Transmission Dipstick Reading

[hylomatt]

Okay, I feel stupid having to ask this but I need some hand-holding, please. I cannot read the dipstick in my RV. I just finished dropping the tranny pan, replacing the filter and gasket and putting in new dexron fluid.
The service manual said 4 pints when changing fluid and that's what I initially tried. With 4 pints, it wouldn't go into gear. It might eventually go into gear but it wouldn't stay there.
I added a 5th pint and it would move but the front wheels wouldn't climb out of a small divot in the yard. After adding a 6th pint, it would go into gear and seemed to drive just fine.
So I drove it around the neighborhood, down the road a few miles and back, and then stopped to check the trans fluid while idling.
I cannot read the level on the dipstick. The fluid is too clean or maybe I'm too inexperienced with water cooled, automatic vehicles. I'm not sure why this is so hard. Thanks to how you fill the tranny, there is always fluid all the way up and down the stick. You wipe it off, put it in all the way, pull it out and read for the level. When I do this, I look at it straight on, turn it slightly so the light will reflect off the stick and fluid, and try to find a place where the fluid runs across the dipstick from left to right edges. I don't see it. I'm 6pts/3qts deep now and I don't see the level.

What am I doing wrong or not understanding about the process? I'm supposed to leave for a trip from FL to GA on Saturday morning, and this is making me worry.
Go ahead and assume that I don't know what you know. I won't take offense at the attempts to help me.

 

[pvfjr]

3 pints doesn't sound like much. Was it supposed to be 3 quarts? On most of the GM hydramatics I've had, reverse is the most sensitive to low fluid levels, and has always been a good indicator that fluid needs added. Normally adding a quart from the "slipping reverse" level will get you on the stick. Is it possible that you're not on the stick yet?

With the trans recently cycled through all gears, sitting in park on level ground, let it idle for a good while so the dipstick tube "drains down", wipe off the stick really well, then try checking it. If the fluid seems like it's coming way too far up the stick, maybe you have a venting issue. If your trans vent is clogged, it has no recourse but to vent through the dipstick tube, which can cause the fluid to bubble around. I imagine that would make it hard to get a good reading.

Also, try checking it in the dark, and try holding a very bright flashlight at different angles.

 

[hylomatt]

Well I started with 4pts/2qts and that wasn't enough. I'm up to 6pts/3qts now and it's moving but as far as I can tell, it's not even on the stick yet.

Where is this vent located? It's possible that this is the reason the stick is always spattered with oil way higher that the indicated low-high marks.

 

[gerryg]

My '78 manual says
Drain & Refill 4 Qts.
After Complete Overhaul 12 Qts

 

[hylomatt]

Oh boy, I just looked up the info again and I transposed the Transmission and Final Drive info.
My 73 manual says drain and refill 4qts, complete overhaul 12qts.
Final drive was 4pts.
Okay so this is possibly why it's not on the stick yet.
I'll get this done tomorrow morning.

 

[hylomatt]

But I do need to find and check this vent. Are we talking about a weep hole? or a valve and hose deal?

 

[hylomatt]

Looking online, I found this. It looks like #44 is the ventilator.

found here: https://nemigaparts.com/cat_spares/epc/oldsmobile/31a-e/04/gm4-2/

 

[Ken B]

You are correct. #44 On a Manny and some other rebuilt transmissions, item #44 has been removed and an elbow installed there. A hose is run from the elbow to some place low on the coach away from the exhaust. Usually it is usually on the bottom of the frame away from the exhaust pipe. A few people have even installed a catch can there. The reason for this is fire prevention in case it ever blows trans fluid out of the vent.

 

[LarryW]

How much did you take out of the transmission? Measure it. that should give you a pretty good idea how much to start with. You say you used Dextron fluid. The fluid you took out should be red in color, maybe tinted darker.red showing the contamination. (normal) New fluid is pink/red in color and should be readable on the stick. Are you checking fluid out the front hatch on the drivers side or under the hatch between the drivers and passenger seat? Sounds to me like you have not put in enough fluid to touch the stick. If it does not read on the stick (clearly pink) add another quart. A pint low cold is roughly full hot. I add to the full mark cold when doing a fluid change. I have found that driving it a while will "burp" some air out and with the expansion, turns out to be full hot. A little over full is not critical. Another way to tell if fluid level is correct is, when on a level surface, run the engine, shut it off and immediately remove the vacuum modulator. If fluid does not come out, you need to add fluid. Correct fluid level is when fluid is barely leaking out of the modulator hole. JWID

 

[Ken B]

Okay, I feel stupid having to ask this but I need some hand-holding, please. I cannot read the dipstick in my RV. I just finished dropping the tranny pan, replacing the filter and gasket and putting in new dexron fluid.
The service manual said 4 pints when changing fluid and that's what I initially tried. With 4 pints, it wouldn't go into gear. It might eventually go into gear but it wouldn't stay there.
I added a 5th pint and it would move but the front wheels wouldn't climb out of a small divot in the yard. After adding a 6th pint, it would go into gear and seemed to drive just fine.
So I drove it around the neighborhood, down the road a few miles and back, and then stopped to check the trans fluid while idling.
I cannot read the level on the dipstick. The fluid is too clean or maybe I'm too inexperienced with water cooled, automatic vehicles. I'm not sure why this is so hard. Thanks to how you fill the tranny, there is always fluid all the way up and down the stick. You wipe it off, put it in all the way, pull it out and read for the level. When I do this, I look at it straight on, turn it slightly so the light will reflect off the stick and fluid, and try to find a place where the fluid runs across the dipstick from left to right edges. I don't see it. I'm 6pts/3qts deep now and I don't see the level.

What am I doing wrong or not understanding about the process? I'm supposed to leave for a trip from FL to GA on Saturday morning, and this is making me worry.
Go ahead and assume that I don't know what you know. I won't take offense at the attempts to help me.

First of all that amount is quarts, not pints. Second that is a starting point because the torque converter leak down rate will add even more to the amount of fluid you really drained. Torque converter leak down is the reason they tell you to read the level with th engine running at an idle. You can do it with the engine stopped if you read the level immediately after you turn the engine off. It is a real pain trying to read new clean fluid on that stick. I bead blasted the lower few inches of the stick to give it a rough surface. With the shine gone it is a little easier to read. The other thing you can do is take a dry paper towel or kleenex and lay the end of the stick across it. You will see the oil level transfer to the towel.

 

[hylomatt]

@LarryW I initially drained the trans because during a trip, I thought the transmission was low, couldn't read the stick, added fluid, was afraid that I had added too much, so I decided to do the service and drain and replace the filter and gasket. My intention was to get the level right this time.
I'm using the dipstick that is on the side of the transmission, below the cabin floor between the front seats.

 

[hylomatt]

@Ken B thanks for that confirmation on #44. Good idea on the bead blasting. I was thinking of taking a wire wheel to it to try to remove the shine. You're right about the difficulty of reading new fluid on the stick.

 

[RF_Burns]

I've always found reading the transmission dipstick is near impossible on every vehicle i've owned (and my father's too). I drilled a small hole in dipstick at the Add and Full marks. If the hole is full of fluid you know its at least at that level mark.

 

[Ken B]

I've always found reading the transmission dipstick is near impossible on every vehicle i've owned (and my father's too). I drilled a small hole in dipstick at the Add and Full marks. If the hole is full of fluid you know its at least at that level mark.

Good Idea Bruce.

I have always had a problem reading the level. I wish someone made a red die that I could add to the fluid to make it darker. Or maybe fluorescent orange or fluorescent green.

 

[RF_Burns]

Good Idea Bruce.

I have always had a problem reading the level. I wish someone made a red die that I could add to the fluid to make it darker. Or maybe fluorescent orange or fluorescent green.

Ken,
My problem is the dipstick gets smeared with fluid above the fluid level so it's near impossible to determine the fluid level.

Growing up on the farm, we had a '30s era McCormick-Deering tractor. The engine oil level was checked by opening a pet-cock on the side of the oil pan and adding oil unit oil came out, then closing it. Something like that would be more accurate considering all the tales of damage with incorrect transmission fluid levels.

I've tried removing the modular valve but fluid was draining down from everywhere!

I'm not sure why running the transmission level a bit higher is going to damage anything. From what I can see, transmission fluid is flying all over the place inside during operation.

 

[Billygoat]

Very interesting on the transmission fluid check guys. Had a simple question on the venting. If you find it might be blocked a bit what is your method of clearing it? Just run some bailing wire thru the tube? Blow air into the tube? I also have a gun cleaning kit with small wire brushes? Just curious what you guys do to clear the vent tube?

TG

 

[hylomatt]

Okay, I have another quart in the tranny now.
I also checked for the vent and the cap is loose and spins freely so it's probably good.
I need to verify the tranny and engine oil levels now.

 

[LarryW]

Again, the transmission is at the proper FULL level when, 1.) the coach is level. 2.) start and run the engine for a couple of minutes. 3.) Shut the engine off. 4.) Pull the vacuum modulator out. 5.) If fluid is flowing out, there is to much trans fluid in the transmission. 6.) Allow to flow out in a catch pan until it stops. 7.) insert the vacuum modulator. This is now the correct fluid level and is a good time to seat and calibrate the dipstick. Fluid level on the stick can be marked with a Dremel , or drill an small hole as full. 8.) if fluid does not come out of the vacuum modulator when you pull it out, there is not enough fluid in the transmission, So, add until it starts to flow out, and then calibrate your dipstick. JWID to find and calibrate my dipstick. FWIW, This procedure was established by transmission specialist Manny Trovao many years ago.

 

[Ken B]

Ken,
My problem is the dipstick gets smeared with fluid above the fluid level so it's near impossible to determine the fluid level.

Growing up on the farm, we had a '30s era McCormick-Deering tractor. The engine oil level was checked by opening a pet-cock on the side of the oil pan and adding oil unit oil came out, then closing it. Something like that would be more accurate considering all the tales of damage with incorrect transmission fluid levels.

I've tried removing the modular valve but fluid was draining down from everywhere!

I'm not sure why running the transmission level a bit higher is going to damage anything. From what I can see, transmission fluid is flying all over the place inside during operation.

I have pulled the modulator on various GMCs. Usually to check the calibration of the dip stick when I did not like what I saw when I was trying to use it. It is simple and quick except for getting under there when on the road due to clearance and with that hot exhaust pipe in the area.

You do NOT have to have the engine running when checking it that way, but you you do need to have just run it to make sure the torque converter is full. What I do is slide underneath and remove the single bolt and vacuum line. (Actually I leave the bolt in on the last thread or two.) Then run it for a while with the dip stick removed and wiped clean. Shut it off and immediately pull the modulator. If fluid runs out, I let it run. If it did not run out, I add trans fluid until it just starts to run. I go back up top and stick in the clean dipstick. There was no oil slop on it and I can check the exact level and mark the stick if it is wrong. I then reinstall the modulator.

Time for another Ken Story.

I was in Northern California. I had flown in for a rally and had a non-refundable return tickets. While there, I let someone talk me into moving a coach back east in late fall. This was suppose to be a "perfect" coach. This coach had a remote dipstick mod on it so you could check the trans level up front under the hood. On the first fuel stop I checked it and the fluid was off the stick - low . It took almost 2 quarts to fill it up It took almost 2 quarts to fill it up to level again on the second stop.

The heater fan was squealing and finally locked up when I was near Fallon, Nevada. So it was a quick run into Auto Zone in Fallen to get another one and install it in the parking lot.

At the third stop for fuel the trans stick again showed fluid missing. It was time to find out where it was leaking. Further investigation showed trans fluid blown everywhere . It was impossible to see where it was coming from. I finally called Manny. Manny said "Did you pull the modulator and check the level?: NO.

I found a parking lot at an abandoned large store that had curbs and pulled the coach front wheels up on the curb for more clearance underneath. Upon pulling the modulator the fluid came gushing out like what you would get draining hot engine oil.
I scurried out of there to keep from laying in it. When it finally stopped there was puddle in the parking lot about 10 feet in diameter and the dip stick read nothing. I was not going to lay in that stuff to reinstall the modulator , so I started it up and moved the coach to a dry spot and reinstalled the modulator. Started the coach and went on my way. The coach ran fine and 2 days later I pulled the modulator again. The fluid level was just fine. I told the owner when I got there that he was going to have to replace that dipstick. I never heard from him about it again. I got chased by a snow storm all the way across Utah and Wyoming and drove one day for 22 hours to stay ahead and away from it. Other that the trip was uneventful.

Ken B.

 

[tmsnyder]

<< I add trans fluid until it just starts to run. I go back up top and stick in the clean dipstick. There was no oil slop on it and I can check the exact level and mark the stick if it is wrong. I then reinstall the modulator.>>

Except after adding fluid (through the dipstick tube) it's impossible to get a good reading b/c residual fluid in the tube gets all over the dipstick on its way in and out. Might have to check it the next day after firing it up and letting it warm up again.