Community Forums

seand1109 · 09-10-2015, 04:24 PM

Also no stop and go traffic and minor hills. Heading to Portland on I84 the problem started west of Pendleton near the I82 junction... mostly down hill actually.

seand1109 · 09-10-2015, 04:28 PM

Tom, I did switch over the coolant from what looked like Prestone to CAT ELC. The engine and tranny temps from portland to Salt Lake and Yellowstone were perfect even in the passes on I84. The radiator tank is properly filled and yes, I run even the heaters when I do radiator work.

palehorse89 · 09-10-2015, 04:38 PM

Quote:

Originally Posted by seand1109

Radiator is clean and as noted it is separate from the engine that was running at normal temps. I am using synthetic fluid. The creep was at a rate of about 1 degree per mile.

What is normal coolant temperature for your engine? What does it run at and what does it go to on a hard pull? Did your tranny temps follow the coolant temps before the service you did when traveling?
I agree with Steve O. that a air lock from changing the coolant could cause this........It happened to me once with a car........in troubleshooting the high temps. I found a high point air bleed.......cured the problem.

seand1109 · 09-10-2015, 04:54 PM

Thanks Palehorse, the engine temps did not stray from their normal range at all so I do not think I have a coolant issue. When I changed the coolant and the tranny fluid, I did a run down to Eugene OR from the Portland area and with the hills and running the heater I am sure there are no air locks in the coolant.

palehorse89 · 09-10-2015, 04:59 PM

I am the second, maybe third, asking about coolant operating temps. , normal driving and hard pulls...........you reply to us but do not answer the questions..........I am going to venture to say it could be 3 things, tranny temp sensor going bad, tranny coolers not getting proper air flow, coolant problem........that is why I asked about operating temps of the coolant.

seand1109 · 09-10-2015, 05:08 PM

Palehorse 89,

"Steve, yes I did a drain flush and replaced the radiator fluid. I do not think it is related because the engine temps have stayed constant in the normal range of 195-204".

Even with the coolant temps within this range, the tranny them was climbing to the 240...

palehorse89 · 09-10-2015, 05:26 PM

Sean, read this thread........pay special attention to post #23!
http://www.irv2.com/forums/f125/tran...-241035-2.html

Steve Ownby · 09-10-2015, 05:48 PM

Here are the facts as I understand them for the previous posts:
1. Transmission fluid and filters changed approx 2000 miles ago to genuine Allison filters and Transynd.
2. Engine coolant changed from standard Ethylene Glycol to Cat ELC.
3. Normal temp range for both engine & transmission is 195-204.
4. On current trip the engine/transmission performed in normal range for 1800 miles.
5. Last 200 miles transmission temps slowly increased above engine temp up to a high of 240. When idled in neutral, transmission temp came down to normal.
6. These temp are from the Aladdin which gets its data from the ECM.

Reviewing the above, I can only think of two very unlikely scenarios.

1. When draining the transmission fluid, did the in/out hoses to the fluid cooler get disconnected to facilitate draining. If so, is it possible the connections were reversed when reconnecting?
2. Could the O rings or gaskets have gotten damaged or misaligned on the filters?

I have no idea if either of the above could cause overheating after a period of normal operation. Grasping at straws. It is true that engine coolant with too high glycol % will not transfer heat very well, but I doubt that could account for 30-35 degrees above engine temp.

If you feel pretty sure about all the possibilities that have been brought up, I would schedule an appointment with a shop with a chassis dyno. It would be a big concern to me that the transmission was suddenly running 35 degrees above engine temp when not under any stress.

Steve Ownby
Full time since '07

seand1109 · 09-11-2015, 09:39 AM

Palehorse 89... It reads very similar to my problem. I do not have the box my filters came in but will be visiting the dealer that sold them to me Monday. I will be also looking to make an appointment for a complete tranny check out.

Steve... Thanks for the great summary of my tranny issue. I will be crawling under to look at the situation this weekend and will double check for any obstructions to the cooler. I will also be checking the hoses although they were not disconnected.

I will let you know what the cure is. Thanks Guys!

Steve Ownby · 09-11-2015, 09:48 AM

Quote:

Originally Posted by seand1109

Palehorse 89... It reads very similar to my problem. I do not have the box my filters came in but will be visiting the dealer that sold them to me Monday. I will be also looking to make an appointment for a complete tranny check out.

Steve... Thanks for the great summary of my tranny issue. I will be crawling under to look at the situation this weekend and will double check for any obstructions to the cooler. I will also be checking the hoses although they were not disconnected.

I will let you know what the cure is. Thanks Guys!

If you got the filters from an Allison distributor you probably got the Allison filters. If just an authorized service independent service location, you could have gotten a Chinese look alike. I only buy filters from one of Allison's distributors. The OEM filters are about $50 for the 2 filter kit.

Steve Ownby
Full time since '07

seand1109 · 10-07-2015, 01:07 PM

Since my last post...

1. Talked with an Allison certified mechanic. If there are no codes and the shifting is smoothness not much he can do without me bringing it in but agreed having a sample looked at would be a good idea. He did not think the higher readings were an issue as long as the fluid was good, did not smell burnt and as long as the shifting was smooth. I am not a fan of this work it until it breaks thinking.

2. Called and talked with another Allison rep and was basically told the same but it could be a stator in the converter sticking and also recommended a sample be done. Anyone know or had an issue with the torque converter stator and if so what was the fix.

3. He also suggested using the laser heat detector to make sure the readings on the Aladdin are correct. It could also be a ground wire issue. I ran the motor in order to pull the sample and got various readings depending on where the laser was pointed. At the hoses from the tranny, one was about 130 the other 100, at the tranny cooler about the same, but on the tranny housing the reading varied from 100 to 147 (The 147 matched the reading on the Aladdin). I shut it down after pulling the sample.

4. Today got the sample report back and the readings were normal (according to the report). No water, no Coolant, no fuel found.

5. I crawled under and there are no leaks, the hoses look fine and the readings from the laser indicate the fluid is cooling. I will check the O rings when I change to filters this weekend.

6. Waiting a call back from another Allison service center. I am considering changing the filters again with a full drain. I will go with the high capacity filters this time.

Thoughts?

Steve Ownby · 10-07-2015, 02:06 PM

Quote:

Originally Posted by seand1109

Since my last post...

1. Talked with an Allison certified mechanic. If there are no codes and the shifting is smoothness not much he can do without me bringing it in but agreed having a sample looked at would be a good idea. He did not think the higher readings were an issue as long as the fluid was good, did not smell burnt and as long as the shifting was smooth. I am not a fan of this work it until it breaks thinking.

2. Called and talked with another Allison rep and was basically told the same but it could be a stator in the converter sticking and also recommended a sample be done. Anyone know or had an issue with the torque converter stator and if so what was the fix.

3. He also suggested using the laser heat detector to make sure the readings on the Aladdin are correct. It could also be a ground wire issue. I ran the motor in order to pull the sample and got various readings depending on where the laser was pointed. At the hoses from the tranny, one was about 130 the other 100, at the tranny cooler about the same, but on the tranny housing the reading varied from 100 to 147 (The 147 matched the reading on the Aladdin). I shut it down after pulling the sample.

4. Today got the sample report back and the readings were normal (according to the report). No water, no Coolant, no fuel found.

5. I crawled under and there are no leaks, the hoses look fine and the readings from the laser indicate the fluid is cooling. I will check the O rings when I change to filters this weekend.

6. Waiting a call back from another Allison service center. I am considering changing the filters again with a full drain. I will go with the high capacity filters this time.

Thoughts?

Allison has sold only high capacity filters for 7-9 years now. If the service center says your current filters aren't high cap then they are not Allison.

Steve Ownby
Full time since '07

Cat320 · 10-07-2015, 06:19 PM

As a side issue, when my trans temp gets to around 205, the fan comes on and usually lowers it about 50 degrees.

seand1109 · 10-10-2015, 09:26 AM

I wasn't sure about the filters being Allison or not but now I am certain after checking with the folks that sold me the first set.... They only sell the Allison filters and that is what I bought.