If you have a Toyota truck with a manual transmission with a considerable amount of miles on it, there's a good chance that you suffer from a common problem that these trucks have. Gears that pop out of gear while driving.
I have a 1996 Tacoma that I bought new. In the intervening time, I've put close to 220,000 miles on it. Around 4-5 years ago, 1st and second gear began popping out especially during warm-up. Fearing that the repair for the problem might be extremely costly, I put off the inevitable for several years.The problem grew worse until I found I was holding 3 of the 5 gears in place. After some research, I discovered that the problem is very common on these trucks and to my surprise, the fix was not only inexpensive ( $20) but easy.
In order to perform this repair, you will need a Philips head screw driver and some general purpose grease. The job takes 30 minutes. You will also need to order parts from a Toyota dealer or equivalent. The parts you need are: 1 shift lever seat and 1 shift lever cap. Bring your VIN number as there were slight variations.That's it! So here it goes.
Step 1: Removing the Shift Lever to Get Access to Shifter Seat.
First, you'll need to get at the screws that hold the rubber boot cover to the transmission tunnel. They are underneath the carpet, so you'll need to pull the carpet back a bit to get at them.The rubber boot is held down with a stamped steel retainer with four screws. Be careful not to lose the screws under the carpet or you'll have to either remove ALL the carpet or find new screws.
The steel retainer was difficult to remove from under the carpet. I had success pulling it out corner first. Once that comes out, the rubber boot easily pops out. Pull up on the boot to get it out of the way so you can get at the shift lever retainer cap. There is a rubber dust cover over the top that easily pops off.
Step 2: Removing the Shifter Lever Retainer Cap.
Then next step is to remove the shift lever retainer cap. The cap is spring loaded and the spring presses it into interlocking pins. Use a shop rag and press down and twist the cap counter-clockwise. Once twisted far enough, the cap will clear the pins and pop up as shown below.
The entire shift lever assembly will come out in one piece.On the very end is the shift lever cap made of nylon. This too will be replaced. Above that is the shifter ball. Inspect it for burrs and rough edges. If there are any, gently file or sand them down smooth. Otherwise, you'll damage the new seat.
Step 3: Inspecting, Removing the Old Seat.
Ah-ha! As suspected, the old hard rubber shift lever seat is completely worn out. Not only that, but it was actually crumbly. The reason it causes the problem of having gears pop out is because as the seat wears, this causes the spring to have less pressure in which to push downward on the shift lever, hence it more easily pops out of gear.
Remove the old seat. There is a rubber seal underneath it. Remove this as well. The new seat comes with a new seal anyway. Be careful not to get any crumbled bits of seat into the transmission. Probably not the end of the world if you do since they are generally soft. I used a vacuum to remove the bits.
Comparing the old seat to the new shows just how much wear the old seat has.
Step 4: Installing the New Seat, Cap, and Seal.
Installing is pretty much as simple as it gets. Just install the new seat and seal- seal first into the shifter socket. No special tools required. Next install the new shifter cap by popping off the old, pressing on the new. Apply a thin layer of general purpose grease on all components.
Now reverse the disassembly instructions and wallah- all done. Happy to say that the truck now shifts and drives better than it did even when new. The grand total cost was $20 and 30 minutes of time, which is a lot cheaper than paying for someone else to do it or worse- having it misdiagnosed and have to buy a new or rebuilt transmission.