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I would like to flush my transmission but I can't seem to find the drain plug anywhere. I have a 1978 f100 4.9l 300 inline 6. The transmission it is has is the 3 speed synchromesh. I read on another forum that it may not come with one.
I was able to find the fill plug without any issues. Hoprfully ,the fine people here on FTE can shed some light on where I might be able to find the darn thing or confirm that it is in fact, a transmission without a drain
When I changed the fluid on my 3 speed manual trans, there were 5 bolts that held the tail housing to the gearbox. The 5th bolt is at the very bottom and when removed allows at least most of the fluid to drain. It’s the one pictured that’s close to the trans crossmember. Have a large pan ready because it will likely drip from that crossmember.
It's not that bad if you have a good sized catch basin. Just loosen the bolts in such a way that the rear of the pan drops lower than the front. Eventually remove the rear bolts. Most of the fluid can be removed this way, then just gently drop the entire pan. I used a large piece of cardboard under everything to catch any drips or overflow.
I was planning to add a drain plug but after seeing how relatively easy it was I didn't bother.
There's a good chance that there is no drain plug. Ford wisdom !
Draining the oil will mean loosening bolts, tilting the pan, and letting the oil pour out into a container. Not a nice job.
Originally Posted by CelticOne
It's not that bad if you have a good sized catch basin. Just loosen the bolts in such a way that the rear of the pan drops lower than the front. Eventually remove the rear bolts. Most of the fluid can be removed this way, then just gently drop the entire pan.
He has a manual transmission. There is no pan.
There is a drain plug somewhere. I don't know those transmissions well enough to tell you where it would be.
Just do the bottom, it's lowest point. No drain, Ford must have save like 4 cents by not drilling, tapping and a plug. It made it past warranty over 35 years ago they knew they didn't need to drain.
Notamechanic253,
I just checked for my RB 435 (4 speed) manual transmission on a document I have at work on my computer, because I changed the gear oil (GO 80/90W) about a year and half ago and it took 7 Pints. Can't imagine your three speed would too much more or less. You could pick up four (4) each quart bottles and return any un-opened quart bottles.
My Haynes manual says that for a ford 3 speed manual transmission (called a ford 3.03 or toploader 3 speed) 3 on the tree takes 3.5 pints. I’m assuming that’s the trans you have and is the trans I pictured in my above post. Buy 2 quarts of gear oil and it’s good to go. Fill it until oil starts to spill back out of the fill hole close it up and call it a day. Haynes manual recommends 140W oil (Ford no. ESO-M2C83-C) in all manual transmissions and transfer cases. It lists no ford manual trans that takes more than 8 pints
