Does anyone know of a temp sender unit that will thread into the reverse light hole? My reverse is out anyhow and I control the light by a switch (I know: illegal in some states/provinces), but would be interested in how my gearbox is doing when I tow my camper. I guess the oil level hole would also do the trick, then add the extra quart thru the top like last time.

 

How about welding a bung to one of the PTO covers?

 

good plan wanna, then I could use the other holes for what they're for.

 

With adapters youu can put one in the drain plug hole.

Bob

 

What would the maximum safe sustained temperature be? Would a water temperature gauge work?

 

That would depend on what fluid you run. Synthetics can tolerate heat better, but much over 200 sustained would be in my red zone. They can get hot running in 5th, even unloaded:

https://www.dieseltruckresource.com/...y-t109531.html

Replace "66.17.171.114" in the links with "stuff.is-a-geek.net" on your browser's address line to see the pics.

 

Well even if you could put a temp sender in the reverse hole, probably wouldn't read much as that is way above the oil level.

I have mine in the oil fill hole on the passenger side. Its just pipe thread, I believe 3/8". Its just a water temp gauge, mechanical.

 

Any decent oil can handle 230 degrees indefinitely. I would shift out of 5th at 250.

 

get the trans-cool, it has ports already drilled for it . cools great, and to give max life fill the transmission one quart over full.

 

That's what I did.

I cut a 1/4" pipe collar to length and welded it into the bottom right corner of the PTO plate and then threaded the sending unit from this gauge in after running it through the shift boot. Towing heavy, I try to keep it under 230* but have run it as high as 240* in 5th before downshifting to 4th; of course, I'm running Castrol Syntec 5W50 with PowerUp additive so it should be OK at those temperatures.

 

What's happening with with the heat (not the oil) is the problem with the terms "sustained" and "indefinitely." It wouldn't be reaching something north of 200 degrees in the first place if it was able to shed the heat as fast as it generates it. It just keeps building. That can eventually turn ugly over longer distances if you are towing in 5th, or not set up right for it.

 

So just a mechanical water gauge does the trick!man I've been missing out of a lot wieghin in at 1300lbs!