Questions about 1987 312-A Lift Lever for deck

[davem1111 2,030]

Let me know if this is not the best place to post this topic, but it seems appropriate to me.

 

My wife bought this 312-A before we were married, but I've been the primary user.  The lift lever has never worked quite right, or if it seemed to be, it would not hold. It has 2 positions that "work":  all the way down, or all the way up.  There is or used to be a position somewhere in the middle which was a good cutting height, but it wouldn't stay there.  Hit a bump or something and it would drop to the full "down" position and usually drop the blades into the dirt.  Lately it doesn't seem to be able to lock into that position even temporarily.  I just got the tractor going again after replacing the hydro pump, and had to hold the lift lever in place manually or tear up the ground.  FYI, I do have the "Toro Quality of Cut" manual and have gone through it but it doesn't seem to cover this topic specifically.   I've gone over the parts diagrams for the lift mechanisms, like this one:

 

 

  

 

But this doesn't say anything about "how" this is supposed to work if it's all functional.

 

Let me ask it this way:  Should there be a middle lever position or just "Up" and "Down" ?  If that's the case then I guess I just need to adjust the eyebolt, chain, etc. to make it so the "down" position is where I want it, i.e. not so low that it's cutting too short.

 

I should mention a few things.  First, the push button (#7) at the top of the lever handle on this tractor does not push down.  (This seems to work better on my 416-8, which I had the deck on briefly but now that one is in the shop).  Since there's a spring (#4) in there and the right-angled bar (#2) at the bottom that the push button should move is supposed to do "something",  my guess is that this being rusted or jammed is somehow limiting the functionality of this whole mechanism.  Also, the 312-A does *not* have the #40 height adjustment knob, that was only on the 414/416.

 

I'm hoping to get this into shape to mow quickly (because the grass is growing like crazy  ), even if it's a temporary workaround and I do more in-depth repairs later if needed.  My other option is to put it back on the 416-8, but I recently found that it had water in the transaxle so I've got it pulled apart trying to drain and flush.  I guess I could run the 416-8 a bit more "as is", but don't want to make matters worse if I can avoid it.

 

Just mess with the eye bolt and chain for desired height with lever all the way down?

[Ed Kennell 38,049]

The deck cutting height should actually be fixed by the position of the two rear wheels on the deck.   The deck should not be hanging from the lift mechanism while mowing.

  With the mower deck installed, the lift lever is full down for mowing and full up up for transport.

 

Download this file and follow the deck cutting height and deck leveling instructions.

 

 

 

The mid position knob #40 is used to adjust the working height of a snowblower, tiller, or mid mount grader blade.

Edited April 17, 2022 by Ed Kennell

[953 nut 55,121]

8 hours ago, davem1111 said:

Hit a bump or something and it would drop to the full "down" position and usually drop the blades into the dirt. 

When you connect the deck to the Tach-A-Matic there is a fork near the center of the bar that supports the mower deck. That fork must slide over the rod on the Tach-A-Matic to keep the deck in position to give an even cut.

[davem1111 2,030]

6 hours ago, 953 nut said:

When you connect the deck to the Tach-A-Matic there is a fork near the center of the bar that supports the mower deck. That fork must slide over the rod on the Tach-A-Matic to keep the deck in position to give an even cut.

 

I had the fork in the right place, more by accident than anything else.  I always wondered if that thing was there for a reason...  

 

But.....  well, duh.  I feel even dumber than I already knew I was.   My deck was missing the Level Adjustment Rod that goes from the bracket the lift arm connects to, to the bracket on the wheel rod. I actually found the one that came off but it was bent at about 45 degrees, so I stole the one off another deck I have that needs some welding and a full rebuild. 

 

This baby cuts "really sweet" now.  I've been wrestling with this for several years now but that was the key.  Thanks for the help!  I didn't have the deck manual or TIPL yet, hadn't seen those. I think I have everything for both tractors, but didn't think to search for the deck manuals.  

[PapR's312-8 9]

I have a question which may be indirectly related to this post.  I also have a 312-8 mower.  I was able to finally get the lever to move into the locked position.  As the gentleman mentions here my deck will drop while the tractor is being operated.  I have to check but it may be possible that the bushings for the lift lever shaft are worn not allowing the shaft to be in the correct position to fully lock.  Is the lift lever suppose to be straight?  Or is a slight bend towards the rear of the tractor normal?  I suspect it is not normal and may be causing the rod/pin inside to have a slight bind that is not allowing full travel to "lock" properly.  I suspect some of the problem this gentleman is having may be caused by some of the same things.  Just to clarify there are only the two positions with the lift lever it is up or down.  Our gauge wheels on the rear of the deck determine the height of the cut.  

[Handy Don 12,177]

 

2 hours ago, PapR's312-8 said:

I was able to finally get the lever to move into the locked position. 

 

It sounds to me like your lift is not getting to the fully locked position.

The first place I'd look for resistance to getting the deck lift to "lock" is the adjustment on the chain that links the deck frame to the rock shaft arm and the rubber "bumpers" that are atop the deck frame. A slight bend in the lift arm is not uncommon, and should not affect the operation.

The bumpers should just hit the bottom of the footrest when the deck is fully lifted (this keeps the deck from moving around during transport)

The chain adjustment is a bolt eye behind the lower panel of the hoodstand console.

If the bumpers are hitting before the lift is fully locked, then the bolt must be loosened. I won't go into detail here, because the manual is very clear.

 

Use the search box on this page to search the forum's files using the model number of your specific deck and download the manual.

When searching, be sure to choose the "search in" option for "Files" and if there are multiple words in you "search for", then select "use all my search terms".

Edited September 30, 2022 by Handy Don

[PapR's312-8 9]

Thank you very much for the response. Handy Don. I do have a few questions.  I downloaded what I believe is the correct deck model. (I'm at work so will confirm later.)  Based on what I can see in the photo diagram it appears there are different positions so the trunnion can lowered or raised for the lift rod chain?  (Not speaking of where the chain goes on the lift bar for deck/plow, snow blower etc..)  I cannot remember off the top of my head if there are different holes for the trunnion on the adjustment nut end.  Based on what I'm reading, I'm doing things correctly. I just cannot get the rubber stops to touch the  bottoms of the foot rests after tightening the trunnion.  When tightening the trunnion to lift the deck up then I'm having an issue whereby the lift arm will not lock when I want the deck off the floor.  Out of curiosity how soon should you feel the tension of the chain when pulling back on the lift lever from the operating position. I apologize for all the questions. I also hope I articulated well enough for you to understand what I'm asking.  

Edited September 30, 2022 by PapR's312-8
Needed to clarify at least one question.

[Lee1977 6,649]

47 minutes ago, PapR's312-8 said:

Thank you very much for the response. Handy Don. I do have a few questions.  I downloaded what I believe is the correct deck model. (I'm at work so will confirm later.)  Based on what I can see in the photo diagram it appears there are different positions so the trunnion can lowered or raised for the lift rod chain?  (Not speaking of where the chain goes on the lift bar for deck/plow, snow blower etc..)  I cannot remember off the top of my head if there are different holes for the trunnion on the adjustment nut end.  Based on what I'm reading, I'm doing things correctly. I just cannot get the rubber stops to touch the  bottoms of the foot rests after tightening the trunnion.  When tightening the trunnion to lift the deck up then I'm having an issue whereby the lift arm will not lock when I want the deck off the floor.  Out of curiosity how soon should you feel the tension of the chain when pulling back on the lift lever from the operating position. I apologize for all the questions. I also hope I articulated well enough for you to understand what I'm asking.  

What you are doing is correct, but 312 are 22 to 37 years old the rubber bumper get old and bent and may not contact the foot boards.

With the gage wheels all the way down at best they bearly leave the ground with the lift up and latched.

Thg\e lift is attached to the lever system on top of the deck that alowes the deck to follower the grade, so when lifting the deck your tighten up this system before you lift the weight of the deck.

 

[Handy Don 12,177]

2 hours ago, PapR's312-8 said:

I cannot remember off the top of my head if there are different holes for the trunnion on the adjustment nut end.  Based on what I'm reading, I'm doing things correctly. I just cannot get the rubber stops to touch the  bottoms of the foot rests after tightening the trunnion.  

The trunnion holding the eyebolt, when used for deck lifting, goes into a specific hole on the rock shaft arm. Putting it elsewhere messes with the geometry of the lift action.

The correct hole is the one closest to the rock shaft on the upper arm, the "all attachments" position as seen here:

 

 

I'm not clear on whether your deck is hitting the bottom of the footrests before the lift arm reaches its locked position OR your lift arm is reaches the locked position but the deck bumpers have not hit the footrests.

What @Lee1977 mentions is valid. It is a tricky adjustment. I've noticed that there is a slight "hump" in the lifting action where as the lift arm "locks" it drops the lift action very slightly from  just before it locked. If the rubber bumpers are no longer flexible, then they cannot "squish" a bit at max lift and still touch the footrest when at locked lift.

 

The lift chain should be slack when the deck is down on the gage wheels (it needs room to let the deck follow a dip in the lawn). Depending on how high you've set the cut, you'll feel the slack come out of the chain sooner for lower settings and later for higher settings. I'll guess the lever may move several inchs before it runs out of slack!

Edited September 30, 2022 by Handy Don

[PapR's312-8 9]

Just real quick. My "understanding" is when the deck and lever are in full up position and locked that is when the bumpers are suppose to touch the bottom of the foot rests.  If that is correct. A. I cannot get the bumpers much closer than 3/4 - 1/2 from the foot rests.  But what happens if they get much closer the lift lever will not go into the locked position. Then I have to back off the adjustment of the lift chain. My thought is the bumpers need to touch so they stabilize the deck from movement. When I get done mowing and place the deck in the upright position it will on occasion drop if I'm going over rough terrain. Maybe I'm incorrect and don't have the deck mounted properly. I've downloaded the deck manual and I need to really look it over just to be sure the problem is not operator error. I thank you all for your help.  I'll let you know if I discover something.  

[Handy Don 12,177]

56 minutes ago, PapR's312-8 said:

Then I have to back off the adjustment of the lift chain

This is clearer.

You are experiencing the normal situation where the bumpers are no longer pliable enough to absorb the lift motion over the "hump".

On mine I was able to tweak it to get only about 1/4" of "looseness" but my bumpers still have a bit of flex to them.

If you are still having the deck slip out of the "locked" position, then you'll have to go over the mechanism and look for worn bits. One relatively common issue for tractors stored outdoors without protection is for the spring (#4) within the arm to rust and, potentially, weaken.

Edited September 30, 2022 by Handy Don