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Tranny temp with retarder

Going down hill with my cargo trailer, I put the retarder into position 3. My tranny temp goes to 200-210 and holds. Seems ok to me. Any thoughts? If I use position 2, it isn't enough on steep grades but doesn't get hot either as I then need to supplement with brakes,
Just keeping it safe
1996 U295-36, Cummins 300hp, 8.3. Build number 4864. Vin number 1F97D536XTNO54271. Purchased October 31, 2019.

Re: Tranny temp with retarder

Reply #1 –
We took our first trip with a display for our retarder fluid temperature.  When the transmission temperature went from 180ish to 210, the retarder temperature went up to 250.  I learned that shutting the retarder off for a moment reduces the retarder fluid temperature quickly.

I wonder if you have a provision for retarder temperature?  I use a Scangauge D, and the sensor was already present.  I love having the retarder!  It is so nice to go down a steep hill and not touch the brakes, but I have committed myself to watching the temperatures.
Matt B
1998 u-320

Re: Tranny temp with retarder

Reply #2 –
Although your retarder is part of your transmission the temperature  gauge for the transmission does not reflect retarder temperature. There is an additional gauge available  in one of the scan tool, gauges. During my last trip on I-70 while watching the retarder temp gauge I realized I could only use level one max on the joystick while downshifting to 4th to maintain retarder temps below 233 degrees. Higher RPMs are your friend. This was without a trailer. I think your retarder temperature was much higher than you are aware that it was. This is permissible but damages fluid and reduces change intervals. I also have the 4060 trans that has a larger retarder compared to your 3060 Allison. Shift to similar gear you would climb in, reduce speed, okay to intermittently use brakes typically under five seconds during application
Scott

Re: Tranny temp with retarder

Reply #3 –
Managing trans / retarder / brake temps is a challenge on long downhills.    But is sure is easier with the joystick, I can tell you that. 

While doing the siskiyou pass at 6% for 6 miles next week I plan to use 4th or even 3rd gear and a little more brake with a little less retarder.  Last year was the first time on that pass with the joy stick and the trans got warm but not even 300.
    This summer I'm thinking of installing a patio sprayer type affair on the CAC , and the water for it where the giant muffler used to be. ( straight pipe now).
Robert and Susan
 1995 36' 280 WTBI 8.3 3060r
 1200 watts on the roof, 720 Ah of lithium's
 Build # 4637. Motorcade # 17599
        FMCA  # 451505
        18  Wrangler JLUR

Re: Tranny temp with retarder

Reply #4 –
It's easy to raise the torque temp. I have torque temperature reading on Silverleaf
and it goes up fast. Yesterday going up the Island highway I would have had to slow
down as there are a lot of lights but with the Jake it was no problem. A couple of times
I added the retarder too.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Tranny temp with retarder

Reply #5 –
DW hates one particular braking habit. Or should say lack of braking.  By that I mean I'd rather coast to a stop instead of braking if traffic permits. 
  The other day it went perfectly. Coasted down to the point that the Torque converter released.  I like to give the guy ahead of me 100 yards if possible.
Robert and Susan
 1995 36' 280 WTBI 8.3 3060r
 1200 watts on the roof, 720 Ah of lithium's
 Build # 4637. Motorcade # 17599
        FMCA  # 451505
        18  Wrangler JLUR

Re: Tranny temp with retarder

Reply #6 –
Quote from: Bob & Sue –
DW hates one particular braking habit. Or should say lack of braking.  By that I mean I'd rather coast to a stop instead of braking if traffic permits. 
  The other day it went perfectly. Coasted down to the point that the Torque converter released.  I like to give the guy ahead of me 100 yards if possible.

I do the same.  Certainly increases MPG and reduces wear on brakes and/or heating of transmission fluid.  Amazing to new RV drivers how much momentum they have/how far they will coast.
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: Tranny temp with retarder

Reply #7 –
I think you may find that tranny retarder fluid temps of 300 are not a problem for Transynd and you will note it cools down very fast after retarder use.

Also dash gauge may not be measuring the highest temps as Foretravel usually puts the tranny temp sender on the large fluid hose that RETURNS from tranny-cooler. Most are not reading the high temp of fluid as it exits tranny on its way to tranny cooler.

We relocated the sender to the tranny output elbow to get more accurate temp readings