Deck tensioner arm slop. How to tighten?

bugdewde

Member
Joined
Jun 16, 2019
Threads
5
Messages
31
46" deck. 2004, I think. This is my 3rd Murray wide body 46" mower since buying my 1st one in '98. I really like them.
I know the decks well, I've replaced numerous spindles, blades, pulleys, belts ..... but I've never dealt with this before. How do I tighten up this slop at the arm pivot bolt?
(See video).

This deck has been in my ownership for about 4 or 5 years. I use and abuse it greatly ... mowing twigs, sticks, small branches and even rocks on occasion.
I have some incidental spindle bearing slop, but this tensioner pivot is a HUGE problem as it causes the pulleys to rub together and occasionally throws a belt at certain angles.
I'm going to remove the deck this weekend and do some annual preventative maintenance and would like to address this pivot point.
I can see shimming the shouldered bolt with washers, but it will lose the auto tensioning function if I do that.
Maybe a sleeve over the shoulder to take up the slop in the deck hole????
Any guidance?
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
65
Messages
24,995
The pivot hole for the arm is flogged outoval because you have not been lubricating it properly
It is still available in OZ so should be available in the USA
Not cheap
Along with that will be the bush it runs on and if it is really bad then the bolt as well
IT can be welded & made round again which I do because it is cheaper to do that than replace the tension arm
 

bugdewde

Member
Joined
Jun 16, 2019
Threads
5
Messages
31
OK. Thanks, Bert. Never knew there was a bushing in there, nor a lube zerk.
I'll tear it down in a few days and see what I can do to fix it.
Thanks for the info.
 

Bertrrr

Well-Known Member
Joined
Mar 11, 2021
Threads
5
Messages
570
There is probably no way to grease this part, I just shoot some penetrant on mine every so often , the bushing or bearing is worn out , the bolt on the arm itself may be worn as well,
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
93
Messages
11,598
I see no bushing on the idler arm just a shoulder screw. Replace both items 35 and 14. Also check item 13 for the same worn out condition. The problem is item 13 is NLA.
1684843337541.png
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
65
Messages
24,995
Interesting
The one I just did had a plain bolt not shouldered and a flanged bush
So either we got a different deck down here or some clever bugger fixed his by machining the flogged out hole bigger & making up a bush .
I turned up a slightly taller bush to replace the grooved one and welded a washer on the tension arm to make the hole round again.
These get a generous spray with either dry pushbike chain lube or dry lithium chassis grease
 

bugdewde

Member
Joined
Jun 16, 2019
Threads
5
Messages
31
Update:
The tensioner arm was indeed wallowed out. The shoulder bolt is still usable.
Maybe I can get someone to weld up a washer in there or weld it up & re-drill it to fit.
Thanks for your comments and knowledge.

20230616_165855.jpg
 
Top