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does synthetic trans fluid lower temps? [message #121210] Thu, 07 April 2011 12:36 Go to next message
hertfordnc is currently offline  hertfordnc   United States
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First, do not take for granted the civility on this forum.

I found a thread on this topic over on the rv.net towing forum but they act like thugs to each other so it's difficult to extract meaningful information.

Someone there suggested that synthetic fluid actually dumps heat better then regular trans fluid and remains cooler.

THen someone else suggested he was an ininformed moron and that synthetic fluids only TOLERATE heat better.

As i plan to keep my eys glued to a trans temp gauge I am less interested in the latter.

THanks


Dave & Ellen Silva Hertford, NC 76 Birchaven, 1-ton and other stuff Currently planning the Great american Road Trip Summer 2021 It's gonna take a lot of Adderall to get this thing right.
Re: [GMCnet] does synthetic trans fluid lower temps? [message #121212 is a reply to message #121210] Thu, 07 April 2011 12:41 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
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The syn fluid provoids better lubercation to the gears and reduce the temp.
There are wat is known as friction modifiers that help the clotch
plates perform bettter.
That is the primary differance between Ford and GM.

On Thu, Apr 7, 2011 at 10:36 AM, dave silva <admin@oldrv.net> wrote:
>
>
> First, do not take for granted the civility on this forum.
>
> I found a thread on this topic over on the rv.net towing forum but they act like thugs to each other so it's difficult to extract meaningful information.
>
> Someone there suggested that synthetic fluid actually dumps heat better then regular trans fluid and remains cooler.
>
> THen someone else suggested he was an ininformed moron and that synthetic fluids only TOLERATE heat better.
>
> As i plan to keep my eys glued to a trans temp gauge I am less interested in the latter.
>
> THanks
> --
> Dave & Ellen Silva
>
>
> Check out the website:
>
> http://www.oldrv.net
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>



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Re: [GMCnet] does synthetic trans fluid lower temps? [message #121235 is a reply to message #121210] Thu, 07 April 2011 15:46 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
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Yeah,

We're even civil to you and you own a REVCON! ;-)

Manny recommends Mobil 1 Synthetic trans fluid so that's what I use.

Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426


-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of dave silva
Sent: Thursday, April 07, 2011 11:37 AM
To: gmclist@temp.gmcnet.org
Subject: [GMCnet] does synthetic trans fluid lower temps?

First, do not take for granted the civility on this forum.

I found a thread on this topic over on the rv.net towing forum but they act
like thugs to each other so it's difficult to extract meaningful
information.

Someone there suggested that synthetic fluid actually dumps heat better then
regular trans fluid and remains cooler.

THen someone else suggested he was an ininformed moron and that synthetic
fluids only TOLERATE heat better.

As i plan to keep my eys glued to a trans temp gauge I am less interested in
the latter.

THanks
--
Dave & Ellen Silva


Check out the website:

http://www.oldrv.net
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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: does synthetic trans fluid lower temps? [message #121279 is a reply to message #121210] Thu, 07 April 2011 21:27 Go to previous messageGo to next message
Hardie Johnson is currently offline  Hardie Johnson   United States
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hertfordnc wrote on Thu, 07 April 2011 13:36

First, do not take for granted the civility on this forum.I found a thread on this topic over on the rv.net towing forum but they act like thugs to each other so it's difficult to extract meaningful information.Someone there suggested that synthetic fluid actually dumps heat better then regular trans fluid and remains cooler.THen someone else suggested he was an ininformed moron and that synthetic fluids only TOLERATE heat better.
As i plan to keep my eys glued to a trans temp gauge I am less interested in the latter.
THanks

Actually you are right about civility. I snoop the BMW forums, too and flaming is a regular part of that adventure. Rick Denney and I knew a place where you could go and get roasted just lurking . . .
Aaaanyway, the factor involved is 'overall heat transfer coefficient' which would address how well the fluid takes up and releases heat as it moves from the transmission to the heat exchanger and back.
I doubt that any real data is available from the manufacturers on this value (couldn't find any on a quick search), but I doubt that the difference between real and synthetic is worth a pinch.
Relax and use what makes you happy, just watch those dials.


Hardie Johnson "Crashj"
1973 26 foot Glacier, White Thing
Raleigh NC
Re: does synthetic trans fluid lower temps? [message #121287 is a reply to message #121279] Thu, 07 April 2011 22:33 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
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If you read all of the Hype then synthetics will do everything including cure lumbago and fry your eggs sunny side up while keeping your orange juice cold.

Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Re: does synthetic trans fluid lower temps? [message #121288 is a reply to message #121210] Thu, 07 April 2011 23:54 Go to previous messageGo to next message
Chr$ is currently offline  Chr$   United States
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Then Why doesn't Manny fill the tranny with that when he rebuilds them????

-Chr$: Perpetual SmartAss
Scottsdale, AZ

77 Ex-Kingsley 455 SOLD!
2010 Nomad 24 Ft TT 390W PV W/MPPT, EV4010 and custom cargo door.
Photosite: Chrisc GMC:"It has Begun" TT: "The Other Woman"
Re: does synthetic trans fluid lower temps? [message #121294 is a reply to message #121287] Fri, 08 April 2011 05:58 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
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Ken Burton wrote on Thu, 07 April 2011 23:33

If you read all of the Hype then synthetics will do everything including cure lumbago and fry your eggs sunny side up while keeping your orange juice cold.

Ee-Gad ! !
Are you trying to say that it won't?
Now, just who am I supposed to believe?

Matt (snickering in his morning coffee) -


Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
Re: [GMCnet] does synthetic trans fluid lower temps? [message #121296 is a reply to message #121288] Fri, 08 April 2011 06:51 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
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Location: Sydney, Australia
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Chris,

I'm confused!

As noted earlier Manny told me to use Mobil 1 Synthetic Transmission fluid,
did he tell you something different?

Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426

-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Chris Choffat
Sent: Thursday, April 07, 2011 10:55 PM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] does synthetic trans fluid lower temps?



Then Why doesn't Manny fill the tranny with that when he rebuilds them????
--
-Chr$: Perpetual SmartAss
77 Ex-Kingsley 455, Power Drive, 3:21 FD, Quadra bag. The Engineer's
Motorhome
Scottsdale, AZ



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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: does synthetic trans fluid lower temps? [message #121299 is a reply to message #121210] Fri, 08 April 2011 07:09 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
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hertfordnc wrote on Thu, 07 April 2011 13:36

First, do not take for granted the civility on this forum.

I found a thread on this topic over on the rv.net towing forum but they act like thugs to each other so it's difficult to extract meaningful information.

Someone there suggested that synthetic fluid actually dumps heat better then regular trans fluid and remains cooler.

THen someone else suggested he was an ininformed moron and that synthetic fluids only TOLERATE heat better.

As i plan to keep my eyes glued to a trans temp gauge I am less interested in the latter.

Thanks
Dave

Dave,

First and directly relating to the thread subject:
There is no real difference in the viscosity or specific heat that would make for better heat transfer with any synthetic. In a transmission of this design there are two major heat inputs, the torque converter and the oil pump.

The torque converter heat input is very much proportional to slip, so it will be greater towing or climbing.

The oil pump is not at all like an engine oil pump that supplies oil primarily for cooling and lubrication. The trans pump mostly is supplying oil that is a working fluid for the framistans and flibijibits that make that all the gears shift and still has to pump enough to overfill the torque converter to keep it cool. So it has to pump about a horsepower worth and that goes to heat.

If someone says he saw a significant decease in his transmission temperature when he switched to a synthetic, just nod, mumble something a walk away. If there is a difference, I defy anybody to validate it outside of a carefully controlled laboratory.

Continued explanation for those that care:

If he changed the fluid and did not complete disassemble the trans and drain the torque converter and all the servos, he has changed only about half the fluid. He does not have what he thinks he has, but maybe the new fluid cleaned the cooler a little bit - maybe.

As a multi-decade Detroit lab rat that specialized in power train testing I am in the interesting yet worthless position of having some first hand knowledge of test results.

I have run tests that you could not imagine. Things like thermocouples in piston rings, high speed photography of moving valve gear and an engine with only triple distilled water in the crankcase - just for starters. For most of it, I had extensive analytical laboratory backup.

The lubrication industry uses a four ball test as a screening tool - synthetics do better than most. In running engine boundary lubrication tests - where lube oil flow is so reduced that failure in imminent - synthetics do well again. In running power train durability, we were forced by some conditions to go to synthetics just for the temperature resistance.

The only difference the only real difference in use between a conventional refined (dino) lubricant and a synthetic that is the reformulation allows higher temperature resistance. All conventional lubricants break down a 305*F. This is not a time/temperature thing. When an oil molecule gets to 305*F, it comes apart and is no longer what it was. The products often are both poor lubricators and may be corrosive. This temperature is easily reached in internal combustion engines, but not so easily in transmissions, but it can still happen.

A related advantage that the synthetics get is a greater resistance to oxidation. This creates byproducts that are very much like those that overheating creates.

These two advantages are what make the coach service a good candidate for synthetics. If your driveline is like mine, it is either idle or at high load. Coaches like mine and yard equipment that is either running flat out or rusting are the places where synthetics become an advantage.

Matt


Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
Re: [GMCnet] does synthetic trans fluid lower temps? [message #121305 is a reply to message #121296] Fri, 08 April 2011 07:15 Go to previous messageGo to next message
emerystora is currently offline  emerystora   United States
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When Manny shipped me one in Oct 2009 it was filled with Mobil 1 fluid.


Emery Stora

On Apr 8, 2011, at 5:51 AM, Rob Mueller <robmueller@iinet.net.au> wrote:

> Chris,
>
> I'm confused!
>
> As noted earlier Manny told me to use Mobil 1 Synthetic Transmission
> fluid,
> did he tell you something different?
>
> Regards,
> Rob M.
> USAussie - Downunder
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
>
> -----Original Message-----
> From: gmclist-bounces@temp.gmcnet.org
> [mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Chris Choffat
> Sent: Thursday, April 07, 2011 10:55 PM
> To: gmclist@temp.gmcnet.org
> Subject: Re: [GMCnet] does synthetic trans fluid lower temps?
>
>
>
> Then Why doesn't Manny fill the tranny with that when he rebuilds
> them????
> --
> -Chr$: Perpetual SmartAss
> 77 Ex-Kingsley 455, Power Drive, 3:21 FD, Quadra bag. The Engineer's
> Motorhome
> Scottsdale, AZ
>
>
>
> _______________________________________________
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Re: does synthetic trans fluid lower temps? [message #121313 is a reply to message #121299] Fri, 08 April 2011 08:17 Go to previous messageGo to next message
Ernest Dankert is currently offline  Ernest Dankert   United States
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I would like to expand upon your discussion of syn oil.

The weak link in transmissions moves from the oil degradation to elastomer failure, seals become brittle.

I seem to recall someone mentioning changing transmission fluid every 12,000 miles as recommended in the service manual.

Expanding the discussion to engines.....

I have 6 vehicles, changing once a year is simpler and cost effective for me.

The lubrication properties of syn are superior, in the event of line failure, coolant leak, or cold weather the lube benefit is of value. I had a head gasket failure and have a '98 350 with cold start knock.

My 403 has "flat" tappets, the benefits of lubrication here have been debated ad nauseum.

I have better gas mileage with syn lube in all power transmission components. How much and is measurable, it is certainly not worse.

Disclaimer; these are my beliefs, some of which have been documented with personal results and data.


1977 Eleganza II
Ogden NY
Re: does synthetic trans fluid lower temps? [message #121335 is a reply to message #121299] Fri, 08 April 2011 14:15 Go to previous messageGo to next message
roy1 is currently offline  roy1   United States
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Mat
What the heck are framistans & flibyibits? When the Trans is serviced should they be replaced?
Roy


Roy Keen Minden,NV 76 X Glenbrook
Re: [GMCnet] does synthetic trans fluid lower temps? [message #121336 is a reply to message #121335] Fri, 08 April 2011 14:36 Go to previous messageGo to next message
Steven Ferguson is currently offline  Steven Ferguson   United States
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You betcha Roy, don't forget the kradammits also.

On Fri, Apr 8, 2011 at 12:15 PM, roy keen <roynpaula@charter.net> wrote:

>
>
> Mat
> What the heck are framistans & flibyibits? When the Trans is serviced
> should they be replaced?
> Roy
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Re: does synthetic trans fluid lower temps? [message #121409 is a reply to message #121210] Sat, 09 April 2011 17:48 Go to previous messageGo to next message
WayneB is currently offline  WayneB   Canada
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Yes Synthetic ATF is better than Dextron,the specs for Dextron were downgraded in the 80's with the widespread use of Lockup Torque converters in GM Hydramatic transmissions as it didnt have to deal with the heat caused by torque converter slippage anymores.

I use Mobil 1 ATF in all of my vehicles with automatics, the Motorhome, Range Rover, Buick,Jaguar, Trans-Am and my daughters VW Bug.


1976 23' GMCII By Explorer
Re: does synthetic trans fluid lower temps? [message #121435 is a reply to message #121409] Sat, 09 April 2011 21:31 Go to previous messageGo to next message
hal kading is currently offline  hal kading   United States
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Dexron VI is synthetic with a very long recommended change interval. GM says good for all hydromatic transmissions.

Hal Kading 78 Buskirk Stretch Las Cruces NM
Re: does synthetic trans fluid lower temps? [message #121970 is a reply to message #121210] Fri, 15 April 2011 22:28 Go to previous message
Bob de Kruyff   United States
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Location: Chandler, AZ
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hertfordnc wrote on Thu, 07 April 2011 11:36

First, do not take for granted the civility on this forum.

I found a thread on this topic over on the rv.net towing forum but they act like thugs to each other so it's difficult to extract meaningful information.

Someone there suggested that synthetic fluid actually dumps heat better then regular trans fluid and remains cooler.

THen someone else suggested he was an ininformed moron and that synthetic fluids only TOLERATE heat better.

As i plan to keep my eys glued to a trans temp gauge I am less interested in the latter.

THanks

Catching up late on all of these posts but synthetic does not at all result in lower fluid temps. GM delayed synthetic lube in differentials because of drastically increased temps inder tough usage.


Bob de Kruyff
78 Eleganza
Chandler, AZ
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