engine running - truck not moving

[dieselponyexpress]

Something in the drivetrain has happened. Now I want to know, if it is
- bad converter
- broken transmission
- broken transfer case
Engine starts as fine as ever, but is shaking terribly. No strange noise from the motor. No cracks on flexplate, removed the cover an inspected it (even while running). If in P, the shaking is most. With rear wheels on jackstands and in P, driveshaft and wheels are turning but I could stop them easily by hand. In D, 1, or 2 with no throttle they do turn stronger but still are stopable by hand and the shaking is not that much. I don't know if this is normal slippage of the converter. When in D and brakes are applied, there's a whinig sound at the converter/transmission area. When NP208 in N and engine running I cannot engage 4H or 4L Trans in N or D, with or without braking); have to shut down engine. So how is the best way to determine where the problem is?

85 CUCV K30 (6,2L TH400 NP208)

Walter

 

[K5dreamer]

im no tranny guy, so i cant even guess what is exactly the matter, but one thing i do know for a fact is that if the tranny is in park, the driveshafts shouldnt budge, let alone be powered, however low that power level may be.

a converter or t-case problem would not cause that. time for a tranny rebuild.

 

[Blue85]

If the wheels are turning in park, the parking pawl is not engaging. Maybe the pin has sheared, or the teeth on the output shaft have stripped. This also implies that the transfer case is engaged to transfer the motion to the rear driveline. Being able to stop the wheels by hand while the transmission is in gear is also very bad.

I would check to make sure the shift linkage is actually working right and you are hitting the gears you think you are. Then it's time to drop the transmission pan, look for chunks and see whats going on with the shift linkage (internal) and the parking pawl.

Not being able to shift the transfer case while the engine is running is kind of normal. You can sometimes shift in park, depending on how everything was lined up when you stopped moving, but it seems like you don't have park.

 

[dieselponyexpress]

Thanks for your answers

Not too good news but at least i know the way to go. After checking the linkage, I think separating the tc from the th400 will be my first step. Then I'll give it a try to test if the shaking is still there. Next would be removing the oil pan to look at the tranny.

Maybe my NV4500/NP205 swap will happen sooner then expected , even if I can't afford it right now (not even have a NV4500 yet)

Walter

 

[K5dreamer]

Maybe my NV4500/NP205 swap will happen sooner then expected , even if I can't afford it right now (not even have a NV4500 yet)

Walter

you and I are in the same boat.... im just waiting in my TH400 to dieeeeee so i can do the manual swap

 

[dieselponyexpress]

Not being able to shift the transfer case while the engine is running is kind of normal. You can sometimes shift in park, depending on how everything was lined up when you stopped moving, but it seems like you don't have park.

Maybe i should have been more specific here, sorry about that. Thing is, when trying to shift out of N (NP208) there's a ratcheting noise from a turning gear (?) that won't engage. Seems that I lost all synchronisation in the tc. I do know how it was before when shifting into or out of 4L: Best when tranny is in N, sometimes it also works in P, depends on how the gears stand to each other.

Raining here, so i didn't have the chance to check the linkage.

Walter

 

[dieselponyexpress]

you and I are in the same boat.... im just waiting in my TH400 to dieeeeee so i can do the manual swap

Lets swap our TH400's, LOL

 

[K5dreamer]

you pay for shipping

 

[dieselponyexpress]

Disconnected the linkage today and tested it by turning directly at the lever output on the th400.
Parking position definitely does work. But in all other positions and with no throttle wheels are turning and I managed to stop them by hand (harder in D than in N). Is this normal slippage of the converter? Seems to me that the converter is causing the vibrations; looks out of round while idling. Still don't know if I should pull the converter first or disconnect the transfer case.

Walter

 

[dieselponyexpress]

Put the new (used) converter in today. Drives like it should be.

Walter

 

[K5dreamer]

well played, very odd that the converter seemed out of round... were the welds on the mounts to the converter broken???

 

[dieselponyexpress]

well played, very odd that the converter seemed out of round... were the welds on the mounts to the converter broken???

when i'd pulled the t/c, i discovered that most of the internals must have come loose/broken. It sounds like a can of needle bearings when shaking it. Maybe it wasn't designed for the 6.2l/th400 (did have the 6 bolts though).

Well, seems that my old CUCV simply creates too much torque.

Walter