2001 3500 NV5600 hard shift after 75 nv5600

[WC Eason]

I have a 2001 RAM3500 5.9 with an NV5600 transmission. After driving about 75 miles at about 70 mph I find that shifting the 5600 is like trying to put your hand through thick molasses. If I stop for a break it shifts smoothly again. Is this some sort of thermal expansion issue at the top of the trans near the shifter.

Any help is appreciated and this is a rebuilt trans with about 40k miles on it and has done this since installed.

 

[Tuesdak]

Rebuilt by who? Warranty? What oil do you have in it and how much? Any lube mods done during rebuild? Why was it rebuilt?

FWIW this is a slow shifting SOB as all the gears are always spinning and need to change speed for a shift. I find the button on the end of the shift stick in the trans wears out to shift sloppy. "Core shifters" gets them where FCA makes you buy the whole shift stick.

IMO they do shift a little faster after warming up and this warm up is part of what you are seeing.

It's possible the clutch is hanging up via a damaged pilot bearing. When hot how easy is it to go from 1st to reverse and back to 1st with the clutch pedal on the floor?

 

[John2713]

This is what I did and it helped mine. I did a hot drain, and filled with amsoil 5-30 syncromesh through the shiftier hole. When full I added 2 extra qts too the gear box. Other than a gear rake when going from 5th to 6th. Greatly improved shift quality. If I shift slowly between 5th and 6th all is good.

 

[WC Eason]

Rebuilt by who? Warranty? What oil do you have in it and how much? Any lube mods done during rebuild? Why was it rebuilt?

FWIW this is a slow shifting SOB as all the gears are always spinning and need to change speed for a shift. I find the button on the end of the shift stick in the trans wears out to shift sloppy. "Core shifters" gets them where FCA makes you buy the whole shift stick.

IMO they do shift a little faster after warming up and this warm up is part of what you are seeing.

It's possible the clutch is hanging up via a damaged pilot bearing. When hot how easy is it to go from 1st to reverse and back to 1st with the clutch pedal on the floor?

Hi, thank you for the reply. The trsnsmitrans shifts perfectly fine when cold or driving in town. It becomes harder to move the stick through the gates after running at 70 plus mph for an hour or two. That is why I thought it may be some sort of metal thrermal expansion in the top of the 5600 where the shifter meets thh trans.

 

[John2713]

Possibly heat could be an issue: however I do not have those issues. There are coolers that can be mounted on the pto opening. The only issue with mine is a gear rake between 5th and 6th and it isn't an issue if i simply shift slowly. I over filled mine 2 quarts through the shift tower with amsoil 5 30 sincromesh. I do not tow more than 4000 lbs usually and all is ok for now. But with 245k will need to address the 5th 6th shift sometime. Hoping for a million good miles. Hope this may be of some help.

 

[Tuesdak]

Hi, thank you for the reply. The trsnsmitrans shifts perfectly fine when cold or driving in town. It becomes harder to move the stick through the gates after running at 70 plus mph for an hour or two. That is why I thought it may be some sort of metal thrermal expansion in the top of the 5600 where the shifter meets thh trans.

IMO Some clearences not set properly. Oil is critical so if you are using the proper oil it's time to harass the rebuilder. Parts are kind of hard to get so fix before you ruin something expensive.

 

[KATOOM]

Sounds like an improper rebuild or it has the wrong fluid in it.