Top loader problem...HELP!!!

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

yellowmach351

Well-known member
Joined
Jan 12, 2014
Messages
49
Reaction score
0
Location
Coal Valley, Illinois
My Car
1971 yellow Mach 1 ram air 351c traction loc 4 speed. Ordered new from the factory in April 1971. 74,000 miles, in excellent condition. Going through complete engine rebuild only to increase horsepower, not because it needed it. Should bring 430 to 450 hp upon completion.
I pulled this transmission when I started the engine rebuild. The only thing I did to it was replace the oils seals on the front and rear and refill with new grease. I did not move the shift levers. Now that it's back on the engine and in the car, it seems there is a gear locked up, I think 4th. I lay under the car and have all three levers in neutral. I can turn the drive shaft by hand ( but the clutch pedal is being held down by a wood block wedged against another piece of wood in front of the seat). I can turn the shift levers with a wrench. Each time I click the lever to a gear, the driveshaft obviously will then, not turn. I get Reverse and neutral. I get 1st, neutral, 2nd. I get 3rd, neutral and then it seems (feels like) to turn to 4th, but will not lock in and I can still turn the driveshaft. With the transmission in reverse, I held the clutch in and started the engine. I started to release the clutch slowly and the engine started to bog down. Immediately pushed the clutch in and shut off the engine. Went back underneath and the result is what I mentioned earlier.

Sorry for this long post, but I've been trying to work this out for some time, hoping I wouldn't have to pull the transmission again, though I think that will have to be done. I always get good suggestions and help from this forum. If any of you transmission guys can help me out, I would appreciate it very much.

 
I pulled this transmission when I started the engine rebuild. The only thing I did to it was replace the oils seals on the front and rear and refill with new grease. I did not move the shift levers. Now that it's back on the engine and in the car, it seems there is a gear locked up, I think 4th. I lay under the car and have all three levers in neutral. I can turn the drive shaft by hand ( but the clutch pedal is being held down by a wood block wedged against another piece of wood in front of the seat). I can turn the shift levers with a wrench. Each time I click the lever to a gear, the driveshaft obviously will then, not turn. I get Reverse and neutral. I get 1st, neutral, 2nd. I get 3rd, neutral and then it seems (feels like) to turn to 4th, but will not lock in and I can still turn the driveshaft. With the transmission in reverse, I held the clutch in and started the engine. I started to release the clutch slowly and the engine started to bog down. Immediately pushed the clutch in and shut off the engine. Went back underneath and the result is what I mentioned earlier.

Sorry for this long post, but I've been trying to work this out for some time, hoping I wouldn't have to pull the transmission again, though I think that will have to be done. I always get good suggestions and help from this forum. If any of you transmission guys can help me out, I would appreciate it very much.
When you removed the front bearing retainer if the input shaft moved forward enough to disengage it from the output shaft, it would allow the roller bearings in the input shaft to fall out, that might cause the problem you described. Just a possibility. Chuck

 
release the clutch.. drive shaft should turn in neutral only.

Try each gear one at a time should lock up driveline.

I believe it is possible in certain situations to get the trans in reverse and another gear

at the same time which will lock up the trans.... it has happened to me. I used to run

a Mr Gasket verticle Gate shifter back in the day and could lock the trans in reverse and another

gear more times than I would like to remember. (reverse had its own lever)

report back on findings.

Paul

 
release the clutch.. drive shaft should turn in neutral only.

Try each gear one at a time should lock up driveline.

I believe it is possible in certain situations to get the trans in reverse and another gear

at the same time which will lock up the trans.... it has happened to me.  I used to run

a Mr Gasket verticle Gate shifter back in the day and could lock the trans in reverse and another

gear more times than I would like to remember. (reverse had its own lever)

report back on findings.

Paul
I will be back on it tomorrow. I think you are correct in that I have a couple gears locked....I seem to remember reading somewhere, that could happen. c9zx had a good point, but I tried to be very careful when I pulled that retainer and don't remember anything unusual, but I'll be sure to check it. I will unfortunately pull the transmission tomorrow after I try what you suggested. If it doesn't want to turn in neutral with the clutch released, I assume I have to bite the bullet and do it...unless you had some other way of releasing them, when this would happen to you.

 
Hmm. Did you replace the top cover gasket?

I would also try to reset the shift levers. Often one can get bumped and knocked out of alignment. You could try your troubleshooting again but loosen the adjustment nuts so that you are certain they are all truly in their neutral position.

 
release the clutch.. drive shaft should turn in neutral only.

Try each gear one at a time should lock up driveline.

I believe it is possible in certain situations to get the trans in reverse and another gear

at the same time which will lock up the trans.... it has happened to me.  I used to run

a Mr Gasket verticle Gate shifter back in the day and could lock the trans in reverse and another

gear more times than I would like to remember. (reverse had its own lever)

report back on findings.

Paul
I will be back on it tomorrow. I think you are correct in that I have a couple gears locked....I seem to remember reading somewhere, that could happen. c9zx had a good point, but I tried to be very careful when I pulled that retainer and don't remember anything unusual, but I'll be sure to check it. I will unfortunately pull the transmission tomorrow after I try what you suggested. If it doesn't want to turn in neutral with the clutch released, I assume I have to bite the bullet and do it...unless you had some other way of releasing them, when this would happen to you.
I released the clutch and with all levers in neutral, the drive shaft will NOT turn. I am draining the tailshaft and in the next day or two, I will pull the transmission to see what's going on. Any suggestions of anything in particular to look for? hopefully once I pull the top plate, I will be able to see the problem.

 
release the clutch.. drive shaft should turn in neutral only.

Try each gear one at a time should lock up driveline.

I believe it is possible in certain situations to get the trans in reverse and another gear

at the same time which will lock up the trans.... it has happened to me.  I used to run

a Mr Gasket verticle Gate shifter back in the day and could lock the trans in reverse and another

gear more times than I would like to remember. (reverse had its own lever)

report back on findings.

Paul
I will be back on it tomorrow. I think you are correct in that I have a couple gears locked....I seem to remember reading somewhere, that could happen. c9zx had a good point, but I tried to be very careful when I pulled that retainer and don't remember anything unusual, but I'll be sure to check it. I will unfortunately pull the transmission tomorrow after I try what you suggested. If it doesn't want to turn in neutral with the clutch released, I assume I have to bite the bullet and do it...unless you had some other way of releasing them, when this would happen to you.
I released the clutch and with all levers in neutral, the drive shaft will NOT turn. I am draining the tailshaft and in the next day or two, I will pull the transmission to see what's going on. Any suggestions of anything in particular to look for? hopefully once I pull the top plate, I will be able to see the problem.
 Just a thought. You say all three levers are in neutral, but is that with a 1/4" diam. pin or drill bit past through the locating hole? If not you could have one lever out of whack. I did this myself after I had the box professionally rebuilt. I felt like the proverbial idiot when I took it back to the shop just to find it was me not doing it right.

 
I will be back on it tomorrow. I think you are correct in that I have a couple gears locked....I seem to remember reading somewhere, that could happen. c9zx had a good point, but I tried to be very careful when I pulled that retainer and don't remember anything unusual, but I'll be sure to check it. I will unfortunately pull the transmission tomorrow after I try what you suggested. If it doesn't want to turn in neutral with the clutch released, I assume I have to bite the bullet and do it...unless you had some other way of releasing them, when this would happen to you.
I released the clutch and with all levers in neutral, the drive shaft will NOT turn. I am draining the tailshaft and in the next day or two, I will pull the transmission to see what's going on. Any suggestions of anything in particular to look for? hopefully once I pull the top plate, I will be able to see the problem.
 Just a thought. You say all three levers are in neutral, but is that with a 1/4" diam. pin or drill bit past through the locating hole? If not you could have one lever out of whack. I did this myself after I had the box professionally rebuilt. I felt like the proverbial idiot when I took it back to the shop just to find it was me not doing it right.
Thanks for the thought. I had a 1/4" drill bit through the locating holes.

 
I missed the fact that you have the shifter/ rods/levers still attached to the trans.

I would unbolt the shift levers from the trans and by hand put it in neutral and confirm the problem.

If the trans is STILL locked up I wonder if you lost the needle bearings off of the end of the input shaft

as mentioned before when U removed the bearing retainer. (The input shaft would have to have come forward

about an inch without the bearing retainer attached to loose the bearings.)

Paul

 
I missed the fact that you have the shifter/ rods/levers still attached to the trans.

I would unbolt the shift levers from the trans and by hand put it in neutral and confirm the problem.

If the trans is STILL locked up I wonder if you lost the needle bearings off of the end of the input shaft

as mentioned before when U removed the bearing retainer.  (The input shaft would have to have come forward

about an inch without the bearing retainer attached to loose the bearings.)

Paul
Linkage is not attached. I had them unbolted and was actuating the 3 shift levers coming out of the transmission by hand. I was just responding to Stanglover, and perhaps I misunderstood his question. Previously when I had all the levers in neutral, before attaching the linkage, I would make sure that all 3 linkage rods were lined up with the 1/4" drill bit through the locating hole.

 
I missed the fact that you have the shifter/ rods/levers still attached to the trans.

I would unbolt the shift levers from the trans and by hand put it in neutral and confirm the problem.

If the trans is STILL locked up I wonder if you lost the needle bearings off of the end of the input shaft

as mentioned before when U removed the bearing retainer.  (The input shaft would have to have come forward

about an inch without the bearing retainer attached to loose the bearings.)

Paul
Linkage is not attached. I had them unbolted and was actuating the 3 shift levers coming out of the transmission by hand. I was just responding to Stanglover, and perhaps I misunderstood his question. Previously when I had all the levers in neutral, before attaching the linkage, I would make sure that all 3 linkage rods were lined up with the 1/4" drill bit through the locating hole.
Also, I don't remember having the shaft move little if at all, but I did that several months ago, so perhaps it did. If that was the case, I assume I will see where the problem is pretty easily, or no?

 
You know, I'm going to sound like a real idiot here, but this has been a long project. Thinking back, I changed the seal at least a year ago, perhaps a bit longer. Looking at diagrams and exploded views on the internet, I didn't change the front seal. I only changed the output shaft seal. That was the only one with a small leak. So...there's that. That takes me back to a couple gears locked....stuck shifter fork??

 
Are U SURE!!!!!!!! that reverse is in neutral position???

if so than...

well you are out of options

I think you will have to pull the trans and pop the cover off to see whats up.

You should be able to hold the input shaft in your hand and turn the output shaft while in neutral.

Paul

Paul

 
Did you ever stand the transmission on its end, or whack the main shaft while installing the seal? Sometimes that can really jam a synchro onto the gear, but I'd think that would pop loose with engine torque if you tried to go into 4th.

 
Are U SURE!!!!!!!! that reverse is in neutral position???

if so than...

well you are out of options

I think you will have to pull the trans and pop the cover off to see whats up.

You should be able to hold the input shaft in your hand and turn the output shaft while in neutral.

Paul

Paul
I am pulling it. As I mentioned in my first post, it seems in neutral except for the 3rd / 4th detents.

"I can turn the drive shaft by hand ( but the clutch pedal is being held down by a wood block wedged against another piece of wood in front of the seat). I can turn the shift levers with a wrench. Each time I click the lever to a gear, the driveshaft obviously will then, not turn. I get Reverse and neutral. I get 1st, neutral, 2nd. I get 3rd, neutral and then it seems (feels like) to turn to 4th, but will not lock in and I can still turn the driveshaft. "

 
One other thought on assembling the shifter to the rods. I'm sure you're doing it anyway, but set the shifter up with the 1/4" drill bit/pin before bolting it to the tailstock. Then set the 3 levers in neutral, checking the output shaft is not locked, then bolt the rods to the levers. This sounds stupid and obvious, but if one rod is just a bit off, you will have a gear catching up. This is what happened to me the first time I put the rebuilt box back in after my 2012 engine rebuild. Like I said previously, I felt like the village idiot, but something so simple caught me out. If not this, then "Houston, we have a problem"

 
One other thought on assembling the shifter to the rods. I'm sure you're doing it anyway, but set the shifter up with the 1/4" drill bit/pin before bolting it to the tailstock. Then set the 3 levers in neutral, checking the output shaft is not locked, then bolt the rods to the levers. This sounds stupid and obvious, but if one rod is just a bit off, you will have a gear catching up. This is what happened to me the first time I put the rebuilt box back in after my 2012 engine rebuild. Like I said previously, I felt like the village idiot, but something so simple caught me out. If not this, then "Houston, we have a problem"
The output shaft is locked when the levers are in neutral...or what seems to be neutral. The issue seems only to be with the 3rd and 4th lever. 3rd gear locks in o.k., neutral seems o.k., but I cannot get it to lock into 4th. 

Once again thanks for the thought. I was busy today, but tomorrow it comes out and I'll get it on the workbench to see what is going on. I was just hoping beyond hope I guess that I wouldn't have to pull it out. Pulling it out not much of a problem but putting it back in again is a pain in the rear. My transmission jack has a slow leak and it will start to lower. I'm not quite as young as I used to be..(turned 67 today ) and I sure don't feel like resting it on my chest anymore!

 
One other thought on assembling the shifter to the rods. I'm sure you're doing it anyway, but set the shifter up with the 1/4" drill bit/pin before bolting it to the tailstock. Then set the 3 levers in neutral, checking the output shaft is not locked, then bolt the rods to the levers. This sounds stupid and obvious, but if one rod is just a bit off, you will have a gear catching up. This is what happened to me the first time I put the rebuilt box back in after my 2012 engine rebuild. Like I said previously, I felt like the village idiot, but something so simple caught me out. If not this, then "Houston, we have a problem"
The output shaft is locked when the levers are in neutral...or what seems to be neutral. The issue seems only to be with the 3rd and 4th lever. 3rd gear locks in o.k., neutral seems o.k., but I cannot get it to lock into 4th. 

Once again thanks for the thought. I was busy today, but tomorrow it comes out and I'll get it on the workbench to see what is going on. I was just hoping beyond hope I guess that I wouldn't have to pull it out. Pulling it out not much of a problem but putting it back in again is a pain in the rear. My transmission jack has a slow leak and it will start to lower. I'm not quite as young as I used to be..(turned 67 today ) and I sure don't feel like resting it on my chest anymore!
 Well, Happy Birthday to you! I know what you mean about not resting the box on your chest anymore. I had a 72Q 4 spd and did a clutch change in my drive, then promptly blew a rear main seal and had to do it all again. That was 1/2 a lifetime ago, 35 years.

It sounds like you do have an internal problem now though and that's beyond my scope of experience. Good luck and I hope it's not too costly to fix. Let us know eh!

 
Pulled the transmission and was able to FINALLY see the problem. 4th gear is indeed the problem. The synchronizer is stuck so I am not able to wiggle the input shaft and slide into 4th. All other gears operate properly. Now, I can still move the shifter lever to neutral and also lock it into 3rd. When I have all three levers in the neutral position, I can turn the input shaft, and the output shaft turns with it, as it should. If the synchronizer has 4th locked in, would I be able to turn the input freely with everything in neutral? That has me stumped, but then I'm not a transmission genius. It would make sense if it was locked in because, as I initially wrote, when I tried letting the clutch out when it was in reverse, the engine started bogging down immediately showing something is locked.. 

Am I explaining this clearly enough?  :chin:

I tried tapping lightly on the side (not the tooth) of the synchronizer with a small screwdriver and hammer. It wouldn't even wiggle, so I quit. Don't need to cause anymore issues. Anyone ever released a stuck syncro ?

 
Back
Top