40c safety blocks

fundytides · Post by **fundytides** » Mon Nov 09, 2015 6:14 pm

Someone has removed the safety blocks from my 40c. I don't know how important they are but I would like to install a pair. Does anyone have a pair or know where they might be available. Used would be good. Part #s are:

M2386T safety block (2)
M2387T V bolts (4)
TE273YT shims (qty ?)

All are for a 4 roller 40c serial#62264 and up.

Stan Disbrow · Post by **Stan Disbrow** » Mon Nov 09, 2015 7:11 pm

Hi,

If a rock gets inside the chain, it will pull the entire frame such that the safety block binds the sprocket and stops the machine before it rips everything apart.

Stan

fundytides · Post by **fundytides** » Mon Nov 09, 2015 7:17 pm

Thanks Stan. Probably a good idea if I can find them

Post by **Lavoy** » Tue Nov 10, 2015 8:48 am

I have them on hand.
Lavoy

fundytides · Post by **fundytides** » Fri Nov 20, 2015 7:52 am

Lavoy,
Tried to send you a message but it ended up in my outbox and wouldn't go. Anyway, I have found a set of blocks locally. Thanks for your effort.
Dave.

mapaduke@yahoo.com · Post by **mapaduke@yahoo.com** » Fri Nov 20, 2015 12:25 pm

Any idea why 440s don't have them?

Stan Disbrow · Post by **Stan Disbrow** » Fri Nov 20, 2015 1:55 pm

Hi,

Hydraulic vs. Spring tensioners.

The hydraulic loosen the tracks. The springs don't. So, with springs you need to halt the drive before it snaps the axle or final drive housing from all the pressure.

Just one of many little improvements they rolled into the 440.

Stan

mapaduke@yahoo.com · Post by **mapaduke@yahoo.com** » Fri Nov 20, 2015 2:22 pm

I'm not doubting you Stan, still a little confused.
There is a spring behind the hydraulic adjuster on the 440?
The only difference I see would be in the actual adjustment unless the 440 spring allows more compression than the 40/420 springs thus not needing the safty block?

mapaduke@yahoo.com · Post by **mapaduke@yahoo.com** » Fri Nov 20, 2015 2:36 pm

Sorry, dibble post lost track were I was.

Stan Disbrow · Post by **Stan Disbrow** » Fri Nov 20, 2015 5:32 pm

Hi,

There is a spring to allow for some leeway, then a pressure vent on hydraulic tensioners to allow the grease to spit out and unload the tension on the track. So, when the rock gets in there, the track will pull back and stay that way.

With the older double springs, they compress to a point and then the loading goes up when they run out of coil space. So, there are blocks to jam the sprocket and stop everything. That scheme tended to not work all that well, actually. Better to unload the tension and have a floppy track in the end than busted stuff.

Stan

mapaduke@yahoo.com · Post by **mapaduke@yahoo.com** » Fri Nov 20, 2015 5:47 pm

Ok Stan, that makes sense now.
Thanks for the info Ron

Stan Disbrow · Post by **Stan Disbrow** » Fri Nov 20, 2015 6:35 pm

Hi,

These machines were really a whole series of running design changes from the MC thru the 1010c. They were constantly improved every couple of years along the way.

It is easy to see this in engines and reversers. Not quite so easy to see in undercarriage, but it is there as well. And not just in extra rollers.

By the time they got to the 'JD' Series, they had it pretty well nailed down. Which is why we split the forums up at that point.

Stan

Post by **Lavoy** » Sat Nov 21, 2015 10:02 am

440 final drive is bolted solid to the rear crossbar, it is not possible for it or the sideframes to move, so track stop would be useless.
Lavoy

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