Torqueflite A998 Auto Transmission Troubles

[TheLeftybar]

Hello, new to the forum and I hope my Truck is allowed on the forum. I have a 1988 Dodge Dakota Sport with a 3.9L LA V6, Torqueflite A998 3 Speed Auto Transmission, and NP231 Transfer Case. I recently got done with a transmission rebuild on the truck after having major leaking & shifting problems. After putting it back together and test driving it, I came up on a major issue and have been struggling to figure out how to fix it. So to help, here are some details on what happens during the rebuild and what's going on.

Me & father planned on installing shift kit but didn't happen cause he wasn't comfortable installing it, ended up setting line pressure to 70psi by accident and wouldn't let truck really shift into 3rd but I lowered it down to 60psi. My father also broke an E-clip for the governor (big man, lil parts) and I ended up getting two thinner E-clips from Bomgars and doubling up (the two were thicker than the original but were talking like a couple thousandths of an inch thicker).

Now the line pressure is at 60psi and "3rd gear is back." When WOT, the transmission won't shift up 2 to 3 and rev up all the way to 65mph (should shift at around 55-60mph) until you let off the throttle, then it'll shift. Then when your driving and you hit about 70mph, the truck then for some reason proceeds to downshift 3 to 2 and rev the hell out of the motor.

I'm thinking I need to lower line pressure until it's about 54psi and adjust the kickdown band again but other than that, I dont know what would be causing this and I would like some feedback.

 

[AJ/FormS]

Here's your tip
Governor pressure commands the auto shifts, working against line pressure.
Throttle-Pressure joins with line-pressure to fight against governor pressure .

Therefore, if the trans stays in gear at WOT, long past a "normal" upshift rpm. AND
Downshifts early, you can bet that the governor pressure is too high.
That rarely happens, unless
You changed the governor parts, changed the rear gear ratio, or put the governor springs in the wrong places.

But since it's also back-shifting 3-2 very early, you may also have a pressure problem in the Direct clutch.
I recommend to
get a service manual, and a couple of pressure gauges, and follow the diagnostics.

 

[TheLeftybar]

Here's your tip
Governor pressure commands the auto shifts, working against line pressure.
Throttle-Pressure joins with line-pressure to fight against governor pressure .

Therefore, if the trans stays in gear at WOT, long past a "normal" upshift rpm. AND
Downshifts early, you can bet that the governor pressure is too high.
That rarely happens, unless
You changed the governor parts, changed the rear gear ratio, or put the governor springs in the wrong places.

But since it's also back-shifting 3-2 very early, you may also have a pressure problem in the Direct clutch.
I recommend to
get a service manual, and a couple of pressure gauges, and follow the diagnostics.

I'm going to do the diagnostic tests again but imma try adjusting the linkages, kickdown band and line pressure first and see if that fixes it, but if it's the governor or the direct clutch that's causing the problem I'm gonna be pissed. It took so long to put the transmission back together

 

[TheLeftybar]

Here's your tip
Governor pressure commands the auto shifts, working against line pressure.
Throttle-Pressure joins with line-pressure to fight against governor pressure .

Therefore, if the trans stays in gear at WOT, long past a "normal" upshift rpm. AND
Downshifts early, you can bet that the governor pressure is too high.
That rarely happens, unless
You changed the governor parts, changed the rear gear ratio, or put the governor springs in the wrong places.

But since it's also back-shifting 3-2 very early, you may also have a pressure problem in the Direct clutch.
I recommend to
get a service manual, and a couple of pressure gauges, and follow the diagnostics.

Oh, I will add, Reverse works and I don't feel any slipping along with 1 & 2. It also upshifts & downshifts fine between 1 & 2 at the correct speeds. Also, when it comes to the transmission getting up to 70mph, it's not that we're at WOT, rather were barely adding throttle to speed the truck up. Would that possibly change what the problem could be? Like could the high line pressure and an improperly adjusted kickdown band keep the transmission from shifting into 3rd

 

[AJ/FormS]

Like could the high line pressure and an improperly adjusted kickdown band keep the transmission from shifting into 3rd

No I think not.

I think you mighta mixed up some springs. I'll have to dig up my manual and see if that's possible.
Are you absolutely sure that you assembled the governor correctly, with ALL the parts.
Don't worry, the E-clips are still there, lol.

I gotta go out for a few hours so, TTYL.

 

[TheLeftybar]

No I think not.

I think you mighta mixed up some springs. I'll have to dig up my manual and see if that's possible.
Are you absolutely sure that you assembled the governor correctly, with ALL the parts.
Don't worry, the E-clips are still there, lol.

I gotta go out for a few hours so, TTYL.

No, we put all the springs back in correctly.

 

[AJ/FormS]

No, we put all the springs back in correctly.

I said that too one time, after building many many torqueflites .......... but I was wrong, lol.
Did you put ALL the balls back in, including the two different sized ones? Yeah I messed that up too one time, lol.

 

[TheLeftybar]

I said that too one time, after building many many torqueflites .......... but I was wrong, lol.
Did you put ALL the balls back in, including the two different sized ones? Yeah I messed that up too one time, lol.

Yeah, I'm sure we left/put every ball in it's original home of all different sizes & shapes. We had the valvebody on a clean drainpan while we were working on it, so we knew when a ball dropped or not

 

[TheLeftybar]

I said that too one time, after building many many torqueflites .......... but I was wrong, lol.
Did you put ALL the balls back in, including the two different sized ones? Yeah I messed that up too one time, lol.

Ok, I was doing some more research on the issue and looking further into the transmission functions. So the governor & it's pressure determines when it shifts, while the throttle/line pressure keeps it from shifting. Well if the governor pressure was too high, then the shifts would be super early, even at WOT. The issue I'm dealing with is the transmission not wanting to shift into 3rd.

When the line pressure was 70psi, I basically didn't have 3rd gear; however, after dropping line pressure to 60psi, I managed to sorta get 3rd gear back.

From the diagram I have (one is when transmission is in 2, and one is when transmission is in direct or 3) shown in my response, governor pressure is red, line pressure is blue, & throttle pressure is green. On one side of the 2-3 valve (which is to the top left) is governor pressure, while the other side is throttle pressure. I believe that the line pressure is still too high and is making the throttle pressure be high. It's pushing more force onto the valve then the governor can supply and is therefore not letting it shift properly.

 

[TheLeftybar]

Unless the governor pressure inside the valvebody is too low or the doubled up snap rings are keeping it from expanding out properly.