4340 shuttle shift no reverse

[imca55]

I have 4340 with a shuttle shift but reverse quit working. I still have the forward gears and the shuttle shift lever still moves to the reverse position but it does not move in reverse. Any ideas?

 

[Renze]

Shuttle boxes are rare, i have no experience with them. I would start at the shiftlever then if necessary take the gearbox lid off.

Not sure if the shifter rod is adjustable but i guess thats ran loose.

 

[imca55]

I took the top off all the shifter forks are ok. The shuttle shift part moves a collar back and forth over a couple of gears. It looks like it is doing what it is suppose to. I am not sure where the reverse gear itself is located. Looks like the tractor may have to be split to service the transmission. Anyone have any experience with that?

 

[Renze]

got a few UR1 transmission jobs done, but not a shuttle. As said, not many people ordered this option.

Have you drained the oil ? the shuttle shift is located in the front part of the gearbox, where in the standard version, the 540/1000rpm pto selector gears are located.

If you manually put it in gear and hit the starter button, will it reverse ? If it does, your problem is in the selector mechanism.

And if it doesnt, can you see e.g. if the synchro coupler cog wheel is stripped ? just try both forward and reverse, and see if the same shafts are rotating.

But anyways, try hitting the starter button with the transmission manually shifted in reverse to check first. a malfunctioning shift lever is way more likely and way less costly.

 

[imca55]

I drained the oil and took the cover off the bottom of the transmission. I found a broken gear laying in the bottom with a bunch of needle bearings. I am proceeding to split the tractor to gain access to the front of the transmission. Thank you for your help .

 

[Renze]

Then you most likely broke the idler gear. Split it between engine and gearbox and remove the figure 8 cover with the tube that holds the clutch throwout bearing. Then pull the PTO gears from the front, to gain access to the shuttle gears.

To get the pto gear to drop, you most likely need to pull the pto shaft from the back first.

 

[imca55]

I just got the service manual and parts book that I ordered. It is telling me that I have to split the tractor between the engine and gearbox (transmission) and between the gearbox and differential. They are saying everything comes out the back of the gearbox? Sounds like more than I thought it would be. They also show pictures of 2 special pullers that would be needed.

 

[Renze]

As said, i havent ever worked on a shuttle transmission, but the shuttle is in the place where normally the 540/1000 PTO gears are. (a shuttle transmission has only 540 PTO)

If you want to take out the gears and shaft of the main 5 speed transmission you indeed need special tools to pull the gear range layshaft out of the gears before moving the layshaft back towards the differential, but i'm 99% shure the shuttle gears comes out on the front without gutting the entire gearbox.

 

[imca55]

Ok Thank you for your reply I will do some more reading before I proceed.

 

[imca55]

Thank you for your input. You were spot on. I split the tractor between the engine and gear box pulled the pto shaft and dropped the pto gear to access the bad gear which turned out to be on the clutch shaft. The two needle bearings that the reverse gear runs on failed. I had to buy a new shaft also along with some other parts. Just got it back together works good. Hopefully this information will help someone else.

 

[Renze]

Thanks for letting us know how it turned out.