So, in other words, if you running 130-140 your OK? I've got two coolers on mine and unless I'm climbing a hill at a real low speed my trans never gets hot. I know that an engine should be up at 200 or so to be efficent, I just didn't know about a auto trans. Thanks

 

Mine barfed fluid out at 230, 250 is the end of my gauge and it never reached that I'm sure of.

 

mine seems to puck fluid around 215º-220º also

but my general rual of thumb, if it's consistantly over 220º it needs more cooler, 190º I will let it sit there all day. I like to see 210º every now and then, boil some water out of the oil if any has gotten in there, just my theory that makes me feel good.

I figure 282K miles on what I am pretty sure is the ford original trans, I must have done something right. factory radiator WTO cooler, with a larger aluminum cooler replacing the factory OTA.

Diesel Rod

 

That is irresponsible!

By saying that the chart is not correct eludes to the fact that running it above 200 doesn't hurt the trans. There are people on these boards that may take your advice as gospel because of your signature.

Case in point; The very next post nelstone74 feels good about running @ 215F or all day over 200. His trans will fail prematurely at those temps. I replace them all the time from heat damage, not just Ford's..all of them. Newer trannys are very weak and prone to damage from heat, even for short periods. If the fluid hit 220 it needs to be changed.

If the chart is indeed from the 60's (it's not) then it helps proves my point. Most trannys from that era were darn near bullet proof, I have a one each: a TH400, C6, and a TF727 that are still going strong and have never been opened up. The TH400 has never had the oil and filter changed. The TF 727 in stock form holds up to 600+HP, the C6 is used for plowing....they all have one thing in common....extra large coolers and stay below 200 degrees.

Heat kills trannies... Anything over 200 will shorten its life expectancy. That's real world (30+ years) numbers not a controlled test by a manufacturer that engineered their product to just barely outlast the warranty.

RANT:
You gotta ask yourself why are most new car warranties now requiring that the trans oil & filter be changed as low as every 15K miles when the same exact trans 2-3 years ago had a 30K or 60K requirement....it's simple..they were paying out too much in warranty calls so they just bumped up the maintenance requirements instead of making a better product. End of RANT.

 

oldbird1965

Your truck is a 96 it has 5/16 cooling lines and no CBV.
You could update to the CBV and 3/8 lines.
The CBV will bypass the cooler if you have a restriction in the cooler or the fluid is to thick (cold). This is so the rear of the trans will get its needed lube and not to damage the trans.

CBV = Cooler Bypass Valve. The valve bypasses under a higher fluid pressure.
1999-2003 Ford 4R100 Transmission Cooler Bypass Valve

Bill

 

I have to remember that all of you that think that 200F is some magical number that should never be exceeded are wasting YOUR money on overcooling, not mine. I really don't care if you needlessly spend YOUR money to cool the trans more than makes sense. Go for it!

And until now I was not eluding anything. Now I'm done with this thread, so I guess you can call that eluding you.

I didn't allude to anything in the threads above. I thought I spelled it out very clearly. Whether you believe it or not is your problem, not mine.

 

I'd rather spend $150 to over cool than $2500 for a rebuilt tranny......

 

Fords overheat to set a code and flash the lamp is IICR 270* at the TFT.
That would give you approx 250* at the pressure port.

Bill

 

Bill that brings up another important point in this debate as to where your temp probe is. Most of us have it in the pressure port and rule of thumb is that is 20 degrees cooler than core temps. So if you are at 200 all day long the clutches and seals are seeing about 220. No thanks!

 

Tim

The TFT sensor is in the S-pack. From my findings the average temp at the pressure port is 20*F less. You could only guess what peak temp could be at the clutch/drums/bearing/bushings ect. I would think much higher which would control some condensation issues.

The Code is for overheat. Big difference in overheat,hot,warm,cold ect.
Fluid has come a long way in the years. Synthetics is the way to go.

I run a bypass filter on the trans like you would on your motor.
I have not seen anyone do this.

Bill

 

Yes, I knew the TFT was there but you are right things would be hotter yet where the work is being done!

Bill do you think CBV is a good unit? Meaning would it be good retrofit for our trucks if we wanted to upgrade to 3/8th line? I have heard stories of it opening before it should, I guess if you have a temp gauge then you would know when its happening but kinda makes me nervous. Also if you didn't add the CBV and wanted to go to 3/8 lines can you just get new fittings there at the trans then add the bigger lines?

 

Bill, I really like that idea. I have the Tru-Cool 4739 MAX with a thermal by pass. I think it operates the same way as the side mount you eluded (hehe) to. Do you think a filter could be added to it?

 

I use the valve with good results. Yes if you bump the line pressure up it will open the valve and bypass. With a stock trans the line pressure while in R or man 1 can/will open the valve. Its why most overheat a trans backing up a trailer. I mod the CBV. It has 4 ports that it has to pass to get to the return. I plug 2 of the ports. I have not tried but you might be able to shim the spring for a higher pressure.
I just like the valve for the fail safe you get with it. I have seen many trans saved because of the valve. (cooler clog). Its a bolton OEM part with the lines.

Bill

 

Cuda

I tapped into the cooler feed line and resupply down the dip stick. Works great! Next time i drop the pan iam going drill and tap the trans case for a return. If i can find a good location for it. The oem in pan filter is crap (it needs to flow) and all the full flow add on filters are only a 30mic so not to obstruct flow. It brings up the question of is the full flow in bypass (open) also.

Bill

 

Tj

If you still have the spare franz. You should rig it for the trans.

Bill