Shuttle shift problems

[Robert_noll]

Good day gentlemen. Ill describe to the best of my knowledge what I've been experiencing. A year ago, I had purchased a 1973 Ford 4500 backhoe with a 4 speed power reversing trans (shuttle shift). When I first got it home, I had moved it to the back yard, and in doing so I was shifting through gears to make sure that everything was operational. As I got into 4th gear, it came to a rolling stop. From this point, I have tried numerous times to assess the problem. I have had a number of different people stop by to figure out what is wrong and point me in the right direction on how to repair it- everything that was suggested is not directly linked to the shuttle shift problem. Some friends have said it may be associated with the torque converter. Others have mentioned it may be because of the not going into gear, but this problem has already been fixed. I have changed the fluids, the filter, and opened up shifting boot and checked everything in there too. The tractor starts every time and all of the equipment works. It goes into every single gear, but the shuttle shift is prevented from engaging. The shuttle shift will not move in forward or reverse in either gear. The torque converter does not spin when the motor is running. the hydraulic filter does not have any fluid going through it. I had not checked the pressure under the bell housing for I do not know what the ideal pressure should be at. If you guys can think of anything beside these problems or issues that might be causing the problem, please respond and let me know. I'm at a loss for how to proceed. I'm new to this and anything you guys will know and can pass along would be greatly appreciated.

 

[Dirtdauber]

" The torque converter does not spin when the motor is running"
I would be checking this out.

 

[franklin2]

Torque convertor not turning is strange. If this system is setup like a automotive type auto trans, the torque convertor outer housing engages and turns the pump for the shuttle, the pump is pumping fluid any time the engine is running. There should be studs or bolts that attach the torque convertor to the flywheel.

 

[Tinkerer]

I am not a Ford type person, but there may be a flex plate between the flywheel and converter. It is quite common for them to fail.

 

[Robert_noll]

I have been curious about the Torque converter the whole time on how it works. I know nothing about tractors but I am Mechanically inclined. I was told that there might be a switching valve on the shuttle shift that could engage the converter and that this valve could be stuck stuck.

 

[Billrog]

I had to replace a converter on a case bh and it was bolted to the fly wheel replaced the pump while I was at it & remember it was to be within 3 or 4 thou. for balancing. It should be turning Tinker may be on to something in hos post as I'm not familiar with Ford.

 

[Dirtdauber]

http://partstore.agriculture.newholland.com/us/parts-search.html#epc::mr49534ar397919

 

[Tinkerer]

Good find Dirtdauber. The flex plate is #2 in the drawing. Robert ; Be sure to clean the screen #49.

 

[Robert_noll]

Im guessing I need to split the tractor to fix this problem? Ugh =( guess I'm going to be learning all about this thing in no time lol

 

[Check Break]

How do you know the TC is not turning. Did you pull the inspection plate under the bell housing and watch the TC when the engine was running. If yes, the your flex plate is broken or the TC is not bolted to the flex plate. Odd that you didn't hear a hell of a racket when the flex plate broke. I've never seen all the bolts shear or fall out. If the TC is not spinning, there's no energy being transmitted to your trans input shaft and your trans pump is not turning so there's no oil going to your clutch pack. You could pull the starter and look at the flex plate and bolts first. Otherwise, the sad news is if your TC is not turning, you're going to have to split the tractor and figure out why which usually means the flex plate broke.

 

[Robert_noll]

I had pulled the plate off the bell housing and cranked the engine. TC stays completely still. I could also turn the TC by hand with the engine off.

 

[Check Break]

TC stays completely still. I could also turn the TC by hand with the engine off.

Pull the starter and take a look at the flex plate. I'm sure you're going to find the center of the flex plate is broken out. A gear wrench ratcheting end wrench is the fastest way to remove the bolt behind the starter, between the starter and the block. If you need help splitting the tractor and you don't get it when you need it here, go over to Yesterday's Tractors, Ford forum. There's a lot of Ford knowledge over there.

 

[Brad Buchanan]

I had pulled the plate off the bell housing and cranked the engine. TC stays completely still. I could also turn the TC by hand with the engine off.

I just rebuilt my 4500 (3cyl. diesel) and the flex plate was cracked near the center. Most likely that is the problem. Tractor needs to be split to fix unfortunately.

 

[oldhousehugger]

This is probably old news but here goes anyway. I am just about to reinstall my engine after a complete rebuild. The repair manual says to remove the fuel tank-steering column assembly to open up the bell housing from the top before you remove the engine to be able to remove the bolts holding the torque converter flexplate to the flywheel. This allows the torque converter to stay installed in the front of the pump so you don’t gink up the seal.

I forgot to read that part! I pulled the engine without unbolting the torque converter. Who knew?

My torque converter sealing surface had been marred pretty badly from previous work done by persons unknown (ok it could have been me). I filed, sanded and polished the surface of the neck that inserts into pump to regain a reasonable sealing surface. I have now taken the steering column etc off to get into the bell housing as directed. I plan to insert the neck of the torque converter into the pump and verify proper connection before proceeding with engine placement.

The manual says to then install the engine with flywheel attached and once the engine is bolted to the bell housing, then line up the bolt holes on the flywheel with the bolt holes in the flex plate, install and torque bolts. This way you don’t put any part of the torque converter assembly in a bind.

So theoretically if a person did not bolt the flexplate to the flywheel the torque converter would not turn when the engine is rotated.

A couple of other things occur to me as to why a tractor refuses to move even though the linkage all looks to be working. There is a drive pin that operates the vertical shaft that works the shifting valve. The drive pin goes thru the bell crank lever and shaft on top of the bell housing. If that drive pin is missing she no shift.

Picture is of where the engine is off but the fuel tank steering column isn't. I took it loose later because I dropped the tube that goes to the oil cooler into the reversing clutch chamber and had to take the pump loose to retrieve it. It also occurred to me that following the instructions in the repair manual might actually save time. I'm waiting for a few dry days to put it all back together.