Just a quick question. What is the max trans fluid temp before it causes damage to the trans or burns the fluid? I have an autometer gauge mounted in the cooler line going to the radiator. I also tow a 7000# travel trailer and don't want to fry my tranny. I have a new cooler that is twice as big as the factory auxillary one that I'm going to install with the factory one.

Thanks in advance for your input.

Dave

 

Just another note, I have seen my gauge at about 225 on a couple of occasions, checked my fluid and it didn't smell burnt or anything. I guess I'm just nervous. It's got 75,000 miles on it and has been service at 30k and 60k.

Dave

 

im not sure about the trans temp but 7k is not a problem for the truck and the tranny should not over heat. the 4r100 is from the F250, 350.

welcome to the forum

 

Hello!

This may help:==> http://tccoa.com/articles/tranny/index.html#

" ... since fluid life is cut in half for every 25 degrees increase in temp about about 170, it's best to know the hottest fluid."

It's not about the tranny - it's about the fluid - and 225 is on very dangerous ground. It's a one-way street; once damaged, the fluid will not recover it's proper lubricating properties and continue to destroy yer tranny over time.

Change the fluid asap. Looks like you may need to beef yer cooling arrangement.

Even more info on temperatures, as well as a really good cooler, is here: ==> http://www.troyerperformance.com/cgi...gno=PPI-ATCKIT

"This is an especially critical issue with Ford automatic transmissions, which use shift solenoids attached to the valve body, as these shift solenoids are constantly bathed in the hot transmission fluid. Fluid temperatures over 190-200 degrees causes premature failure of the shift solenoids (which were a bit "weak" anyway up until about the 2000 model year or so), as well as premature wear on the friction materials such as clutches, steels, bands, etc."

BTW - where are you measuring it? This makes a difference; the hottest spot is in the line going to the cooler.


MGD v4.2

 

If you are going to run tranny temps over 200, you should use a high quality synthetic fluid such as Amsoil.

 

No doubt ...

http://www.amsoil.com/storefront/atf.aspx

If you can believe Amsoil's claims, the fluid will still break down, but will take about twice as long to do it, as compared to Ford's OEM ATF. But - break down it will ...

Also - the standard 4-ball wear test is conducted at 167 deg F ... which is the most ideal operating temp for ATF.

 

Thanks for the info. I have the sender for the gauge in the cooler line going to the rad so that is the hottest fluid in the system. I do have another cooler that I will put in very soon.

Again, thanks.

Dave

 

Does anybody use Royal Purple ATF? i hear it is better than Amsoil.

 

It's supposed to be real good, but I don't see where it would be any *better* than Amsoil. I think I've also seen advice here from tranny pros that says not to use RP in a 4R70 but Amsoil is fine. I dunno why, but when these guys say something I usually listen. I also don't know if that caution applies to a 4R100.