Cold weather trans temp

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Jan 19, 2011 | 07:43 PM

#16

roadrunner01

More Turbo

Joined: Aug 2009

Posts: 551

Likes: 19

Quote:

Originally Posted by Mark Kovalsky

The 4R100 did not have any thermostat inside or outside the transmission. It did have a pressure bypass, but it was not a thermostat.

Well another idea shot, thanks for chiming in Mark.

I'm still going with the hot flush and see what happens.

I do know that there are thermostats available to handle what is needed, I actually have one on a marine transmission. The manufacturer is Amot and they offer a wide range of temp/pressure ratings.

Jan 20, 2011 | 08:54 AM

#17

Kert0307

Thread Starter

Senior User

Joined: Nov 2010

Posts: 419

Likes: 1

From: Iowa

Just to give an update, I went for a drive last night and the trans leveled out around 90 deg f. This morning on my way to work it was right at 100 deg. I'm not really sure why it's going up now other than the winter front. I think that maybe the winter front is allowing the truck to get warmer and flowing more coolant through the rad heating the trans fluid?

I don't know how much a hot flush would help the truck as about 1500 miles ago I dropped the trans pan to inspect it and put in a new gasket because I had a trans fluid leak. The pan was spotless, and the fluid looked great. I topped of the fluid with 8 qts of new Mercron SP and replaced the external trans filter. I would think if the fluid was bad enough to clog the thermostat I would have had a lot more "sediment" in the pan.

Edit: Pic of the 09-10 SD winter front on my 05.

Jan 20, 2011 | 01:19 PM

#18

ljutic ss

Posting Guru

Joined: Apr 2008

Posts: 2,392

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From: Green Lane, Pa.

These are readings I got this afternoon with a air temp of 27 f. after 16 miles of driving around 50 mph. ECT 187 EOT 189 trans oil 143 truck unloaded.