Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: MarkC on September 25, 2023, 08:40:24 pm

Title: Transmission Heating Up
Post by: MarkC on September 25, 2023, 08:40:24 pm
Headed from Colorado to HWH going across I-80, ambient temperature 85 degrees, running at 1700 RPM, coolant temp 185 which is about normal.

Transmission temp is usually just a bit higher than the coolant temp, but all of a sudden it jumped up to 202 and as high as 210 averaging about 208.

2001 8.3 Cummins with the Allison 3000.

At idle it cools back to about 195 after a few minutes.

Any help on figuring this out is appreciated.
Title: Re: Transmission Heating Up
Post by: John44 on September 25, 2023, 08:45:20 pm
Check the obvious first,fluid level,with the dipstick not the shift pad,check coolant level.
Title: Re: Transmission Heating Up
Post by: MarkC on September 25, 2023, 08:58:18 pm
Yes, I should have added that. Fluid is good.
Title: Re: Transmission Heating Up
Post by: Geodmann on September 26, 2023, 07:53:14 am
Bad gauge?  I don't trust any of my gauges, they are all off when checked against other sources.  Are you using VMSPC
Title: Re: Transmission Heating Up
Post by: MarkC on September 26, 2023, 09:42:19 am
Yes, using VMS, gushes seem accurate
Title: Re: Transmission Heating Up
Post by: Zach on September 26, 2023, 01:16:31 pm
When using VMS, do you also have your retarder temperature enabled? I'd like to know the difference between the two. When I'm using the retarder, I usually try to limit it to 260, but my trans temps don't ever go above 200, even climbing up a pass. This is on a 4000 though, so things may be a bit different on a 3000.

Also
"Straight from Allison Website:

Q4: What is the "normal" 3000M transmission operating temperature?

Answer: Normal operating temperature for Non-Retarder transmissions should be between 60 deg. C and 120 deg. C. For Retarder transmissions maximum temperature can increase to 150 deg. C during Retarder operation."

So, 140-248F is considered normal but generally 100F above ambient.