Idlers for drive belt on C175 vs 312H

[mikeeyre74 289]

I have a 312H and my friend just got a C175. I notice that he doesn't have an idler  between the engine and transmission that you can "pull up and off" to disengage the engine from the transmission. His has just a spring tension idler thats just always on. It looks like the 520H is the same way. Why is that??

[Ed Kennell 38,715]

I wondered why they eliminated the disengagement feature also.   My guess....cost savings.

[shallowwatersailor 3,213]

I have tractors with that can disconnect the drive belt to lessen the load on starting the engine. Frankly, I haven't used it as the tractors for winter are garaged. Could it have been a feature when battery technology was such that there weren't the CCA of today's batteries?

[doc724 925]

I wondered the same thing.  My C125 has one, the 416H does not.  Cost reduction could have been one reason.  Another could be that prior to 1981, only Sunstrand Hydros were used.  Starting in 1981, the Eaton 1100 became available.  Is it possible that the Sunstrand hydros did not have a relief valve at low revolutions (like cranking) and would start to build pressure while cranking and the Eaton's may not build up pressure until the rev's come up?  WH kept the disengagement feature up to maybe the early 90's.  As Ed suggests, someone was looking at cost reduction opportunities and asked "why do we still have that thing?"  Sometimes that is all it takes to get engineers to think differently.

[cleat 6,398]

One of my old 520's came with this setup.

The other 3 did not.

 

I got rid of it on the one that had it as I never used it and it just rattled all the time.

 

Cleat

[R. L. Addison 299]

My release lever's are always rattling (and never) used on my C141's, and a source of noise and wear. My bet would be that is the main reason for elimination. I have run one for two years or more with the lever in the spare parts bin, and I think that is a good place for it unless / or until I sell it. I think PO put the wrong idler (too small) on the other one, and when I check it out, that lever I'm thinking will join the first. The first & only clue was the belt coming off while pushing snow (temperature barely above zero).

[EricF 589]

Agreed that it probably wasn't needed on the Eaton -- in neutral, it seems to have enough relief to keep from dragging on the starter. So, one fewer pulley mount bushing and pulley bearing to fail... probably a good thing.