Skip to main content ↑ ↓
Topic: Transmission Coolers (Read 1773 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

Transmission Coolers

Yahoo Message Number: 23395
I have experienced high transmission temps also; it gets a mite warm in FL just like most of the lower states.
I am not sure I want my investment to be waiting on some solution from the factory (if there ever is one) as I feel damage to at least the ATF might be happening already.
I can't find much on the web about sources for add-on transmission coolers for our type of rigs.

Does anyone have any sources, prices?

Bob Handren

'05 Country Coach Inspire 51178
'00 JGCL

Re: Transmission Coolers

Reply #1 –
Yahoo Message Number: 23397
Here is how I understand the effect on automatic transmission fluid temperatures: (synthetics may change this a bit)
At 175 degrees, the fluid should be able to last 100,000 miles - but that's probably pushing it.

For every 20 degree increase in temperature, cut the mileage in half.

At 195 degrees, 50,000 miles

At 205 degrees, 25,000 miles

At 215 degrees, 12,500 miles

At 225 degrees, 6,250 miles

At 245 degrees, 3,125 miles

Now I don't care where the Silverleaf OR the dash gauge temperature sensors are located in the fluid flow. If those temperatures are hit anywhere in the system for any length of time whatsoever, the effect is as indicated. If the fluid isn't changed out appropriately, it rapidly becomes useless.

If the temps suddenly start getting high, it's probably a maintenance problem. If they are high and have been that way since the coach came out the door, it's a design problem - pure and simple.

Of course, that's just dealing with the expected life of the fluid.
The other affects on the transmission itself can be:

220 degrees - varnishes form

240 degrees - seals harden (think leaks)
260 degrees - plates slip (this is when things start to get nasty and you don't make it up the hill) This also causes the temp to rapidly rise.

315 degrees - seals & clutches burn out; oil burns up
It doesn't take much research to come up with the above information.
My MD3060 generally runs under 200 per the dash gauge (No Silverleaf).
Rarely, on the longest grades on Route 70 between Denver and the intersection in the west with I15 do I see it get over 200 while towing a Subaru wagon.

If I had temps such as I have been reading in this forum, I would be standing on top of somebody's desk.

Mike Cebula
'95 Magna #5266

Quote from: Robert Handren\[br\
] > > I have experienced high transmission temps also; it gets a mite warm
in FL just like most of the lower states.

Quote
>

I am not sure I want my investment to be waiting on some solution
from the factory (if there ever is one) as I feel damage to at least the ATF might be happening already.

Quote
>

I can't find much on the web about sources for add-on transmission
coolers for our type of rigs.

Re: Transmission Coolers

Reply #2 –
Yahoo Message Number: 23398
The following is the reply I received from a Country Coach tech after asking the questions about transmission temperatures:
"I've seen some trans coolers installed on C-13's only. The below is right out of the Allison owners manual. Starting on Page 31 at the bottom.

HIGH FLUID TEMPERATURE

The transmission is considered to be overheated when any of the following temperatures are exceeded:

Sump Fluid 121C (250 F) Silver Leaf Fluid to cooler 149 C (300 F) Dash Gauge"
It's on page 36 of the manual I have but he is correct - that's what the manual says. You can find it at http://www.allisontransmission.com/servlet/DownloadFile?Dir=publications/pubs&FileToGet=OM3349EN.pdf
There is also the issue that the ATF must reach a high enough temperature to ensure flow rates and to provide the lubrication designed into it.
For the auto transmissions I have been using over my life, I always believed anything more than 20 degrees or so above normal engine temp is to be avoided.
So, whether CC agrees there is a problem or not, I would like to investigate how I can keep mine in that range and I would appreciate any leads you fine folks may have.

Bob Handren

'05 Country Coach Inspire 51178
'00 JGCL

Re: Transmission Coolers

Reply #3 –
Yahoo Message Number: 23399
The optimal solution would be an external oil cooler (Hayden) and a regulated thermostat (still looking) that would maintain a constant transmission oil temperature of 175-180 degrees. One of the folks on the CAT forum with an SOB installed such a solution.

Bob

'05 Intrigue 11872 C13 with Hayden Oil Cooler and 165 on the Silverleaf

Quote from: Robert Handren\[br\
] > > I have experienced high transmission temps also; it gets a mite warm
in FL just like most of the lower states.

Quote
>

I am not sure I want my investment to be waiting on some solution
from the factory (if there ever is one) as I feel damage to at least the ATF might be happening already.

Quote
>

I can't find much on the web about sources for add-on transmission
coolers for our type of rigs.

Re: Transmission Coolers

Reply #4 –
Yahoo Message Number: 23400
After driving two new CC units one an Intrigue the other an Allure, both showed trans. temps in excess of 250.
" The trans. sending units are not callibrated correctlly, and units are coming out into the field to correct this situation."

That is all I know.

Thank you,

Jim Spivey

Re: Transmission Coolers

Reply #5 –
Yahoo Message Number: 23401
Of course, Hayden has made coolers forever - I wonder why google didn't come back with a hit on that? Since I suffer from CRS I depend on google to find things for me.
As for a thermostatically controled fan, it was SOP for autos to run the ATF through the aux cooler before going into the tank in the radiator. This prevents the oil from getting too cold by applying some heat from the engine.
Since we live in the south and don't ever plan to visist the frozen north, I wonder what effect it would have to bypass engine cooling system all together and go straight to the existing trans oil cooler.

Bob Handren

'05 Country Coach Inspire 51178
'00 JGCL

Re: Transmission Coolers

Reply #6 –
Yahoo Message Number: 23409
The thermostat I mentioned controls the oil going through the oil cooler. It's set for 175-180 and when the fluid temp exceeds that setting it opens and routes the fluid through the cooler, when below those temps it closes and routes the fluid around the cooler. In both cases the fluid passes through the radiator to maintain fluid temps in cold weather.
Bob

'05 Intrigue 11872

Quote from: Robert Handren\[br\
] >

Of course, Hayden has made coolers forever - I wonder why google
didn't come back with a hit on that? Since I suffer from CRS I depend on google to find things for me.

Quote
>

As for a thermostatically controled fan, it was SOP for autos to
run the ATF through the aux cooler before going into the tank in the radiator. This prevents the oil from getting too cold by applying some heat from the engine.

Quote
>

Since we live in the south and don't ever plan to visist the
frozen north, I wonder what effect it would have to bypass engine cooling system all together and go straight to the existing trans oil cooler.

Re: Transmission Coolers

Reply #7 –
Yahoo Message Number: 23420
I have now driven two new CC's one a Allure and the other an Intrigue. I have read tons and have received tons of notes, one of which actually looked at temp. verse life of transmission. What i can see is no matter how you slice or dice it running in the 250 plus range is just not smart.
What is takes to bring the temp. down is another issue. More data when it becomes available.

Thank you,

Jim Spivey

transmission coolers

Reply #8 –
Yahoo Message Number: 23402
Yes, I agree with most everyone, our 3000MH's are running too hot. I have talked to Allison and they know and agree. They can not do anything because CC assembles all the components. That was Allisons response. The response from CC is the same I have gotten. The Haydon solution is a great fix but what will happen if CC engineering finally decides to do something about THEIR problem. Will they elect to use the Haydon fix or what? When units fail and they are possibly still under warranty, who is going to pay the bill, Allison or CC? Hopefully, the West Coast Reunion will come up with some answers. If not, then we need to act as a group towards CC to get answers. Maybe Allison can help us. Maybe register letters on near the same date.
Any ideas ????

Re: transmission coolers

Reply #9 –
Yahoo Message Number: 23404
After reading all these notes, it does not appear that anyone has gone back to his dealer and had him go to bat for you at CC. Phone calls don't cut it. Lazy Days took care of us and our Magna now runs at 165 degrees on the transmission. It takes time but we are now very pleased with the engine & transmission temperatures. We were one of the first C-13s and yours is running cooler then ours ever ran. I will add one more thing. Our Magna is not as heavy as most Magnas. It is only a 40 feet with 3 slides and we do not tow any big trailer. We built it with 3 slides because we saw how heavy coaches were getting and we felt that we were putting to much of a load on all of the conponents that were available at the time. Our coach is already 2 years old and in that time every manufacturer has learned more about the C-13. Unforturately there was a learning curve involved and some of us got caught in that curve.

Bill G. 2005 Magna #6425

Re: transmission coolers

Reply #10 –
Yahoo Message Number: 23405
Ned,

Do you have anything in writting (e-mail?) from Allison indicating there is a problem with these temps?
Being from Florida we can't make the west coast so I hope attendees post what they learn here.

Bob Handren

'05 Country Coach Inspire 51178
'00 JGCL

Re: transmission coolers

Reply #11 –
Yahoo Message Number: 23410
i spoke to allison and i was told that if the temp got up to 265 it was within normal range and that the tranny would normally run 10 to 20 degrees higher than engine temp but if it got to 300 to stop and let it cool ddown if temp runs 220 to 240 that is good and will not hurt tranny

chuck kelly

2004 magna limited edition with c15 engine

Re: transmission coolers

Reply #12 –
Yahoo Message Number: 23412
Chuck,

I've seen similar info but the question is where are these temps taken? At the sump, before the cooler, after the cooler?
I spoke with the manager at the Detroit Diesel-Allison shop in Ocala, FL today. He said TranSynd can get as high as 350 degrees in a retarder equipped system for short periods with no problem. It's tough stuff.
He also agreed that transmission temperatures exceeding the engine temps by more than 20-30 degrees would indicate a problem of inadequate cooling to him.

sonny6296@... wrote:
 

Transmission coolers

Reply #13 –
Yahoo Message Number: 23407
BOB No, nothing in writing, just sitting down with the service manager on two occasions. Not what we need, sure wish I had it in writing. In a week, I'm going to another Allison shop to talk to them. That will be in Ohio. Hope this weekend, in Oregon, comes up with something.
Ned 2006 Inspire 51677