My OC46 stoped dead in its tracks today. The universal joint behind the shuttle transmission spins when the clutch is let out, but the tractor will not move. I tried all four gears (1-2-3-4-R) with same result. It appears that the transmission gears are "catching" when it is put into gear as you can feel the gears slip over each other and lock in. I am not looking forward to taking the whole transmission out for overhaul. Any ideas would be greatly appreciated.
Deron
What happens when you pull the stering lever each at the time?
will it try to move? if the driveshaft to the sprocket wheel is broken it will stand still. if it moves if you pull the lever on the right side and it will try to move then it is that side that is broken same for the left side.
When I pull the lever to the left, it moves. When I pull the lever to the right, it moves. It only moves straight, but it doesn't seem to matter which lever is pulled.
Deron
Deron,
I've had a similiar thing happen on an aux transmission drive, could feel gears engage, but no power through drive when the clutch was deployed. My problem was the pin in the rear universal was sheared. Could this be your problem? You would see the drive spin, and under no load it would tranfer a little friction to the gears to make it feel like they were engaged.
Just a theory.
Hope this helps.
Mark
Mark,
I can see the rear universal joint spin when the clutch is let out. If a pin were sheared then the tractor shouldn't move when one or the other of the steering levers is pulled back, right?? I will take another good look at the rear universal joint just to be sure it's ok though. Thanks for the help!
Deron
It sounds like you have problems with the final drive axel or final drive gears. Most likely a broken axel shaft. With a differential your crawler will not move with a broken axel unless you pull one or the other steering lever.
As far as figuring out which side has the problem, you will need to push against something and one track will have traction and the other will not. the latter is the side to check.
Good luck
Ray Z.
Deron,
Ray is right on. i also have an OC-46 (a 1957 4 cyl though) and last year i went through what sounds exactly like what you are experiencing.
to clarify what Ray mentioned (and emphasize), here is what i did to diagnose the problem.
first, due to how the standard differential works in these crawlers, the crawler will move forward in basically a straight line when either brake is partially applied, even if one of the final drives is not getting power (broken axle, stripped bull gear or pinion, etc.). i do not know how the Slo-Lo or any other funky transmissions will work, only the plain old standard differential like i have in mine.
now, do exactly as Ray suggested. i used a big chunk of concrete block wedged in front of my tracks. i first wedged it under the front of the left track. i then started the crawler and applied the LEFT brake ALL THE WAY (pull back on it like you want to STOP). the crawler started going forward as the brake was applied, but once i LOCKED the left side, the crawler attempted to turn to the left. make sure you don't have anything of value on either side of the crawler as it tries to turn one way or the other, as these babies turn on a dime when they want to. i then kept the concrete under the left track and applied the RIGHT brake. the crawler just sat there like it was in neutral (the left drive pinion was totally stripped on mine).
then, to verify things i moved the chunk of concrete to the right side. when i pulled the LEFT brake, the crawler attempted to jump up over the chunk of concrete. i then applied the RIGHT brake and while the crawler attempted to move forward for a second, it did not go over the concrete and just sat there like it was in neutral again.
if this is what happens when you try these tests, it means power is not getting to one of the final drives (which one depends on the results of the tests). pulling apart one of the final drives is not all that big of a deal. a small come-along, a 10-ton bottle jack, and a bunch of wrenches really are the only tools needed. it took me an afternoon to get mine apart, and only a few hours to put everything back together.
let us know what the results of your testing are and we can talk you through the rest. i had an advantage in that i only live a bit over an hour from Zimmerman's, so i just drove down with my broken parts and they set me up with what i needed to get back in action.
good luck with the project,
andy b.
Thanks for the help diagnosing. That is exactly the info I was looking for. The problem was with the left final drive attatchment to the sprocket. Somehow all of the lug bolt got sheared off. No idea how that would have happened unless when I broke a track link on that side last week it provided enough uneven torque??. Will be a little bit of a pain to get the broken studs out of the drive gear, but all things considered is a relatively easy fix. Thanks a ton for all the help!
Deron
Deron,
good to hear you found the problem. i'm not sure how those bolts could shear unless they were loose. i'd say check the bolts on the right side as well to be sure everything is tight.
andy b.