Troybilt Bronco Lower Trans belt Oscillation

[@aniolet1]

I’m having the same problem eating belts! I even had the same missing spring you had… just received my new idler spring and OME belt …will put everything together for a test run tomorrow. Here’s a easy short cut putting the belts around the variable pulley … my (2011 bronco) has (2 bolts on the outside frame) 1/2” bolts heads that when taken out (bolts hold the variable pulley in place) the belts slip on in seconds. 😊

[@zippiezoo9319]

Thanks, let me know how it goes.. I have been running 3 seasons now since I made the video.. both drive belts are in good shape.. I wish you luck..

[@Keith-n6e2w]

Good shots

[@deborahcuster8142]

best way to stop that belt from dancing it self to death is to mount [bolt ] a horizontal backing idler pulley to the side frame . best type to use is the one where you can manually adjust the forward tension . p.s. wash that mower, all that catch all dirt will rot everything.

[@zippiezoo9319]

This makes sense... that span is too long with support.. do you have any photos or links where this has been done? Thanks

[@paulbains9152]

@@zippiezoo9319 I think youre right . The yardworks similar drives , have a hoop half way , but one or two pulleys makes more sense . The long spring on the tensioner pulley assembly looks like it could cause oscillation too . Wonder it you could have a shock ,like on a hatch back window to dampen that . Im just in the process of fixing one of these . I may have a further comment when I get it going ?

[@patmadix5706]

I see the spring I am missing

[@ronh382]

My lower drive belt is arranged like ours, but on mine there is a ~1/4" pin that the slack side of the drive belt goes around. It takes out some of the oscillation. Mine is located across from the belt tensioner assembly. Some models use a removable pin. Could yours have fallen out?

[@zippiezoo9319]

Thx Ron, Its been doing fine now for 2 seasons with the oscillations..checked the belts a couple of weeks ago and they look like new.. but I am going to take another look to see if I can see where there might have been a pin.. Appreciate the input..

[@philliphall5198]

Rusty ones will not shift or change speed, remove and sand it tell free Keep out of the weather 😊😊😊

[@stevefranklin9920]

How do you replace the lower drive belt on this particular mower? Haven’t seen any other videos that show the exact model I’m working on other than yours. My vari speed pulley is attached to a bracket that has a hook on it that hooks around the transaxle tube.

[@deborahcuster8142]

that is because his model mower is a bronco. i have one here exactly like that model . and another that is different. there is no double idle pulley system under the other one, it is just straight ( from the crankshaft pulley to the VSP [ variable speed pulley ] . the VSP is controlled by a tension load by spring . . . . as is the idler pulley for the top transmission belt , that spring is a 4 inch spring ( for anyone that wants to know ) . to replace the lower drive belt : 1. remove the crankshaft bolt from the pulley 2. slide pulley down until the top belt can slide past the belt keepers 3. loosen both idler pulley nuts [ do not remove them ] so the belt can slip by the belt keepers 4. now that the belt has plenty of slack you can now remove the drive belt from the crank pulley with ease . 5. remove the top tramsmission belt so the main drive belt can be removed. 6 to install just do the reverse as stated from #5 to 4, 3 , 2 , and 1 . your welcome .

[@426superbee4]

The Craftsman T140 got the same junk setup. Idk how in the world ! it can jumps threw the belt guard on the idler pulley~ but it does. and a royal pain to stick threw to the idler pully on the transmission belt , They put lock bolt on the dam nuts. You have to beak them off ~ Plus idk why its doing this for? Its got a belt guard on the idler pully . Every time it want move, i take the battery out and it jumped the dam pully! 😡 Every thing else looks correct.

[@harleysmith3830]

Did you ever find the cause? I’m having the same issue

[@426superbee4]

@@harleysmith3830 I just parked it for now. I think its the drive belt to the transmission idler pulley. Lip not over lapping far enough and over shoots the idler pulley > THAT WHAT I THINK IT IS? The idler pulley arm could be bent to? NEEDS A STRONGER ARM. I think a high raise idler pulley the same size would work. I don't know right YET FOR SURE? If you fine a fix let me know! BUT THAT MY GUESS Cheers buddy