47RE help 0 front servo pressure

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desertboy

New member
Ok, I know everyone hates transmission questions *bdh* but I'm going to ask before i pull it out as i appreciate any input so i can test instead of saying nope didn't try it.

So the trans is a rebuild by me first off with a lot of information gained from here. It had about 250 miles on it before issues began. The following are the pressure readings, in any position the front servo is at 0 psi though it will drive around the block in any position (that's as far as i'll take it).

In reverse rear servo idle ~200 psi
In drive accumulator (90-130psi) Front servo (0 psi)
In manual low rear servo (90-130psi) accumulator (90-130psi)
In manual second accumulator (90-130psi) Front servo (0psi)

I pulled the servo which is a DTT unit and all sealing rings looked good, reinstalled with liberal application of tranny assembly lube and got the same results.

I had noticed the lack of power being put to the ground and pulled the pan originally to raise the pressure. The pan had a bit of clutch material as well as small gold and silver flakes. I tried to brake stand the truck after this and it acts like it is under load but also acts like its blowing through the trans as the rpm's increase

So i need to know what pertinent information i would need before pulling the trans so i don't wonder later. How would the trans shift and run fine (not under full power) with 0 front servo pressure on the band? I'm thinking it sounds like a valve body issue but would like something to confirm this as it's eaten through this trans. Any input is appreciated.
 
Pressures were read in gear (1st, 2nd, D, and R) with the throttle valve lever full forward and tied full back.
 
desertboy said:
Pressures were read in gear (1st, 2nd, D, and R) with the throttle valve lever full forward and tied full back.
Click to expand...


But were they read with the truck moving? The front servo won't read pressure until the truck shifts (or attempts to shift) to second gear.
 
Checked when i got home from work yes i have front servo pressure when driving. It is not in limp mode, it was kicking into limp mode shortly after i built it and the valve body assistant (voltage regulator) fixed that. It is a 1996 truck so it's not obdII so i don't have a scanner to run it on but the obdI has no codes but it also doesn't read much also.

It's coming out on Friday after the holidays so i will see what i have then, i just like to run any possible test prior to pulling so if i need need help (from you guys) i have an answer instead of saying i don't know which seems to happen often in these posts.
 
ok tans is out as of this afternoon. Front clutch pack looks new, rear clutch on the other hand looks slightly burnt (rear clutch is a 4 clutch pack) clutch thickness is .061. The bronze bushings look slightly worn/scored as well. Nothing here looks out of the ordinary not be slipping in all forward gears.

Nothing at this point shows where the aluminum flakes came from, i'm assuming the gold flakes came from the bushings.

So slipping in all gears even though it's a new torque converter i'm leaning toward it though not everything has been taken down yet.
 
By the way, with Chrysler stuff, and OBD 1, you should be able to turn the key on and off five times face (ending on) and the check engine light will blink to tell you codes. I know it's that way for my jeeps (95's) all the way up to my old 01 (this one actually shows the numbers where the odometer is).
 
Seriously this sounds like it was taking off in 3rd (also may be the reason why you didn't see any pressure in the front servo because it never shifted into 2nd.

Metal flakes are normal after a rebuild. It's from being broken in.

Anyone having problem with sluggish take off, try this;
1) stop the truck
2) put it into N or P for a second
3) then abruptly shift it into 1(low)
4)then start moving to confirm its not sluggish via its actually in 1st gear, not 2nd or 3rd.
5) if it does accelerate freely in 1st, up shift to 2nd when the rpm go to ~2k
6) up shift to 3rd (D) if it did shifted to 2nd

I had tons of governor transducer dying problem and I at one point had to manually shift it to get all gears when I was grossing 20k going through passes in Colorado and others from Denver to Las Vegas.

I finally got my transducers to last more than a month at most by to have the valve body replaced with a Goerend unit. No more foamy fluid and shifted like dream. I had my valve body modified with TransGo Jr. with cranked line pressure.
 
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