78 hilux 5 speed manual. I would like to change the transmission fluid. I have never done it since I bought the truck. I have some questions for those that have done it.
What type of fluid?
Does the truck have to be level? Mine is really low I wont fit under it to unscrew the drain plug.
Is there a dip stick or a some sort of level check?
Where is the drain plug and where is the fill whole?

 

you are gonna need to get the truck up on ramps or something to get it elevated so you can get under it.
No dip sticks on manuals
drain plug is on the bottom of the transmission.
Fill plug is on the side of the transmission, fill till it starts it level with the fill plug.
Time to get dirty

 

If it's difficult for you to get to it may be worth paying a shop to do it. Apart from fluid, it shouldn't take any longer or cost much more than an oil change.
It is a simple enough task for any amateur mechanic. But it's a job that is made possible by having the transmission above you and generally, yes, on level ground.

Remove the fill plug (big bolt on the side) before you remove the drain plug (big bolt on the bottom) in case your fill plug is seized in there and you drain it without being able to refill it.
Look through your old fluid for metal or shiny brass flakes just so that you lose more sleep at night.

Adding fluid back in, you'll have to pump it in there with one of those big detergent-hand-pumper bottles or typically you can remove the shifter and pour in through the top. I'm not sure that works for every manual trans.
I used Redline MT-90 but any manual transmission fluid that's formulated to help condition brass synchros should do the job. Fill until it runs out the big hole on the side of the transmission.

 

I don't ft under my pickup (any longer, I got fatter ), but I can reach under, laying on my back, far enough to get a socket on both bolts. Pull the fill first always, like was said, in case it's seized. You CAN fill a manual trans from the shifter, but how will you know when it has the right amount of fluid in? I have a small impact driver that runs off the battery, and it works great to get the bolts broken loose without trashing them, or the threads. Plenty of room to work under there, just have to reach a little.

I've always used just regular, average, everyday tranny fluid in them. When I lived in Yuma, Az, I used straight 90 weight, cause it's friggen HOT there. Now I'm in Oregon, I use the 70w-90. I believe, and I may be wrong, or have this bass-ackwards, but you want GL-5 for the tranny, and the GL-4 for the pumpkins, but I might well have that reversed. I'm sure someone will tell me if I'm wrong. Great community.

I change mine at no more than 50,000 miles, but you can sooner if you drive under harsh conditions. Dirty/dusty, like it was in Yuma (nasty, miserable place!), or lotsa water/snow/mud. If you go through any water that might get in through the breathers, CHANGE THE OIL! Very important.

While you're under there, if your driveshaft's U-joints have the zerts for it, may as well grease them up. I do my 4Runner's u-joints, and the double cardan, not less than once a year. If we get a lot of snow, or slush, I do them every few trips. It's worked so far. The Runner still has the factory u-joints, and double cardan, in it. Pretty impressive.
The u-joints and so on, only had small little bolts in the holes where the grease goes. I put zerts in them as soon as I bought it. There's more places for them than you might think.

Good luck!
Pat☺

 

Thanks guys this is great stuff. I will see what I can do about getting the truck high enough.

 

You can use the jack that comes with the truck, jack up one side, put a jack stand under there, jack up the other side, put a jack stand under there. The truck is lifted up.
I picked up a hydraulic jack. I'm lazy, and they're easier to use

Just lifting up the front end is quite sufficient. The oil will drain nicely, and the amount you need to fill 'er up is unchanged. Maybe a little difference, but nothing major.
Having said that, if you only jack up one side, the amount to fill it will be increased. Not what you want. Jack up both sides, so the whole front end is lifted.

You should always use jack stands any time the truck is up at all. It's a safety thing. Do NOT trust the jack alone. Never try to get under the truck if it's up on the jack. Put a jack stand under before you go for anything else. Let the weight of the truck down onto the jack stand. You don't have to pull the jack out, if you don't want to. Just lower it a ways, so all the weight is on the jack stand. Then, when you're ready to take it down again, just reverse the procedure.

Easy as pie. Or cake, if you prefer.

 

@2ToyGuy Thanks man, I appreciate your concern for my safety. My truck is supper slammed I scrape lane reflectors. My plan was to jack up the truck and put a 4x4 under each tire, that would get me 4" off the ground plus what ever height the truck has it would be enough for me to slide the pan and my fat a$$ under to reach the bolt.

I also own a hydraulic jack, and stands, the hand cranking jacks are a joke and so flimsy. Was always so scared of using those on the side of the road when I had a flat tire.

 

Toyota uses 75-90 gl5 typically. Your trans, do not just start pulling plugs that look like drain plugs. You might lose a detent for the shift rails.

 

I've used the Toyota, crank up jack, a number of times. I don't have a cover of any sort on the bed of the pickup any longer, so I leave the hydraulic jack in the 4Runner. Gotten a few flats over the last 30 some years
The Toyota jack does the job nicely, but it does seem flimsy. I do keep a jackstand in the pickup for safety reasons. Any work I do, I do at home, so I have several jackstands.
I only need to get the truck up a few inches, and I can fit most of the way under, from one side or the other. Far enough to reach most of the "stuff" under the truck. Drain plugs, filler plugs, drive line bolts, etc. Thank you for long arms

If you're going to put it up on a piece of 4X4, and it would be better to use two per wheel, make certain you not only set the parking brake, and put it in gear, to prevent movement of any kind, but make yourself a pair of wheel chocks. Take a piece of 4X4, and cut it in half so the you get two triangular pieces of wood, and jam them in good and tight under the rear tires. Wheel chocks are also available from places like Harbor Freight, and most auto parts stores, but I'm cheap. Once you make your own, you can toss them in the back, behind a seat, whatever.
I always chock the wheels, whether I'm working on the front or back of the truck. Like they say on Dirty Jobs, "Safety third!"

Have fun!
Pat☺

 

No GL5 oil in a manual transmission, it'll eat yellow metals. GL4 oil ONLY!