Splitter splits rough

Hope it all works out well for both of you.

 

I have a similar issue on a rebuilt 15 speed I just bought. When I split and go from 5th to 6th it will grab hard and bang unless I use the clutch. If I skip 6th and go 5th to 7th I have no issue.

 

When I asked the guy at Peterbilt of Fargo he said my tranny (RTLO18918B) already has the updated splitter valve cover with the updated orifice holes. I replaced it today and it did NOT have the updated valve cover. On top of that it was missing 2 of the three O-rings that should have been there. The small one on the orifice hole on the side that mounts flush with the back of the tranny was gone. The other one was the big one that is placed around the nut inside the valve cover cap. I also noticed when I took the small air line off of the old one tranny fluid started dripping out of the air line. I am at a loss of how that got in there.

I also replaced the regulator today and by looking inside it I couldn't see anything obviously wrong.

I was not able to try it out because I am in the process of moving my air dryer from behind the fuel tank to in front of the drivers step where they usually go.

I will let you all know later on next week if it worked or not once I get her back up and running.

 

I got a reman 18 spd a couple years ago. Mine did the same thing when I got it back. Had to split it in neutral mine upshifting. They changed the O-ring first and then changed the actuator housing. They said different covers can have different size holes in it for the air to travel through. Apparently it changes how fast it pre selects. The cover was on the back side of the trans around the 7 oclock position. Sounded a little hokey to me but they changed the cover and I've never had a problem since.

 

Looks like you have a good handle on the issue!
As far as the trans fluid in the air line goes, it appears that the gearbox was being pressurized by the air system through missing/leaking orings. When the air pressure was down in the line, trans pressure that couldn't be relieved by the trans vent had forced oil from the gearbox into the line. This is fairly common in air shift transmissions and power divider differentials.

You might want to check the vent on the trans to make sure it's open and breathing.

 

That would be the splitter valve cover that I replaced on mine yesterday. The new one I had did have the smaller orifice holes on it. Ill know if it worked later on next week....hopefully.

 

Makes sense to me. Thanks alot Bender I never would have thought of that. I will be dang sure to check that vent line. I just cleaned the ones on the rear ends yesterday. The old motor in this truck had a massive oil leak at one time and everything under there is covered in gunk. I would not be the least bit surprised if that tranny vent has at least a partial obstruction

 

I should have also mentioned that a pressurized gearbox can cause fluid aeration of the gear lube causing some loss of ability to cool and lubricate. This could have contributed to the burnt fluid in your trans.

 

Well for anyone who is interested I finally took the truck for a ride this morning. The splitter now splits as it should very smooth up and down shifting. Id like to say Thank you to Bender, Pablo-Ua, Pulling Trucker, Nevs, One Shot, Prarie Boy, HI Speed428, ENR, KW Forage, and Special K for responding and helping me figure this issue out.

 

Glad you got it figured out!