jd lt155

[Luffydog]

came in because it wouldnt move. sure check the simple first. hydro release wasnt pull and then went to look at the belt sure enough hanging down. simple fix or should be. heres the problem.. put it on 3 times and all 3 it came back off. checked pullies and made sure all clear and free and they was. the springs was haning when it came into shop. last time i put the belt on after cranking i noticed when u pushed the brake down to start it had a bad vibration in the pedal. the belt stayed on until the delivery man was going to take it back and sure it came off. need pics of where the springs locations and where and what they hook to. this is a new belt and it comes off at the back at the trans.thinking it might have or started to have trans troubles. pulley looks good. kinda of lost first time i had to put a new belt on for the 4th time. thanks for any ideas. if u could or have pics of the springs in place might be a help out. thanks again to all....

[bgsengine]

1) Check the frame for cracking and flexing when speed or direction is changed
2) check for piece of wood or debris jammed in pulley grooves (especially considering the vibration you noticed)
3) check for pulleys bent or dented
4) missing belt keepers

Of the 4 I would bet on #4, #2, #1, #3 in that order, in sequence of what is most likely - That's just a few things off the top of my head that I have seen with those Deeres Then there's mis-aligned idler brackets, worn out idler plate bushings, to name a couple things in the clutch area..

I doubt that spring hookups would solve the basic issue, though they may contribute to it.

[Luffydog]

thanks bg ill check it out in am if i have a chance before the holiday. if i had hair i would be bald. just hate the redos and the the do overs and still being lost. everything appears to look good but might not always be. he tried to fix but didnt get any where fast as i am finding out as well. just wish he wouldnt have cut the belt off and lefet the springs on it to be fixed.. thanks again for the helping hand.

[bgsengine]

Yeah I have had no less than 4 different machines, including a LT155 where the frame was either rusted so badly or it was cracked to where the frame would flex and allow the transmission to shift up or down or sideways and throw the belt off - either at direction changes, or sudden lateral movement or just going through a bump or dip in the yard.. Have also had a few where there were bits of twigs (yard debris) jammed in the pulley grooves, and a couple where someone else trying to "fix" it cheap without having to unbolt stuff (to clear belt guides) by prying on pulleys and belts , bending the pulley flange in a spot or two causing the belt to "jump" in the groove at that spot (vibration in clutch pedal)

If the springs are not actually hitting the belt or moving things out of alignment, I do not think they will be the cause of the belt throwing off. (Slipping maybe, or improper engagement, but unlikely to throw it off)

Did have a Deere earlier in the year that kept throwing the PTO belt (manual clutched PTO) and it was caused because the last person to try to fix it actually CUT the belt guides off! (had to order in and replace the whole guide assembly)

[KE4AVB]

last time i put the belt on after cranking i noticed when u pushed the brake down to start it had a bad vibration in the pedal.

I think this is key to your problem as the brake/clutch should disengaging the drive belt so there should be no movement of the pedal. It may take using a remote starter with the plug wire(s) disconnected and watching the drive belt path when the brake is locked down to see what is moving that isn't suppose to. That double idler assembly should disengage the drive belt when pedal is down and the counter pull spring should pull back on when the pedal is up. Can be a bear to hook up sometimes.

I wish I had taken a picture of the LT150 drive I had in back in the summer but I didn't. It does sound like something isn't routed correctly or there is a bad pulley bearing. As BGS said that rear pulley is suppose to have a have belt guide in place so the belt should be coming there especially if your using the 1/2 x 83". There is plenty adjustment in idler assembly for a variance in belt length.

[KE4AVB]

Here is an link to some instruction on changing the LT155 Drive belt I found on the net; has pictures.
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=12&cad=rja&uact=8&ved=0ahUKEwiup8X836zJAhXK6CYKHRC0AcE4ChAWCD8wAQ&url=http%3A%2F%2Fwww.instructables.com%2Fid%2FHow-to-change-the-traction-belt-on-a-John-Deere-LT%2F&usg=AFQjCNHFf4mWYh5nnJQkUlAI4UZGX3Xrjg&sig2=8eNfgLdxeK2SKEVYbNZd7A

[Luffydog]

sorry for the late post. turns out the pulley on top of the trans was a little worn. has a inside that was worn and a little wobble was there but not enough to kick the belt off. the real problem was the little fan on top of this pulley. it was hitting the belt and pushing it off. had a guy to sit on it after we safely got it up on a jack. he cranked it up while i was watching it.fan came up hit it kicking it right off the pulley. thanks for everyones replies. sorry it took so long but wanted to make sure before i posted it being solved. thanks again to all who chimmed in to help.

[KE4AVB]

Good work...thanks for the update and final solution.

I have heard of the hydro fans breaking and giving problems. I have had one on a X325 hitting the tension spring on disengage but was because I had the spring upside down. I can see how the blades could get bent especially when you got feed the new drive belt on through the blades on some hydro setups. That particular X325 was constantly tossing it drive belt but it was to due drive path changes that JD made and they had noted the wrong serial number break in the IPLs. This resulted in the drive belt being an inch shorter than the earlier belt listed in the IPL.

[Ron]

Sitting here reading through some old posts as I don't get on here much. A few years back a customer brought me his tractor that was having the same problem. Had it to another place and got it home and belt came off again. Ended up at my place. Much like you, I had to engage the drive and watch what was going on. The fan blades drooped down enough to flick the belt off. New fan solved the problem. Good catch, Luffydog!