1977 20ft Argosy Transmission Temp?

[fabofabo]

Just took a long, long weekend to drive up to Yosemite, still beautiful, and noticed the Transmission temperature sky high to 260. Is this reasonable?

[thenewkid64]

Originally Posted by fabofabo

Just took a long, long weekend to drive up to Yosemite, still beautiful, and noticed the Transmission temperature sky high to 260. Is this reasonable?

Come to your own conclusions. Here is a post from long ago, I don't know where frank went, but he had a ton of neat knowledge.

[Silvertwinkie]

Your trans at that temp will die very, very shortly. No question about that if the temp you are seeing is correct. It is true that synthetic fluid will take upwards of 260, however, your bands, seals, etc are cooking big time (round about way of saying the fluid would take it but the trans won't). If you are using conventional trans fluid, it's no doubt totally shot or in need of replacement as conventional oils can't take as bad of a beating as synthetic. Your trans temps should not go over 200 degrees for extended periods of time. 260 is transmission suicide. Typically you should be between 175 and 200. That link Brett posted is 110% right on correct.

Here is a link to the Amsoil site for a bit more info about what the trans fluids can take...not the trans themselves:

http://www.amsoil.com/products/atf.html

Also keep in mind that 260 degrees is even high for engine. At that temp, you would be well near or in the red zone for overtemp of the engine, let alone a trans.

[fabofabo]

Originally Posted by thenewkid64

Come to your own conclusions. Here is a post from long ago, I don't know where frank went, but he had a ton of neat knowledge.

THANKS A TON GREAT INFO , I BEST START SAVING SOME PENNIES.
F

[Silvertwinkie]

Originally Posted by fabofabo

THANKS A TON GREAT INFO , I BEST START SAVING SOME PENNIES.
F

Either that or find out what is causing it to overheat. Look into a trans cooler (a good one) if it does not have one. Also, if the trans goes into the radiator for oil to water cooling, make sure the engine is also not overheating. If the engine is above 210 degrees regularly, you should look into a thermostat or water pump as an overheated engine with the trans going through the radiator will raise temps on the trans.

[krowsea]

Originally Posted by fabofabo

THANKS A TON GREAT INFO , I BEST START SAVING SOME PENNIES.
F

You don't need to save much, a good transmission cooler will typically run in the $65 - $85 range, plus any installation if you don't feel comfortable doing it yourself. It's really quite easy though. The most efficient way to cool (the engine and the trans) is to keep the original cooler line from the transmission to the cooler located inside the radiator, then run the return line to your brand new stand alone cooler mounted behind the grill somewhere, then out of the cooler and back to the trans. Thsi method helps lower the engine and trans temperatures. Remember, it's easier to keep it cool than it is to get it cool.

John-Boy

[thenewkid64]

One of the other things to consider is getting a "transmission service" Have the pan dropped and the transmission checked. If there is a blockage in the in pan filter, or a band that is slipping it could be the issue that is causing the higher than normal temps. You should also have the in radiator cooler flushed as they can get clogged and cause lack of cooling flow.

The Aux cooler will not hurt, I added one to my 28 footer as soon as I got it home. Get the biggest one you can fit. Not only will it shed heat, but it will also increase the total volume of fluid in the system.

[overlander63]

Originally Posted by Silvertwinkie

Either that or find out what is causing it to overheat. Look into a trans cooler (a good one) if it does not have one. Also, if the trans goes into the radiator for oil to water cooling, make sure the engine is also not overheating. If the engine is above 210 degrees regularly, you should look into a thermostat or water pump as an overheated engine with the trans going through the radiator will raise temps on the trans.

IMHO, the absolute worst thing that could have been done, is to put the transmission cooler inside the radiator. The fluid will only be "cooled" to maybe 185 degrees or so, because that is the temp of the water.
If you want to leave the transmission cooler connected, or "in the loop" for extended city driving, make sure the fluid passes through the cooler in the radiator first, then into an auxilliary cooler, then back to the transmission. It will do little good if you cool the fluid to 160, then run it through a 185 degree heat bath.
Terry

[john hd]

IMHO, the absolute worst thing that could have been done, is to put the transmission cooler inside the radiator.

maybe in florida!

in wisconsin in january, we call that "being able to get your tranny out of first gear"!

john

[87MH]

Originally Posted by argosy20

IMHO, the absolute worst thing that could have been done, is to put the transmission cooler inside the radiator. The fluid will only be "cooled" to maybe 185 degrees or so, because that is the temp of the water.......

At least on the '86 and '87 motorhomes, "they" (Airstream?) put the tranny coolers in the hot side radiator head - the idle temp of my engine is 205 degrees - so the "coolest" temp the tranny fluid would see (I would think) would be the temp of the water FROM the engine to the radiator - 205 degrees (a bit more during a hard pull on a hot day). The oil cooler is internal to the "cool" side radiator head (horizontal flow radiators - not vertical flow).

In light of the post referenced by thenewkid64 (refer to "Frank") above, IF the fluid degradation numbers posted by "Frank" are accurate - (they certainly seem reasonable, I have no reason to doubt them) - it makes sense to "preheat" the tranny fluid only in the northern climes - as john hd said. Since I do not anticipate to do any "cold weather" driving I would opt for "tuning" the tranny temp maintenance system to "Southern Hot" conditions......thought - an aircooled heat exchanger with a valve bypass. Control the valve system to force the fluid through the air exchanger in hot conditions - bypass the air exchanger in cold conditions - maybe even a thermostat control as on the engine water cooling system.

FWIW - a secondary air-cooled heat exchanger for the tranny fluid is on the "short list" of things to do on the MoHo. Also on the to do list - when I redo the gauge panel - oil and transmission fluid temperatures (before and after coolers) as well as radiator in and radiator out temps will be displayed.

[Silvertwinkie]

Folks, the oil to water is a key part of the cooling process. In the winter or cooler months, the engine gets the trans fluid to temp. It is VERY BAD to operate a trans regularly under 160 degrees. A trans works on the princ of friction. Too cold can do similar damage as too hot. The sweet temps for a trans is between 160-185 degrees. The oil to water is not designed to cool the trans very much, but more to take the edge off or help provide heat in the cooler months. It will not usually add trans temps as has been described unless you have a run away engine cooling issue where the engine is pushing 260 degrees (which is not normal). Even then, at those temps it would not push the trans to 260 degrees for a while, if at all. This thought that it can is flawed logic.

How do I know this, well from mechanics, car club forums where this has been debated over and over and over and from my direct, personal, real world experience? I had a 185 degree thermostat on my prev tow vehicle (GCVW or 11685lbs). The engine (a 350ci) would regularly get between 195 to 205 degrees. The trans (4L60E) would get upwards (per the gauge I installed for the trans temps) 190 degrees (keep in mind this is with a the trans going into the radiator, then to an external cooler and then back to the trans where the temp sending unit is located).

So then I placed a 160 degree thermostat in the car. The engine temps lowered to between 175-188 degrees (depending on towing and outside temps, A/C on or not). The trans pretty much stayed the same as it did when I had the 185 degree thermostat in the car, maybe lost 2-3 degrees on the best days.

Adding a better cooler or in my case an additional oil to air cooler dropped my trans temps to between 170-175 on average, warm outside, towing. Sure it peaked to near 200 when moving 11,685lbs up a hill, but it would come right back down to about 175 towing and 160-165 not towing on very warm days. Cold days not towing the trans would park right at 160 and cold days towing, stay at between 165-170. Even though when I tow the car engine temps per the PCM (not the temp gauge) clearly showed when towing the 6300lb Safari, that the engine temps were near 190 degrees, the trans rarely got above 175 degrees.

That said, leave the trans oil to water connections alone. Fix your cooling problem and add a good external trans oil to air cooler and you will be VERY happy with the end results. I spent over a year playing around with engine and trans temps. Feel free to do all the testing and hit or miss on your own as some aspects will be unique to your need.

Two additional suggestions when it comes to trans cooling. Make your torque converter cover look like this one:

http://www.clearimageautomotive.com/...Drivetrain.htm

(Click on the Neal Torque Converter Cover for pics)


This particular one was made for the 4L60E, but you can see the princ of why to do it the second you see the old one. This cover allows air to pass the torque converter. The stock one is a closed cover, and acts like a blanket, trapping heat and increasing trans temps. It may only cool it a degree or 2, but for $50 if you can find one for your app or spending the time to make a custom one, is well worth it, particularly if you do it in conjunction with the next suggestion.

Find and install a deep pan kit for your trans. It can add upwards of 2 extra quarts to the trans pan. It's a no brainer.....To me the thought was sound. If you place 2 similar pots of water, oil, whatever on a stove. One is half full, the other is 3/4 full and turn the stove on to full heat, the pot that is half full will boil or reach temp faster as there is less volume to heat.

The same holds true in the trans. Adding more fluid makes it more difficult for the fluid to take one for the team when flash heat is applied (taking the load up a fair grade).

So the reader's digest of all this is:

-Don't mess with the rad tank trans cooler
-Get a great external trans cooler and add it in line with the rad cooler
-Modify or buy a torque converter cover to release boxed in heat
-Get a deep trans pan kit (with required deep well filter) to make it take longer to heat the trans and deal with flash load creating heat)
- Find out why your engine is overheating and fix that problem
- Look into an experiment with a 160 degree thermostat, knowing that if you drive in the colder months, you might need to restrict airflow to get the engine to come to temp.