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727 Fluid Level

Belle66

Belle66

Well-Known Member
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Hi, I've got a vintage 1964 Torqueflite 727, rebuilt 25,000 miles ago, it has a shift kit, recently installed 5800 rpm governor, and sits behind a 2400 rpm stall PTC converter. Was a stock converter before.

The transmission will leak fluid until just at the low mark on the stick and stop leaking. Any of y'all have this happen? Is it something to be concerned about?

Also, if the car sits for a day or more, it takes a lot of rpm and some time for the converter to engage. This is something that's been going on for the 8 years I've been driving it. The converter engages normally if I've driven it recently. I recall on such me GM transmissions there's something you do to prevent the converter frm draft ing back. Might this be the case? Any of y'all have this happen. Is it something to be concerned about?
Thanks,
Joel
 
Also, if the car sits for a day or more, it takes a lot of rpm and some time for the converter to engage.

Converter drain back, 727 notorious for that. Just start your car in neutral and the pump in the transmission will work right away to fill the converter, shift it to a gear and off you go. Most shift kits fix that problem of converter drain back!!
 
Yup, I keep mine in neutral until the choke is kicked off.... I can't stop mine from leaking, only leaks after it sits for 4-5 days..when I drive it more than once a week it doesn't drip a drop!
 
I agree that the car sitting for days before next use allows the torque converter to drain back into the pan. When cars were new and being used very day, this was not a problem. The higher than designed- for fluid level also stresses the pan gasket and fill tube "o" ring, resulting in leaks. To help alleviate this problem, I install deep transmission oil pans on my 727's, but fill them with factory recommended amount of fluid. This gives the excess fluid on converter drain back somewhere to go without over filling the transmission case itself. I measure the depth of stock pan, and subtract this measurement from the depth of new deeper pan. This new measurement tells me the height of the filter extension I now need. I have found that sometimes the filter extension included with the deep pan kit does not put the filter close enough to the bottom of the pan. If filling the deep pan to the full mark on dip stick, this would not likely be a problem because you now have a couple of extra quarts of fluid in the pan.
I use my new filter extension to mark a new "FULL" mark on the dip stick. Hold the top of the extension at factory "full" mark. Mark where the bottom of the extension is on the stick, and drill a small hole as your new "FULL" mark. Repeat this procedure to mark new "ADD" position on dipstick. The factory placed the filter almost on the bottom of the pan, where a deep pan kit does not always do this. A&A Transmissions has a selection of different height filter extensions. Remember that cable shift transmissions take the 2 hole filter and extension. Using the factory A518 pan gasket with o-ringed pan bolt holes is another defender against fluid leaks. Where I live, the jobbers don't carry them and I have to buy them at Mopar parts counter.
I have tried that anti drain back valve and find that it does not really prevent drain back. It allows the torque converter to fill when running in park, which the factory shift valve does not. I found it a lot of extra work for little improvement. I always start my old Mopars in neutral and let them idle for a minute before pulling in to gear.
 
No need to start in neutral. Start in park and before moving place in N for a few seconds.
 
A characteristic of Torqueflites. Very little fluid flow while in park,hence putting it in neutral.Do it with all my old Mopar cars & truck.
Usual leaks on the pre 66 trannies it at the shift cables.Also the park cable housings are known to crack.
66-up shifter shaft seal and kick down shaft leak is common.Yep they are known to not leak at all if driven daily.When they sit and the converter drains back the fluid level raises and floods the seal. Pull the dipstick out and see how high above the full mark it is after sitting a week.You will be surprised.
 

The transmission should be at its normal temperature before checking, and the car should be on truly level ground. Apply the parking brake firmly with the engine at idle, then shift into each gear, momentarily ending in Neutral - not Park.

The fluid level should be at the full mark on the transmission dipstick, or slightly below it - definitely not above Full. If it is below the "add one pint" mark, add fluid and check the level again as per above to ensure the level is between "ADD" and "FULL".
 
Last edited:
Dave6T4 said:
I agree that the car sitting for days before next use allows the torque converter to drain back into the pan. When cars were new and being used very day, this was not a problem. The higher than designed- for fluid level also stresses the pan gasket and fill tube "o" ring, resulting in leaks. To help alleviate this problem, I install deep transmission oil pans on my 727's, but fill them with factory recommended amount of fluid. This gives the excess fluid on converter drain back somewhere to go without over filling the transmission case itself. I measure the depth of stock pan, and subtract this measurement from the depth of new deeper pan. This new measurement tells me the height of the filter extension I now need. I have found that sometimes the filter extension included with the deep pan kit does not put the filter close enough to the bottom of the pan. If filling the deep pan to the full mark on dip stick, this would not likely be a problem because you now have a couple of extra quarts of fluid in the pan.
I use my new filter extension to mark a new "FULL" mark on the dip stick. Hold the top of the extension at factory "full" mark. Mark where the bottom of the extension is on the stick, and drill a small hole as your new "FULL" mark. Repeat this procedure to mark new "ADD" position on dipstick. The factory placed the filter almost on the bottom of the pan, where a deep pan kit does not always do this. A&A Transmissions has a selection of different height filter extensions. Remember that cable shift transmissions take the 2 hole filter and extension. Using the factory A518 pan gasket with o-ringed pan bolt holes is another defender against fluid leaks. Where I live, the jobbers don't carry them and I have to buy them at Mopar parts counter.
I have tried that anti drain back valve and find that it does not really prevent drain back. It allows the torque converter to fill when running in park, which the factory shift valve does not. I found it a lot of extra work for little improvement. I always start my old Mopars in neutral and let them idle for a minute before pulling in to gear.
Click to expand...

BRILLIANT!!!
I've been having THIS problem exactly. I bought a deeper pan, shop I had to a Hagerty fire paint repair installed the pan, USING RTV!?? Isn't that a "NoNo"? So they had also put ATF+4 in it, from what Ive learned this is SYNTHETIC fluid, as with engines, synthetic say "50W"? Puts put a LOT of extra psi. Resulting in valve cover leaks Ive never had. Id beleive same goes for ATF? I drained 2 1/2 Gallons out of mine, (19 PINTS) including T.Converter...
Now its time to change the fluid, I am hoping the STP DEXRON II/MERCON fluid I bought will work fine? I know the damn pan holds 2 gallons!!
Also hoping this gasket from Global Transmission parts is as good as advertised?
A727/A518/A618/48RE "Molded Rubber", thing is 4.5mm or 1/8" thick..
Any advice greatly appreciated!
 
ATF+4 is not 50w. It has the consistency closer to water. So extra pressure ??? Dexron II/ Mercon are old school fluids and not a good as DexronVI . The new fluid types do not increase pressures but have additives that have less slippage/shudder properties. ATF+4 is totally compatible with the older 727/904 trans, Just more expensive.
Fluid level stressing the pan gasket and o-ring ? Make sure to have a good/new o-ring installed. Does your dipstick have an airtight seal when it is inserted in the tube ?? So why would there be stress on the gasket. Does the weight of the extra fluid put stress on the gasket ?? These arguments make no sense when you stop and think it thru.
You can install the molded gasket dry and tighten to 115 inch lbs per the factory service manual.
 
MoparLeo said:
ATF+4 is not 50w. It has the consistency closer to water. So extra pressure ??? Dexron II/ Mercon are old school fluids and not a good as DexronVI . The new fluid types do not increase pressures but have additives that have less slippage/shudder properties. ATF+4 is totally compatible with the older 727/904 trans, Just more expensive.
Fluid level stressing the pan gasket and o-ring ? Make sure to have a good/new o-ring installed. Does your dipstick have an airtight seal when it is inserted in the tube ?? So why would there be stress on the gasket. Does the weight of the extra fluid put stress on the gasket ?? These arguments make no sense when you stop and think it thru.
You can install the molded gasket dry and tighten to 115 inch lbs per the factory service manual.
Click to expand...

Yeah, I was comparing 50W MOTOR OIL to ATF+4, I have a 2-3/4" deep pan that a shop used RTV silicone sealant on.. Have pan off, all cleaned up with the best gasket, but not sure if I need to install a filter extension? Being that bottom of pan is 3/4" away from filter, and if only about 1/4" of dipstick extending PAST filler tube into pan is correct?

Could put all 19 pints of the ATF4 back into it I guess & hope for the best.
Thanks!
 
Does this appear to be correct, dipstick past tube? Depth?
20210602_134336.jpg
20210602_134328.jpg
 
Dave6T4 said:
I agree that the car sitting for days before next use allows the torque converter to drain back into the pan. When cars were new and being used very day, this was not a problem. The higher than designed- for fluid level also stresses the pan gasket and fill tube "o" ring, resulting in leaks. To help alleviate this problem, I install deep transmission oil pans on my 727's, but fill them with factory recommended amount of fluid. This gives the excess fluid on converter drain back somewhere to go without over filling the transmission case itself. I measure the depth of stock pan, and subtract this measurement from the depth of new deeper pan. This new measurement tells me the height of the filter extension I now need. I have found that sometimes the filter extension included with the deep pan kit does not put the filter close enough to the bottom of the pan. If filling the deep pan to the full mark on dip stick, this would not likely be a problem because you now have a couple of extra quarts of fluid in the pan.
I use my new filter extension to mark a new "FULL" mark on the dip stick. Hold the top of the extension at factory "full" mark. Mark where the bottom of the extension is on the stick, and drill a small hole as your new "FULL" mark. Repeat this procedure to mark new "ADD" position on dipstick. The factory placed the filter almost on the bottom of the pan, where a deep pan kit does not always do this. A&A Transmissions has a selection of different height filter extensions. Remember that cable shift transmissions take the 2 hole filter and extension. Using the factory A518 pan gasket with o-ringed pan bolt holes is another defender against fluid leaks. Where I live, the jobbers don't carry them and I have to buy them at Mopar parts counter.
I have tried that anti drain back valve and find that it does not really prevent drain back. It allows the torque converter to fill when running in park, which the factory shift valve does not. I found it a lot of extra work for little improvement. I always start my old Mopars in neutral and let them idle for a minute before pulling in to gear.
Click to expand...

Would you say this, looks to be CORRECT dipstick depth PAST tube into pan?
May just go with the ATF+4, Some are saying the Dexron II/MERCON isn't so good these days, I also have a 2 3/4" deep pan. Seems like 19 pints total out of trans was a LOT!? If so, Im guessing my "Reading" on this 18 3/4" stick may need adjusted?
My filter is about 3/4" away from bottom of pan..

Thanks a bunch!!
20210602_135632.jpg
20210602_134328.jpg
20210602_130516.jpg
20210602_130347.jpg
 
WM23M9 said:
Would you say this, looks to be CORRECT dipstick depth PAST tube into pan?
May just go with the ATF+4, Some are saying the Dexron II/MERCON isn't so good these days, I also have a 2 3/4" deep pan. Seems like 19 pints total out of trans was a LOT!? If so, Im guessing my "Reading" on this 18 3/4" stick may need adjusted?
My filter is about 3/4" away from bottom of pan..

Thanks a bunch!!
View attachment 1118787 View attachment 1118788 View attachment 1118789 View attachment 1118790
Click to expand...
If that's the stock dipstick and tube that would be correct. The full mark doesn't change because you installed a deep pan and the level is above the gasket.
 
Oh thank God! LoL
Think Id need make ANY adjustments? Say on Dipstick? Here's filter, looks like an extension?

yes, you have the filter extension
 
toolmanmike said:
If that's the stock dipstick and tube that would be correct. The full mark doesn't change because you installed a deep pan and the level is above the gasket.
Click to expand...

Thanks so much!!
(This is why I specialize in ELECTRICAL! LoL)
Just easier for some reason.

Thanks for ALL of EVERYONE'S help!!
 
toolmanmike said:
If that's the stock dipstick and tube that would be correct. The full mark doesn't change because you installed a deep pan and the level is above the gasket.
Click to expand...

Wow, ya know, just seems so strange, that fluid running back UP INTO tube would be correct! I guess thats the way it works! These clowns using RTV is probably where my seepage comes from..
:monkeyleft:
 
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