1975 C160 Auto belt tensioner and adding belt tension.

[ebinmaine 67,552]

Folks we've got the newly restored C160 Automatic in the shop because the belt tensioner system makes a pretty wicked noise when engaging and doesn't seem to have enough belt tension.  

 

Is there a fix for this?

 

Do we have everything in the right place?

 

Thoughts comments questions suggestions welcome.   

 

 

 

 

 

 

 

[953 nut 55,280]

The engine pulley PULLS the lower portion of your belt toward the engine when the slack is removed and the belt guard is in place. The belt guard catches the slack on the bottom when there isn't Tension applied to the belt stopping the belt movement. The amount of slack you have is about the same as I had on the on the GT-14 with Sundstrand and the 418-C with an Eaton 1100. The belt seems to creep a bit when not tensioned but once the tensioner wraps it around the driven pulley it works great. My guess is that is the reason for larger pullies on Hydros than gear driven transaxles.

[ebinmaine 67,552]

1 minute ago, 953 nut said:

The engine pulley PULLS the lower portion of your belt toward the engine when the slack is removed and the belt guard is in place. The belt guard catches the slack on the bottom when there isn't Tension applied to the belt stopping the belt movement. The amount of slack you have is about the same as I had on the on the GT-14 with Sundstrand and the 418-C with an Eaton 1100. The belt seems to creep a bit when not tensioned but once the tensioner wraps it around the driven pulley it works great. My guess is that is the reason for larger pullies on Hydros than gear driven transaxles.

 

 

Makes sense Richard.  

 

We'll close 'er up and readdress later.  

 

[squonk 41,136]

On that tension lever the pivot pin wears down and also wallows the hole it fits in. Check that too

[oldlineman 1,481]

I have replaced the the plastic pivot bearing with a brass bushing where the tensioner arm pivots.Not a hard job just drill out and insert a flanged brass bushing, I bought from McMaster Carr

[squonk 41,136]

I'm talking about where the 2 pieces of the arm pivot. 1 piece has a pin and fits into the hole on the other where that cotter pin is.

Edited April 29, 2023 by squonk

[peter lena 8,632]

@ebinmaine  agree with @oldlineman with brass/ bronze bushing improvement , have also added heavier springs  to well lubricated areas , making for a very solid / smooth  action . that entire linkage related set up really responds to functional detailing . like an aerosol red grease , on extension tube for tight spots . have done all my lever / linkage set ups , there is no sloppy play , and they move with total ease . washers and grease , have also tried adding heim joints in those areas .  never had a failure.  talk  to you next Saturday  , pete 

[clueless 3,002]

So is the noise still there when you run it with the belt guard on?

[squonk 41,136]

8 minutes ago, clueless said:

So is the noise still there when you run it with the belt guard on?

Judging by the slop where that cotter pin connection is, I would say it's probably there.

[ebinmaine 67,552]

9 minutes ago, clueless said:

So is the noise still there when you run it with the belt guard on?

It changes tone some but yes. Belt guard there or not. 

 

I'm leaning towards thinking it's a combination of several points of looseness that need to be addressed.  

 

 

Just now, squonk said:

Judging by the slop where that cotter pin connection is, I would say it's probably there.

Yessir.  

That and the main pivot may be the two biggest culprits.  

[Handy Don 12,233]

Agreeing with comments that the “elbow” joint in the tensioner is gonna rattle.

 

The area I had to fix on one machine was the cross-shaft that holds the tensioner pulley arm. It had wallowed in the frame AND worn the shaft (more on the right but also on the left). The resulting slight misalignment of the tensioner pulley then just made things worse.

 

The frame got bushing-ed (?) but I had to get a good used unworn cross shaft.

 

Finally realized that the small “bounce” of the belt against the spring from the normal variations in belt flex plus jouncing of the machine causes lots of friction in that small area. High frequency, varying pressure, and small displacement--a real challenge for bearing surfaces.

Edited April 29, 2023 by Handy Don

[953 nut 55,280]

51 minutes ago, ebinmaine said:

1 hour ago, clueless said:

So is the noise still there when you run it with the belt guard on?

It changes tone some but yes. Belt guard there or not. 

With the right exhaust system modifications you will never hear that noise again.      

[ebinmaine 67,552]

1 minute ago, 953 nut said:

With the right exhaust system modifications you will never hear that noise again.      

 

WWHHHAAAATTTTT ??!!???? 

[953 nut 55,280]

Could you please repeat that?     

[SylvanLakeWH 25,594]

23 minutes ago, 953 nut said:

Could you please repeat that?     

 

That is the exact technique Mrs. Sylvan uses...  I usually listen then...

 

The kids... now that's another thing... nothin' works for them... 

[kpinnc 12,066]

12 hours ago, ebinmaine said:

Is there a fix for this?

 

Up to you, but I have removed the park brake/ tensioner from every auto I have. I just put a strong spring on the pulley swingarm, and remove the rest. Gravity holds the park brake open, and they are typically worn anyway. 

 

Runs quiet as a mouse.

 

 

Edited April 30, 2023 by kpinnc

[ebinmaine 67,552]

9 hours ago, kpinnc said:

 

Up to you, but I have removed the park brake/ tensioner from every auto I have. I just put a strong spring on the pulley swingarm, and remove the rest. Gravity holds the park brake open, and they are typically worn anyway. 

 

Runs quiet as a mouse.

 

 

 

 

I'd had that recommended a couple years ago by someone else too. I like the idea and thought about doing exactly that but held off for a winter to see how I'd like the Auto. 

 

I'm glad I did because last winter (pre-restoration) I discovered that the machine was REALLY resistant to starting to cold 🥶 starting with the transmission engaged.  

I found that below 25⁰ or so it needed a minute or two of running the engine alone - then engage the trans.   

 

 

[squonk 41,136]

No way in cold climate would I remove that tensioner. When I start my C160 cold I let the engine smooth out with no choke before engaging and then it bogs the engine pretty good for 10 - 20 seconds. Plus I have to jump off the tractor quite often to pick up dog muffins I missed while mowing and I could dee that tractor taking off with the hydro engaged

Edited April 30, 2023 by squonk

[pfrederi 17,741]

I have 6 Sunstrand hydros.  The D200 has no disconnect but it also has 20 hp it starts and can move but she doesn't get used in the real cold.  The others are all 12-16 hp and in winter have to run for a few seconds before you can engage the hydro or they will stubble and/or stall.  I used the 4x4 parking brake for awhile but it isn't that hard to fix the parking brake and it is a lot safer.  One thing I have noted over time you can get the neutral setting adjusted in the summer but when it gets cold they may creep.

[peter lena 8,632]

@kpinnc agree with you on the fix, on a repetitive  problem there is a track or failure spot , usually enhance / improve as I go . its amazing to me how easily linkage / levers work with snugging up / washers  lubrication , change an end connection to a heim joint. most of the stuff I see is solid neglect . pete

[ebinmaine 67,552]

1 hour ago, pfrederi said:

  One thing I have noted over time you can get the neutral setting adjusted in the summer but when it gets cold they may creep

Thanks for bringing that up. I've noticed the same on mine. 

Not likely I'll attempt to adjust it immediately because I use the park brake so much.  

[gt14rider 763]

Here are some mods that I did on my auto 12. Welded new pivot pins, brass bushings and nylon bushing

Edited May 3, 2023 by gt14rider
Pics

[gt14rider 763]

[ebinmaine 67,552]

14 minutes ago, gt14rider said:

Here are some mods that I did on my auto 12. Welded new pivot pins, brass bushings and nylon bushing

 

VERY nice work!

 

I'm picking up a smaller welder this weekend so we can do repairs like that.