Well crap.
If you don't know much about cars, know this: Popping out of gear means a lot of money or time is about to be spent. Okay, that or a few bucks for a bungie cord to keep that sucker in position. Of course, me being fresh off of doing all sorts of cool stuff to this car I figure "how bad can it be to rebuild a transmission?"
Step 1 - Make Damn Sure It's The Transmission
On these cars, the shifter actuates a linkage that does the actual shifting in the gearbox. The bottom of the shifter sets in a little plastic bushing. If that bushing is worn it won't move the linkage enough to shift. So, step one: inspect the bushing.
Somewhere in this little puddle of goo...
Pump out the old oil, remove the busted bushing, install your shiny new bushing, put the shifter back in and go drive.
The End!
Step 2 - Damn, It's The Transmission...
Now that replacing that bushing didn't work, it's time to get dirty.
First some background. The Volvo 1800S in the US came with Volvo's M41 transmission. This is a four speed gearbox mated to an electronically controlled hydraulic overdrive. Basically this means you shift normally from reverse up to fourth gear, but you get to press a button to shift into fifth and that is cool as hell. You know, in the figurative sense. It also means that instead of one itty bitty box that weighs a few dozen pounds, you have a combo unit that weighs in excess of 90. Not the end of the world, but not quite something a tiny nerd like me could manhandle in and out of the car.
Before we get too far into it, this is not a rebuild guide. If you use my rantings as a guide to rebuild your transmission, I will have to call CPS (Car Protective Services) and have your wrenches taken away. If you want to do this to your own Volvo, first get the Hayne's manual, then read Phil Singher's excellent primer and rebuild guide. Then take your car to a shop anyway because it's gonna take a lot of time and probably make you bleed on several occasions, not to mention you will be without your car for weeks or months because you are slow and don't know what you're doing.
On with the show. . Start by removing the transmission from the car.
(For the sake of sensitive audience members, some details of this process have been removed)
It's going to be covered in slime. Clean it before you go any further. I used simple green and a pressure washer hooked up to the hot water that was supposed to run to the washing machine. Use caution around any orifices and avoid the black plastic doohicky - this houses the overdrive solenoid and you wouldn't want to have to replace it as well. Since you'll be replacing the fluid along with all the seals and gaskets, a little water intrusion otherwise is not going to end your day (as far as I know...).
Pressure washers are magical
Good work. Now pop the top by removing the remaining five bolts on the cover. The sixth was attached to wires, you did notice that in the guides, right? Now seems like a good time to go over the basics of a manual drivetrain.
- The crankshaft connected to the flywheel
- The flywheel connected to the clutch house
- The clutch house connected to the pressure plate
- The pressure plate connected to the input shaft
- The input shaft connected to the counter shaft
- The counter shaft connected to the output shaft
- The output shaft connected to the drive shaft
- The drive shaft connected to the differential
- The differential connected to the wheel hub
- The wheel hub connected to the rubbery bits
- Now hear the word of Thor!
In other words, the engine turns the flywheel which can be connected or detached from the transmission input shaft using the clutch. The input shaft turns the counter shaft which turns the output shaft which make you go. The input, counter, and output shafts are literally bristling with gears which allows the output shaft to turn at a different rate from the input shaft, thus giving you first through fourth gears.
Open up... See what's inside...
Now that you've pulled the lid you can see the guts. The bars on top move to and fro, pushing a geared collar between two sets of gears. The one on the left is for third and fouth, the middle one is for first and second, the right hand one is for reverse. Underneath that a pile of gears.
In my case, the problem was caused by a bent shift fork. They really shouldn't bend unless you're doing bad things. Who knows, maybe the prior owner was doing bad things. Hard to tell from the pic here, but the one on the right was the original fork and had a noticeable bend to it. I measured several thousandths of an inch bend away from the fourth gear cog.
These are the same, right?
In my case, the problem was caused by a bent shift fork. They really shouldn't bend unless you're doing bad things. Who knows, maybe the prior owner was doing bad things. Hard to tell from the pic here, but the one on the right was the original fork and had a bend of a few thousandths of an inch.
Again, some steps (and several weeks) might have been omitted.
Since I was this far in I figured I'd pull more apart and replace more bits. Front and rear bearings were replaced, circlips refreshed, and no other issues found in there. Part of reassembly requires a surrogate spindle to hold all of the countershaft bearings and washers together. I cut a piece of copper pipe to length which worked splendidly. Also, for the love of Thor don't do what I did and try to pull the countershaft up to mesh with the rest of the gears, turn the whole gearbox upside down and everything just falls into place. Yes, it says this in Phil's guide. Yes, I struggled with it for a good half hour before re-reading the spindle assembly.
Reassembly had some of it's own challenges. First, I found the front cover was broken and had been from the start. I suspect it broke sometime before taking the transmission out - miniscule score marks were on the input shaft. I'm hoping to notice a better feeling clutch when I get back on the road, time will tell.
Transmission needs to be out to replace the clutch, clutch kits are only a hundred bucks or so. Just replace it while you're in there. Future you will be grateful. Removal and replacement is very straightforward. Loosen the bolts around the housing a little at a time in a star pattern to keep the springs from bending anything. This kit is from Sachs and included a pilot bearing and handy dandy tool to align the pressure plate with the flywheel. This handy dandy tool naturally fits perfectly into the pilot bearing so can double as an extractor for said bearing. Pack the space behind the pilot bearing with grease, stick the tool in, tap with a mallet. Install the new bearing, stick the new clutch up there on the centering tool and bolt back in a bit at a time.
I seem to have stopped taking photos at this point, mostly because it's accompanied with heaps of cursing and swearing. Installing a transmission is not for the feint of heart. It's heavy, bulky, unwieldy, and generally a big pain in the bum. I used two jacks and a lot of elbow grease to get it up and bolted in. One jack to tilt the motor back a bit, one to lift the transmission into place. I could not seem to get this installed with the bell housing mounted on the transmission and spent many fruitless hours trying to make that work. I ended up installing the bell housing and clutch fork on the back of the motor, then installing the transmission and tightening up those hex bolts from the opening in the transmission tunnel.
And we're all done!
Oh wait, we're not...
Reassembly had some of it's own challenges. First, I found the front cover was broken and had been from the start. I suspect it broke sometime before taking the transmission out - miniscule score marks were on the input shaft. I'm hoping to notice a better feeling clutch when I get back on the road, time will tell.
Speaking of that clutch!
Transmission needs to be out to replace the clutch, clutch kits are only a hundred bucks or so. Just replace it while you're in there. Future you will be grateful. Removal and replacement is very straightforward. Loosen the bolts around the housing a little at a time in a star pattern to keep the springs from bending anything. This kit is from Sachs and included a pilot bearing and handy dandy tool to align the pressure plate with the flywheel. This handy dandy tool naturally fits perfectly into the pilot bearing so can double as an extractor for said bearing. Pack the space behind the pilot bearing with grease, stick the tool in, tap with a mallet. Install the new bearing, stick the new clutch up there on the centering tool and bolt back in a bit at a time.
I seem to have stopped taking photos at this point, mostly because it's accompanied with heaps of cursing and swearing. Installing a transmission is not for the feint of heart. It's heavy, bulky, unwieldy, and generally a big pain in the bum. I used two jacks and a lot of elbow grease to get it up and bolted in. One jack to tilt the motor back a bit, one to lift the transmission into place. I could not seem to get this installed with the bell housing mounted on the transmission and spent many fruitless hours trying to make that work. I ended up installing the bell housing and clutch fork on the back of the motor, then installing the transmission and tightening up those hex bolts from the opening in the transmission tunnel.
So, how does she drive?
New clutch, (hopefully) repaired transmission, new transmission and motor mounts. Now all we need to do is put it on the ground and go for a drive! How could that could that possibly go wrong?
Coming up next week: Exactly how that could possibly go wrong while we repair an oil pan and replace an oil pump!
