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Topic: transmission temperature (Read 654 times) previous topic - next topic

transmission temperature

We took a short trip a couple of weeks ago to check out how the Foretravel towed the ram 2500.  I noticed when we were in the hills
(not mountains) that the trans oil temp was running around 195-200 range and we didn't have the side-by-side loaded on truck yet.
What is an acceptable trans oil temp?
Thanks
Chris
1999 U 320 DGFE
Build Number 5523
Chris & Elka Lang
In the field, Lonoke AR

Re: transmission temperature

Reply #1 –
Chris what was the engine temp? Mine runs similar to each other when we towed the 3500 megacab. 7200 lbs empty
Scott

Re: transmission temperature

Reply #2 –
Our oil temp follows the coolant temp except in town where we are not in lockup. It gets to about 200 in San Francisco with all the hills. Probably averages about 180 or so.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: transmission temperature

Reply #3 –
My ISM11 engine oil temps are 198-201 under most conditions. Work the engine a bit and it will get to 208.  Cummins tells me internal engine oil temp thermostat opens at 225.  And not all M11s are the same. Miles, time, wear will make this change.  My engine oil temps went up a bit after the engine was rebuilt, probably tighter fits.

My transmission fluid (synthetic) temps generally run about +10 over coolant temp.
Chris, your temps look within a normal range to me.

I thought Pierce was talking about engine oil temps. 
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: transmission temperature

Reply #4 –
Quote from: Roger & Susan in Home2 –
M11 is not the same as a DD.
My DD post about was about transmission temperature from Chris's post at the top. I should have included the word "trans" in my post. Naturally, the engine oil temps will be different from engine to engine.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: transmission temperature

Reply #5 –
the water temp was running 175-180 engine oil temp was 190 range
I guess my real question should be what is to hot for trans oil temp?
thanks for input
Chris
1999 U 320 DGFE
Build Number 5523
Chris & Elka Lang
In the field, Lonoke AR

Re: transmission temperature

Reply #6 –
Chris,

Here is a graph.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: transmission temperature

Reply #7 –
Thanks Pierce
Chris
1999 U 320 DGFE
Build Number 5523
Chris & Elka Lang
In the field, Lonoke AR

Re: transmission temperature

Reply #8 –
Quote from: Pierce & Gaylie Stewart –
Chris,

Here is a graph.

Pierce

Pearce,

Do you know if that is the table/graph for Dexron  or for Transynd??
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: transmission temperature

Reply #9 –
Quote from: wolfe10 –
Pearce,
Do you know if that is the table/graph for Dexron  or for Transynd??
Excellent point Brett. I'm assuming it's for Dexron as synthetic ATFs are much like synthetic motor oil so I would expect the flash and fire points to be perhaps 60°C higher than conventional ATF.

Translation to me would be that not only would the synthetic ATF have a longer lifespan but when used in a early non-lockup Allison, the most difference would be seen as they run higher trans temps because of the torque converter slippage.

I have not changed to Transynd or other synthetic ATFs as we are in lockup most of the time so the ATF temp is toward the bottom of the graph but probably the biggest reason is that the torque converter can't be completely drained so you can't easily make a 100% change over without spending a lot of $$.



In the case of Transynd fluid, yes it's Allison approved but there are other synthetic ATFs that while not being Allison approved , meet the same specs. It costs a lot of money to do the testing to get Allison approval.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)