Specs: 1979, F150, 4x2, 460, XLT Lariat, and an OJT mechanic..yours truely!

Alright...heres my delima:

The gentleman I bought my truck from said the transmission leaks a "little bit". What is that? 2 Cups? 2 Tblspoons?...I don't know...*L* Anyway, I know what the transmission looks like...the big funnel thing underneath by the engine...but I'm not seeing any leaks there. NEXTLY, I see only two places to pour in fluids...the oil is on the right side (as you look at the engine) and then there is this yellow lid that has a 2" dip stick on the right side but more twards the front. Is that my transmission spot? There is another dip stick on the left way at the back also...I'm assuming that is my dip for the tranny but where do I add the fluid? Nothing is labled? Why can't we have a big neon arrow blinking: "OIL!", "Tranmission Fluid here", "Cut your finger here" "Look for leaks here and here!" *L*

Serriously, all I have ever done is change the oil in my other rides but I'm trying to learn more because I'd really like to be able to restore older vehicles. I work nights mostly so any of the neighbors around here who might know something are all at work during the day when I'm working on my truck...so I have no one really to ask but ya'll. Trust me, I have a million and one (seemingly stupid) questions!

So, with all that said....where to do check the fluid level?...where do I add it?...where do I look for leaks other than beneath the machine?

 

Most Auto's fill through the Tranny dipstick tube. Usually it's the one furthest back toward the firewall of the truck. Pull it out and the fluid should be red. If it is, you got the right stick .

Take a small funnel and fill it up through the dip stick tube. Make sure to check the level while the truck is idling in park.

Most service stations will have a small funnel behind the counter if you ask them for it. They do in Canada anyway.

 

Hey Canuck Oh cool! It's red! Thats easy enough....color coded fluids! Right back through the same tube ya say? I'll be laying on the engine trying to reach it...*L*...thanks for helping me out! I'll check it today.

Any idea on possible leak points to check ya'll?

 

There are two types of leaks. Leaks that just leak, which you can see by placing newspaper under the truck overnight (wet paper indicates a leak), and the leaks that occur when the vehicle is being used.

The way to check for "moving" leaks is to pull out old towels, spray the transmission with something like WD40 or engine degreaser, and let it sit for 10 minutes. Then wipe it as clean as you can, then drive around normally and check it every so often.

You'll see tranny fluid on the top, side and bottom where things are leaking, assuming it is leaking.

Check around the perimeter of the pan, the threaded bungs and plugs, the dipstick tube where it joins the tranny case, the modulator if it's externally mounted, the shifter linkage points where they enter the transmission, and of course the rear seal where the tailshaft comes out.

 

dont worry, there ain't no such thing as stupid questions, only stupid answers. now don't listen to fred, he don't know nothin. the way to look for leaks when you are drivin is to open the door, then stick your head down under and you will see the leaks.







see?? i warned you about them stupid answers.

and as far as askin the neighbors questions, how many men do you think would answer them,
or help you fix your rig??

i bet most would not help you for fear you would show them up.

 

Yup, I'm a Maritimer(AKA canadian redneck). I agree with frederic. Check the transmission lines and pan gasket for the obvious leaks. I hear the modulator valve is a popular one. I had a leak in my Camaro that I could never find....ended up being the TV cable seal.

For anything else you will have to listen to the Ford guys. If you have any problems with a Honda or Chev, I'm MUCH more knowledgeable haha.

 

Ya'll are so freakin' smart on this stuff! I purchased some transmission fluid seal'em'up stuff today to tide me over till I find the trouble. The shifting never 'seemed' funny or hard but thats prolly because I don't know what it is supposed to feel like therefore when it is wrong, how am I to know?..*L*....anyhow...thanks again ya'll!

 

It's not that we're smart... it's that our trucks leak.

I hit 391K on the odometer a week and a half ago. Lets just say my truck reminds me of the mileage by leaking on the driveway. And the firewall. And the underside of the truck. And people behind me LMAO

 

Like Frederic, I drive a lot of old vehicles. It's not about being smart....it's more like experience. If you have enough things fall off your ride, you figure out how to put them back on by yourself because you can't afford to have someone else do it.

Heck, If I was smart I would buy something new that has a warranty haha.

 

I fix things because I'm cheap. It's also a good excuse to be "too busy" to chisel at my "honeydo list". See, I've managed to finish all the fun, or potentially fun things on the honeydo list. All that's left are the "nasty, no I don't want to do that" stuff.

Yeah, well, that's hit or miss it seems.

 

If you do not see any leaks I would not put any "seal'em'up stuff" in it.

If it is low with the engine running in park, add a little at a time, it won’t take much to bring the level up. If the fluid goes down with out seeing any leaks then more than likely you have a broken diaphragm in the modulator. The modulator is the device on the back area of the transmission with a rubber hose on it, this is a vacuum hose. It is easy to replace, pull the hose off, unscrew, screw the new one in and put the hose back on.

 

Toolgirl,,If you can't find a leak anywhere after good effort than find the modulator valve at the back of the tranny beside the pan going into the tranny housing. It's got a vacum line goin g to it. Sometimes they can start to suck tranny fluid right through that vavle via vacum house and your engine will burn it.If it's a small enough amount,then you won't have any side effects besides missing some fluid from time to time. Change valve...very easy one bolt. Nice to see some girls getting dirty instead of getting hosed from the local garage.. Good luck.

 

Heya neighbor, ToolGrrl, I see yer listed as being in OK. Good to see more of these trucks being kept on the roads. I would think the first suspect would be the trans pan and gasket. It should cost more than a few bucks for a new trans pan seal and some fresh trans fluid. I would try that first. And then properly tighten the bolts down on the pan without squishing the cork gasket into pieces. Then recheck/retighten the bolts after a few miles and then check every few weeks.

 

ToolGrrl, Common places for transmission leaks,

• Check the rear seal on transmission tail housing (just in front of the u-joint),
• check the transmission pan,
• check the transmission lines from the transmission to the radiator,
• Check the front transmission pump seal (located behind the flexplate/torque converter) will need to remove the transmission inspection plate, between the engine oil pan and transmission pan to inspect the front seal for leak.
• modular valve as 78 short stated.
• the transmission filler tube where it join the transmission housing.

Transmission oil sticks are located near engine firewall on the passenger side, just between the heater core and the valve cover, the oil stick tube is usually one (1) inch in diameter.