in 1st gear unless I keep pressure on the shifter. Im assuming its the detent in my transmission and might be the same for you.

 

[JesseJ]

Ok, so I finally got my transmission out and apart to find the problem. I don't have pictures yet, but I'm going to try to get some to put up here tomorrow. It's hard to explain without pictures, but I'm going to try. 6th gear rides on a bearing on the mainshaft and it has a larger sprocket type looking gear attached to it. That's what the sliding shift collar locks into to give you 6th gear. Well, that larger sprocket looking gear spun on 6th gear. It created tons of heat as evidenced by my now cooked synchronizer for 6th gear. I don't know if it was just a press fit or friction welded together but either way, it didn't hold. Good news is no mainshaft damage, and while everything else looked pretty decent, I'm going to replace all bearings, synchros and seals so I hopefully will not have to tear into it for another 150k miles. I guess this is what happens when you turn the adrenaline up to 10 and lug it in 6th gear for a smoke show. :-laf Now you've all been warned, it can happen to you.

 

[Gordon Maney]

Ok, so I finally got my transmission out and apart to find the problem. I don't have pictures yet, but I'm going to try to get some to put up here tomorrow. It's hard to explain without pictures, but I'm going to try. 6th gear rides on a bearing on the mainshaft and it has a larger sprocket type looking gear attached to it. That's what the sliding shift collar locks into to give you 6th gear. Well, that larger sprocket looking gear spun on 6th gear. It created tons of heat as evidenced by my now cooked synchronizer for 6th gear. I don't know if it was just a press fit or friction welded together but either way, it didn't hold. Good news is no mainshaft damage, and while everything else looked pretty decent, I'm going to replace all bearings, synchros and seals so I hopefully will not have to tear into it for another 150k miles. I guess this is what happens when you turn the adrenaline up to 10 and lug it in 6th gear for a smoke show. :-laf Now you've all been warned, it can happen to you.

Do we have good parts availability on these transmissions now?

 

[JesseJ]

I didn't have a problem with parts availability, but they sure were proud of them! I got a complete bearing and seal kit from Quad 4x4 in Montana it was only $350-400. I wanted to get all my parts from Quad 4x4 because I have had good experience with Dan and exceptional customer service. He has always been willing to answer all my questions. However, he doesn't want to sell us cheaply made replacement parts for them and hasn't been able to find a good source yet. I called Blumenthals in OKC to get a synchronizer kit, shim kit, 6th gear, and the 5/6 syncrhonizer hub since they were cooked. Blumenthals said they had to go O. E. to find the 6th gear and synchronizer hub and those two parts alone were $450! If you're just going to go through one of these trannies, bearing, seals, synchros and such, it's fairly cheap. It's the parts that broke that cost a fortune.