Stock Trany Shifting Questions

[joesco715]

Still working on completing the body work and paint on my Hercules Repower M715. I had to have the clutch rebuilt and beefed up this recently to keep up with the torque of the intercooled turbo Herc.

Now I am starting to drive her again and find it very hard to shift during the first 15 minutes of driving. I did a complete fluid change in the tranny, t-case and diffs using the recommended, conventioinal gear oil. Levels look fine.

Is this tranny problematic when it is cold (New Hampshire weather)?

Also, even after it is warmed up, it is very difficult to downshift from 4th to 3rd, to 2nd. Any suggestions or comments welcome.

The truck is going in for paint on December 7th, Dodge Candy Apple Red.

I will post some pics when it is back.

Thanks for any help!

[fng]

Don't NO-BODY EVER critisize my paint color choice again!!!!!

Sounds nice bud, post some pic's when you get it done.

[Barrman]

Does it go into gear ok with the engine running and the truck sitting still? If not, then pilot bearing issues are my guess.

The downshifting part is hard to diagnos because I don't know how you drive. Driving along at 45 mph in 4th, pushing the clutch in and trying to jamb the gear shift into 3rd is going to be a hard shift to complete. But, driving along in 4th at 35, pushing the clutch in, reving the engine about 500-1000 rpm, pushing the gear shift to 3rd and then letting the clutch out should be smooth as glass.

It is all about equalizing the speed of the different parts. 2nd to 3rd and 3rd to 4th will drop engine rpm about 1000 rpm per shift. A non braking down shift needs the engine rpm to be raised about 1000 rpm between gears to make all the parts mesh together correctly.

Also look at the max speed per gear plate on the dash. 11, 22, 40 and 60 are the max speeds for each gear in high t-case range. That is with the stock engine. If your Herc has a 2600 rpm redline, those should be adjusted down to about 7, 15, 30 and 45. Try doing the down shifts below these speeds with a little throttle blip and it should work.

[wrecker]

I would venture to guess that maybe your clutch pedal linkage isn't 100 percent adjusted. Check if it turns over differently with the clutch fully depreesed as compared to with the tranny in neutral. If you're getting a noticible difference in cranking speed, your clutch is not being fully released by the pedal.

[kwai]

Don't NO-BODY EVER critisize my paint color choice again!!!!!

Green metal-flake shiny paint. HAHAHAHAHAHAHAHAHAHAHA.





Just kidding...

[brute4c]

When I used non synthetic at 80W90, on a cold morning, anything under freezing for sure, the trans shifting gets stiffer...tcase doesnt lie to go into low range right away and the acceleration is sluggish...guessing all the gears from the trans to the axles need some heat to move easily again.

Changed to synthetic 75W90 and it seems to start at a little lower temp...same presentation though...I know at sub zero temps, the synthetic is easier to get going with and warms up quicker...a big plus.

Not sure how cold it has been that you have been having issues...

[fng]

Thanks Kwai...

[5quarter]

double clutch

[joesco715]

Thanks!!!! Yes, it goes into gear fine with the truck still and engine going. Change to 50w gear oil in the trans and now a very noticeable difference. Thanks for all the comments and suggetions!!!

Does it go into gear ok with the engine running and the truck sitting still? If not, then pilot bearing issues are my guess.

The downshifting part is hard to diagnos because I don't know how you drive. Driving along at 45 mph in 4th, pushing the clutch in and trying to jamb the gear shift into 3rd is going to be a hard shift to complete. But, driving along in 4th at 35, pushing the clutch in, reving the engine about 500-1000 rpm, pushing the gear shift to 3rd and then letting the clutch out should be smooth as glass.

It is all about equalizing the speed of the different parts. 2nd to 3rd and 3rd to 4th will drop engine rpm about 1000 rpm per shift. A non braking down shift needs the engine rpm to be raised about 1000 rpm between gears to make all the parts mesh together correctly.

Also look at the max speed per gear plate on the dash. 11, 22, 40 and 60 are the max speeds for each gear in high t-case range. That is with the stock engine. If your Herc has a 2600 rpm redline, those should be adjusted down to about 7, 15, 30 and 45. Try doing the down shifts below these speeds with a little throttle blip and it should work.