2001 2500HD auto trans heating up

"Kenneth Pierce" <pierce.RemoveThis@oregontrail.net> wrote in message
news:11enrtlikpbonb4@corp.supernews.com...
> When towing a fifth wheel or carrying a camper my Silverado seems to be
> overheating the tranny, even though these loads are well within the rated
> capacity of this truck. The tranny temp gauge shows about 190F when the
fan
> starts to engage I understand there is some kind of "protective mode"
for
> the transmission when it gets too warm. The dealers I have talked to
don't
> seem to have knowledge of how this works. Recently there was a kind of
> ringing noise (an extra noise) in the area of the tranny when I stopped
> after a hot day of carrying the camper up and down hills, though the noise
> was not there the next morning. I am wondering if others have had
similar
> experiences and how concerned I need to be. Thanks.
>
P.S. I should have mentioned that it is the 3 speed plus OD tranny, not an
Allison. When the temp nears 200 the fan engages and there is a loss of
power. Truck has 56K with normal maintenance at 30K.
---Ken>
 >> Stay informed about: 2001 2500HD auto trans heating up 

Kenneth Pierce wrote:

When towing a fifth wheel or carrying a camper my Silverado seems to be overheating the tranny, even though these loads are well within the rated capacity of this truck. The tranny temp gauge shows about 190F when the fan starts to engage I understand there is some kind of "protective mode" for the transmission when it gets too warm. The dealers I have talked to don't seem to have knowledge of how this works. Recently there was a kind of ringing noise (an extra noise) in the area of the tranny when I stopped after a hot day of carrying the camper up and down hills, though the noise was not there the next morning. I am wondering if others have had similar experiences and how concerned I need to be. Thanks.

There is no cause for concern with 190 degree tranny temps. THis is normal range (180 to 200) so is not cause for concern but you do not want to get much above 210 on a long hard pull and if you get to 220 and above, it is time to throttle back and gear down and let it cool a bit. It is not that it will toast at 225 but it will take a toll in tranny life.
 >> Stay informed about: 2001 2500HD auto trans heating up 

once more

biggest cooler that will fit behind the grille

bypass the radiator cooler

if you're really serious, use a mix of Dex3 and MobilOne 5w20 synthetic
engine oil (50-50)


"Kenneth Pierce" <pierce.DeleteThis@oregontrail.net> wrote in message
news:11enrtlikpbonb4@corp.supernews.com...
> When towing a fifth wheel or carrying a camper my Silverado seems to be
> overheating the tranny, even though these loads are well within the rated
> capacity of this truck. The tranny temp gauge shows about 190F when the
fan
> starts to engage I understand there is some kind of "protective mode"
for
> the transmission when it gets too warm. The dealers I have talked to
don't
> seem to have knowledge of how this works. Recently there was a kind of
> ringing noise (an extra noise) in the area of the tranny when I stopped
> after a hot day of carrying the camper up and down hills, though the noise
> was not there the next morning. I am wondering if others have had
similar
> experiences and how concerned I need to be. Thanks.
>
>
 >> Stay informed about: 2001 2500HD auto trans heating up 

TranSurgeon wrote:

once more biggest cooler that will fit behind the grille bypass the radiator cooler if you're really serious, use a mix of Dex3 and MobilOne 5w20 synthetic engine oil (50-50)

If you are serious about not screwing up your tranny, do not follow this advise. NEVER mix engine oil with tranny fluid. Also, you can overcool your oil but there are those that seem to think they know more than the engineers that designed and built them and will tell you otherwise.
 >> Stay informed about: 2001 2500HD auto trans heating up 

"Kenneth Pierce" <pierce.RemoveThis@oregontrail.net> wrote in message
news:11eofkkbr94s1bc@corp.supernews.com...
>
> >
> P.S. I should have mentioned that it is the 3 speed plus OD tranny, not
an
> Allison. When the temp nears 200 the fan engages and there is a loss of
> power. Truck has 56K with normal maintenance at 30K.
> ---Ken>
>
>
what engine? How heavy is the camper? I ask which engine as the fan will
pull
some power when it kicks in. Also confused by what you mean by 56K with
"normal" maintenance at 30K.
Whitelightning
 >> Stay informed about: 2001 2500HD auto trans heating up 

Whitelightning wrote:

I ask which engine as the fan will pull some power when it kicks in.

The "power" the cooling fan uses is the least of your concerns when towing heavy loads, only its cooling performance is important.
 >> Stay informed about: 2001 2500HD auto trans heating up 

"SnoMan" <UseLinkToEmail RemoveThis @AutoForumz.com> wrote in message
news:1_639816_0633732e76fdfc8acdd4c5e085572267@autoforumz.com...
> "TranSurgeon" wrote:
> >once more
> >
> >biggest cooler that will fit behind the grille
> >
> >bypass the radiator cooler
> >
> >if you're really serious, use a mix of Dex3 and MobilOne 5w20
> >synthetic
> >engine oil (50-50)
> >
> >
>
> If you are serious about not screwing up your tranny, do not follow
> this advise. NEVER mix engine oil with tranny fluid. Also, you can
> overcool your oil but there are those that seem to think they know
> more than the engineers that designed and built them and will tell you
> otherwise.

how many have you run with the mix in it ?

(deafening silence to follow)................
 >> Stay informed about: 2001 2500HD auto trans heating up 

My '04 2500HD with the Allison already has a huge external transmission oil
cooler. Are you suggesting that he bypass the factory external cooler and
put in an aftermarket unit, or did you just not realize that it already had
one?

Cheers - Jonathan

"TranSurgeon" <nobulltrans.TakeThisOut@mchsi.dotcom> wrote in message
news:xdWGe.226019$nG6.54830@attbi_s22...
> once more
>
> biggest cooler that will fit behind the grille
>
> bypass the radiator cooler
>
> if you're really serious, use a mix of Dex3 and MobilOne 5w20 synthetic
> engine oil (50-50)
>
>
 >> Stay informed about: 2001 2500HD auto trans heating up 

yes, but does HIS 01 2500 have an Allison or a 4L80E ???????


"Jonathan" <Fire_Capt651.TakeThisOut@hotmail.com> wrote in message
news:lN6He.7593$Uk3.2374@newsread1.news.pas.earthlink.net...
> My '04 2500HD with the Allison already has a huge external transmission
oil
> cooler. Are you suggesting that he bypass the factory external cooler and
> put in an aftermarket unit, or did you just not realize that it already
had
> one?
>
> Cheers - Jonathan
>
> "TranSurgeon" <nobulltrans.TakeThisOut@mchsi.dotcom> wrote in message
> news:xdWGe.226019$nG6.54830@attbi_s22...
> > once more
> >
> > biggest cooler that will fit behind the grille
> >
> > bypass the radiator cooler
> >
> > if you're really serious, use a mix of Dex3 and MobilOne 5w20 synthetic
> > engine oil (50-50)
> >
> >
>
>
 >> Stay informed about: 2001 2500HD auto trans heating up 

Jonathan wrote:

My '04 2500HD with the Allison already has a huge external transmission oil cooler. Are you suggesting that he bypass the factory external cooler and put in an aftermarket unit, or did you just not realize that it already had one? Cheers - Jonathan

It is EXTREMELY foolish to bypass your built in cooler but some think they know more because of a name. The tank cooler helps stabilze your tranny temps and keep the range of temp swing a lot narrower because you tranny will work better and last longer with a more constant temp. If you follow the advice to bypass cooler completely, you will have a sluggish tranny in cold weather and possible reduce cooling in cold weathewr as well because the thick oil will have considerable more drag and resistance to flowing thru a big cooler when cold. Also, when you try to dump all of the tranny heat completely in front of radiator with a BIG cooler you will reduce A/C effectiveness because air reaching it will not be virgin and it will be hotter and it will reflect back to engine cooling to and a added restriction to airflow path too. Even the warm tank water can cool the tranny fluid some and since the tank water circulates rapidly on a hot day it will still cool oil some without effecting engine cooling as much as a full bypass. The correct way to do it is tank first then aux cooler and if your temp are at or under 200 towing there is no cause for concern at all. I have a 26 year old THM400 that has had a very hard life with a small aux cooler after tank cooler and it still works like new and a 16 year 700R4 with 173k and same setup and it still works like new to. I have been if cars with too big a cooler or a full bypass too and they do not fuction well in cool and cold weather.
 >> Stay informed about: 2001 2500HD auto trans heating up 

On 31 Jul 2005 21:45:58 -0500, SnoMan <UseLinkToEmail RemoveThis @AutoForumz.com>
wrote:

>"Jonathan" wrote:
>>My ’04 2500HD with the Allison already has a huge external
>>transmission oil
>>cooler. Are you suggesting that he bypass the factory external
>cooler
>>and
>>put in an aftermarket unit, or did you just not realize that it
>>already had
>>one?
>>
>>Cheers - Jonathan
>>
>>
>
>It is EXTREMELY foolish to bypass your built in cooler but some think
>they know more because of a name. The tank cooler helps stabilze your
>tranny temps and keep the range of temp swing a lot narrower because
>you tranny will work better and last longer with a more constant temp.
>If you follow the advice to bypass cooler completely, you will have a
>sluggish tranny in cold weather and possible reduce cooling in cold
>weathewr as well because the thick oil will have considerable more
>drag and resistance to flowing thru a big cooler when cold. Also, when
>you try to dump all of the tranny heat completely in front of radiator
>with a BIG cooler you will reduce A/C effectiveness because air
>reaching it will not be virgin and it will be hotter and it will
>reflect back to engine cooling to and a added restriction to airflow
>path too. Even the warm tank water can cool the tranny fluid some and
>since the tank water circulates rapidly on a hot day it will still
>cool oil some without effecting engine cooling as much as a full
>bypass. The correct way to do it is tank first then aux cooler and if
>your temp are at or under 200 towing there is no cause for concern at
>all. I have a 26 year old THM400 that has had a very hard life with a
>small aux cooler after tank cooler and it still works like new and a
>16 year 700R4 with 173k and same setup and it still works like new to.
>I have been if cars with too big a cooler or a full bypass too and
>they do not fuction well in cool and cold weather.

Is there any standard as far as which line is the input to the
radiator tranny cooler, the upper line or the lower line.
 >> Stay informed about: 2001 2500HD auto trans heating up 

"SnoMan" <UseLinkToEmail.RemoveThis@AutoForumz.com> wrote in message
news:1_640216_9ae9c3c027f0718e72d1232e8562a8a4@autoforumz.com...
>
> It is EXTREMELY foolish to bypass your built in cooler but some think
> they know more because of a name. The tank cooler helps stabilze your
> tranny temps and keep the range of temp swing a lot narrower because
> <snip>
>The correct way to do it is tank first then aux cooler and if
> your temp are at or under 200 towing there is no cause for concern at
> all. I have a 26 year old THM400 that has had a very hard life with a
>
I've just tried all this stuff. '87 Chevy Pick Up, THM400 transmission.
'Mr Transmission' guy says to bypass the rad cooler, -"as it's probably
plugged anyway".

I go home, do as he suggests and as I'm about to pull my trailer for the
first time in my life, I install a temp. gauge in the trans oil line. Not
pulling the trailer the tranny runs at about 100 degrees... max 110 on a hot
day. Too cold I figure. When pulling the trailer she is about 175 to 190.
The trailer part is OK but we have winter here and if I can't get her up
over 110 in the summer she will be worse when minus 30 degrees.

The instructions that come with the kit suggest as you do, that I run first
through the built in cooler then the aux cooler. I'm thinking... this isn't
going to work. If I'm cooling too much already, by doing it like the
instructions or you say I'm going to end up with the same or even less
temperature (the rad cooler cools it some then the aux cooler, -now starting
with a cooler transmission oil, cools it even more).

What I did.

First I ran it through the aux cooler. This drops the temp to about 100
(from my original testing). Then I run it through the original rad cooler.
This then heats the transmission oil to about 140 - 150 degrees when my
engine is warmed up and running around 190 degrees. Seems to be quite
stable but I've yet to pull the trailer with it set up this way. I'll be
testing that shortly.

Dave
 >> Stay informed about: 2001 2500HD auto trans heating up 

On 31 Jul 2005 21:45:58 -0500, SnoMan <UseLinkToEmail.RemoveThis@AutoForumz.com>
wrote:

>"Jonathan" wrote:
>>My ’04 2500HD with the Allison already has a huge external
>>transmission oil
>>cooler. Are you suggesting that he bypass the factory external
>:|cooler
>>and
>>put in an aftermarket unit, or did you just not realize that it
>>already had
>>one?
>>
>>Cheers - Jonathan
>>
>>
>
>:|It is EXTREMELY foolish to bypass your built in cooler but some think
>:|they know more because of a name. The tank cooler helps stabilze your
>:|tranny temps and keep the range of temp swing a lot narrower because
>:|you tranny will work better and last longer with a more constant temp.
>:|If you follow the advice to bypass cooler completely, you will have a
>:|sluggish tranny in cold weather and possible reduce cooling in cold
>:|weathewr as well because the thick oil will have considerable more
>:|drag and resistance to flowing thru a big cooler when cold. Also, when
>:|you try to dump all of the tranny heat completely in front of radiator
>:|with a BIG cooler you will reduce A/C effectiveness because air
>:|reaching it will not be virgin and it will be hotter and it will
>:|reflect back to engine cooling to and a added restriction to airflow
>:|path too. Even the warm tank water can cool the tranny fluid some and
>:|since the tank water circulates rapidly on a hot day it will still
>:|cool oil some without effecting engine cooling as much as a full
>:|bypass. The correct way to do it is tank first then aux cooler and if
>:|your temp are at or under 200 towing there is no cause for concern at
>:|all. I have a 26 year old THM400 that has had a very hard life with a
>:|small aux cooler after tank cooler and it still works like new and a
>:|16 year 700R4 with 173k and same setup and it still works like new to.
>I have been if cars with too big a cooler or a full bypass too and
>:|they do not fuction well in cool and cold weather.


you ever actually try plumbing it this way? it works fine on my '88
K2500 w/ a 700-r4. it shifts fine when it's -15F (3 out of 4 mornings
in January), my AC works wonderfully even when it's 98F out (aka last
week). my truck's temp doesn't creep up anymore while pulling my 14ft
box trailer loaded at 6500lbs, like it did plumbed conventionally.
I also dropped my trans temp from 225F to 175F while towing my
trailer.


your logic boggles the mind as far as heat transfer goes... I don't
even know where to start. the heat shed by the external trans cooler
is but a fart in the wind compared to a 250F-300F AC condensor.

-Bret
 >> Stay informed about: 2001 2500HD auto trans heating up