Eric_White 7 #1 Posted February 4, 2014 OK, got a 70 commando 8. When trying to plow snow, 3rd gear NOW goes slower than secondand grinds going into gear. Seems like loosing power all together. there is pleanty of 80w90 gear oil in the trans. anyone got an idea what is wrong? see attached pics 1 Share this post Link to post Share on other sites
Kai Thomsen 17 #2 Posted February 4, 2014 Worn out drive belt ? 1 Share this post Link to post Share on other sites
stevasaurus 22,701 #3 Posted February 4, 2014 (edited) Nice looking horse. I like what Kai said about the belt. Is 1st and reverse OK? I would add to take a look at the hubs and those key ways...it does not sound like an internal transmission problem with what you said. Maybe check the input and engine pulley key ways also. Also, check to make sure none of the tabs on the belt cover are not broke...there may also be a tab or 2 mounted on the engine block or the tins under the guard. Edited February 4, 2014 by stevasaurus Share this post Link to post Share on other sites
Terry M-(Moderator) 2,175 #4 Posted February 4, 2014 Steve, I'm just guessing here, but because this tractor has a vertical shaft VH-80 tecumseh engine, the trans probably isn't your typical uni-drive...or is it??? 1 Share this post Link to post Share on other sites
stevasaurus 22,701 #5 Posted February 4, 2014 Good point Terry...I did not realize that. In that case...I am not sure what is wrong...I was not sure in the first place. I would still go with the stuff I listed first...it still does not sound like internal until you check the out side stuff first. Dropping the trans is the last resort. I will check the manual. Thanks Terry Share this post Link to post Share on other sites
stevasaurus 22,701 #6 Posted February 4, 2014 (edited) Terry...you are correct...not the trans I am used to. I have not been in one of these. WOW, sorry Eric..need TT or someone familiar with these to hop in here to get the correct help. Eric...I sent a PM to TT... Edited February 4, 2014 by stevasaurus Share this post Link to post Share on other sites
TT-(Moderator) 1,131 #7 Posted February 5, 2014 I probably won't be much help due to thick cobwebs in the brain syndrome. It's been years (10 or more) since I was inside a 5066/5067 Uni-Drive. Other than the typical stripped 3522/3523 input shaft / 2nd-3rd gear that plagues the "normal" three speeds, the only other thing I can think of that was problematic was the face teeth on the "ring gear" wearing. This style tranz has a worm type pinion shaft which has a tendency to push away from the ring gear under load. I sent a very tired Commando to the scrap yard about a year or two ago. It was supposed to have a good tranz, but when I flipped it up to have a look, I found this: 1 Share this post Link to post Share on other sites
Eric_White 7 #8 Posted February 5, 2014 Thanks Kai and Steveasaurus... I took your advice and checked the drive belt...YEAH, so loose. Checked the manuel and its a 73.8" belt so I had to go with a 74". OMG what a difference. 1 Share this post Link to post Share on other sites
stevasaurus 22,701 #9 Posted February 5, 2014 After seeing TT's picture of the transmission and going back and forth with him in PM.s...I think we are all glad it was the belt. I would go buy a lottery ticket if I were you. Just saying. It sounds like they are a real bear to tear down and work on. Share this post Link to post Share on other sites
