How do you replace the transmission in a Geo Metro?

Answer 1

Replacing the transmission can be difficult if you're inexperienced or lacking the proper tools. I recently replaced my own on a '97 3 cylinder 5 speed. Mind you, this quick guide will explain how to remove a manual transmission.

Make sure you are working on a clean, concrete surface since you will be lying directly on your back with no room for a creeper. The first thing you need to do is jack up the driver side front until the tire is at least 4" off the ground and place a jack-stand securely under the frame. Shake the car a little to assure that it's being held up securely as you don't want it falling on you.

Start off under the hood and:

• Remove battery (2 10MM nuts)
• Remove battery tray (3 14MM bolts)
• Remove the speedometer cable (remove clip and pull)
• Remove clutch cable (14MM nut)
• Remove clutch cable bracket (2 12MM bolts)
• Unplug reverse light connector
• Remove ground cable and clean it (14MM bolt)

Next thing is to get to the axle shaft removed.

• Drain the transmission (3/8 ratchet)
• Remove the LF tire (4 19MM)
• Remove the brake caliper and pads (12 MM)
• Remove the axle nut with a impact wrench (1 1/4 nut)
• Push in axle shaft to see if it's free

Remove the lower ball joint pinch bolt (14 MM bolt). Use a chisel to spread the pinch area and pound down on the control area to separate. Pull the complete knuckle outwards and push axle through until free. Use a prybar and pop out the axle shaft and set aside.

Now it is time to get under the car and here is where all the fun starts. First thing is to place a floor jack with a block of wood under the oil pan to support the engine. If you are lucky enough to have an engine sling, then use it. Jack the engine/trans assembly up slightly to take tension off the mounts.

Directly behind the trans under the car, you will find the shift rod linkage and the brace. These may look like ordinary bolts and nuts, but I found they can actually be fairly tricky. These are actually pins going through a bushing and if they are seized up, use lots of penetrating oil (PB Blaster) and strike the housing part (eye) many times with a hammer to break up the rust. The shift rod link is a double joint and you can take it off from either location. Heat is not recommended and don't try whacking the threaded side with a hammer unless you have a nut on it flush.

Now it's time to remove the actual transmission.

Get back under the shift linkage and directly above it, you will see the rear mount from the firewall to the trans.

• Remove the 2 lower nuts from mount (2 14MM)
• Remove the bushing bolt and nut and remove that bracket piece (14 MM)
• Remove the trans mount bolts and remove from trans (3 14MM)
• Use the floor jack holding engine to help you.
• While there, remove the one bell housing nut below starter (14 MM nut)
• Get out of there and remove the rear brace where battery was (3 14MM bolts)

Before removing the rest, look on the steel coolant tube and remove the bolt going to the trans case. It's easy to miss this and you don't want to break that tube.

• Under the car: remove bell housing flywheel plate (2 10 MM bolts)
• From the top of the car: remove the starter (2 12 MM bolts)
• Make sure you removed the bell housing nut under starter on earlier step (14 MM)
• Remove 3 remaining bell housing bolts (3 14 MM)

Lean over the car and grab the trans and begin carefully wiggling it loose from the engine. Use a pry-bar to help pry away from block. Stop part way out and go back under the car and pop the other (right) axle shaft. Finish yanking and carefully set it on the ground or get help from someone if you are not all that strong (like me). The transmission (depending on what kind) weighs about 60 - 70 lbs.

Now in step #1 I mentioned jacking the car so the tire is at least 4" off the ground. If you didn't, the trans won't clear and you will have the engine on a piece of wood and be attempting to raise the car. It'll be difficult.

Getting the new one back in is essentially the same thing, in reverse. Make sure your clutch, pressure plate, pilot bearing, flywheel, etc are lined up properly (most clutch kits come with an alignment tool, if you're going to be replacing that as well). If they aren't, you'll never get the splines to line up properly and transmission won't slide on. The hardest part of the job (for me anyway) is getting the that spline aligned. Once you have it lined up correctly, the trans should slide on like butter.

Get the transmission back in and make sure you still have something helping to support it and the engine's weight. Start bolting the mounts back on, hook up the shift linkage, the starter, axles, etc. Getting the clutch cable back on properly can sometimes be a pain too. When you get to that part, get inside the car and look at your clutch petal. Underneath (and behind) the petal, there's a hook, which you'll have to feel for, that the clutch cable loops over. Make sure the cable is attached. You may need someone to hold it in place while you bolt the cable back onto the transmission as you'll be pulling it towards you. The clutch can easily be adjusted by tightening (or loosening) the nut at the end of the cable (the one facing the radiator). If you have an automatic transmission, this won't be a problem.

Don't forgot the fill up your fluids again! You may have opted to drain the radiator too depending on what else you might have removed for easier access to the transmission. Top off your coolant and Transmission Fluid. The trans should take about 2 and a half quarts. Penzoil or GM Synchromesh are preferred.

Pop your tires back on, hook the battery back up and you should be good to go!