856 tranny problems

[876wheelhorse 46]

ok i have a 1966 wheelhorse 856....... i changed the rear end fluid in it last weekend after it didnt seem to want want to pull very hard. last summer i put a new oem belt on it. well drained the fluid and wow looked like it was mudd brown if i could figure a easy way to post a pic i would. refilled it with 80 90 gear oil. hooked onto the roller. started off better but later found out it was worse than i thought. took off in 3rd it would stop pulling then 2nd it would go then it would get slow then first it would go. it is going in all 3 gears that is why i dont think it is the belt. i have noticed that when it isnt going the belt isnt moving either it is just slipping on the pulley on engine.......i dont know to give up on it or what.

[Martin 2,133]

well, i think you have two problems......

one is the trans has got water in it, so most likely the shifter boot is needing to be replaced as water is getting in there, this is the most common way for it to get in. also check to see if you have any bolts missing or loose in the top of the trans. theres two that hold the hoodstand/toolbox on. you need to flush the trans a few times to make sure and get it all out. i use diesel for this, but others could have more suggestions.

the other problem is belt slip. if the belt is slipping on the engine pulley then maybe the belt needs replacing (which you have done) or you have a tension issue with the spring on the brake side of the trans, maybe spring needs replacing or something is hanging up and not allowing the idler to take up tension properly.. if the engine pulley is small, like i have on my 1057, then belt condition/tension is going to be critical as the small pulley doesnt have alot of surface area to grip that belt.

if the slipping started soon after replacing the belt, is the belt the correct length, number etc.?

[rmaynard 15,608]

I purchased an 856 a couple of years ago that had a similar problem. Somehow the set screw in the input pulley to the transmission has worked loose, the pulley moved, and the woodruff key fell out.

[stevasaurus 22,867]

It sounds like it is a belt or pulley issue. To be sure, jack the rear end off the ground and turn the input pulley by hand in each gear. The tires should turn, but in opposite directions. If you did not flush it out, I would drain the fluid at some later point this year and see what it looks like. If the input pulley turns the trans and sounds good, your issue is the belt, spring, pulleys on the outside. Do you have the old belt yet? See if it is the same size as your new one. There really is nothing to adjust here as far as tension, any adjustment is for pedal height. Try cleaning the groove in the pulleys and the belt with mineral spirits. Do not use belt grip, but the surfaces need to be clean. Let us know and we can go from there. :)

[876wheelhorse 46]

where can i purchase a boot so water doesnt get in there? mine is ripped big time i looked at it. ill try that and a new belt thanks guys

[stevasaurus 22,867]

Your Toro dealer has them for maybe around $5...could be a little more now, but reasonable .

[Rooster 191]

You do realize this is a manual transmission and the transmission itself cannot "slip" . I noticed you talked about it "wanting to pull" . Internally it is either engaged and pulling, or it is not! Unlike a hydro or an automatic transmission in a car, there are no internal clutches to slip, all gear to gear.

SO whatever is "slipping" is external in the belt drive some where. ...it could be caused by a problem internally, something binding up....like rusted gears?