312-8 climbs up but rolls down hill

[Tractorhead 9,064]

Independently what any kind of booklet say‘s

my own experience of Belt transmissions tells me follow:

 

A belt transmission needs friction to transport torque and load wearfree any loose shall eliminated quickly.

 The more the slip on the belt, the more the Wear on the Belt that simple.

A beltspanner is allway‘s on a Load free side.

 

a belt transmission also needs the friction of the sidewalls from the Pulley‘s.

the bottom part of a Belt is not able to transport some torque - as squonk allready say‘s.

 

i ain‘t have a 312, but i designed my FEL Hydraulics on my 212 where the Hydro pump is brought

in the middle of old Belt. Because i had absolutely no measure how long the belts must be,

i have to measure myself for the right lenght ( your advance, you ain‘t must do that)

 

 

if i had any slip like your belt shown, nothing of that Picts here can happen.

There were no torque to move the pump and lift the Bucket or even torque to move the tractor with Snow.

 

Yes, it is a Vertical Shaft, but the Rules of friction are given for each Belt transmission.

Btw. I would trust more the Brake Belt on a 312 than the mini Brakedisc on my 212 or your 211.

This is spring loaded, but the brakepads wears on 3 or maybe 4 day‘s on hard working.

they not designed to keep much Load. Even the Gearbox is not designed to last much load.

You sure can sale your 312, it‘s up to you, your decision.

 

However

also your 211 have something about 400-500 lbs of weight what is also not funny, to see roll over yourself.

so on that steep’s a ROPS is Highly recommended and definitively no wasting of Money independently on wich machine.

 

again

check your Belt on the 312 it‘s definitely too loose  (exchange it with the right one)

Check brake belt on left side of the gearbox

think about an ROPS ( i would highly recommanded on both machines)

use it as needed.

 

but it‘s up to you

[wallfish 16,985]

It's clear from the pics that belt is too loose. It's slipping around the engine pulley when descending the hill and basically free wheeling. The brake doesn't work if it only slows it down on flat ground and not on the hill.

Fixing the belt and brake will stop the free wheeling.

[oldlineman 1,481]

Yes what everyone has stated, belt is too loose you can see that clearly in picture # 39. I have a 1989 414-8 which is heaver than your tractor and a 1979 c101-8  and have steep inclines in my yard and have no issues with run a away  going down them. That 312-8 is twice the tractor what your other lawn mower is. Get a new wheelhorse belt and check tension er you won't be disappointed. JMHO I have owned and used these tractors for over 40 years with no issues. Bob

[Jhatch13 31]

I bought a toro brand belt from the dealer this morning, ordered a new  clutch spring, and one of rmaynard's brake liners. Hope to have it torn down and put back together next week.  If these dont fix it, then the hill is either too steep or its just not going to work.

 

I also spoke to 4 different dealers/service centers and not one had a single clue what could cause the issue. One said it might just be an issue with that particular model. All said they could take a look, but how can you fix what you cant diagnose as broken?

Edited June 22, 2020 by Jhatch13

[kasey54 305]

I agree those are service shops to avoid. While you are in there check the tension pulley to make sure its fastened tight , and

its bearing isn't shot allowing slop .

[oldlineman 1,481]

Those aren't service shops just parts changers. More experience with these tractors on this form than any 10 modern day shop.

[wallfish 16,985]

For the brake. Look at the brake band and drum and the side of the case behind the drum for evidence of gear oil. If gear oil is leaking from the case seal for that shaft, that causes the band to slip on the drum when it's soaked with oil. That's a common issue. The oil seal can be replaced from the outside of the case and fairly simple to do if required.

 

A service place isn't going to diagnose anything over the phone for you. They want you to bring it in so they can paid. There's no money in telling you how to fix it yourself and they loose the time spent explaining it too.

[Jhatch13 31]

6 minutes ago, wallfish said:

For the brake. Look at the brake band and drum and the side of the case behind the drum for evidence of gear oil. If gear oil is leaking from the case seal for that shaft, that causes the band to slip on the drum when it's soaked with oil. That's a common issue. The oil seal can be replaced from the outside of the case and fairly simple to do if required.

 

A service place isn't going to diagnose anything over the phone for you. They want you to bring it in so they can paid. There's no money in telling you how to fix it yourself and they loose the time spent explaining it too.

No visible leaks or residue. The calls to service centers were in search of parts. Typically they will ask what the issue is or why youre buying the parts so they can push thier own repair services. I dont expect anyone to diagnose it for free, especially sight unseen. I do find it odd that they had never heard of the issue before, so it is either uncommon,  or theyre inexperienced. 

 

I avoid chains and franchises if I can. Some of these small family owned businesses have been around a while and seen a few things. I agree that the usual parts counter guy knows nothing more than how to push computer buttons and find something in the location its in, often without even knowing what it is that they are grabbing. But every now and then you might run across someone who is a wealth of knowledge. And on the rare occasion, i have had mechanics tell me I can easily fix it myself along with how to do it. From thier perspective, being honest and saving someone a few bucks will earn thier business in the future.

[wallfish 16,985]

2 hours ago, Jhatch13 said:

i have had mechanics tell me I can easily fix it myself along with how to do it. From thier perspective, being honest and saving someone a few bucks will earn thier business in the future.

Exactly!

The lining Bob sells will grip that drum good so you should be all set after the brake and belt repairs.

Please update us and maybe a pic of the hill too.

[Jhatch13 31]

Ive tried to take pictures of the hill, but none of them turn out good enough to show the steepness of the grade. The worst part is after about 40 feet of flat at the bottom, there is a small drainage ditch, and everything is surrounded by briar patches, so if I go for another wild ride it could turn out worse.  If i'm lucky and athletic enough to jump off (which Im not) the tractor could possibly roll into the neighbors house.

 

Ive never felt like the 211 was struggling or out of control unless I hit a wet patch and would get a little sliding. I thought the extra power, weight, and wheelbase of the 312 would help keep it planted, but the center of gravity is definitely higher and probably why it feels so squirley in comparison. Maybe I can get video of the next try after everything is back together. If it doesn't work then at least it will be cheap entertainment. 

[Jhatch13 31]

I replaced the clutch spring and the drive belt this evening. It was definitely shorter than the aftermarket one that was on it. (Original on top, new on bottom).  After inspecting the brakes, it looked like the original liner was in good shape, so I decided to hold off on replacement and just made some adjustments and it locks up the rear wheels solidly now.

 

We had a big thunderstorm going on as I was working so I did not get to try it on the hill. Hopefully it will dry out tomorrow and Ill get to report back a successful descent and climb.

[Jhatch13 31]

Tried the hill about 5 minutes ago in low 1 and again in low 2, same result.........rolls right down the hill, but climbs like it isnt even a challenge.  Guess ill be sticking with the 211 for now and looking for another vertical shaft.

[kasey54 305]

Did your repairs make the belt tighter? It needs to be tight with your foot off the clutch pedal. I can tell you are very frustrated. If you have some one to help you , you could push the 312 on flat ground, or tow it with your lawn mower. In 3rd gear as its rolling forward you should be able to determine what is slipping. If your engine doesn't turn ,and it rolls easily something is slipping. This is a fact. You could have a bad key in your hubs,(rear wheels will turn on the axle shaft . check both of them) You could have a bad key on your input  transmission shaft(pulley will turn but shaft don't). If your idler pulley is bad the belt will slip over the engine pulley. There is a pinned arm that moves the idler pulley tighter clutch out, loosens it clutch in. If that movement is absent, or not enough it won't tighten your belt. When you let up on the clutch the spring is supposed to pull the idler pulley tight.(even in neutral). Any of these keyed shafts can wear and in effect make a ratchet like situation. They will grab in one direction, but in this case if the tractors momentum is pushing it faster than the gears are going they may be slipping, and not holding it back.

  To see if the transmission shaft is slipping in its pulley you need to remove the belt guard to see.

  If  you see this  through you will find the 312-8 is twice the machine (a garden tractor) that your 211 is.(a lawn  mower)

  Good luck, please keep us posted. 

[kasey54 305]

953nut , any thoughts?

 

[953 nut 55,075]

On 6/22/2020 at 8:51 PM, Jhatch13 said:

Ive tried to take pictures of the hill, but none of them turn out good enough to show the steepness of the grade. The worst part is after about 40 feet of flat at the bottom, there is a small drainage ditch, and everything is surrounded by briar patches, so if I go for another wild ride it could turn out worse.  If i'm lucky and athletic enough to jump off (which Im not) the tractor could possibly roll into the neighbors house.

Take a long board and a level out there and calculate how many inches of rise per foot of run (like a roof slope).

28 minutes ago, kasey54 said:

you could push the 312 on flat ground, or tow it with your lawn mower. In 3rd gear as its rolling forward you should be able to determine what is slipping. If your engine doesn't turn ,and it rolls easily something is slipping

When you do as you have suggested the clutch pedal will vibrate up and down because the load has now been transferred to the top which has a spring loaded idler.

You are basically pushing a rope. I covered this in post # 40.

it seems to me that the laws of physics can't be overlooked here. When the engine is transferring power to the transmission  the lower half of the belt is doing the work. Your engine pulley is turning counter clockwise PULLING the belt toward it. The belt clutch tensioner is just taking up the slack on the lag side of the belt.

When you are headed down hill the engine is turning the same direction but slower than the transmission so the lag is on the bottom half of the belt and the driven tension is being applied to the spring loaded clutch tensioner on the top half of the belt.

Your owner's manual tells you to avoid steep grades.  Be safe and follow the manufacturer recommendations

[Jhatch13 31]

The belt is tight. Idler pully is fine and adjusted properly,  so is the arm. It will only roll when in neutral if being pushed.

 

My buddy just brought over chains to see if traction was an issue. Tried high and low range in all gears,  same problem.  I think the hill is just going to be too steep for this machine to make it down safely. I tried it on a smaller hill that wasnt as steep and the gear holds and the brake allows me to stop and hold on the hill. On the big hill, the brake just causes it to slide, and then letting off it never regains traction until on a flat spot.

 

It may become a plow machine, or I might just put it up for sale and use the proceeds to buy a supply of roundup so i dont have to mow the hill anymore. 

[kasey54 305]

953 nut , I thought  there was  a wire belt guide to prevent that slack belt from falling away from the drive pulley on the slack side of the engine. I'll have to do some checking on that. You have me thinking.

[kasey54 305]

Okay Jhatch. I'm truely puzzled. But if it just skids that's pretty steep.

[Jhatch13 31]

14 minutes ago, kasey54 said:

Okay Jhatch. I'm truely puzzled. But if it just skids that's pretty steep.

I would have thought that the bigger, heavier, and higher horsepower tractor would have been the answer but I think Steveasaurus nailed it.....greater friction with the vertical shaft vs horizontal.  Just have to hope the 211 doesn't wear out and keep a lookout for other vertical shaft horses  in the meantime so i have a backup. The 312 will make someone else a nice machine, as long as they dont have a bunch of hills.

[Pullstart 62,791]

A week late to the party... but  @Jhatch13!

[tom2p 2,394]

smh and puzzled 

 

I'm able to go down steep grades with my 312-8 with engine/trans braking to the point where the rear tires will begin to lose traction 

 

almost hear slight engine increase (rpm) similar to complete gear driven power train 

 

[Jhatch13 31]

I tried to get some pictures of the hill. Its steeper than it looks. Im guessing 40-50 feet from top to bottom, with about a 20 degree grade. 

[Jhatch13 31]

I had my wife video me going down the hill. It does look like one tire is spinning the opposite direction of the other. This happens shortly after it starts to accelerate forward down the hill.

[lynnmor 7,302]

1 hour ago, Jhatch13 said:

I had my wife video me going down the hill. It does look like one tire is spinning the opposite direction of the other. This happens shortly after it starts to accelerate forward down the hill.

 

Now it appears that wheel weights and better tires are needed.

[echris 1,425]

I know it's hard to judge a grade from a photo, but that looks similar to one of the hills in my yard and my 310-8 goes down it just fine, even with a slippery carpet of white pine needles on the hill.

Have you looked at the wheel hubs? It sounds backwards, if it holds torque up the hill it should hold going down, but it's harder to walk down a hill than up. Maybe a slight slippage?

The one tire spinning the opposite direction comment made me think of that. Dunno of that makes sense though.