Strange sound when turn key

As Shifter mentioned, mower belts barely stretch, the wear thin on the sides so sit deeper in the pulley & go loose.
In a mower of that age all the deck mounts will be substantially worn and despite the fact that they take your jaw off when you remove them, the springs will have weakened.

This is your deck lift mechanism https://www.partstree.com/parts/mtd/mowers-lawn-garden-tractor/13a4667f118-yard-machines-lawn-tractor-1998-sam-s-club/deck-lift-hanger-assembly/
The spring part # 45 is what puts tension on your belt via the movement of the deck engagement lever part # 40.
When the blades are in the dissengaged position the spring is stretched and 20 years of you leaving the mower with the blades dissengaged means that spring has been sitting with that spring stretched.
However as previously mentioned look at the myramid of links & shafts and don't overlook the holes on the deck itself.

bertsmobile1 said:

As Shifter mentioned, mower belts barely stretch, the wear thin on the sides so sit deeper in the pulley & go loose.
In a mower of that age all the deck mounts will be substantially worn and despite the fact that they take your jaw off when you remove them, the springs will have weakened.

This is your deck lift mechanism https://www.partstree.com/parts/mtd/mowers-lawn-garden-tractor/13a4667f118-yard-machines-lawn-tractor-1998-sam-s-club/deck-lift-hanger-assembly/
The spring part # 45 is what puts tension on your belt via the movement of the deck engagement lever part # 40.
When the blades are in the dissengaged position the spring is stretched and 20 years of you leaving the mower with the blades dissengaged means that spring has been sitting with that spring stretched.
However as previously mentioned look at the myramid of links & shafts and don't overlook the holes on the deck itself.

Click to expand...

Wow- that's what I was going to ask you, Bert, where I need to begin to do restoration. That diagram sure helps. perhaps new springs, which are suspect, can be ordered, and replaced, I will let you know asap! Going to poke around down there today, if it doesnt rain........

OK, after spending some time observing the levers/springs/pins as one lifts/lowers the main lever that controls the height of the mowing I learned something.

I understand now that when the deck is in "STOP" (farthest position toward the driver) the deck is shifted FORWARD, releasing pressure on the belt. Then , as you lower the deck to mow the lever system first advances the deck BACK to tighten the belt so it can engage the blades' pulleys to turn, then drops down for lower cut settings.

I discovered that as you move the notch from STOP position the belt does not tighten (does not engage blades to turn) until AFTER it passes the 1st cut notch (highest cut setting) and only engages the blades (gets tight) on the SECOND notch. . That is my problem! Can one adjust this? Springs seem tight(?). I guess I could always but that spring #45 on the diagram.

I cant remember how it behaved when new. But I dont remember having a problem cutting at the highest notch. Am I on the right track, people?

Anyway, feedback appreciated.

rigoletto said:

Wow- that's what I was going to ask you, Bert, where I need to begin to do restoration. That diagram sure helps. perhaps new springs, which are suspect, can be ordered, and replaced, I will let you know asap! Going to poke around down there today, if it doesnt rain........

Click to expand...

The two most important tools you already have.
Eyes & a brain.
So lay alongside the mower while some one moves the deck slowly through all cutting heights , back & forth.
Watch closely the movement between the dissengage position & the highest cut position.
Because the engage lever works backwards ( against the spring ) to what you are expecting it is a little confusing.
Inside the dash, tower, turret, whatever you want to call it there should be an adjuster connected to the deck lever.
They are next to impossible to get to and many are difficult to adjust because the original mower had a much smaller engine.
You might get away with an adjustment .
If you have the gear or know a welder who enjoys a "free drink" then all the ovaled holes can be welded & remade.
Some of the worst links can be replaced
The plate at the back with the 2 rods running through it usually wears the worst.
A piece of thick angle iron welded / bolted to the inside of the lips both sides is the easiest fix.

Good thing is you are ending your mowing season so you can spend some quality time with your mower in the shed.
Those old mower deck lifts are complicated but all the bits are easy to fix and a lot of them are still available

Thanks for the continued support and advice, Bert. Based on your last post it looks like this might be a bit too much for me- Im OK with changing 2 springs, although, I imagine that has got to be even harder than doing springs on auto shoe brakes. Welding, etc etc- Yikes. I learned much here, will see where to go now. Hate to settle for cutting at the second notch, as it is too low. Butchers my lawn.

rigoletto said:

Thanks for the continued support and advice, Bert. Based on your last post it looks like this might be a bit too much for me- Im OK with changing 2 springs, although, I imagine that has got to be even harder than doing springs on auto shoe brakes. Welding, etc etc- Yikes. I learned much here, will see where to go now. Hate to settle for cutting at the second notch, as it is too low. Butchers my lawn.

Click to expand...

Start with locating the adjuster and adjusting it.
If there is no joy then the cheats way is to fit a smaller belt.
The problem with that is a shorter belt can prevent the blades dissengaging so then you have to go back and readjust.
Most of the linkages are still available.

bertsmobile1 said:

Start with locating the adjuster and adjusting it.
If there is no joy then the cheats way is to fit a smaller belt.
The problem with that is a shorter belt can prevent the blades dissengaging so then you have to go back and readjust.
Most of the linkages are still available.

Click to expand...

I found the adjuster rod, Bert!! It is a rod (#71) the "speed control link",about 1/4" thick, with as thread on the end which has a kind of round-ish nut (ferrule #109) which determines at what point the main lever engages the blades!

This is going to be fun! Give me a day or so and I will get back to you on this! (Forgive my enthusiasm, as there is not much excitement going on right now here....)

Take your time, watch what is happening as the lever is pulled.
Then of course hang by the rafters trying get to the adjuster.

Yipee!! (sorry for delay, been too busy). I fixed it, Bert!! Yup. loosened the back end of that rod, and turned it until the ferrule sat just right so as to allow the lever to sit at the higher cutting level! Wow- no new springs, etc. Wonder how it ever got to that point(?). 20 years, I suppose, it creeped up on me. Anyway, that mower still works well, as far as Im concerned. Why buy new.

Big thanks, Bert. I know youre a busy guy.

rigoletto said:

Yipee!! (sorry for delay, been too busy). I fixed it, Bert!! Yup. loosened the back end of that rod, and turned it until the ferrule sat just right so as to allow the lever to sit at the higher cutting level! Wow- no new springs, etc. Wonder how it ever got to that point(?). 20 years, I suppose, it creeped up on me. Anyway, that mower still works well, as far as Im concerned. Why buy new.

Big thanks, Bert. I know youre a busy guy.

Click to expand...

Over time all f those rods & holes that are always under tension from the spring and vibrating against each other will wear.
Deep down in the owners handbook will be a diagram that makes no sense at all showing an oil can on these linkages.
No one ever oils them & they slowly wear.
You don't notice that your grass is slowly being cut lower and the clippings do not throw as far till like you, the deck fails to cut at the top setting.
Sort of like looking in a mirror and actually seeing yourself as an old man.
A can of white spray grease applied to everywhere that has t pieces of metal bearing on each other will work wonders.
As you have now worked out the deck lever sort of works backwards to how you think it would.

Glad to hear you got it sorted.
Whenever the belt is changed that adjuster is supposed to be moved then tightened up each season but no one does it.