Engine/Transmission (1998.5 - 2002) transmission cooler/ oil cooler questions

[MRose]

What is the flow path for the transmission fluid, does it go through the enginge oil cooler then to the grill mounted cooler? Also how are our motors with oil temp? What does it take to get our oil hot?

 

[rweis]

I'm reasonably sure:



Out of the transmission hot line up to the rear port of the water heat exchanger, out the front port of the water heat exchanger, to the front air exchange cooler, back to the transmission.



I put an additional transmission cooler w/fan before the water heat exchanger rear port so when I back my 5er I can turn on the fan and keep the transmission hot line temps in check.



Bob Weis

 

[MRose]

Thanks, what temps to people see on a regular basis? With my MagHytec double deep pan its rare to see the temp gauge even move let alone over 140. Is this normal?

 

[rweis]

Well for the pan and not towing. What are your hotline temps?



Bob Weis

 

[MRose]

Not sure, those are pan temps. My transmission guy told me not to look at pressure side of the cooling system because those will always be high from the TQ, but the real test is to see how cool it gets after circulating.

 

[rweis]

I'm not sure I go with the pan temp only concept. The hot line will tell you when you are close to scorching the fluid and therefore losing your lubricating ability and killing your transmission.



My worst case is backing up where there is no air cooling as you would have in forward.



NOT locked up towing I see 50* difference from pan temp to hot line temp. LOCKED up I see about 10* difference from pan temp to hot line temp.



Reverse I can get 75* difference from pan temp to hot line temp.



I put a transmission cooler / fan on mine for backing up and still on long backups I still have to stop and let the transmission cool before continuing the backing routine.



See sig, Mag-Hytec DD. with the cooler I put in 20 quarts (5 gallons) of fluid and still have to watch it in reverse. Where I park it I have to backup, uphill, in sand.



If I could only have one transmission temp I think I would want it in the hot line so I would know when the transmission was getting in trouble temp wise.



My . 02



Bob Weis