TFT and EOT Difference help

Reply Subscribe

Thread Tools

Search this Thread

Apr 29, 2016 | 06:59 AM

#16

lhud

Elder User

Joined: Dec 2006

Posts: 718

Likes: 2

From: Chattanooga, TN

During say 80 deg. days and after the engine has warmed up the TFT will be approximately twice the ambient temperature as seen on the overhead indicator. The EOT will then run approximately 35 deg. to 50 deg. (depending on ambient temps) higher than TFT. Remember, these are not exact numbers but good ball park numbers.

Apr 29, 2016 | 07:25 AM

#17

Tugly

Hotshot

Joined: Jan 2011

Posts: 18,849

Likes: 179

From: Puget Sound

Quote:

Originally Posted by Mark Kovalsky

Nope. You've described torque converter slip. Transmission slip is measured by turbine speed (TSS) and output speed (OSS.)....

Crap. You caught me before my coffee kicked in. Thank you for the correction, I amended my post to match your information. Without the coffee, my senior moments are frequent.

Apr 29, 2016 | 07:32 AM

#18

Mark Kovalsky

Frmr Ford Trans Engr

Joined: Aug 1999

Posts: 24,731

Likes: 2,658

From: SE Florida

Quote:

Originally Posted by Otto396

I checked this on my way home and noticed transmission slip is within a very small amount when in 3rd gear but as soon as I shift into OD the difference becomes huge. Almost double. I assume this is due to gearing?

No, I think that's due to bad calculations on whatever you're looking at for this information. Unless the transmission has failed transmission slip will always be well below 10 RPM. And that's just noise, in reality there is no slip inside a transmission when a shift is not occurring.

The torque converter does slip, and slips a lot when it isn't locked.

Apr 29, 2016 | 07:51 AM

#19

Tugly

Hotshot

Joined: Jan 2011

Posts: 18,849

Likes: 179

From: Puget Sound

My TC slip reads under 10 in 3rd gear and OD. If I press the OD cancel button... the TCLU drops out and I'm slipping again, but the TCLU re-engages if I press the throttle and my TC slip drops back down to under 10 at the higher RPMs.

Apr 29, 2016 | 09:55 AM

#20

Otto396

Senior User

Joined: Oct 2015

Posts: 444

Likes: 0

Quote:

Originally Posted by Tugly

My torque converter locks around 35 MPH and stays locked. The only time it disengages is if I am in OD and I drop below 40. Then it will let go. If I disengage OD manually though the TC stays locked and disengages just below 30MPH. I was told I have a factory tow thing from the fella I bought the truck from. The transmission won't shift into OD until I hit 55 OR I press the OD button on the column. Otherwise I can rev the **** out of it and she stays in 3rd.