has reverse but no drive....HELP

B

Big Bertha

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Mar 14, 2013
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Okay, I know this is going to be a bit hard to help with since your not around to see whats actually happening so I'll do my best to explain the issue, I cracked the front hub gear in half on my 47re, I took it apart and replaced the gear and input shaft, put it all back together, torqued the band to 72 inlbs and back it off 1 1/2 turns and torqued to jam nut, it has a ats triplelock convertor, and a aftermarket valve body which were already installed before i bought the truck. I put everything back in the way I took it apart, now with that said heres the fun part. I started it up, filled it up on atf and now I have reverse(which I drove it around my neightborhood in reverse the other night) but I have no drive. I put it in low, 2nd, and drive and I have nothing, but it was rolling backwards and I dropped in it drive and it held it there. I put it in 4low and I was able to get her to move 3 foot and then it disengaged, I can run the rpm up to 2k and still nothing. Ive had people say the valve body needs cleaned which could be plausable but I never took it off. Any ideas would be help full, I know a pressure check would be helpful to see what pressures Im getting which I will do tonight.:bang
 
Sounds like the forward clutch pack is not applying properly. I could be a torn seal from the cracked front hub gear ordeal that was missed in your teardown.

It's the clutch with the bellville spring:
Transmission13.jpg


Transmission01.jpg
 
Big Blue24 said:
Sounds like the forward clutch pack is not applying properly. I could be a torn seal from the cracked front hub gear ordeal that was missed in your teardown.

It's the clutch with the bellville spring:
Transmission13.jpg


Transmission01.jpg
Click to expand...

This, missing seal on input shaft, or loss of pressure/plugged filter.

Sent from my DROID3 using Tapatalk 2
 
im thinking missed seal on the new input shaft. gonna tear into the trans either tonight or tomorrow. thanks guys for the input
 
I think you or a friend called me about this yesterday, Id put money on the steel sealing ring at the base of the input shaft is missing or broken.

Lavon
 
No forward would be the rear clutch. Not the front clutch. Front clutch and rear band is reverse. rear clutch is applied in all forward gears.
 
Big Blue24 said:
Sounds like the forward clutch pack is not applying properly. I could be a torn seal from the cracked front hub gear ordeal that was missed in your teardown.

It's the clutch with the bellville spring:
Transmission13.jpg


Transmission01.jpg
Click to expand...


I see you have doubled up the return spring, and it looks like it is hitting the carrier. On that note, does the added pressure your running offset the effect of having to distort the second spring? How much line pressure are you running with the setup?
 
zstroken said:
I see you have doubled up the return spring, and it looks like it is hitting the carrier. On that note, does the added pressure your running offset the effect of having to distort the second spring? How much line pressure are you running with the setup?
Click to expand...

He went back to the single return spring setup on the Junker Truck according to a later post in his build thread. Running two was causing wear issues you had mentioned
 
thanks everyone for the help. the pictures do help a lot. I'm assuming the seal I'm missing sits in the intermediate shaft where the input shaft sits on that copper bushing?
 
zstroken said:
I see you have doubled up the return spring, and it looks like it is hitting the carrier. On that note, does the added pressure your running offset the effect of having to distort the second spring? How much line pressure are you running with the setup?
Click to expand...

The pictured setup was a text book fail!

I tried to run the double spring at high pressure an go back to the 4 friction setup. As you can see in the picture the 4th clutch fell off the forward gear splines and so only 3 clutches were engaged. I got a few 12 second 1/4 mile passes out of it before it slipped so bad it was only putting down mid 13's then 14 second passes. This was with a minimum of 175 psi at any time and upper rpm pressure reaching 200 psi.

I have since gone back to a 100% stock forward clutch setup with 225 psi peak pressure on cold fluid and around 210 psi peak pressure on hot fluid. So far this has been the most reliable setup. In talking with a few of those southern cummins racing guys like Darren M., they are able to get the stock forward clutch setup to hold till about 1000 rwhp with 215-225 psi line pressure. So I decided to give it a shot and so far it has been reliable.
 
fox said:
No forward would be the rear clutch. Not the front clutch. Front clutch and rear band is reverse. rear clutch is applied in all forward gears.
Click to expand...


Most professional transmission builders and repair manuals refer to the forward-most clutch as the direct clutch as-in 1:1 direct drive ratio based on the torqueflight's heritage/roots when it was a 3 speed tranny with no overdrive. Likewise, most tranny builders and manuals refer to the rear-most clutch in the main case as the forward clutch as-in forward gear clutch or clutch that is applied for forward motion and released for reverse.

You are right that the clutch pictured is sometimes referred to as the rear clutch, we're not here to discuss semantics though, we are here to discuss a broken transmission.
 
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