new transmission, slipping, help diagnosing

[frankenstien]

ok so i have another thread here http://www.gmsquarebody.com/forum/showthread.php?t=14731

had the intermediate sprag race explode.

ok so i just got it back in, my clutch pack clearances were good, but as of now, it shifts hard from 1-2(supposed to) 3 is firm, not hard, it wasnt before. but its shifting at about 3500rpm, and my rpm at 55 is like 31-3200, which its ususally 2500-2600. if i give it gas in 3rd, the rpms just pick up it goes but not like it should, it is too cold out, and the transmission isnt overheating or running hot.

the only thing i can think of is, when i air checked the clutches, the fwd's had some blow by the rings, but not by the piston, maybe the ring sealing surface area is damaged? when i built the trans the first time(8 years ago) there was some blow by on the fwd rings as well, but it was a brand new fwd drum

here is my logical(to me) reason i think the issue is the FWD clutches, it has a 2500 stall converter, which is usually like a light switch at 2500rpm. when in D i stall it with the foot brake, it will clime to 3000-3200 but never break the tires loose, accodring to my book, only the fwd clutches are used in D1.

according to the book in L1 the fwds and the low reverse clutches are used, when stalled up with the foot brake again, it breakes the tires at 2500 rpm.

the other issue i had is my detent cable wasnt adjusted right, and may be stretched beyond, but i adjusted it, and its much better, havet test drove again, also, the fluid was about 1qt overfull, im having a hard time getting the fluid level right, hard to see, and no level ground near me.

any insight is appreciated, i am by no means a transmission guy, just need to get it going

 

[crazy4offroad]

Did you disassemble/clean the valve body? Could be a sticking valve. Did the directs spec out ok? Sounds like you have a couple other things to sort before you can point the finger at the internals just yet.

 

[crazy4offroad]

Also read on another forum a guy's vacuum modulator wasn't seated all the way in and the seal was missing but he didn't specify if it was only slipping in 3rd or all the time. Also read someone suggest driving the vehicle in reverse some distance to refill the TC but again, that would imply slippage in all gears.

 

[frankenstien]

i did fully disassemble the valve body, cleaned all the bores and valves with brake clean, made sure the moved freely, lightly sanded where needed. also replaced all springs from transscat shift kit, followed instructions and used 2 balls. my direct clutch clearance was i want to say .035 or .038, as it was just under the .015-.045 "tighter" specs in my book.

i put a new o ring on the modulator, and made sure the bracket was tightened, i will double check after work.

can the high fluid level and detent cable cause my issues?

i also read somewhere on here about driving backwards to re fill the converter, how does that even work?

i filled the converter when i re installed it, i kept pouring fluid in until the air bubbles almost stopped purging, about 1/2 cup spilled when i put the converter on

EDIT i forgot to say this 2x now, when i pulled the stick to suck out some fluid, wiped it on a nice white towel, had a little bit on black on it, that doesnt give me good feeligns

 

[crazy4offroad]

There is a spring in the VB, it has a large end and a small end, I put the ************ in wrong and toasted my directs. It wouldn't pull at all in any gear. I was being really easy with it though. I'll find a diagram and show you...

 

[crazy4offroad]

This is it

 

[frankenstien]

i dont think i did, i laid everything out, and swapped springs accordingly, it already had the trans scat kit in it, i was just refreshing the springs.

mine pulls hard in 1 and 2 3 is just running higher rpm's, and the slipping while stalling

at this rate its looking like im pulling the trans again

 

[frankenstien]

also, i just realized i did NOT replace the teflon seal on the end of the input shaft that goes into the lower part of the trans, dont know if that makes a huge deal

 

[crazy4offroad]

Are you talking about the teflon seals on the stator? I've heard they don't air-check very good sometimes. I used steel on mine and it air-checked solid.

 

[frankenstien]

Mine are the 3 steel and 2 aluminum, the forwards had some leak by, which ive had happen before, with no issue, maybe thats the problem?

At the moment, had some family stuff come.up, if the detent adjustment doesnt fix, im going to have to oull it and have a local guy look it over, dont have the time to keep messing with it at the moment.

 

[frankenstien]

Just had him look at it, he said its not backshifting, starting out in 2 or 3 says he thinks its valve body or govenor related

 

[crazy4offroad]

Good deal, keep us posted what it turns out to be!

 

[frankenstien]

will do, thanks for the help. he test drove it and was like no, so we will see, he sounded pretty confident its either the vb or governor

and in all honesty, i dont know why it would be starting in 2 or 3, or why it doesnt go back to 1 at a stop

 

[frankenstien]

so far, i forgot to put a spring in the 1-2 shift valve, my governor was about to fall apart, the weighted part was super wobbily off the top, and my vacuum modulator was on the wrong port,(has been for about 4 years, never noticed) but he said its working good now

 

[crazy4offroad]

Awesome, glad it was a relatively easy fix and no parts got burnt up. Now we need video confirmation lol