# Need help, Slow turning deck blades



## Jethro210

My MTD 1997 model 825 lawn tractor has an issue with the deck blades rotating slow when you try to mow taller grass. I can change the deck belts and it still seems to do it. I have another older MTD tractor of the same design and it doesn't have this problem. Anybody have an idea on what could be causing this problem? Any help would be greatly appriciated!


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## Thomas

Is there belt adjustment?
Do the spindles feel and sound good?


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## TecumsehBriggs

Sounds like an adjustment.


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## Jethro210

TecumsehBriggs what do you mean by adjustment? I am wondering if the drive pully is worn out and letting the drive belt for the deck to slip?


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## dangeroustoys56

Most MTD's use a single deck belt - wraps from drive pulley to the deck mandrels - spring controls the tension ( in some cases) - i cant tell if your deck might use two belts from your av pic. Most larger GT type tractors use a belt on the deck and separate one to drive it. You are using brand new belts also right?

If it does have two belts, were both changed? Id never herd of a drive pulley wearing out. Usually when blades 'slip' means the belts arent tight enough or as mentioned somethings dragging too much ( like a mandrel or idler with bad berings) - id do a lil investigating .


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## Jethro210

Thanks dangeroustoys56. Belts are not new but it seems that when I change the belts it does not help. I will have to check the deck bearings and and tension spring on the deck. This deck has a belt runing to all three blades and one belt that supplys power from the crank pulley.


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## dangeroustoys56

Its possible the deck belt ( driving the blades ) could be stretched just a bit, or slipping - the tension spring could be weak as well .

I had that issue with my 69 simplicity broadmoor - deck has the 2 separate belts as well- i put a new belt that drives the mandrels and even replaced the belt tension spring , just didnt seem to have alot of tension before in the belt ( that and it was probably original)- works alot better now.


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## TecumsehBriggs

There is an adjusting rod underneath the chassis, about halfway back on the right side. You have to find the rod that connects the deck engagement lever to the stabilizer shaft assembly. Remove the cotter pin or hitch pin at the stabilizer shaft, then screw in or out one turn, then reinsert pin. Check operation. Repeat as necessary. Let us know if that did the trick.


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