Same old question: Tranny fluid?

[Ambush]

Okay friends ...merry Christmas first of all to the forum members. But here's my dealio. I need to add some transmission fluid to my 1965 Imperial Crown. It is the original motor ( no rebuilds ) and has 90+ thou mileage to date. From what I've read Dexron III, or Mopar ATF+4 are both good modern equivalents for the AQ-ATF suffix"A" (Type A -suffix A ) fluid the manual calls for. Now this may be a dumb question; but aren't these 2 equivalent fluids synthetics? Wouldn't the original type-A fluid used back in '65 been a conventional type ( minerial oil based or something ) rather than a synthetic? Maybe they were using synthetics back then, but I don't know.

So for an original 413 motor w/ 90+ miles on it ...what would be the best ATF to use? Is there any non-synthetics still out there that would be a good choice in my case ...or are the synthetics okay to use? I'm a bit of a purest w/ these cars - try to stick to the original Chrysler engenneers guidelines where possible. They kinda knew what they were doing

Thanks.

 

[USSMOPAR]

 

[CBODY67]

Dexron III is still "dino", Dexron VI is syn. ATF+4 is part-syn, I believe, but not full-syn?

Chrysler changed its prior Typa A Suffix A fluid to the first Dexron in 1967 or 1968.

Dexron III is now terned "Type III" by ACDelco. On other brands, it is "Multi-Make", but dialogue on the bottle states the primary vehicles it can be used in are GM vehicles prior to the Dexron VI spec.

Not getting in to a "what's the best fluid", just "equivalent fluid" comments.

Considering the Chrysler 3-spd automatics had no lock clutch torque converters back then, any fluid will work. As things have evolved, better additive packages in the normal Dexron fluids have become better than back then. In many respects, anything more can be over-kill for what is actually needed.

Any full-syn or syn-blend fluid can make the existing stuff inside last longer, but if the old fluid has got things this far along, a fresh change to new DexronIII should keep it going quite a bit longer. Just my observations.

IF doing a full rebuild, then you might want to consider going to full-syn DexronVI or similar. That way, any internal seals/bushings will have 100% of their life ahead of them and protecting that with full-syn atf can help them last longer than that.

You can always usually tell if the fluid is dino or full-syn by the price of it. Seeing that difference, normal Dexron III can be just fine. Just change it every 40K miles or so if not trailering anything.

Hope this might help,
Happy Holidays,
CBODY67

 

[RemCharger]

Dex lll

 

[bronze turbine]

You can put just about anything in a TF and it will work, as long as it's compatible with what's already in it. I think what you want is the cheapest universal ATF fluid you can buy at your local service station.

 

[bronze turbine]

But yes, Dexron III, generally speaking.

 

[Ambush]

Never can learn too much on this topic ....great info, thanks guys

 

[Just Carbs]

The synthetics don't burnup as fast. So, you probably won't have to change it if you manage to overheat the car.

 

[cbarge]

Speaking from experience..ATF4 is more expensive and when travelling not all gas stations or truck stops carry it.
I had a 904 rebuilt and used ATF4 in it.
It leaked and drank that synthetic schit.
Yes it gave crisp shifts but the 318 Coronet was no muscle car either
I rebuilt my 68 Newport 727 with a light stall and shift kit and use el cheapo Dexron III. Need a top up? No problem buying it anywhere and no leaks.
So if you are just doing a " service" Dexron III with a bottle of Lucas trans conditioner.
Adjust the bands and yer golden.
Hope this helps.

 

[Ambush]

So I started this thread because after performing a check w/ the car hot. I found I needed to add more fluid according to my dipstick readings, which had the fluid level very low ...at the very tip of the dipstick, about the length of a pencil eraser. Looking at the feedback here, I went and got some Dex III to add. But a strange thing happened when I started to do the job.

Now if anyone is familiar w/ the operation manual for a 1965 Imperial, it states there are 2 ways to check the ATF level ...
1: When the car is at operating temps and after going through the gears, & stopping in Neutral, etc... If you check it this way, the manual says it should read at the "FULL" mark, or just below.
2: When the car is cold. If you check it this way the reading should be at the "Add A Pint" mark or just below. (Note- the "Add A Pint" mark is lower on the dipstick than the "FULL" mark )

Keeping this in mind, here's the strange thing that I saw when I was going to add some fluid. The car was cold, I pulled out the stick and cleaned it. Just to get my bearings I put it back in to get a proper reading. Now since I was WAY low when I checked the tranny fluid when the car was hot, I fully expected the reading I'd see checking it cold would show WAY below where the manual says it should be for a cold car check ( which would be far below the "Add A Pint" mark, and maybe not even show up at all on the dipstick). But what I got instead was the opposite. The fluid level reading was WAY past and above not just the "Add A Pint" mark, but past the "FULL" mark. And not just a little above the "FULL" mark, we're talking about 1inch above the mark. This is crazy. I can't figure why this is measuring this way.

Basically I don't know which reading is right. Which do I believe? The test showing the fluid very low, with the car hot. OR the test with the car cold, showing there's way too much fluid in the car. Has anyone seen this before? What am I missing here, why would the tests for a hot engine vs a cold one be so opposite? Regardless the only other indication that the fluid may in fact be low is the car has been shifting sluggishly and rougher than before, and a bit more noisy too ... But if it is indeed low, with the odd readings I'm getting on the dipstick, how can I be sure what amount of fluid to add, and know how to gauge that I've added the right amount? I mean if one has to relay on the dipstick to check that they don't add too much, etc... and the dipstick shows unreliable readings ...then what? This should be so cut and dry... uhhgg!

BTW- I've checked the dipstick itself and it looks in great shape, and nothing odd about the down-tube that this dipstick rest in either ...they both look fine.

 

[Dan Scully]

Out of stock at the moment, but cheapest I have found.

https://www.lowes.com/pd/MAG-1-Mag-1-Auto-Trans-Fluid-Dex-Mer-2-5-Gal/5001933159

 

[CBODY67]

When cold, how much run time had happened before you checked the level? Did you cycle the selector through the gears as the other method mentions?

Reason? Torque converter drain-back with engine stopped. Line pressure in "P" is much lower than in "N", which also relates to "lube pressure" and fluid flow rate.

The vehicle is on level ground when you are making these checks?

Just curious,
CBODY67

 

[Just Carbs]

So I started this thread because after performing a check w/ the car hot. I found I needed to add more fluid according to my dipstick readings, which had the fluid level very low ...at the very tip of the dipstick, about the length of a pencil eraser. Looking at the feedback here, I went and got some Dex III to add. But a strange thing happened when I started to do the job.

Now if anyone is familiar w/ the operation manual for a 1965 Imperial, it states there are 2 ways to check the ATF level ...
1: When the car is at operating temps and after going through the gears, & stopping in Neutral, etc... If you check it this way, the manual says it should read at the "FULL" mark, or just below.
2: When the car is cold. If you check it this way the reading should be at the "Add A Pint" mark or just below. (Note- the "Add A Pint" mark is lower on the dipstick than the "FULL" mark )

Keeping this in mind, here's the strange thing that I saw when I was going to add some fluid. The car was cold, I pulled out the stick and cleaned it. Just to get my bearings I put it back in to get a proper reading. Now since I was WAY low when I checked the tranny fluid when the car was hot, I fully expected the reading I'd see checking it cold would show WAY below where the manual says it should be for a cold car check ( which would be far below the "Add A Pint" mark, and maybe not even show up at all on the dipstick). But what I got instead was the opposite. The fluid level reading was WAY past and above not just the "Add A Pint" mark, but past the "FULL" mark. And not just a little above the "FULL" mark, we're talking about 1inch above the mark. This is crazy. I can't figure why this is measuring this way.

Basically I don't know which reading is right. Which do I believe? The test showing the fluid very low, with the car hot. OR the test with the car cold, showing there's way too much fluid in the car. Has anyone seen this before? What am I missing here, why would the tests for a hot engine vs a cold one be so opposite? Regardless the only other indication that the fluid may in fact be low is the car has been shifting sluggishly and rougher than before, and a bit more noisy too ... But if it is indeed low, with the odd readings I'm getting on the dipstick, how can I be sure what amount of fluid to add, and know how to gauge that I've added the right amount? I mean if one has to relay on the dipstick to check that they don't add too much, etc... and the dipstick shows unreliable readings ...then what? This should be so cut and dry... uhhgg!

BTW- I've checked the dipstick itself and it looks in great shape, and nothing odd about the down-tube that this dipstick rest in either ...they both look fine.

There is a reason for the anomalies when checking your fluid level and you will figure it out.

On the subject of what fluid to use, adding even a small amount of ATF+4 to a trans that has old fluid in it can have a very beneficial effect.

I suggest that you consider pumping out 4 quarts of the old fluid through the dipstick tube and adding 4 quarts of ATF+4.

 

[Ambush]

When cold, how much run time had happened before you checked the level? Did you cycle the selector through the gears as the other method mentions?

Reason? Torque converter drain-back with engine stopped. Line pressure in "P" is much lower than in "N", which also relates to "lube pressure" and fluid flow rate.

The vehicle is on level ground when you are making these checks?

Just curious,
CBODY67

So I first checked it on 12/22 when engine was at warm operating temperature ( level ground) and I cycled through the gears, stopping in "N" and leaving it there as I checked. That's when I got the very low readings. I immediately checked it a number of times after that, (same day ) just to be sure it was right and consistent..which it was, always showing very low.
I did the "cold" check today 12/24, also on level ground, and got the readings showing about an 1 inch above the "Full" mark. I also checked it a few times today and it was consistently above the "Full" mark. I did not initially cycle through the gears, since the car is not running, for the cold check. But later I did cycle through them ( with the car NOT running) , leaving it in "N" for the cold check ...didn't change anything ...still showing way too much fluid.

If I'm low, as the warm check constantly indicates that I am, why is the "cold" check not reading the same ...but instead is constantly reading that I'm over filled? I've got to be missing something. If in the end we get this figured out, and I do actually need to add fluid ...am I to do so w/ the engine warm ( car running) or cold ( car not running )? ...Right now cold is telling me not to add, but to drain.

 

[Just Carbs]

Engine running in neutral after going through all the gears with the engine running is all I can tell you.

 

[bronze turbine]

You answered your own question. Reread your manual. Literally. Based on your description of what you did, your results are exactly as would be expected.

 

[CBODY67]

"Engine not running" is the KEY. For the oil pumps in the transmission to work, the engine has to be running. The intent is to check fluid level with the engine running, not stopped. Therefore, with the engine stopped, the "putting the selector is each gear position" is meaningless as there is no fluid flow into those circuits.

In the car's engine, with the crankshaft turning just above where the oil is, no way to get a good check on oil level. In an automatic transmission, not that way. So the engine checks with "engine stopped" and the automatic transmission checks with "engine running".

Typically, atf temperature parallels engine coolant temperature. BUT that temp does not mean the transmission itself is fully up to operating temperature. Hence, a 10 mile drive on the freeway/highway can help ensure everything is "up to temp". ONCE you have the level where it needs to be, THEN you can maybe you can read the "engine not running" atf level for what it really is. BUT only after the car has been inop overnight and the torque converter has drained-back as much fluid as it normally does.

Happy Holidays!
CBODY67

 

[Ambush]

I see ... when the manual says what it does about the "cold check" it doesn't mean the car motor is not running and these are the results you should see, etc... it's just means IF for some reason you have to check the levels BEFORE the motor has reached normal operating temp, and is still considered "cold", then you will get the "cold temp" readings lower on the dipstick as described in the manual. I think I have it, by George ...and if that's is right, I will say then that the check I did when I got home after driving that day for a half-hour, was accurate, and I am low.

One last thing when I add the fluid, I will need to do so with the motor running, and in neutral to accurately gauge on the stick when I've added enough ...Yes? Thanks for everyone's patience, now I know what a "dipstick" feels like.

Happy Christmas to all.

 

[CBODY67]

Yes, all atf checks and adds should be done with the engine running.

Merry Christmas!

 

[bronze turbine]

You can add it with the engine running but I wouldn't because it's just easier without all the wind from the fan and the heat from the manifolds. If you are seeing a little drop on the bottom of the dipstick add 1/2 quart, then check it again after driving it. After a while you get a feel for how much you need to add to bring it right to the full mark. But always check it with the engine running, lever in N.