A good friend of mine called me a couple of weeks ago, worried about her ’92 Toyota truck. The transmission was acting up. She couldn’t shift it into or out of gear. But only after she’d been driving it for awhile.
I had a good feeling about what was probably wrong with her truck’s transmission because my gut (and experience) told me there probably wasn’t anything wrong with the transmission.
I suspected there was something wrong with what was in the transmission. Or rather, what wasn’t in it or perhaps not enough of it.
Gear lube.
The fact that the transmission only acted up after she’d driven it for awhile suggested the hard-shifting was the result of increased friction, caused by increased heat, caused by not enough gear lube to keep things meshing smoothly. And sure enough and luckily enough when I removed the upper fill plug, nothing dribbled out.
It’s supposed to dribble a little if there’s enough lube in the box. You should at least be able to feel some on your finger if you stick it in the hole. I did, and my finger came out dry.
Uh-oh.
I could have just topped it off, but that would have left whatever much-abused (overheated) lube was still in the transmission. It would be like not changing the oil filter when you change the engine oil— only worse because most manual transmissions do not have filters at all. So if you leave old, burned-up lube in the box, it, and all the fine metal shavings, will blend with the fresh lube and circulate freely, probably shortening the transmission’s life.
Besides, I was curious to see what the remaining fluid looked like. So I removed the drain plug and found out.
A couple of pints out of the eight that should have been in there poured out like Dickenesian gruel only I didn’t say, “Please, sir — may I have some more?”
The stuff was dark brown verging on black probably because it had been cooked. I let it drain until nothing remained, saving the ugly pool of goo to show the truck’s owner.
Then I added eight pints of fresh and honey-colored lube to the transmission, which I swear made purring sounds as I did so. This job, if you’ve not done it, looks tough but is mostly just messy.
It’s easier if you use a hand pump to transfer the lube from the bottle it comes in to the transmission. Or you can use AMSOIL which comes in a clever squeeze bag which eliminates the need for the hand pump.
If you haven’t got a pump and don’t use AMSOIL, you can use a section of flexible rubber fuel hose to feed the lube into the fill hole from the plastic bottle most other brands of gear lube come in. Cut a length of line to suit, put one end on the bottle’s entrance and the other in the hold and squeeze!
This takes longer, but it’ll git ‘er done.
Be sure to fill until the transmission dribbles. Make sure you’re not getting a false positive. Wipe the area outside the fill hole clean to make sure. If a little lube is seeping from the hole, you’ve filled it. Now install the plug, being careful not to overtighten it. Most transmission cases are made of aluminum, and if you want a problem that’s not easily fixed, you don’t want to crack the case. A little more than hand tight is usually just about right.
I lowered the truck and started her up. But I didn’t drive her—not just yet.
I let it idle in neutral for a couple of minutes (clutch out) to give the fresh lube a chance to circulate and deliver some much-needed lubrication to those parched synchros and gears. Then, muttering a prayer to the Motor Gods, I put her in first, let out the clutch, and took her for a drive.
No trouble shifting into second, third, fourth or fifth either.
After half an hour, I smiled, knowing my friend would not need a new transmission. This repair was really just maintenance and only cost my friend about $60 for the lube and a home-cooked dinner for me.
Not $2,000 for a new transmission.
But it could have cost her that if she hadn’t called me (or someone) to check. Small and easily remedied things of this nature can become big and expensive things when not remedied in good time. If she’d run that transmission 60 percent empty for much longer, 60 dollars and a home-cooked dinner would not have fixed it.
It’s analogous to paying attention and doing something about a weird-looking mole on your body before it becomes more than just a weird-looking mole.
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