BX25 Transmission filter relocation and COOLER

[Tachdriver]

Before I installed anything, and the original filter was in the stock position, I ran the tractor for several hours and turned it off and could not keep my hand on the Transmission housing. I did not have a temperature reference for that but it was darn hot. Now I can lay my hand on it a lot longer without removing it.

That is a good question though. If anyone is running a temperature on the case then I like to hear it. I read somewhere it is 200F. Does the Japanese Kubota have a trans temperature reading ? If anyone can tell me FOR SURE if there is a plug on the case that I can insert a temperature sender then I'll hook on up

LAter

 

[Tachdriver]

Calling on CTJAY - is there a plug in a circuit on the BX transmission that I can pull and insert a temperature gauge sender - 1/8" npt ?

later

 

[rdsaustintx]

HANDS DOWN the coolest mod I have seen in seven years of reading this board.

Just plain outstanding.

 

[OrangeRidge]

This is as hot as it's got . Top reading is sun shining on the
units in-built sensor . 95f in the shade that day . 2 hrs cutting.
Trans quickly reduces to 170f at idle ( within 10 mins of PTO off ).

 

[jakell2010]

I don't want to step on any toes,,,,but

Sometimes there are reasons why fluids run at the temperatures you experience, for example,,,maybe To give you an idea that your overworking a specific machine. Or that the fluid " was designed" to operate OPTIMALLY at a temperature which you would consider hot.

I've found that there are people who are much smarter than me who design these machines that we buy, and something's ( especially with things where I don't know ALL THE REASONS of why they are what they are) things MAY NOT be an improvement to the original design

 

[ModMech]

I would not care to comment specifically on UTF, but for ATF 140*F is "too cold" and 170*F is "optimum", with 190*+F being too hot.

UTF (Universal Tractor Fluid) is a lot thicker than ATF and closer to engine oil in viscosity and lubrication requirements. 230*F is widley regarded as approaching dangerous temperature for engine oil, I would ASSume that similar temperature limits exist for UTF.

I do recall my uncle's old Farmall would heat up the hydraulics hot enough that you DID NOT want to touch it and that was just from cultivating.

 

[Volfandt]

Modtech, you just may have commented/answered the UTF question in your post inadvertantly

You indicate that UTF is closer to engine oil in various categories and to expand on that, some L&G HST manufacturers (Sunstrand in particular) changed from ATF to engine oil in the early days and all if not most now require engine oil for cooling, lubrication and operation of modern L&G HST's.

In looking at the oil cooler Tachdriver used. He used an engine oil cooler w/a thermostaticlly controlled bypass. Basically the oil bypasses the heat exchanger until it meets/exceeds 140f, then it reroutes the hot oil through the heat exchanger to cool it off.
I think we can surmise that cold oil seems to work better and when testing out HST's one of the major recommendations is to see how it operates once its warmed up, as it's more prone to fail once the fluid has heated up to operating temps.
Cooler oil also does a better job of dissapating heat of the component it's circulating through.

IMHO, the HST cooling system of our BX's is good -to- adequet when considering all the extremes it's designed to operate in. I'm sure the engineers determined that as long as we run the proper oil (UDT/SUDT/SUDT2) which is designed to operate in these extremes, that the tractors will operate and not destroy themselves in these extremes. But thats not to say that cooling that HST fluid down when finish mowing 2 or more acres on a 90degree day is a bad thing either

SCUTs are the only modern utility tractors that utilize a driveshaft driven fan to cool the HST and it's oil down. All the others use a heat exchanger, normally mounted in front of the engine radiator so it can utilize the same fan to draw cooling air through both. Some of these "others" have similar power and are the same size as the SCUTs.
It's also of note that JD's newest SCUT has done away w/the HST cooling fan setup and gone to an external heat exchanger.

It would be nice to have an engineer contribute and let us know what the "ideal" HST oil temp should be. I could be wrong but I'd guess it's alot south of the temps OrangeRidge posted and more inline w/what Tachdrivers HST heat exchanger provides.

Dave

 

[ModMech]

Dave,

Sounds like the same thinking Allison was using 20 years ago when they advised we transition to a C4 rated engine oil in our ATs - to lubriace better and cool more effectively.

 

[dodge man]

Very nice mod, and very well executed. Is this mod necessary? Probably not. Is this mod make the tractor better and make the life of the HST better? I'd say yes!

 

[jcy110]

Looks great. I see in your photos that you have the older model stabilizer lock (bungee cord....LOL), I have the newer model. Its one of the 1" nylon straps with a hook on each end and a cinch buckle that holds the tension until you release it. Flip the feet upward, attach hooks and pull to tighten. they never move at all until you loosen them manually. Nothing worse than parking the BX somewhere and returning to see the stabilizers laying out like a dead spider against something you don't want scratched!