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Topic: Transynd vs conventional temperature limits (split from Re: Help Air leak from top of the transmissi (Read 587 times) previous topic - next topic - Topic derived from Help Air leak from to...

Transynd vs conventional temperature limits (split from Re: Help Air leak from top of the transmissi

Quote from: Running Odometer –


 I have been using the retarder a lot after Mr. Larger fixed my transmission. Retarder is a wonderful thing.
Hopefully this is helpful; I hope you are monitoring your retarder temperatures with a retarder temperature gauge. The transmission gauge never shows what the retarder gauge shows. It is much faster to rise up into IMO higher than acceptable temperatures. I doubt it will hurt the retarder, but the oil can be damaged operating at hi temperatures. I was truly surprised to realize the difference between dash indicated and actual temperatures once I got a actual retarder operating temperature indication. Yes the retarder is a wonderful tool. Hi rpm is your friend.
Scott

Re: Transynd vs conventional temperature limits (split from Re: Help Air leak from top of the transmissi

Reply #1 –
I'll second Scott's advice. Before I had a VMSpc and could see the retarder temp I used the trans temp for the information. After going down the same grade I had in the past and using the same gears and retarder as I always had the retarder temp was at 260 deg. and climbing before I shifted down 2 gears and started using the brakes periodically. I had no Idea how hot the fluid had been getting so I changed it out with fresh Transynd before this trip even though I had changed to Transynd fluid when I bought the coach.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Transynd vs conventional temperature limits (split from Re: Help Air leak from top of the transmissi

Reply #2 –
Quote from: craneman –
the retarder temp was at 260 deg. and climbing
This begs the question: With Transynd transmission fluid, what should be my personal caution and red line temperatures for the retarder temperatures?
Jan & Richard Witt
1999 U-320  36ft WTFE
Build Number: 5478 Motorcade: 16599
2011 Jeep Wrangler Unlimited w/Air Force One
Jan: NO5U, Richard:KA5RIW
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Re: Transynd vs conventional temperature limits (split from Re: Help Air leak from top of the transmissi

Reply #3 –
All I could find was opinions, some seemed accurate and some were crazy low. it also depends on how long the temperature stays at the high temp.

What is max Temperature for Transynd in Allison 1000 - iRV2 Forums(intermittent).
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Transynd vs conventional temperature limits (split from Re: Help Air leak from top of the transmissi

Reply #4 –
Since temperature-caused degradation of transmission fluid is cumulative, not sure there IS a finite answer.

I can tell you that Allison considers any of their transmissions with a retarder as SEVERE DUTY, and fluid recommendations (Transynd or perhaps the new fluid they just released) and filter change intervals are quite a lot more frequent than for the same transmission without the retarder.

As already stated, use high engine RPM when using the retarder for lower fluid temperatures.
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: Transynd vs conventional temperature limits (split from Re: Help Air leak from top of the transmissi

Reply #5 –
What I have read about Transynd is that occasional high temps (275°-300°) will not hurt the fluid.  250° is OK.  High fluid temps for extended periods will shorten fluid life and very high temps can start to damage the transmission.

Retarder temps tend to run about 10° above transmission temps until you start using the retrder then they go up very fast.  I set the yellow warning light on retarder temps on VMSpc to 235° and the red warning light at 250°.  235° is conservative and just lets you know that some change in operation is indicated.

Using the brakes with the retarder on will spike the retarder temp.  Using a notch or two on the joy stick and a lower gear will mange speed on long downhill grades with very little service brake use and keep retarder temps around 235°.  Going to a lower gear increases engine and transmission cooling and helps manage speed in conjunction with the retarder.

http://ddwt.us/Allisson_4000MH_Transmission_Owners_Manual.pdf
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Transynd vs conventional temperature limits (split from Re: Help Air leak from top of the transmissi

Reply #6 –
My personal high temp cut out is 250 deg.
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: Transynd vs conventional temperature limits (split from Re: Help Air leak from top of the transmissi

Reply #7 –
Here is a chart to go by for conventional fluids.

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

Re: Transynd vs conventional temperature limits (split from Re: Help Air leak from top of the transm

Reply #8 –
Split side discussion of fluid temperature out from air leak topic.  Thank you to the member who reported it - Michelle

Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Transynd vs conventional temperature limits (split from Re: Help Air leak from top of the transm

Reply #9 –
I've read this here, I think.  And have verified that when the retarder temp as reported by VMSpc gets to 254º or a bit above an internal valve will open and flush the hot coolant through the transmission.  I've seen it a couple times and the temp will drop down to 220º or so.  Not positive of the temps but it seems to be a design to protect the coolant and tranny.
Forest & Cindy Olivier
1987 log cabin
2011 Roadtrek C210P
no longer 1999 36' U320 build #5522
2013 Rzr 570 & 2018 Ranger XP1000
2006 Lexus GX470
2011 Tahoe LT 4x4
Previous 1998 45' 2 slide Newell, 1993 39' Newell
 

Re: Transynd vs conventional temperature limits (split from Re: Help Air leak from top of the transm

Reply #10 –
Quote from: Roger & Susan in Home2 –
  Using a notch or two on the joy stick and a lower gear will mange speed on long downhill grades with very little service brake use and keep retarder temps around 235°.  Going to a lower gear increases engine and transmission cooling and helps manage speed in conjunction with the retarder.

I agree with the above and is how I have found to best manage retarder temp, transmission temp, gear selection, and speed going down hills.  2 clicks on retarder, lower gear and sharp/quick brake pressure if needed but if gears and retarder are correct you usually don't need the brake.

2000 GV320 4010 build #5712  2019-?
1999 Bounder 2000-2008
Bardstown, KY
🥃The Bourbon Capital of the World🥃