I've been rolling an idea around in my head for a few weeks. I spoke today with Mr Zimmerman that rebuilds lots of rear ends from the Cletrac dozers (same part as our IMP rear end but with a flipped ring gear) and is rebuilding mine.
My theory is thus:
The dozer version of these machines rarely ever has an issue with the rear end. According to Mr Z. the units only turn at a maximum of about 1800 engine RPM input. Of course.. dozer operations are lots of back and forth, much slower than a snowcat, and rarely ever just go and go and go in one direction, like say a groomer pulling a drag.
By design.. this unit seems to be cooled by fluid, mass of the iron housing, and I would guess the idea that with it's low ground clearance, dragging it thru the snow. That would make those using it for non pulling chores have better results. Cabin access guys would be going thru deeper snow more often.
A guy like me, who would be grooming trails, would be going out after the air has been knocked from the snow. Very little snow 'flying' around to cool the rear end. The duty would be pulling, and generating more heat. Likely way more turns grooming trails then just heading out for a cabin.
SO....
I've made up my mind to install a rear end cooler on my cat. I'll "T" into the fill port for the fluid (this will make me purposefully run an inch or two over on my fluid level, not all that uncommon I guess) Top port in the T will be used for a temperature sensor. Side port will go to a self priming, gear type pump. I've seen several that are used for racing applications. 3gpm or so is the flow. I figure while using the fill port as a input to pump.. if I had a catastrophic hose blowout on a line on the pressure side... The pump will starve and the rear end will still have it's fluid in the pan like it always did.
After the pump, I'll install a spin on filter. Mr. Z said while the fluid stays pretty clean (assuming he said a good shift boot on the unit) he said the dirty material from brake band breakdown might not cooperate with my oil pump.
After the filter I'll run back to an access plug on top of the unit. Mr. Z was concerned that I make sure I have this cooler 'switched' so I can let the fluid warm up to start out.
He's not much of a 'synthetic guy' but he did say MANY of the issues he's seen with these units is from improper oil or water infiltration. He stressed that GL5 spec oil should NOT be used due to many bronze seals used in the construction of the C4. I looked up the amsoil power shift fluid 50w. Discovered it's a GL1 fluid. He says all should be well.
Now.. is all of this overkill? Probably! but.. if I can spend a few hundred dollars 'insurance' to protect what is the most costly part to fix or replace on the cat. I think it's worth it.
Ideas? Comments? Criticism?
JP
My theory is thus:
The dozer version of these machines rarely ever has an issue with the rear end. According to Mr Z. the units only turn at a maximum of about 1800 engine RPM input. Of course.. dozer operations are lots of back and forth, much slower than a snowcat, and rarely ever just go and go and go in one direction, like say a groomer pulling a drag.
By design.. this unit seems to be cooled by fluid, mass of the iron housing, and I would guess the idea that with it's low ground clearance, dragging it thru the snow. That would make those using it for non pulling chores have better results. Cabin access guys would be going thru deeper snow more often.
A guy like me, who would be grooming trails, would be going out after the air has been knocked from the snow. Very little snow 'flying' around to cool the rear end. The duty would be pulling, and generating more heat. Likely way more turns grooming trails then just heading out for a cabin.
SO....
I've made up my mind to install a rear end cooler on my cat. I'll "T" into the fill port for the fluid (this will make me purposefully run an inch or two over on my fluid level, not all that uncommon I guess) Top port in the T will be used for a temperature sensor. Side port will go to a self priming, gear type pump. I've seen several that are used for racing applications. 3gpm or so is the flow. I figure while using the fill port as a input to pump.. if I had a catastrophic hose blowout on a line on the pressure side... The pump will starve and the rear end will still have it's fluid in the pan like it always did.
After the pump, I'll install a spin on filter. Mr. Z said while the fluid stays pretty clean (assuming he said a good shift boot on the unit) he said the dirty material from brake band breakdown might not cooperate with my oil pump.
After the filter I'll run back to an access plug on top of the unit. Mr. Z was concerned that I make sure I have this cooler 'switched' so I can let the fluid warm up to start out.
He's not much of a 'synthetic guy' but he did say MANY of the issues he's seen with these units is from improper oil or water infiltration. He stressed that GL5 spec oil should NOT be used due to many bronze seals used in the construction of the C4. I looked up the amsoil power shift fluid 50w. Discovered it's a GL1 fluid. He says all should be well.
Now.. is all of this overkill? Probably! but.. if I can spend a few hundred dollars 'insurance' to protect what is the most costly part to fix or replace on the cat. I think it's worth it.
Ideas? Comments? Criticism?
JP