Trans Temp too cold?

[Rdnck84_03]

I was told by a reputable local trans builder that if you can keep the temps below 165 on a full correctly rebuilt transmission ( all new wear parts, and fixing the known weak points, and a proper shift kit for the application) that it would outlast most of the vehicles they are installed in. Not sure how true this is, but I have never heard anything other than good about his work so he must know what he's doing.

I myself hate autos so if I buy something with one, I normally just run it until it craps out and d a manual swap. I have never had good luck with them.

James

 

[trackspeeder]

Does the E4OD prevent 4th gear or lockup until it reaches a certain temp?

I feel like I read that somewhere, and I feel like last winter I noticed it would hold 3rd a LOT longer. But my mind likes to play tricks on me

The E4 will shift through all its gears hot or cold.
To warm the fluid faster the TCM will prevent the converter clutch from locking.

 

[Cant Write]

That's exactly why I'm asking. I've seen plenty of charts that show an inverse life expectancy/temperature curve for automatic transmissions. But I've rarely seen anything that shows performance data for temperatures below 170F.

If you used to build them for a living, I'm very interested in your view.

There a video on YouTube from an engine who decided to quit his day job and become a RV delivery guy.

He has, I think a 2007 GM D/A combo. He is meticulous on records. Original engine/trans. Drives 55mph whether loaded or not.

He said he purposely deleted the external cooler. He sees trans temps near 200. Saw 1.5-2 mpg increase from running a hotter trans.

Says the new fluids handle temps just fine. I’m speaking out of my comfort zone and just regurgitating what he was saying.

I’m still of the 170* mindset, but just thought I’d throw another side into the coin.

The experts @trackspeeder and @XOLATEM please chime in regarding these newer fluids and their ability to handle the higher temps...

And @david85 if this is derailing too much, please shut me up

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[david85]

And here I thought I had a long term ownership with my truck. The guy's been around.

Makes me wonder if I should get some Michelin LTX tires next time. This isn't the first time I've heard good things about their longevity. I like my current Toyo AT3s but they're done after 2 years. Admittedly, I spent plenty of time on gravel, but still. And as for cold weather, I remember rescuing a couple guys in Alberta once when it was -35C. Was driving a duramax, too.

 

[XOLATEM]

I'm thinking of adding a thermostatic oil cooler bypass to bring the transmission temperature to a steady 170F.

What do you folks think?

Ok david85...here goes....

Disclaimer...I am no 'expert' and do not claim to be...and...although I try to keep up with the latest in the industry...I have not been working in the field for over ten years...so...the latest on fluid development is not in my quiver...

I did get a chance to have a pretty long conversation with Dr. Philip Landis of Lubeguard fame...back in '88 at the Trans Expo in Memphis...really smart guy...everybody else was drinking and dancing and I was getting all of my questions answered...

So...that being said...

Says the new fluids handle temps just fine.

It is the seals in the transmission that you should be worried about...that is the weak link in the chain...


I agree with trackspeeder on the temps...nothing to worry about so far...

I would not add the oil cooler bypass and add extra complexity and possible failure point to your system...

...a lot of the factory systems that do that very thing are giving the aftermarket transmission industry more stuff to address when they rebuild a unit that failed from one of those clogging up or failing in some way...they are having to either bypass the factory system or add aftermarket corrections to get them to work...

As far as losing MPG with colder oil...U2slow is probably correct but losses occur with not only pumping...as in resistance to the flow into and out of the actual pump and torque convertor...but also parasitic losses once the fluid leaves the cooler and cools the geartrain and bleeds off into the sump...My opinion is that sure...dead cold in the Great White North you are going to loose some efficiency...but you are also losing it until your engine fully warms up so trans losses are the least of your problems...and...the minor difference you would see between, say...130F and 195F of fluid temp...well...you would need to test that under more exacting methods than just filling up to the top at the filling station...you would need a way of measuring BSFC and run repeatable tests...probably on a chassis dyno...

On the factory cooler...to use it or not....I had come to the conclusion that factory coolers...the ones in the radiator surrounded by engine coolant....were a cheap and convienient way to facillitate quick warm-up...and not much else...especially in the colder northern climates...

Yes...they have the capability to actually cool transmission oil in some conditions...but they cannot cool the oil any lower than the temperature of the engine coolant that surrounds it...so...if you work your unit hard and the oil leaving the torque convertor is hitting in excess of 200-230F...then yes...it can help bring it down to around 190-195F...but not lower than the surrounding coolant temp...

I tried a test on a truck that the owner had me install a guage for the trans....(where you put the sensor makes a difference in your readings, too...)...and I found out pretty quickly how fast you can peg the needle and how long it takes to get that heat back out of it...

It only take seconds of powerbraking to generate massive amounts of heat....

Once you see 280F on the guage...well....you know that it is easy to ruin a unit-load of fluid...and...once you get the heat in it...well...you hope like hell you can get it back out of it....but you will dig your fingernails in the steering wheel for a good while before you see the guage needle drop any significant amount...

Factory coolers have their place...in average conditions...

..we (those of us with IDI's) are generally pushing our trucks past what Ford envisioned them to do...and running them longer than 'They' wanted us to...we are not running in 'average' conditions...

When it comes to factory coolers...you have to consider whether you want to run the risk of it fracturing and totally hosing your precious automatic transmission...the industry term for a coolant-contaminated unit was 'strawberry milkshake'...

Yes...you can get lucky and some coolers will last longer than others...but it is only a matter of time before it springs a leak...when copper or aluminum heats up and cools down (thermal cycles) it is bound to open up a crack at some point...and coolant will ruin your week...or month...I would just install aftermarket coolers on most of the trucks I fixed...

He said he purposely deleted the external cooler. He sees trans temps near 200. Saw 1.5-2 mpg increase from running a hotter trans.

Sure...but how long is it going to last before he cooks the seals...I would counter with he better save that money in a jar for his eventual rebuild....and...we really don't know if it actually is something else he is doing to achieve the extra mileage...and...where in the unit is he actually measuring the temperature..?

Speaking of fluid...you have synthetic and you have regular paraffin based oil and you have synthetic blends...one of the differences was the uniformity of the molecules that make up the fluid matrix...

As I understood it...synthetic fluid was more resistant to damage from heat...but the damage would be localized...where the overheat occurred...and not affect the whole chain of fluid...synthetics have a much higher heat tolerance before damage would occur...

With regular paraffin-based oils...the heat damage would affect the whole chain...so...overheat your fluid and you are kinda hosed from here on out until you change it...

Speaking of overheating fluid...remember the older dipsticks and tubes...? Pretty simple affairs...tube and a stick...with markings...

Remember later in the late 80's-early 90's...when the sticks had a lever that you would push down and the stick would lock to the tube...? Want to know why..? Because overheated fluid could Flash
and pop the stick out and burp fluid on the exhaust...especially the catalytic converter...and catch a vehicle on fire...

'They' fixed that by eliminating the tube and stick...

On the warmup thing...with units not shifting and no lockup until they reach a certain temp...Can't Write brought that up...yes...'we' were told in continuing education to watch out for that...can't remember what make or model it was...and not waste any time and money trying to 'fix' that factory strategy for a customer...

Now...on the internal seals that make up a large part of the hydraulic integrity of the unit...depending on what kind of material they were made of...that is going to be the limiting factor in your transmission longevity...there are a few different types of rubber that the aftermarket uses...as a rebuilder...you just had to go with what you had a 'feel' for...whatever you had good luck with...certain brand names of kit suppliers were reliably good...and some would cheapen up and cause you trouble...I don't want to name names here...but I was told by my suppliers that I was one of the pickiest guys they knew...

The breaking point is how much heat the seals could stand before they break down...and it is my belief that the breaking down process starts as soon as heat and wear start ...and the effects are cumulative...you might be able to get away with a little overheating here and there...you are thinking...but you would be wrong...you will pay for it in the long run...

You ever go to a tire warehouse and smell that new-tire smell...? You know what that actually is..? The solvents or otherwise volatile ingredients in the tire rubber compound that keep the tire pliable...

...well....transmission rubber seals are made up much the same way...and when the volatile ingredients are cooked out of the rubber...from heat...then what is left is the solids that the synthetic rubber is made of...and the seals shrink....

Heat is the enemy of transmission longevity.

You want the thing to last..? Limit it's exposure to heat...

You are not going to totally protect your unit from the effects of heat...but you can...as they say...manage the decline...

last winter I noticed it would hold 3rd a LOT longer.

I suspect you are correct but I would attribute the delay of shifting higher than third to the TCM calculating a higher load when things are colder...and then delaying the upshift...and/or the possibility of the colder, thicker fluid not wanting to flow though the VB plate orfices as quickly as it would at normal operating temps...the way to figure out which it is would be to tap in an LED signal monitor to get a visual as to when the computer sends the upshift signal.

This is all I have for you at the moment...

Bottom line..? I would leave it alone...if you have a good grade of synthetic fluid in it and your filter seal is holding up...you are good.

Happy guage watching....

 

[david85]

...everybody else was drinking and dancing and I was getting all of my questions answered...

Respect. I'd have done the same.

I got 13 years out of the first build, and it only failed because I installed one of the seals backwards (intermediate clutch piston)

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. They were pretty pliable when I tore it down. Hopefully the new ones will last as well (2 years, and counting).

I am running synthetic engine oil (100% synthetic, not "full synthetic"), so I could consider switching over to synthetic ATF. As for parasitic hydraulic losses, I could look more into what the viscosity change really is, from room temperature to 200F. Or to 100F in my case.

There are some mixed opinions on the E4OD/4R100 cooler bypass. The more I think about it, it was probably there to allow flow in the event of a blocked inline cooler filter. I remember Ford was requiring an inline filter be installed on all rebuilt units back in the day (or so I was told...). Although, the only way any debris get sucked into the pump, is if the main filter in the pan breaks off. Which is possible, I suppose.

Thanks for the sharing. That was the kind of info I was hoping for.

 

[XOLATEM]

E4OD/4R100 cooler bypass. The more I think about it, it was probably there to allow flow in the event of a blocked inline cooler filter.

Very good observation...I never thought about what it was meant to do other than allow quicker fluid warmup...the bypass has clogged at times and caused shops a lot of misery...enough to be a topic to address at seminars.

Ford was requiring an inline filter be installed on all rebuilt units back in the day

I remember that...I had bought a unit from the Ford Dealer when I had a customer not want to wait for me to build his core...I always wondered who it was that they contracted out the rebuilding of their E4OD's...because I had another one where I was re-rebuilding a former Ford authorized rebuilt unit...the paint on it was extremely hard to remove...and I wanted the aluminum case to be able to breathe...and cool the fluid better.

Thanks for the sharing. That was the kind of info I was hoping for.

Thanks for listening...and...thanks for thanking me...

 

[Cant Write]

@XOLATEM thank you very much for your thoughts and expertise.

I’m going to try and write this concisely, but prolly unlikely. And know I’m not trying to paint you or anyone into a corner, just learn from your experiences.

I always understood the radiator cooler to do 2 things:
1- aid in warm up, which sounds like is a non issue with how much heat a TC can create (gotcha)
2- aid in low speed cooling of the fluid, down to rad temps only.

2 observations to the above:
1-David has experienced no ill effects on FS roads with A2A only
2-I boiled a 4l80 over in 2nd gear 4-hi and it ONLY had the rad cooler. After 6-7 miles of not extreme but sustained climbing, it was puking fluid from seemingly everywhere as I looked under it......locking dipstick held....I added a quart of fluid and drove it on the highway another 4 hrs hoping to blow it up. Still working to this day.....that was 2 years ago. I added an external A2A inline after the rad. have done the same climb again in 2nd/4-hi trying to replicate, could not boil it over. Done steeper climbs in 4-lo/2nd with no issue.

My A2A only experience. Couple owned a 94 Buick century wagon, 3.1L/4T60e with only the rad cooler. Hot summer day in SD, the trans got hot, downshifted and didnt upshift. They blew the engine up on I-90. Dad got the car for free (40k miles) we bought a junkyard engine, changed all the trans fluid, bypassed the rad cooler with A2A, and drove it to 232k miles before the trans lost 3/4 gears.

Questions:
1-in your professional opinion, what is the simplest most robust approach to trans cooling? Large A2A cooler only with inline filter?
2-If internal seals fall victim to too much heat, how do C6’s and TH400’s last so long with non-OD and often times only a Rad cooler?

I only ask cause I want my auto’s to last. I’m of the 170* and below mindset as well. In no way is any harm, or Ill-intent a part of this post. I’m an “auto-tranny-idiot” and am here with both ears open and my mouth shut.

 

[david85]

I think mine may have reached 190F at one point while climbing (ramming) uphill through snow melt (heavy stuff). The worst of it was early in the summer, before I installed the temp gauge so I don't know for sure how hot it was. But I figured it was safe to say some heat would be generated by a slow crawl that lasted 3 - 5 miles uphill, which is more common for the roads I visit. If I ever get my laptop working again, I want to try programming a lockup function when running in low range. Again, fuel economy is my main concern.

The attached photos tell the story of that particular run. Took about 2 dozen attempts to get through, but I wanted to reach the lookout.

 

[XOLATEM]

I always understood the radiator cooler to do 2 things:
1- aid in warm up, which sounds like is a non issue with how much heat a TC can create (gotcha)
2- aid in low speed cooling of the fluid, down to rad temps only.

I agree with you on that...

I boiled a 4l80 over in 2nd gear 4-hi and it ONLY had the rad cooler. After 6-7 miles of not extreme but sustained climbing, it was puking fluid from seemingly everywhere as I looked under it......locking dipstick held....I added a quart of fluid and drove it on the highway another 4 hrs hoping to blow it up. Still working to this day.....that was 2 years ago. I added an external A2A inline after the rad. have done the same climb again in 2nd/4-hi trying to replicate, could not boil it over. Done steeper climbs in 4-lo/2nd with no issue.

The fluid came out of the vent on top of the case...or...(possibly)...out of the front seal area around the convertor neck...until it cooled.

Your aux. cooler is working and you proved that the 4L80 is a tough unit.

My A2A only experience. Couple owned a 94 Buick century wagon, 3.1L/4T60e with only the rad cooler. Hot summer day in SD, the trans got hot, downshifted and didnt upshift. They blew the engine up on I-90.

This is why Steve Younger told us to advise customers to "Slow down, subtract weight, and travel at night". in the late 90's...

I had much the same experience with a similar car...but I stopped short of blowing up a customers engine...after some head scratching...I discovered that the computer strategy was to fall out of lockup and overdrive to speed up the engine and increase transmission pump speed to flow more oil through the cooler in an attempt to cool things down...turns out the car was a flood salvage and the radiator fins were clogged up with river debris....the ECM was commanding the forced downshift.

Dad got the car for free (40k miles) we bought a junkyard engine, changed all the trans fluid, bypassed the rad cooler with A2A, and drove it to 232k miles before the trans lost 3/4 gears.

Dad was crafty enough to make out like a bandit...(meant as a compliment)

1-in your professional opinion, what is the simplest most robust approach to trans cooling? Large A2A cooler only with inline filter?

Depends on your conditions and desires and budget...and if you want to chance an early rebuild...one of the reasons I quit is it was looking like I had to sell a radiator with every rebuild and it was a hard sell...I just stopped fighting it...people seemed to think they knew more about what their vehicle needed than I did....

And...I was not going to cave...and let people talk me into doing a bad job just because they did not want to spend the money on it...

It was entirely possible to have to pay people for the 'privilige' of touching their vehicle...

Can't make even a meager living like that...

With a more specific situation...I would venture a recommendation...

I liked to use the derale style coolers side-by-side in front of the radiator and bypass the factory cooler...but I was in a warmer climate...

2-If internal seals fall victim to too much heat, how do C6’s and TH400’s last so long with non-OD and often times only a Rad cooler?

Because having no OVD. forces the TC to reach coupling point more often under 'normal' driving conditions...less heat buildup...

Having at least a 3.25-4.10 rear gear helps too...the TC spends more time at and around coupling point.

Unless you go around powerbraking your unit just to see how long you can go before you burp fluid out of the fill pipe and shoot the stick through the hood...

I only ask cause I want my auto’s to last. I’m of the 170* and below mindset as well. In no way is any harm, or Ill-intent a part of this post. I’m an “auto-tranny-idiot” and am here with both ears open and my mouth shut.

Understood...we are in alignment on this one...

Thanks for making me feel useful again...I kinda miss my shop...

Maybe some day...

Also...thank you for the exercise...you seem to always have good things to contribute to any discussion that you dive into...

Wishing you-all the best...

 

[Cant Write]

I think I’ll continue to follow the rad inline with a 20k or bigger external cooler and a Pan temp gauge and filter as nice add-ons

Thanks again!!! I’m a standard trans guy but don’t wanna swap my van!! The suburban I’m still on the fence

 

[Cant Write]

@david85 beautiful country!!

Can you command lockup in 2nd?

 

[trackspeeder]

Ford developed the bypass valve to save the tranny from total failure do to blockage. Its pressure based, not thermal.

What happens during a blockage is the rear of the tranny starves for fluid. This will cause the output shaft bushing to spin.

 

[david85]

@david85 beautiful country!!

Can you command lockup in 2nd?

I've read that you can command lockup all the way down to 1st gear but I never tested it. I did run 2nd gear lockup on the highway without issues. Actually I miss being able to do that with the 3.08 gears. That was perfect for blasting up 10% grades at 2500 RPM with a trailer in tow.

 

[david85]

Depends on your conditions and desires and budget...and if you want to chance an early rebuild...one of the reasons I quit is it was looking like I had to sell a radiator with every rebuild and it was a hard sell...I just stopped fighting it...people seemed to think they knew more about what their vehicle needed than I did....

And...I was not going to cave...and let people talk me into doing a bad job just because they did not want to spend the money on it...

It was entirely possible to have to pay people for the 'privilige' of touching their vehicle...

Can't make even a meager living like that...

Sounds a bit like running an autobody shop. You can do a good job, or you can earn a living; you can't do both because a good job costs more than what most are willing to pay.

Most folks who need a transmission rebuilt can't afford to pay what it takes to make it bullet proof. It's a grudge buy to begin with, so after a big repair bill, many have their eyes on the next trade-in. And as the builder, you can never know what needs replacing until you tear it apart.

I spent about 3k CAD on my last rebuild and that was just parts. Of course, during "those three years" it was harder to get things and I ended up ordering extra and paying a fair amount just on shipping and brokerage across the border. I'm sure shops with vendor pricing can get better deals but it still adds up.

However, even if I didn't have to deal with supply chain issues, it made me wonder how online sellers can offer a "bullet proof" E4OD for only $2500 USD. Much less a rebuilt one for $1500. It also made me appreciate the $5000 price tag ATS had at the time. Not sure what the going rate is these days, now that inflation is "supposedly" slowing down.