denno

Hiya
Old spring and drive belt on my MTD 13AN772G729 (2007) self-destructed, so I bought new ones (belt is aftermarket, kevlar, 5/8 x 35). This is where you take out the battery to get at everything.

Got them installed with some difficulty. Tractor goes again, but not up to speed. I'd suspect a slipping belt, but it is pretty taut and was hard to get around all 3 pulleys.

Belt is a bit warm to touch and so is tension pulley. How could it be slipping?

Other possibilities?

Thanks

jhngardner367

OOOOPs! Deleted, due to double post!

__________________
" I'm busier than a one-legged cat in a sandbox!"

God gives only that which we can handle......."WHAT'S He drivin' that DUMPTRUCK for!!"

"I can't fix what ain't broke...you want I should break it?"

jhngardner367

Welcome,Denno! That unit is a vari-drive system,and it sounds to me like the belt you put on is too short. The two belt used on that unit are p/n : 954-04001A, and954-0241A.Some after market belts are not an exact fit,and can cause problems,when used. Also,are you certain it takes a 5/8" belt,or could it take a 1/2"wide belt.If the belt is too wide for the groove in the pulley,it will ride too high,and bind.I would suggest double checking the belt size.

__________________
" I'm busier than a one-legged cat in a sandbox!"

God gives only that which we can handle......."WHAT'S He drivin' that DUMPTRUCK for!!"

"I can't fix what ain't broke...you want I should break it?"

Country Boy

I'd suspect an incorrect belt as well. Some of the belts for those variable drive systems were actually more like 3/4" wide rather than 5/8". Had to order a couple recently and they were all pretty wide. I'd stick with the OEM belts for that system because length and width are important to make the system work properly. Aftermarket belts work where the belt is under constant tension and has a spring to take up any difference from the OEM belt.

__________________
'76 IH 1066 Turbo Diesel, '73 IH 766 Diesel, '72 IH 574 Utility Gas, '56 IH 350 Utility Gas, '46 Farmall H Gas, '08 Bobcat Toolcat 5600 Turbo

Nobody puts that "C" word in front of MY International!

dangeroustoys56

MTD's take the wider 5/8" belts , smaller width belts wont work correctly in the pulleys- theyre designed for the wider ones - besides owning several MTD's - pop and i replaced the factory OEM 18 year old drive belts on my '92 White last week - Ill admit, the belts are a serious pain to install - had to remove the seat, battery , variable pulley, retainers..... the rear belt was pretty tight - had to remove the idler pulley spring to get it on there- the original belt had all kinds of chunks missing- so it was due .

New belts will be a tad shorter, because old belts stretch some- we still had the OEM belts complete and were able to read the numbers and match em up .


While the tractor was apart, did you check the variable pulley and idlers? The vari pulley is supposed to have the center part slide up and down easily, is also supposed to rotate - doesnt hurt to add some WD40 to the center to it to free it up .

The whole assembly moves forward and backward in the chassis, depending where the gear selector is - the actual transmission IS the variable pulley, not the transaxle - that is a 1:1 unit with forward, neutral and reverse only.

denno

Hey---thank you all. Didn't get your messages in a timely fashion --- thought I'd signed up for instant e-mail notification, got to look at that.
I looked online generally and found a suggestion for belt dressing (and some cautions against it) and tried that and seems to have fixed the problem. For the moment, anyway. So maybe just brand-new belt being slippery?

OEM and the belt I bought both specify 5/8 X 35. I have not checked for pulley wear, tho' the machine has few enough hours it would surprise me.

Had to remove the biggest pulley to get the belt past the keeper. Variously pried on the idler arm, turned the pulleys to get the belt on. Took two of us last time; I managed it myself this time.

Regards,
Denno

denno

aarrgh! WHERE do I go to set up that e-mail notification?

dangeroustoys56

As i mentioned, the rear idler pulley has a spring - its easy to remove the spring - a pain to reinstall because of its awkward place in the tractor , w/o tearing the whole thing apart. MTD sure didnt make it easy to change belts.

The email thing is under your profile settings somewhere.

denno

I seem to be getting the e-mails now.
Yeah, one hand down the hole where the battery sits, one under the right fender, and generally hard to get an effective lever on the idler arm. Like, take it to the dealer, right?

dangeroustoys56

I was about two minutes away from draining the gas and oil from the motor and flipping the tractor on its side to get that spring on...... same goes for the deck spring - the one that runs to the transaxle - took me about 15 tries and a pair of vise grips to get that thing back on- youd think theyd of had a different alternative to something like that.

denno

OK, there's a big hole and a little hole on the chassis for the spring. It was easy to insert going thru the big hole first; looked like it would be less likely to come out the other way around, but that was NOT going to happen w/o some kind of bending of the end of the spring. Having given up that concept, wasn't hard to insert the spring into chassis and arm. Hard to keep it settled there while I was stringing the belt.
Process was, if I recall:
Attach spring.
Unbolt biggest pulley and get the belt inside the groove past the keeper.
Rebolt the pulley.
I T-h-i-n-k I next put the belt around the middle pulley (with the speed lever on highest). Needed third hand to keep belt out of the groove on the biggest pulley.
Then inserted a prybar (big screwdriver) between idler arm and chassis pulled toward middle of tractor, and sweated belt around idler pulley. Needed third hand to keep belt out of groove in largest pulley.
Then fed belt into largest pulley by turning pulley.
Sheesh.

denno

I don't know if I can publish a pretty long post, but having had to do the thing all over again because the pulley and hub also needed replacing, as it turned out...here is

HOW YOU REALLY CHANGE THE TRANSMISSION PULLEY OR THE TRANSMISSION DRIVE BELT ON AN MTD RIDING MOWER!


I've had all these things happen to the transmission belt system which stop the mower working:

Idler arm spring breaks. (Not nearly as much fun as they say it is in Florida).
Spring merely comes off.
Belt breaks or otherwise destructs.
Pulley hole &or pulley hub wears out, no longer lock together by the splines. Pulley may spin or slip
sideways, or work its nut off and come off the shaft.


First, take out the battery and its supports.


OK. S'pose just the belt, --- this is the upper rear belt, goes around 3 pulleys beneath the battery --- s'pose that breaks. Removal is easy, just pull it out. If it is more like frayed, cut it and pull it out.

Got your new belt? Here's the rub: over on the right side of the crammed, difficult-to-work-in space you are trying to work in, the biggest pulley stands close enough to the side wall or some other structure that the belt won't squeeze down (or up, for that matter) between pulley and wall. This is a nice keeper once the belt is installed, but sort of a problem for installing it.

You have to remove the pulley. Oy. So first you want to loosen the nut. The manual suggests an impact hammer. Well, see, there is this bar across the compartment, above the big pulley. This is a mount for the lever that raises and lowers the deck. It's in the way for putting a socket onto the pulley nut. Sez earlier models you could unscrew some other part of the mount, but in mine it is welded in place. Other suggestion in manual is to hold the pulley with a strap wrench and use a crescent wrench on the nut. Frankly, I did not think I could get a strap wrench in there and then get any purchase or leverage. Not a lot of working room.

There are two holes in the pulley, and I put a large screwdriver through one and got the pulley/screwdriver wedged against something to hold it, and then, with all the difficulty you'd expect, put a double-ended wrench on the nut and applied a lot of strength at a disadvantageous angle and got it loosened.

Now you can shift the pulley enough to get the belt into its groove. Then you reverse the pulley/nut process. Pulley hole has to lock into the splines on the pulley hub, remember.

We'll get back to getting the belt around the 3 pulleys, but we interrupt the process to consider:


WHAT IF YOU NEED TO REPLACE THE PULLEY?

Well, whee! As you try to remove the pulley from the compartment you will discover it gets stuck. First place is between the pulley shaft on which it is mounted and a corner of part of the aforementioned mount for the deck lever.

I did in fact get mine out without anything too fancy. If you raise or lower the deck (I forget which and am not going outside right now and pull the battery and look!) all the way you get a smidgin more space and can pretty much force the pulley through the gap. Next, however, it wants to stick in the geometry between the shaft and --- ! --- the (twice aforementioned) bar running across the pulley compartment. Again, however, I got it through by using some force. Nothing bent or broke.

BUT --- I say “but!” --- when I got the new pulley by mail order, it proved to have a little lip standing up on the rim, rendering it about 1/8” thicker in cross section than the old pulley. God bless the MTD engineers! No way to get it back through that shaft/bar squeeze.

Turns out, you get down at the rear of the machine, look at the left and right of the transmission/axle, and there are some bolts four on a side. Two of them seem to hold the upper and lower shells of the transmission together, and the other two (the inside pair) partly hold the upper and lower frames of the mower body together. It's the four frame bolts you want to take out. Then you can slip (or pound) a pry bar in between what was formerly held together, and pry or lift, and gain enough clearance to get the new pulley in under the crosswise bar.

SOMEWHERE IN HERE IT IS VERY NICE TO HAVE TWO PEOPLE. If it is your wife, and she, as mine, is strong-like-bool and furthermore left-brained, if she makes a suggestion by all means do the Monday Night Football thing and make a derisive comment --- but TRY it!

We discussed all kinds of ways of getting the belt around its three pulleys. In the end, this worked:

First, mount the pulley and tighten it up, with the new belt in the groove of the big pulley.

Now, to gain maximum slack, step on the brake pedal, put the speed lever up to the top, and let go of the brake. This shifts the position of the second-biggest pulley backwards and gains a little slack. Next, there's the spring on the idler arm.

About that spring.... It attaches at one end to an extension of the idler arm. There's a hole for it to hook into. On the chassis side there are two holes, a large and a small, that the other end of the spring hooks through. I've had the hook slip out of there a couple of times. Looks to me as though it would stay in place better if the hook on the end of the spring were run through the small hole from the inside out first, and hooked back through the large hole. That probably is pretty un-doable for the following tricky finish to mounting the belt. (So I have squeezed the curve of that hook a little tighter, hoping that will help).

Detach the hook from the chassis side, leaving it hanging from the idler arm. This allows you to move the arm inward; getting the belt around all three pulleys should be no difficulty.

Next, attach something to the chassis end of the hook, reaching in through the larger of the two fastening holes. Some kind of tool, metal bar, whatever with a hook or at least an L on its end could work. (Think crocheting hook, only stronger and probably longer.). We used a dog leash with a small snap hook. Ran it from the outside in through that larger hole, hooked it to the spring....and PULLED. Pulled the hook and idler arm back toward the chassis.

Entirely to my surprise, it was not difficult to pull far enough that the hook end came through the hole and then could be set to hold there. Easy to get the snap hook off it. Then I used a paint can opener, with its sort-of hook end, to drag the spring end over to drop into the smaller hole. (Took 3 tries to coax it to the right position).

And that was it. Put the tranny/chassis bolts back in --- took a little wiggling and banging and pulling to get them lined up again. That was it. I suppose it could be done by one person, but two was a relief.


I am not going to get started on what I think of the engineering that keeps various forums and repair sites busy with strategies for changing a mower belt, or the prospects of my buying another MTD product.

Good luck! Remember that auto parts store fan belts are not tough enough to be used in this sort of application.