36” R/D deck belt tensioner spring

[ranger 1,783]

A quick question? If anyone could help me please? I’ve just bought another Wheelhorse! A C161. It has a 36” r/d deck can anyone give me a rough idea of the dimensions of the deck tensioner spring, the P/O substituted the spring for a threaded rod for adjustment? I’m not collecting it until Sunday.

Thanks in advance,

Doug.🇬🇧

[gwest_ca-(File Mod) 11,266]

Your tractor is a 1978 or 1979 model with a single-cylinder or a twin-cylinder engine.

That is not to say the mower deck is the same vintage so you need to identify the mower deck model. Here are the possibilities

Mower DNA

1972 model 5-0620 replaced by

1973-1974 model 5-0621

1975 model 5-0622

1976 model 65-36XR01

1977 model 75-36XR01

1977 model 75-36XR02

1978 model 85-36MR01

1979 model 95-36MR00 (Blades up to this point have the 5/8" x 3/4" double-D center hole unless the spindle has been upgraded)

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------

(These decks used blades with a 3/4" center hole)

1979 model 95-36MR01 replaced by

1980-1982 model 05-36MR01 - Last year for bearings with 3/4" ID

1983-84 model 05-36MR02 - First year for bearings with 17mm ID unless older spindles were updated.

1985 model 05-36MR03

1986-1990 model 05-36MR04

1991-1993 model 05-36MR05

1993-2006 model 78305

 

Note - 17mm is .669"

[peter lena 9,097]

@ranger  your belt tensioner issue brings up a tweak that I added to my decks , that long unsupported belt , at back side of pulleys is easily improved with a flat belt pulley at about the middle of that area . drill 1 hole in deck ,add elastic lock nut to bolt stud . no more belt bounce , pete

 

[ranger 1,783]

Hi Pete,

I’ve only seen this tractor once, a C161, K341. It belonged to the local flying club I’m a member of. It apparently has a habit of shredding belts. The main, engine to deck belt destroys itself regularly. When I saw it in action I noticed the new belt is an “SPB” section instead of the “4L” or “A” section. Although it fits the pulley grooves it is way too thick in depth to cope with bending back and forth around the relatively small diameter mule drive pulleys, especially the flat one! After the few minutes I saw it in action the belt was red hot to the touch! Then the deck belt snapped! They also try to mow at the lowest setting possible, with the blades constantly hitting the ground. When I saw it, the deck height lever was actually outside of the quadrant with the blades on the ground. All the spindles spin freely, (when raised). Trying to drive it results in “Wheelies” except in top gear, when it doesn’t want to move. The transmission drive belt is either, worn out, stretched, the wrong size, or the tensioner pulley is shot. When the clutch is engaged, (engine stopped) you can reach through to the belt and lift the lower run to touch the upper run, whilst holding the clutch pedal up! I was later told the machine was nothing but trouble and did I know anyone who would be interested in buying it. I then thought long and hard about it for a couple of seconds and said “I’ll have it”, collecting it this Sunday!

Doug.
 

 

Edited May 11, 2023 by ranger

[Rick3478 434]

15 minutes ago, ranger said:

Good find!  It sounds like your flying club created their own problems by putting the wrong belts on.  The right parts adjusted correctly should last you a long time.

 

[ranger 1,783]

1 hour ago, Rick3478 said:

 

Yes, my 312-8 42” S/D deck still has the same belts on it’s had on all the time I’ve had it, 20 odd years, with no real problems!

Edited May 11, 2023 by ranger

[ranger 1,783]

On 5/11/2023 at 6:22 PM, Rick3478 said:

 

Picked it up yesterday, after showing the correct belt to the chairman, he told me that they had been replacing the belt each time with the same size/type as it had on when they bought it! It needs new tyres/tires, etc, but I have plenty of spares. Deck is, I believe, a 1980 36” R/D.

Edited May 15, 2023 by ranger

[Rick3478 434]

Just what I can see, the PTO to deck belt looks totally normal.  I have not seen that particular tensioner modification on a deck belt, you might want to un-do that and put a normal spring on it.  As for the other (drive) belt, if that 2500 is what they were using, it may be both too long and too wide, which could certainly cause problems.  If it takes the same 7473 belt as most of my 8-speeds, it should be 5/8" by about 82".  Also, if they were using a belt that much too long, they may have routed it incorrectly outside the guard or something.  Aside from that, it looks like it's pretty much all there, and with minor corrections and cleanup should become a reliable worker.

[gwest_ca-(File Mod) 11,266]

Deck is a 1982 model with the 1292 build date - 292nd day of 1981 - Monday October 19, 1981

[ranger 1,783]

38 minutes ago, Rick3478 said:

Just what I can see, the PTO to deck belt looks totally normal.  I have not seen that particular tensioner modification on a deck belt, you might want to un-do that and put a normal spring on it.  As for the other (drive) belt, if that 2500 is what they were using, it may be both too long and too wide, which could certainly cause problems.  If it takes the same 7473 belt as most of my 8-speeds, it should be 5/8" by about 82".  Also, if they were using a belt that much too long, they may have routed it incorrectly outside the guard or something.  Aside from that, it looks like it's pretty much all there, and with minor corrections and cleanup should become a reliable worker.

The SPB2500 belt is the belt they were fitting for the pto to deck belt, 5/8”” wide instead of the correct 1/2” wide, and getting on for almost twice as thick! This thickness caused major issues running around the mule drive pulleys, especially the flat one. The belt was very hot after only a few minutes running, being much less flexible than the narrower and thinner correct belt. The tensioner mod someone had carried out took away any anti-shock protection the spring provided when the blades hit the ground due to the operator trying to cut the grass at the lowest setting over uneven ground. The 7473 belt I changed was the correct size, but not a Kevlar reinforced type, and had stretched and thinned out over around a foot or so. This caused the wheelies etc!

[Rick3478 434]

1 hour ago, ranger said:

The SPB2500 belt is the belt they were fitting for the pto to deck belt, 5/8”” wide instead of the correct 1/2” wide, and getting on for almost twice as thick! This thickness caused major issues running around the mule drive pulleys, especially the flat one. The belt was very hot after only a few minutes running, being much less flexible than the narrower and thinner correct belt. The tensioner mod someone had carried out took away any anti-shock protection the spring provided when the blades hit the ground due to the operator trying to cut the grass at the lowest setting over uneven ground. The 7473 belt I changed was the correct size, but not a Kevlar reinforced type, and had stretched and thinned out over around a foot or so. This caused the wheelies etc!

 

Ah, I see.  I wasn't clear on all the photos.  Sounds like you have it well in hand, then.

[ranger 1,783]

All I need now is the tensioner spring. or some idea of the dimensions. I have a selection of various springs that may or may not work. I don’t particularly want to pay Toro prices, even if I could get one this side of the pond. Another thing I am trying to find over here is a supplier of friction material to use to re-line my pto clutch discs!

[Rick3478 434]

11 hours ago, ranger said:

All I need now is the tensioner spring. or some idea of the dimensions. I have a selection of various springs that may or may not work. I don’t particularly want to pay Toro prices, even if I could get one this side of the pond. Another thing I am trying to find over here is a supplier of friction material to use to re-line my pto clutch discs!

 

I'm going to call mine about an inch diameter, and the wire gauge appears to be a bit less than 1/8".  Maybe 3/32" or 7/64".  Length you can figure from the tensioner.  Without a belt, it should take up all the slack in the slot.  It should be pretty stiff, and unless you're very strong you probably won't be able to pull it into place and just drop the belt on.  I find that I have to use the mechanical advantage of rotating the belt up over the side of a blade pulley.

[Lee1977 7,049]

On 5/16/2023 at 7:14 AM, ranger said:

All I need now is the tensioner spring. or some idea of the dimensions. I have a selection of various springs that may or may not work. I don’t particularly want to pay Toro prices, even if I could get one this side of the pond. Another thing I am trying to find over here is a supplier of friction material to use to re-line my pto clutch discs!

Check out slip clutches fot tractor equipment, brush cutters. Don't know if you'll find the right diameter, I've see some that look close to the right size.

[ranger 1,783]

1 hour ago, Lee1977 said:

Check out slip clutches fot tractor equipment, brush cutters. Don't know if you'll find the right diameter, I've see some that look close to the right size.

I looked at slip clutches etc, but, nothing the right size. Then I found a company that specialises in this field, they supplied me with four discs, cut to my dimensions for around £10.00 each. I’m still playing with springs for belt tension, but found a piece missing from the lower pulley flange. Very little chance to find one over here, so I think it’s, “fire up the lathe time”, and start machining!

[peter lena 9,097]

@ranger  yes that combo of high gass and lowest cut setting is just plain wrong , never letting the deck discharge or clean itself out . always cut at my highest setting  , think from what ai acan see of that field grass , would have a field flail mower open that up , and maintain it . the stress / drag on a lawn tractor set up was made for lawns , think its a wrong  type of  deck . just too much . pete   the belt shreading  is something tnat I  have never had  . pete 

[Brockport Bill 1,832]

hard to tell from photo - did you check if the 2 mule pulleys are correct pulleys? Is outside pulley an idler pulley or v pulley ?

[ranger 1,783]

4 hours ago, peter lena said:

@ranger  yes that combo of high gass and lowest cut setting is just plain wrong , never letting the deck discharge or clean itself out . always cut at my highest setting  , think from what ai acan see of that field grass , would have a field flail mower open that up , and maintain it . the stress / drag on a lawn tractor set up was made for lawns , think its a wrong  type of  deck . just too much . pete   the belt shreading  is something tnat I  have never had  . pete 

The grass in the photos is at my stables. The grass “They” were mowing would only be a couple of inches, (mostly weeds). They want a “bowling green” finish, lowest possible setting! The belt shredding was due to the SPB section belt they used which is twice as thick, + wider than the correct belt and couldn’t bend backwards around the flat idler properly. I’ve replaced all of the pulleys, ( much quieter now), I fitted cheapo belts to test everything, before I fit the correct belts. The outer spacer for the mule drive spindle was missing, the pulley was worn away by the flanged clamping nut not contacting the inner race!!! A few minutes on the lathe and that’s sorted. The blades had apparently just been sharpened?  I re-sharpened them and it cuts fine, then it shredded the deck belt because a section of the deck centre spindle lower pulley broke off. So now in pieces again, but this spindle does need new bearings. If I want to cut longer grass, I use my 4ft cut flail mower, or the BCS, 30” single blade - 16hp Vee twin Vanguard - which will literally cut it’s way through a jungle!!! My 312-8 - 42” SD which I’ve had for around 20/25 yrs, has never had new belts, and is still going strong, although it does have a noisy outer spindle on the deck. - Doug.

Edited May 27, 2023 by ranger

[peter lena 9,097]

@ranger  thank you for the update , your detailing filled in the gaps .agree with proper belt wear , my belts also last a long time . been years since I did my decks over , on spindle rebuilding , they all operate the same , once I  found the cure , did it to my 3  and also the mule drives . that functional detailing at each step , made me change things , grease totally eliminated bearing whyne / noise , refit the pto lever set up , no play at all, heim joint replaced trunnion . as I went and tried a change , it just kept gettg better . every time I  hear another mower deck start , its the same screaming  , whyne . none of mine do that . found tractor supply belts , to be very good , also detailed all of my idler pulleys , with a re grease, silence . stay on it , pete  

[Geoff Cornwall 75]

I got clutch material for my pto , just sent them the sizes and they sent them before i even paid , first class service .jamesautoindustrial@gmail