Community Forums

rrtribble · 09-13-2019, 07:35 AM

Just got back from trip to Pigeon Forge with Scan Guage D. Trans temp would climb up to 130 with engine temp at 190.

Was towing 2002 Jeep Liberty, 3,550 lbs and driving 64 mph on cruise. Temp rose throughout the day of driving - 10 hrs by the time we reached home. In automatic mode, on cruise with engine brake on.

2007 Itasca Meridian 34H Gross weight is less than 30,000 lbs, which we are way under. Tires Michelin 22.5 running 80 psi front and 90 psi rear based on 4 corner weight.

Tans is MH 3000 6 speed. Changed fluid to Transynd August 2018 and filters. Fluid level at full on dipstick. No froth or foaming indication.

What temp should be the shut down temp?
What should the normal suggested range be?

Is there anything else I should be concerned about?

Thanks in advance for your assistance - Richard

palehorse89 · 09-13-2019, 07:43 AM

My Allison has always run about 10 degrees cooler that engine coolant, warmer on a hard long pull........

JNSNWT · 09-13-2019, 10:12 AM

Kudos to RRTRIBBLE for giving plenty of details when asking a question. Too many people ask questions without giving any details which will help solve their problems. I’m sure this is an oversight on their part.

I have never worried about trans temp before shutdown but I do make it a habit to slow down
(I’m really just looking for my exit) and let everything cool down. Then I slowly drive around looking for my spot before shutting down.

Now for the joking part. 😂
To give you a better answer I’ll need to know
1. When did you last wash your roof AC cover
2. Do you have a leather or plastic steering wheel cover?

gmc70 · 09-13-2019, 04:42 PM

I just came back from a trip and mine got to 160 with the outside temp at 96 degrees. When temps are in the 70's I ran 150 which is still well below the engine temp which I believe has a 180 thermostat. Please correct me if I am wrong. So 130 seems very cool to me.

rrtribble · 09-14-2019, 07:11 AM

JNSNWT

Haven't washed it this year but I checked and it is a clean as …. well, it's clean,

No steering wheel cover but have been considering hanging those large dice from the bottom of my TV to warn me about hitting my head. (LOL)

Enjoy the laugh - Richard

dbarton291 · 09-17-2019, 08:44 AM

Maximum allowable fluid temperature for an Allison is 300 deg F at the to cooler port and 250 in the sump.

Dsrtrider · 09-22-2019, 09:16 PM

Do you know what temperature sets the check trans temp message?

dbarton291 · 09-24-2019, 08:46 AM

Code is set at 250 F. Some calibrations light the check trans light and some don't depending on the vehicle. My opinion is you're better off using your own gauge, just to have that peace of mind.

rrtribble · 09-29-2019, 06:45 AM

Thanks everyone. I've never paid attention to the trans fluid temp except when I pulled a TT with my old Chrysler - which, it seems was in a former life.

Normally TF runs around 96 at 63 mph but on this trip it climbed to 130 and hung there fluctuating down to 125 so was a little concerned even though no check light came on. Feel much better now that ya'll have provided better information.

Getting ready to head out again next week.

Drive safe and enjoy - Richard

Larry · 10-01-2019, 08:40 PM

Mine always rune 180-190 degrees.

W5CI · 10-01-2019, 08:54 PM

I thought water cooled trans coolers were done way with 25 years ago, if you want the best cooler convert it to Air cooled and don't worry about water in your trans

dbarton291 · 10-02-2019, 09:23 AM

Quote:

Originally Posted by danny285

I thought water cooled trans coolers were done way with 25 years ago, if you want the best cooler convert it to Air cooled and don't worry about water in your trans

Water cooled transmissions are alive and well in the commercial vehicle market. Given the heat rejection requirements of an Allison oil to water coolers are still the most efficient way to go. Automotive is another whole environment and they can get away with air cooling much easier than a commercial duty powertrain.