You people do know that they tried air cooled "radiators" back in the early days of automatic transmissions, don't you? Didn't work to well and killed many transmissions. In hot weather they didn't take enough heat out of the oil and degraded the oil. In cold weather they didn't let the oil get to the correct temperature and killed the clutches in the transmission. The oil to water cooler was what was settled on as the best and easiest way of keeping the transmission alive. The add on air to oil coolers like the Hayden type are put in the output line of the oil to water heat exchanger and most use a thermostat to bypass them when temps aren't over a certain point.

So you guys are saying that a ~15 to 20 PSI radiator is a problem for transmission oil at ~50 to 70PSI ? A broken oil cooler doesn't get water into the oil when running but when the engine is not running.

 

So you guys are saying that a ~15 to 20 PSI radiator is a problem for transmission oil at ~50 to 70PSI

The way I learned it is that the fluid going to the cooler is overflow from the pressure regulator right after the front pump, and the "cooled" fluid is dumped back into the pan. That isn't very many PSI. You might have a different design than the Fords that I studied.

I understand the theory, that's why I said 250F is its normal habitat, but with 50 years to figure out a better way and with Mercon V at $4.27 a quart I can hope a multi-viscosity transmission fluid will be invented some day.
https://www.walmart.com/ip/Super-Tech-MERCON-V-Automatic-Transmission-Fluid-1qt/17134874

 

Yeah, I'm a GM guy. The cooled fluid is before the regulator on them, to feed cooler fluid through the trany.

 

You people do know that they tried air cooled "radiators" back in the early days of automatic transmissions, don't you? Didn't work to well and killed many transmissions. In hot weather they didn't take enough heat out of the oil and degraded the oil. In cold weather they didn't let the oil get to the correct temperature and killed the clutches in the transmission. The oil to water cooler was what was settled on as the best and easiest way of keeping the transmission alive. The add on air to oil coolers like the Hayden type are put in the output line of the oil to water heat exchanger and most use a thermostat to bypass them when temps aren't over a certain point.

I dunno about that (Re: modern automatic automatic transmissions/transaxles) in light of several aftermarket transmission manufacturers' (e.g. Hewland, Allison) and re-manufacturers' (e.g. Jasper) explicit stipulation that the warranty is void in the event that the oil cooler is other than a strictly oil to air exchanger - A condition disclaimed in bold (yelling?) text on the invoice --- That said, I have been advised (by an Allison Rep) that many 'DIYers' damage transmissions via use of undersized exchangers when converting to air-only coolers...

In cold weather they didn't let the oil get to the correct temperature and killed the clutches in the transmission.

Hence the manufacturer recommended 5 minute idling time prior to engagement at ambient temps ≤ -10°F and fully 10 minutes at ambient temps ≤ -40°F --- As per the manufacturer, it seems the torque converter heats the oil sufficiently in said time while idling in park/neutral -- In any event I'm here to tell ya - it works!-- The sole failure I've experienced with an automatic transmission owed to an 'in radiator' oil cooler leak

So you guys are saying that a ~15 to 20 PSI radiator is a problem for transmission oil at ~50 to 70PSI ? A broken oil cooler doesn't get water into the oil when running but when the engine is not running.

Whether contamination of the hydraulic fluid secondary to a leaky immersed exchanger occurs when the engine is stopped warm or during operation as a result of aspiration of engine coolant/emulsion corollary to 'stasis' following rupture of a cooler line - I think we might agree it's a condition worthy of avoidance at all costs?!

Very best regards
HP

 

The cooled fluid is before the regulator on them, to feed cooler fluid through the trany.

So... Does that mean the valve-body is the next 'port of call' (sans filtration) for any debris inadvertently introduced into the lines (while disconnected for maintenance, etc...)??? -- Thus a single grain of sand might be one's 'ticket' to a loooong walk in grizzly country! -- Detroit has much to answer for

Very best regards
HP

 

As per the manufacturer, it seems the torque converter heats the oil sufficiently in said time while idling in park/neutral -- In any event I'm here to tell ya - it works!

It's as simple as that old experiment with paddles in water to find the energy in a weight dropping while pulling a string. (James Joule) However many shaft horsies come out of the engine at idle speed, they simply stir the transmission fluid and it heats.
https://www3.nd.edu/~pdunn/www.text/joulelab.pdf

I think it was 1970 when I saw a guy trying to stay warm by running his car at a high idle. After about 10 minutes, smoke started coming out from under the car! He might have been throwing 50 HP into that oil for 10 minutes.

Then again, I recently saw where a guy in Colorado got a ticket from a cop for letting his car warm up in the driveway for 5 minutes. So, warm up your car if you must, but don't do it in Colorado. The nanny state will get you!

 

I dunno about that (Re: modern automatic automatic transmissions/transaxles) in light of several aftermarket transmission manufacturers' (e.g. Hewland, Allison) and re-manufacturers' (e.g. Jasper) explicit stipulation that the warranty is void in the event that the oil cooler is other than a strictly oil to air exchanger - A condition disclaimed in bold (yelling?) text on the invoice --- That said, I have been advised (by an Allison Rep) that many 'DIYers' damage transmissions via use of undersized exchangers when converting to air-only coolers...

As I don't have or have never worked on a Formula One (Hewland manual shift) or an over the road or bus, or industrial vehicle (Allison automatic) I can't comment on what they say in there "instructions". But with cars I know of no OEM that uses a standalone air to oil heat exchanger. The size and weight of the air/oil unit that would be equal to the water/oil unit is too much of a difference in these days of making things lighter and smaller for more fuel efficiency. But for heavy duty use they do add small air/oil units to increase capacity, like when towing.I personally haven't seen any oil cooler failures since the 1980's, in a GM vehicle.

You do know most industrial heat exchangers are water based don't you?

think we might agree it's a condition worthy of avoidance at all costs?

Agreed.

So... Does that mean the valve-body is the next 'port of call' (sans filtration) for any debris inadvertently introduced into the lines (while disconnected for maintenance, etc...)??? -- Thus a single grain of sand might be one's 'ticket' to a loooong walk in grizzly country! -- Detroit has much to answer for

No filtration is the FIRST port of call, before the pump is even involved. At least in any car transmission I've ever worked on, of any make. And yes you can and do have people work on things not following procedures to save time or money, but this means flushing all lines before reconnecting them during a repair. You do know that the hydraulic system in a transmission is very reliable and is a dirty environment in it's self, a "single grain of sand" is not a problem.

 

You do know most industrial heat exchangers are water based don't you?

Re: OEM equipment - absolutely!

I personally haven't seen any oil cooler failures since the 1980's, in a GM vehicle.

AFAIK It is, indeed, an uncommon failure mode in domestic passenger cars (with which I have very little experience beyond my erstwhile 'hobby' as a collector of same {a bad habit 'acquired' from my Ex}) - annoyingly, it happens all too frequently on a range of European products (equipped with automatic and 'cooled oil' manual transmissions). --- Returning to domestic vehicles; Owing to the risk (albeit modest) of oil contamination secondary to a cooler leak - coupled with the added liability attending interdependence of engine and transmission temps inherent to such schemes (i.e. an overheated engine=an overheated transmission) as well as to my own intense distaste for finding myself 'marooned' - I view it as a needless risk - especially as (in my experience) dealerships are more than happy to install ATF-to-air only exchangers at the time of sale

The size and weight of the air/oil unit that would be equal to the water/oil unit is too much of a difference in these days of making things lighter and smaller for more fuel efficiency.

Agreed! 'Proper' oil-to-air only exchanges (i.e. those required by warranty) are well-neigh the size of the engine radiator!

a "single grain of sand" is not a problem.

By that am I to understand that a 'permanent' coarse strainer precedes the valve body? Or is it merely that clearances are such that a small particle is unlikely to 'pin' a valve (i.e. lodge in a port in such a way as to interfere with valve operation)?

Very best regards
HP

 

By that am I to understand that a 'permanent' coarse strainer precedes the valve body? Or is it merely that clearances are such that a small particle is unlikely to 'pin' a valve (i.e. lodge in a port in such a way as to interfere with valve operation)?

Yes, the brass screen is the inlet filter to the front pump. There were no other filters in the Ford transmissions I worked on.
I have opened a transmission and found a trail of clutch particles leading like bread crumbs to the first pressure regulator valve in the valve body. That was the definitive reason why that transmission failed.

A grain of sand has little chance to "hang" a valve because a grain of sand is so large compared to the valve and bore tolerances. Throw in a hand full of sand and you will get some likely suspects. A flake of paper from a clutch plate? Definitely. I have seen it happen.

I have also seen a brass screen so plugged up that it was sucked into the front pump and used for grinding compound all through the transmission. That one required a kit of 14 spacer washers to restore the, "stack height" within specifications.

 

Then again, I recently saw where a guy in Colorado got a ticket from a cop for letting his car warm up in the driveway for 5 minutes. So, warm up your car if you must, but don't do it in Colorado. The nanny state will get you!

Mn residents are prey of that particular 'species' of legislative nonsense (in certain communities) as well -- The 'official' rationale for same being one or all of; noise, air quality, fire safety, theft prevention, etc... (for some unaccountable reason 'augmentation of municipal revenues' is conspicuously absent? -- Golly, golly) --- How truly the degree of privilege attendant to residing well outside of city limits cannot be overstated!

they simply stir the transmission fluid and it heats.

Indeed! Viscosity is a but an analog of resistance/friction/etc... --- There is indeed intrigue to be found in the observation that all the rules are the same -- merely the 'words' change discipline to discipline


Very best regards
HP

 

{a bad habit 'acquired' from my Ex}

HP being fair you need to admit you had a lot of fun and made a lot of money cuz of that _bad habit_! So I say you're just taking uncalled for 'swipe' at dad for no reason which I say is just lame cuz you know he doesn't even know abt this site

 

HP I was just thinking u can do Faraday shield for HV meter with black anodized Al screening! It's a lot more transparent than than bare Al cuz of low _albedo_ so less glare! Also if you want it perfect u could make it moving assembly so visual system like _integrates_ it all the same as Bucky-Potter grid?

 

HP Here's another question:

So for MAGNATUDE of electrical impedance everyone is totally happy with like
Zseries=√(R^2+X^2)

Which is just magnitude of a vector

So I say impedance magnitude of parallel circuit is given by:
Zparallel=(RX)/√(R^2+X^2)

But most ppl aren't comfortable with that for no specific reason so I'm asking what's the deal?

 

HP being fair you need to admit you had a lot of fun and made a lot of money cuz of that _bad habit_! So I say you're just taking uncalled for 'swipe' at dad for no reason which I say is just lame cuz you know he doesn't even know abt this site

---Emphasis Added---

Not quite! - I was taking a justifiable swipe at my adoption of a very silly, time-consuming, 'hobby' which held no interest whatever for me

HP I was just thinking u can do Faraday shield for HV meter with black anodized Al screening! It's a lot more transparent than than bare Al cuz of low _albedo_ so less glare!

Sounds promising - I'll check it out!

Also if you want it perfect u could make it moving assembly so visual system like _integrates_ it all the same as Bucky-Potter grid?

I daresay said project has been sufficiently protracted sans introduction of yet another 'enhancement'

So I say impedance magnitude of parallel circuit is given by:
Zparallel=(RX)/√(R^2+X^2)

But most ppl aren't comfortable with that for no specific reason so I'm asking what's the deal?

What exactly are you asking? -- The formula is correct... While I very much doubt that 'most people' are 'uncomfortable with it' - I am, nonetheless, bound to suggest that you direct your inquiry to them!

So... With that unparalleled feat of cerebration - might I be forgiven for assuming that 'see spot run' is too advanced to bear addition to this year's syllabus?

Best regards
HP

 

HP I was just thinking u can do Faraday shield for HV meter with black anodized Al screening! It's a lot more transparent than than bare Al cuz of low _albedo_ so less glare!

Bravo! --Finally! A 'bearable' solution! You may rest assured that you have my undying gratitude (and that of my office staff whom I've mercilessly badgered and cajoled into brainstorming this problem!)

So... Inasmuch as shielding is unnecessary below 25kV - the mesh will be mounted in a readily removable metallic frame sized to cover the exposed area of the movement...

Again, many thanks!

Best regards
HP

 

@Aleph(0)

Thanks to your solution of the 'Faraday cage problem', I'll be moving ahead with the EHT indicator construction article within the next fortnight -- please try to bring JC on board! -- His input is especially valuable at this juncture inasmuch as he and many of his associates represent our 'target demographic' as it were... As I understand it his rally ends on Sunday? So... I'm hoping he'll be available by the following weekend (i.e. by the 19'th?)...

Very best regards
HP

 

By that am I to understand that a 'permanent' coarse strainer precedes the valve body? Or is it merely that clearances are such that a small particle is unlikely to 'pin' a valve (i.e. lodge in a port in such a way as to interfere with valve operation)?

Yes, the brass screen is the inlet filter to the front pump. There were no other filters in the Ford transmissions I worked on.
I have opened a transmission and found a trail of clutch particles leading like bread crumbs to the first pressure regulator valve in the valve body. That was the definitive reason why that transmission failed.

Wow, didn't know Ford was still using the screen. Many, many years ago(1970's?) Gm went to a resin/felt filter, when you look at the 'pan' of a GM transmission that is about the size of the filter inside of it. It is made like an 'envelope',two sided sealed on the edges and bolted to the bottom of the valve body. The way GM shift valves are made there's little chance they can get hurt by a "grain of sand" or anything else that would get into the hydraulic system. They would just pass through and land in the actuators and probably stay there.

GM automatic transmissions are pretty much fool proof, like the rest of their engines, drive trains, electronics. Back years ago when I was doing mechanical work as a second job, Ford and Chrysler products were about the only automatics I ever had to change out. GM tranys are so good many Ford powered drag racers even use them behind a Ford engine.

 

Wow, didn't know Ford was still using the screen.

I don't know either. The last time I worked on transmissions I was buying Found On Road Dead Aerostars at police towing yards, rebuilding their A4OD transmissions, and selling them for a profit. Those were probably from the 1980's.

 

Bravo! --Finally! A 'bearable' solution! You may rest assured that you have my undying gratitude

HP Tnx but sry I didn't think of it sooner cuz I didn't know some dark screens are made out of anodized Al wire instead like polymer fiber or like that! So discovery was a happy accident!

please try to bring JC on board! -- His input is especially valuable at this juncture inasmuch as he and many of his associates represent our 'target demographic' as it were...

HP Getting JC on here isn't a problem but I say getting objective opinions from him is just impossible cuz of his affection for you So I have an idea! I can get him to circulate tutorial among his electronics minded friends so we can gauge strengths and weakness of presentations by questions they ask? So I say that's better than just soliciting comments cuz some ppl feel like that's putting them on the spot.

As I understand it his rally ends on Sunday? So... I'm hoping he'll be available by the following weekend (i.e. by the 19'th?)...

HP that's right! Sunday the 13th! So if he follows usual itinerary he'll prolly be back Wednesday night or Thursday HP if you want I can text him for better idea of his plans?

GM automatic transmissions are pretty much fool proof, like the rest of their engines, drive trains, electronics.

shortbus I don't know vry much abt US domestic cars but I totally agree abt high quality of GM cuz I know from first hand experience that GM V6 motors run for like 400K miles!

Found On Road Dead

#12 LOL! I thought it was Full Of Repairs Daily! #12 being fair I say F150 is way better than Jeep for off road reliability! So just for one example F150 front axle pan is made out of 1/16" steel plate but Jeep's is just sheet metal which I say isn't good plan for off road driving!

 

HP Tnx but sry I didn't think of it sooner cuz I didn't know some dark screens are made out of anodized Al wire instead like polymer fiber or like that! So discovery was a happy accident!

No need for embarrassment! -- I had several yards of stock, knew what it was fashioned of, and blithely overlooked its 'possibilities'

So I have an idea! I can get him to circulate tutorial among his electronics minded friends so we can gauge strengths and weakness of presentations by questions they ask? So I say that's better than just soliciting comments cuz some ppl feel like that's putting them on the spot.

Excellent! --But let's get the message across that comments are welcome...

HP if you want I can text him for better idea of his plans?

No need! - Please let him enjoy his 'pilgrimage'

Best regards
HP