Transmission is Terrible

So I'll start this post with a disclaimer: SAAB V4 transmissions and transaxles are NOT weak. This is a conception I come across just about everywhere I've done any research in forums and anywhere else. They claim that these units just fall apart. They are strange, they have components that don't really benefit them (cough freewheeling hub) and some of the design is highly questionable (bushings that have no way of keeping their lubrication), but they are plenty strong. I base that they're plenty strong on first hand remarks from both Mark Ashcraft and Tim Nines, both of whom have used Sonetts in Motorsport, with greatly boosted engines (125+ hp) and never had problems with the transmissions keeping up, Nines said he broke axles before the trans-axle gave up the ghost.

Make no mistake, they are finicky. The freewheeling hub remains a problem child until it is neutered, and the the shift bushing on the outside transmission itself has no grease fitting and tends to give up sooner than similar units in other cars. They need fresh gear oil, more often than you change the motor-oil. Ashcraft recommends changing your gear oil every month and using synthetic Amsoil 80-90. Synthetic oil is going to do what it's designed to do: fill every nook and cranny it can get into (read: it will find any holes/cracks in gaskets or other seals.).


You may remember, or I may have not posted anything about it (oops), the latest with the transmission had been that it wouldn't get into gear. To refresh: when I was working on prepping the door sills for paint I backed the car down my hill (which is stupidly steep) to turn it around and work on the other door sill, at the bottom rolled to a stop, went to shift into first to turn the car around and heard the awful sound of gears grinding. From that point on the car has not gone into gear. At first every signal indicated that it was a problem with the clutch control system, the slave was leaking and the pedal wouldn't hold pressure. That was all rebuilt bled and tested, not the issue. The next thought was linkage, the collar on the shift linkage was hitting the shift tower and it never felt like a gear was even being selected. We jacked the front end off the ground and tried to see if we could feel through the wheels any kind of moment in the transmission when the shifter was moving, nope. We could look down and see the linkage on the outside of the transmission case moving so it wasn't bound up. After fiddling with the linkage for several hours I placed a befuddled call to Ashcraft.

He walked through all my symptoms and was equally perplexed unless the problem was with a selection fork inside the trans being worn down or broken, in which case I would have to pull the motor and trans (which I very much wanted to avoid) and have the transmission rebuilt. Then he had a eureka moment and asked about the freewheeling switch, which had totally slipped my mind. I sprung for his 50$ book on transmission diagnoses and fixes, which so far has been quite helpful.

Quick lesson: the SAAB V4 trans-axle has a freewheeling hub, a remnant from the 2-stroke Sonett days. Honestly SAAB couldn't be bothered to redesign a new transmission, for god's sake these cars were already being built with the bits they had just lying around, so they reused the two-stroke transmission. The free-wheeling hub is a gear in the transmission that actually turns the axles. For the car to actually accelerate the car the flywheel has to exceed the rotational speed of the freewheeling hub for the centripetal force to propel the car forward. This is an excellent design for a two-stroke motor, it makes it so applying the gas (to keep the engine from seizing) while braking when going downhill is no longer the most terrifying, seat-browning experience because unless you really jam on the gas the car won't accelerate faster than gravity is pulling it down the hill. However this feature introduces more points of failure into an already fairly complex mechanism and is completely unnecessary in anything other than a two-stroke motor. It does allow you to hypothetically drive the car without using the clutch to do anything other than coming to and setting off from a full stop.

The free-wheeling hub position can be locked out or engaged using a switch mounted on the top of the transmission case. The switch is pulled into the lock-out position (pointing toward the firewall) or pushing into the engaged position (pointing toward the engine block) using a small lever located above the gas pedal. Well it would be if mine wasn't totally missing.

This is what it should look like, rod through a grommet in the firewall

I didn't have one, so I made one. Simple enough, just a piece of rod bent in a vice that I tapped on both ends. Engine side to attach a nut/washer to hold it in the grommet and handle on the other end.

Before tapping I tested fitment and movement, seems to work well.

 Well that didn't fix the problem so I decided before I continued any further I could at the very least change the gear oil. So I put the car up on jack stands, crawled underneath and loosened the drain plug. I used a jack with a block of wood to apply pressure on the back of the ratchet while I yanked on it with the jack handle, made breaking the plug loose a bit of a faff but fairly easy.

While I was under there I did notice this, the flywheel is totally exposed to the road. I really question this being the stock configuration, I would expect some kind of something to protect it from the elements.

Plug is loose now

Gear oil draining, that doesn't look so bad but boy did it sound bad...

Clunk! That's the first batch of metal bits that came out with the gear oil. They look fairly important, and at the very least shouldn't be bouncing around in a transmission. Not good.

So now I know the trans is dead in the water. Something internal has either broken, come lose, or simply fallen apart. That isn't terribly important beyond the fact I'm going to have to pull the drive train and have it professionally rebuilt. So at that point that was the next step. close back up the plug hole, put gear oil back in the tranny so the internals aren't exposed to the air any more. Then I began the arduous process of pulling the motor and trans.

*UPDATE!* The little springs and rollers that fell out here are indeed from the free-wheeling hub inside the trans-axle. Further lending proof to the fact that the hub needs to be neutered so it doesn't break other stuff.