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Allison article in"Family Motor Coaching"

Yahoo Message Number: 22157
I just read the article in Family Motor Coaching about Allison transmissions and was a bit disturbed. It says that the normal operating temperature is between 160 and 200 degrees F. As many of you have experienced, as I have as well, my transmission temps rarely run below 200 and more normally run between 208 and 235. The article, quoting Keith Duner the Allison Transmission Service Technology Support Group Manager also stated that when temperatures go above 175 degrees F each 20 degree increment shortens the transmission fluid life by 50%. There are many other good pieces of information as well.

I am still awaiting a reply from CCI about my Inspire transmission temperature documented issues, but I am seriously concerned now because CCI is saying my temps in 208 to 235 range are just fine and I should not worry about it. This article definitiely states otherwise and with a 50% decrease in fluid effectiveness I feel I need to change my tranny fluid about every few trips. 175, 195, 215, 235 is 50%, 50%, 50% which means I have maybe 12.5% life left with my fluid effectiveness if I did not count the many trips we have taken over this past 11 months, yikes!!!

Anyone else see this article and have any comments?

Re: Allison article in"Family Motor Coaching"

Reply #1 –
Yahoo Message Number: 22159
Hi,

I think the issue is what does the transmission do with the temperature reading - at some point doesn't it downshift, disengage, etc. I would ask Silverleaf (Martin Perlot) what he knows. Rmemeber that Allison is protecting their warranty terms.
Fred Kovol

Quote from: kary993
I just read the article in Family Motor Coaching about Allison > transmissions and was a bit disturbed. It says that the normal > operating temperature is between 160 and 200 degrees F. As many of > you have experienced, as I have as well, my transmission temps

rarely

Quote
run below 200 and more normally run between 208 and 235. The

article,

Quote
quoting Keith Duner the Allison Transmission Service Technology > Support Group Manager also stated that when temperatures go above

175

Quote
degrees F each 20 degree increment shortens the transmission fluid > life by 50%. There are many other good pieces of information as

well.

Quote
>

I am still awaiting a reply from CCI about my Inspire transmission > temperature documented issues, but I am seriously concerned now > because CCI is saying my temps in 208 to 235 range are just fine and

I

Quote
should not worry about it. This article definitiely states

otherwise

Quote
and with a 50% decrease in fluid effectiveness I feel I need to

change

Re: Allison article in"Family Motor Coaching"

Reply #2 –
Yahoo Message Number: 22160
Quote
I think the issue is what does the transmission do with the > temperature reading - at some point doesn't it downshift, disengage, > etc. I would ask Silverleaf (Martin Perlot) what he knows. Rmemeber > that Allison is protecting their warranty terms.
I would also ask Martin Perlot what his background and qualifications are to give advice about such matters. Personally, I would rely much more on what Allison says.
Tom Fisher
Dallas, TX

Re: Allison article in"Family Motor Coaching"

Reply #3 –
Yahoo Message Number: 22161
Yes, the transmission will shut itself down once it reaches upward toward 300 degrees F. That is far too hot and likely a serious problem has occurred when you get there. I am talking about longevity of the tranny for normal use where the coach is maintained.

Kary

05 Inspire 36
#51499

Quote from: fredkovol

Re: Allison article in"Family Motor Coaching"

Reply #4 –
Yahoo Message Number: 22162
I agree that Allison should be the standard by which to evaluate from.
I race cars and know what tranny's go through and try and keep those temperatures down below 200 degree's as well. If they are higher additional cooling is necessary otherwise it will be a $10K for a new race transmission. Having my coach run consistently in the low 200, 210, 220, and 230's just seems wrong and Allison seems to think so as well. Their warranty is 5 years from my coach documentation which is not very long in the scheme of a coach like this so keeping a careful eye on these temperatures and questioning CCI on whether or not 230 degrees is normal or not seems prudent to me regardless of whether Allison is protecting themselves.
Kary

05 Inspire 36
#51499

Quote from: TBooneFisher

Re: Allison article in"Family Motor Coaching"

Reply #5 –
Yahoo Message Number: 22163
Kary,

Do you have the "Allison Transmission Operators Manual" in your documentation folder? Mine has two sections regarding temperature, one indicates that a "sump" temperature in excess of 250 deg. F is considered overheated. And, "exit" fluid temperature in excess of 300 deg. F is considered overheated. Elsewhere, under diagnostics it states that under 140 deg. F is too cold and over 220 deg. F is too hot. It seems to indicate that over 220 deg. F sump temperature would issue an error code.

This appears to me to be consistent with the statement that "Normal" is between 160 - 200 deg. F in the "sump". Have you checked to see if you have error codes? Does your oil temperature gauge measure fluid in the sump or the outlet hose going to the cooler? If it is the hose to the cooler, then you are probably just fine at 235 deg. F, as there is a 50 deg. F difference between the "sump" and "exit" temperatures. I would have an Allison facility check it out to be certain.
Since my coach has no tranny gauge I have to have to watch out for codes to know. I have never logged a transmission overheat error code even when the engine was running on the high side - a GOOD thing! Also, I tow between 4500 and 5500lbs. most of the time.

Dave Hills

2000 Allure 36'
#30444

kary993 wrote:

Re: Allison article in"Family Motor Coaching"

Reply #6 –
Yahoo Message Number: 22165
Kery / Dave

I agree with your statements. I had at one time some temp facts on the GM 400s, Had one in a gas coach and the interesting fact on that transmission was! at stall with full power on the engine the temp rise for the torque conveter is 1 deg F / second, with the engines that we are using in our coaches today the temp rise is much more and faster. Allison rates their tranys in watts. But I am not shure over what time frame the rating's are based. but iI find that to be an outstanding number.

Quote from: Dave Hills\[br\
\[br\]\[br\]\[br\]\[br\]\[br\]] >

Kary,

Do you have the "Allison Transmission Operators Manual" in your > documentation folder? Mine has two sections regarding
temperature, one

Quote
indicates that a "sump" temperature in excess of 250 deg. F is > considered overheated. And, "exit" fluid temperature in excess of

300

Quote
deg. F is considered overheated. Elsewhere, under diagnostics it

states

Quote
that under 140 deg. F is too cold and over 220 deg. F is too hot.

It

Quote
seems to indicate that over 220 deg. F sump temperature would

issue an

Quote
error code.

This appears to me to be consistent with the statement
that "Normal" is

Quote
between 160 - 200 deg. F in the "sump". Have you checked to see

if you

Quote
have error codes? Does your oil temperature gauge measure fluid

in the

Quote
sump or the outlet hose going to the cooler? If it is the hose to

the

Quote
cooler, then you are probably just fine at 235 deg. F, as there is

a 50

Quote
deg. F difference between the "sump" and "exit" temperatures. I

would

Quote
have an Allison facility check it out to be certain.

Since my coach has no tranny gauge I have to have to watch out for

codes

Quote
to know. I have never logged a transmission overheat error code

even

Quote
when the engine was running on the high side - a GOOD thing!

Also, I

Quote
tow between 4500 and 5500lbs. most of the time.

Dave Hills

2000 Allure 36'
#30444

kary993 wrote:

>I just read the article in Family Motor Coaching about Allison > >transmissions and was a bit disturbed. It says that the normal > >operating temperature is between 160 and 200 degrees F. As many

of

Quote
you have experienced, as I have as well, my transmission temps

rarely

Quote
run below 200 and more normally run between 208 and 235. The

article,

Quote
quoting Keith Duner the Allison Transmission Service Technology > >Support Group Manager also stated that when temperatures go above

175

Quote
degrees F each 20 degree increment shortens the transmission fluid > >life by 50%. There are many other good pieces of information as

well.

Quote

>I am still awaiting a reply from CCI about my Inspire transmission > >temperature documented issues, but I am seriously concerned now > >because CCI is saying my temps in 208 to 235 range are just fine

and I

Quote
should not worry about it. This article definitiely states

otherwise

Quote
and with a 50% decrease in fluid effectiveness I feel I need to

change
 

Re: Allison article in"Family Motor Coaching"

Reply #7 –
Yahoo Message Number: 22166
Hi David,

My statements were to get someone to respond with some empirical data - I appreciate your response.
Fred Kovol