641 tractor

onetommy

New User
Long time reader, first time poster............ I tried the fail proof way of unlocking a 641 transmission, by backing the engine up and got the transmission free and all shifters appear to work as designed & work properly. However when I put the top cover back on and fire the engine with clutch disengaged I am able to shift through all gears smoothly but if I start to engage the clutch the motor starts to bog down no matter what gear that its in, including neutral. My conclusion is that there is still something locked up / broke. I have heard no pops or bangs and everything looks OK, but; I still have a locked up problem. PLEASE HELP......ta
 
Well first lets address your terms. Disengaged is when the pedal is down engaged pedal up.
Is the PTO out of gear??? It could be locked up and cause the problem.
Are you 100% sure it is not stuck in 2 gears at the same time???
If it was winter I would say maybe ice in the transmission but not this time of year unless your in the land down under that is
 
Clutch down, I can start & run tractor. When I start letting the clutch out the engine starts to go under load with no movement. PTO does not change anything in or out. If I start to let clutch out in any gear or neutral the tractor starts to load and I push clutch back in. It acts as if still locked up but everything is moving as it should and all is lined up as picture shows but, I have no out of gear ( neutral )..........ta
 
First jack up one rear tire. With it in neutral can you spin it?? If you can not then jack up the other one so both are off the ground. Can you spin them?? Does one turn one way and the other the other way when in neutral. If yes then you have something wrong in the transmission and something is locked up in it. Can it be pushed/pulled in neutral and move as it should??
 
old,

Thanks for your reply and I will try your suggestions in the next day or two & will repost. Currently I'm working 6 to 6 on night shift and there is just not enough time in the day to check it out. Again THANKS and I will be back......................ta
 
(quoted from post at 19:34:54 08/02/15) First jack up one rear tire. With it in neutral can you spin it?? If you can not then jack up the other one so both are off the ground. Can you spin them?? Does one turn one way and the other the other way when in neutral. If yes then you have something wrong in the transmission and something is locked up in it. Can it be pushed/pulled in neutral and move as it should??

Old,
THANKS, I went and jacked up one rear tire and forward or reverse it would not turn, and the all of a sudden it started rolling backwards, still real tight for about 1/4 of a round, then it got easy and all was free. I started it up and all gears ran OK and all is great except third gear has a little knock, Next I will be pulling it in my basement to drain fluid and check to make sure I got no bottom metal and all my teeth........Thanks again.......ta
 
Sounds like you may have something coming apart in the transmission and when you messed with that one tire it fell down and out and freed things up.
 
Yep, I, have at least a half a tooth gone in what I think is 3 rd. gear. Getting ready to drain oil out next and look around some more......ta
 
(quoted from post at 13:16:10 08/07/15) Yep, I, have at least a half a tooth gone in what I think is 3 rd. gear. Getting ready to drain oil out next and look around some more......ta
rd shares a countershaft gear with reverse, so may want to check all 3 of those gears.
 
Part of a tooth being bad is not good thing since it may or may not hold up over time. Plus as JMOR says look things over real good.
 
jmor,
Sorry, I'm not aware of any "modern view" Please advise, and Thanks in advance for your concern & help...........ta
 
(quoted from post at 08:36:19 08/08/15) jmor,
Sorry, I'm not aware of any "modern view" Please advise, and Thanks in advance for your concern & help...........ta

Never mind' I found modern view Thanks.....ta
 
Well it looks, not good at All. Found where two teeth and a partial went, but I found three teeth and a partial in the bottom. Any one got a good transmisson?......ta
 
If it is only one gear like that you can buy just the gear and install it. I would also do all the bearings at the same time just for good measure
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top