Skip to main content ↑ ↓
Topic: Looking for info on Allison 4000. What is to hot? (Read 725 times) previous topic - next topic

Looking for info on Allison 4000. What is to hot?

I have a 2004 foretravel with Cummings and Allison 4000. On my trip to get it serviced the transmission temp got to 237 And would only drop to 230-235. Coolant temp was in the normal range 188-195. the trans temp usually stays in that range. Highest I have ever seen it was 214. Got to the service center and checked on the keypad and it showed normal. No codes showed up either. it seemed a little sluggish but seemed to shift ok. Service center said the dipstick was way overfull. The color was reddish brown not like trans-syn. Didn't seem to have any coolant in it. Coolant wasn't low. Decided to change all trans filters and put in new fluid. They put in 8 gallons as usual dipstick showed high and the keypad showed 3 qts high. Drained out the 3qts. Keypad showed ok but the dipstick was still high. Drove 20 miles and the temp got to 215 and wouldn't come down as would be expected with unit in neutral. Fans were running in high all the time. Usually they drop to low in a couple minutes after stopping. any help would be appreciated. Thanks Bruce
Rebecca & Bruce Clark
2004 U320
Paluxy, TX

Re: Looking for info on Allison 4000. What is to hot?

Reply #1 –
That is running hot. I had to replace my trans cooler a while ago when mine did that. The overfill bothers me but when new fluid was added it showed the same so that is good.
2025 Wanderbox Outpost 32 on F600 Expedition Motorhome
2015 Born Free Royal Splendor on Ford 550 nonslide version  for sale
Former Coaches  covering. 360,000 miles
1999 34 U270
2000 36 U320
2001 42' double slide U320
2018 Jeep Rubicon

Re: Looking for info on Allison 4000. What is to hot?

Reply #2 –
Attached are a couple of ATF color and temperature charts. Good to pull the dipstick and smell the fluid. Any burned odor indicates a problem. A simple ATF change does not get rid of all the contaminated ATF as quite a bit is still left in the torque converter.

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

Re: Looking for info on Allison 4000. What is to hot?

Reply #3 –
Thanks Pierce,
We were between slightly used and replaced.  Replaced fluid and filters but I am still concerned about the temperature.  I'm not sure which is the transmission cooler on the passenger side.

Thanks
Bruce
Rebecca & Bruce Clark
2004 U320
Paluxy, TX

Re: Looking for info on Allison 4000. What is to hot?

Reply #4 –
When I was at MOT in Nov, I had them blow out the radiator and trans cooler...it looked like a Sahara dust storm in the shop.  I had driven in slushy, sanded roads, which contaminated the fins.  Just a thought to try before replacing expensive kit.  Woody.
2001 4010 U320 build #5865 "Bluto-d-Bus" since 09/18
2006 Honda Element ESP Toad
Full timing since 2016 in Western MT
Copilot: Sitka
1975 GMC 260 Avion: sold

Re: Looking for info on Allison 4000. What is to hot?

Reply #5 –
YUP, if the side of the coach is dirty, many, many times that amount of dirt has been sucked into the CAC and radiator.  It is behind the rear tires, so lots of extra dirt enters.
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: Looking for info on Allison 4000. What is to hot?

Reply #6 –
In the first post the engine temps are normal. The trans. cooler would not be affected by dirt in the fins if the engine is running normal.
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: Looking for info on Allison 4000. What is to hot?

Reply #7 –
Thanks all, I am at MOT and the first thing they did was blow out the fins.  It was very dusty but didn't seem to help as much as I had hoped.  Drove it to Douglas ~ 20 miles and the temp was up to 215 and took a long time to drop.  Granted there are a lot of hills but I also drove on Hwy 59 and it kept gradually climbing and never dropped much even just idling.  On our 2004 U320 there are 2 coolers on the passenger side a big one and a little one.  Doesn't anyone know which one is the transmission cooler and what the other one is?
Rebecca & Bruce Clark
2004 U320
Paluxy, TX

Re: Looking for info on Allison 4000. What is to hot?

Reply #8 –
Actually, no "hills" between Nacogoches and Douglas that should increase transmission temperature.

SO, let's start with the basics: Are  there any Allison codes-- like torque converter not locking up???

If you need instructions on checking (easy from the driver's seat, but only once the transmission is warm) let us know.
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: Looking for info on Allison 4000. What is to hot?

Reply #9 –
No there are no codes. Checked that on Friday.  Once the temp gets higher than normal the fans are running on high and it really doesn't seem to bring the temp down.
Rebecca & Bruce Clark
2004 U320
Paluxy, TX

Re: Looking for info on Allison 4000. What is to hot?

Reply #10 –
Fan speed is determined/controlled by engine coolant temperature, not transmission temperature.

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: Looking for info on Allison 4000. What is to hot?

Reply #11 –
I guess my point is the fans are on high but it doesn't seem to bring the Transmission temperature down.  Before my trip down here a week ago the transmission and coolant temperature stayed pretty close.  But now the engine temp will drop but the transmission temperature never does.  It just keeps climbing.  I don't understand.
Rebecca & Bruce Clark
2004 U320
Paluxy, TX

Re: Looking for info on Allison 4000. What is to hot?

Reply #12 –
Can you use a temp gun to check the lines or oil pan to verify the temp?
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Looking for info on Allison 4000. What is to hot?

Reply #13 –
Yes the sump temperature was about 195 when the gauge and DIC were showing ~215.  I am trying to figure out which cooler is the transmission.  The larger one looks like it goes to the transmission cooling ports, but then it also looks like it connects to the hydraulic cooling fan motors, which doesn't make sense.  The smaller cooler hoses go up from the side compartment and I can't seem to find them to trace them.  Thanks for the help, and appreciate any ideas.
Rebecca & Bruce Clark
2004 U320
Paluxy, TX

Re: Looking for info on Allison 4000. What is to hot?

Reply #14 –
Quote from: BnBClark –
Thanks all, I am at MOT and the first thing they did was blow out the fins.  It was very dusty but didn't seem to help as much as I had hoped.  Drove it to Douglas ~ 20 miles and the temp was up to 215 and took a long time to drop.  Granted there are a lot of hills but I also drove on Hwy 59 and it kept gradually climbing and never dropped much even just idling.  On our 2004 U320 there are 2 coolers on the passenger side a big one and a little one.  Doesn't anyone know which one is the transmission cooler and what the other one is?
You have a fuel cooler, radiator, CAC and hydraulic cooler on the passenger side. Not sure what you are calling the big one? Either CAC or radiator. Your trans cooler is on the passenger side of the engine down low and is a cylinder.
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: Looking for info on Allison 4000. What is to hot?

Reply #15 –
Thank you Craneman, so is it just air cool and not influenced by the radiator and the cooling fans?  Does it have what looks like a quick connect on the end of it?
Rebecca & Bruce Clark
2004 U320
Paluxy, TX

Re: Looking for info on Allison 4000. What is to hot?

Reply #16 –
It is a heat exchanger water cooled.
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: Looking for info on Allison 4000. What is to hot?

Reply #17 –
Ok thank you very much!
Rebecca & Bruce Clark
2004 U320
Paluxy, TX

Re: Looking for info on Allison 4000. What is to hot?

Reply #18 –
Here's a link with cooler info:

Transmission cooler arrived
Dave and Kelli
1997 U295 40' Build #5188 CSGI
1995 U240 36' Build #4621 SBID-SOLD
2006 Jeep Wrangler Rubicon