Transmission isnt Moving!!!

[Redrider2911]

Hey guys. I went through this 47RH building it up last year when I built my truck. Been driving it the last few months without issue.

Here is what is happening now. The truck can be pushed forward by hand when in neutral all though it feels a little harder than before. However, it CANNOT be pushed backwards. It just locks up. I get no movement in drive at idle, all though I can still push it forward by hand and still cant push it backward. When shifted into reverse, I get a ever so slight lurch Forward where there it sits. It then cant be rolled forward or backward by hand. Any ideas?

These are the events leading up to this.

I snapped the input shaft the other day on a 2-3 locked shift. Tore the transmission apart, installed a billet input, and inspected the front half of the trans. (left the overdrive unit attached and intact. The only noticeable wear was on the direct drum. I ordered new frictions and rebuilt that clutch. After talking to Big Blue we concluded that the wear was due to not enough line pressure. I turned the line pressure from the Transgo recommended 4 turns to 7 turns in from flush. I also turned the kickdown screw all the way in per Big Blues suggestion to try to take care of some early shifts on half throttle.

I drove the truck home and it was acting funny. It would stall in reverse if you didn't have your foot on the gas. The torque converter felt REALLY tight. Like you could idle off the line to 15mph. It didn't feel like there was any lockup or overdrive. Drove it back to work in the morning, same symptoms. Hooked up a pressure gauge and line pressure at idle was like 135. I went to go take it for a drive while watching the gauge and all of a sudden I had no forward movement. Then no reverse. Then by what I am sure was just pure coincidence, the rubber transmission line blew under the heat exchanger.

I concluded that the torque converter was the issue because when the input shaft broke, it shoved the front piece in to the converter a good inch or so. Thought I would get lucky, but I guess not. I sent the torque converter back to Revmax to have it looked at. Its going to be TWO WEEKS before they can even look at it. I didn't want to wait, a local trans shop had a PDQ torque converter on the shelf. Part number 655A-SHD-STE. They said they installed it for a guy, he ran it for 50 miles and didn't like how tight it was, so they sold it to me for a great price. I took out the direct and forward drum just to have a quick look see. Everything looked fine. Didn't even take off the valve body. I did replace the filter as there were some decent sized chunks of input shaft in it.Put it all back together. Rechecked endplay is at about .030. Then I installed the transmission and have the results above upon filling the fluid on first start.

Any help would be much appreciated as I'm starting to get frustrated.

[Redrider2911]

I should add I guess that before I tore the transmission down. It rolled forward and backward by hand perfectly fine.

[Big Blue24]

Did you remove the low/reverse drum and sprag assembly during the rebuild? It almost sounds like the low/reverse drum is bound up.

If the forward clutches somehow welded together, it would have that weird forward lurch in reverse then act like a trans-brake was engaged meaning not movement in either direction once the slack was taken up out of the geartrain. However, a welded/permanently engaged rear clutch would have still have all the forward gears.

The fact that it can't be moved in neutral would be my determining factor to pull the transmission because a hard part failure or bind-up is likely and therefore a tear-down is in order.

[Big Blue24]

Another thought: about 75% of the time we get a transmission in for repair/service with a broken input shaft, the pump stator also gets damaged, you might have a cracked pump and/or stator that is causing a cross leak between the forward clutch and the 3rd/direct clutch. This could cause the reverse bind-up (simulated transbrake), I still can't come up with a theory why this would make the truck not move in neutral though.

[Redrider2911]

I removed them when I rebuilt the the whole transmission a year ago. And I did a quick inspection when I installed the billet input. Had to pry out the intermediate shaft to remove it and tap it back in with a mallet to reinstall. I assumed this is normal because of the torque when shifting in and out of overdrive? Splines looked fine.

The forward clutches looked fine when I put in this torque converter. Just took a quick peak. And both forward and direct drums seemed to reinstall fine.

Yea. I found the rolling forward but not backward while in neutral to be the big determining factor. I was just checking to see if I may have missed an obvious possibility. I really don't want to have to pull the cab and transmission again for a 3rd time in like 3 weeks. Lol. Is it possible for the parking rod to cause it to only lock up backwards while in neutral? It's the only other thing I could think of, but like I said; I didn't remove the valve body or parking rod.

[Redrider2911]

I honestly didn't take the pump apart. But I did a good visual inspection externally and didn't see any cracking or anything that looked damaged.

[stubz616]

Why are you pulling the cab to do a transmission? I agree with BigBlue on the low/reverse drum being bound up. Maybe the sprag came apart and locked it up.


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[stubz616]

Sorry. Just switched to web view from Tapatalk and saw its in a Willys.


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[jlbayes]

Originally Posted by stubz616

Why are you pulling the cab to do a transmission? I agree with BigBlue on the low/reverse drum being bound up. Maybe the sprag came apart and locked it up.


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He might have a heck of a time getting to the bell housing bolts with the setup being in a 49 willys pickup.

[Redrider2911]

Originally Posted by stubz616

Sorry. Just switched to web view from Tapatalk and saw its in a Willys.


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Exactly. Its a tight fit. I'm down to about 1-1/2 hours to pull the fenders, brake booster, steering shaft, electrical, cab bolts, driveline, t case, and transmission. I think I can do it with a blind fold by now. lol

I'm going to start pulling it back apart on lunch. Ill let you guys know what I find cause I know you just gotta be curious... I'm just going to tear down the whole thing to make sure I don't miss a single piece of debree that could be lodged somewhere.

Another somewhat interesting thing we tested on break. We pushed it back into place with a forklift. No pop, snap, or screeching of the tires. So whatever is jammed up is allowing it to give.

Thanks for all your input guys!

[Redrider2911]

Stupid me. In a rush and was messing with trying to get the anchor seated and the band on through the front of the case since the valve body was on. And I didn't notice that the direct drum lost mesh with the shell. Looks like I got lucky though. I don't see any internal damage.

[Redrider2911]

Got it all back together. I have a good positive 1st gear, second gear, and what some seems to be a weak 2nd gear lock up while in "D". No reverse, 3rd, or 4th. Tomorrow I will go through and get pressure readings on the ports.

Below is a list of the only things I have changed since the last time the trans worked properly and I snapped the input shaft.

Turned line pressure from 4 turns to 7.
Turned kickdown screw from stock to all the way in.

My end play was like .125 or something so I did some changing of the selectables to get to about .030.

3 tab output washer from .068 to .083
Plastic shim between forward and direct drum from .061 to .102
Plastic shim between direct drum and pump from .085 to a .061 +.085 stacked.

I'm pretty sure those were the thicknesses I ended up with looking back at my notes. I felt a little sketchy stacking the shims behind the pump but I measured the distance to center of port on the pump vs center of port on the direct drum and they lined up perfectly with the shims.

I cant think of anything else I have done. This is going to be the end od me...

[Redrider2911]

I did also readjust the rear band. But I believe that would only effect reverse or 1st while in manual 1st correct?

Maybe I missed something in the valve body. Hopefully the pressure tests tomorrow will be conclusive.

[zstroken]

Originally Posted by Redrider2911

Got it all back together. I have a good positive 1st gear, second gear, and what some seems to be a weak 2nd gear lock up while in "D". No reverse, 3rd, or 4th. Tomorrow I will go through and get pressure readings on the ports.

Below is a list of the only things I have changed since the last time the trans worked properly and I snapped the input shaft.

Turned line pressure from 4 turns to 7.
Turned kickdown screw from stock to all the way in.

My end play was like .125 or something so I did some changing of the selectables to get to about .030.

3 tab output washer from .068 to .083
Plastic shim between forward and direct drum from .061 to .102
Plastic shim between direct drum and pump from .085 to a .061 +.085 stacked.

I'm pretty sure those were the thicknesses I ended up with looking back at my notes. I felt a little sketchy stacking the shims behind the pump but I measured the distance to center of port on the pump vs center of port on the direct drum and they lined up perfectly with the shims.

I cant think of anything else I have done. This is going to be the end od me...

I would be curious is how you picked up nearly .1 in end play. Didn't you say it initially was .030 when you first put together, and then it became .125?

[Redrider2911]

Huh? No. When I first built the transmission a year ago I didn't have selectables in order to get the end play tighter. So I just ran it at the .125 or so that it was at. I was running it like that for the last 3 months. When I broke the input shaft (the last time this Trans was working fine) BigBlue was nice enough to send me some selectables. So upon installation of the new input, I checked end play. It was like .125. Then I changed/added the selectables to get it down to about .030

[Redrider2911]

So it's gotta be something in the direct/front clutch drum or apply circuit. If the broken input shaft caused enough side load to wear the bushing down, would that leak enough to completely lose reverse, 3rd, and 4th? After hooking a gauge to the pressure port, I'll remove the valve body and run some air through the clutch apply port to see what happens.

[Big Blue24]

Yes, it sounds like a no-apply condition on the 3rd/direct drum since it's used for 3rd, stays engaged for OD, and is used for reverse. The last input shaft I personally broke took out the 3rd gear drum with a crack along with the pump stator support. If nothing is cracked you likely have a blown seal, missing seal, or installed a seal backwards on the drum/piston itself. The bushing being worn can allow the drum to wobble and wear but it's not going to immediately make it lose 3rd/Reverse.

Your air check is going to be a good place to start. And next time you pull the tranny, be sure to air check it before you install the VB, it's much easier to open it up after a bad air check when it's sitting on the work bench....

[Redrider2911]

Originally Posted by Big Blue24

Your air check is going to be a good place to start. And next time you pull the tranny, be sure to air check it before you install the VB, it's much easier to open it up after a bad air check when it's sitting on the work bench....

If only I was this smart 2 installs ago!

I know for sure the stator isn't cracked. Didn't freakin think about checking for cracks in the drum. I would be really happy if it's a valve body issue or cracked front band servo, from my understanding it's on the same circuit.

[Redrider2911]

Started up the truck today to move it into the shop. Barely moving in 1st gear now.

[Redrider2911]

Line pressure is 125.