Any video gamers in our Vintage Saab crew these days? If there are, you might remember (or even still play) a game called Skyrim. Honestly, it’s one of my all time favorites. It’s sort of like Dungeons & Dragons meeting Halo. In this game, there is a mission called Discerning the Transmundane, where the primary character meets a brilliant, but now mad, scholar who needs to transcribe this weird ancient Dwarven lexicon under the direction of an evil god. Playing through it really made me think…why did this seem familiar? I know, I have a weird ancient V4 gearbox to rebuild!
There aren’t many people volunteering to tear into the V4 gearboxes these days. ‘It’s one of those components that many people look at like a mysterious black box, or a nuclear reactor, or an IRS tax form. Honestly, I’m probably one of those people. I understand the basics of how a transmission works, but that’s a far cry from feeling confident enough to tackle a tear down and rebuild. And to make matters worse, we’re adding a bunch of power to an already-questionable gearbox (depending on whose opinion you read online). And while I may not be doing the actual gearbox rebuild, since I’m involved you know we’re going to sneak in some “custom enhancements”…
As you may remember, I dropped off the Sonett gearbox a few months back after 47 applications of “environmentally friendly” degreaser. While that was getting taken apart, I was given a homework assignment of my own: fix up the gearbox linkage & drivers, throwout bearing arm, and bellhousing. First up was to disassemble the bellhousing to get the tension rod and throwout bearing arm out. The arm was in good mechanical shape, and did not need rebuilding thankfully. So with the arm, tension rod, and drivers in hand; I brought them all down to Western Mass Powdercoating for sandblasting and powdercoating. The original paint on the drivers was some sort of green (leftover from Saab’s WWII production?), so I did my best to match that up with the powdercoat colors that were available, and asked them to not only powdercoat the drivers, but to also do the tension rod, linkage bracket, and throwout arm. They took them in and about a week later they were ready to go back home. Kind of like when our daughter drops off her cats for pet sitting…after a week, I’m ready for them to go back home too!
While the gearbox as apart, I knew the freewheel was going to get “neutered”. This is a common V4 gearbox “mod”, but as always, there’s more to the story. Sonett guru Jack Lawrence was worried that even that might not be enough given the power I’m trying to add to my engine. If you’ve even seen the freewheel hub assembly, there are a bunch of little teeth that engage to transfer the power, and to make matters worse not all of the teeth are engaged at any one time. So even with the freewheel typically “locked out”, the freewheel “teeth” are just not that beefy, so Jack suggested a custom method of eliminating the freewheel. First he machines the hub to receive a steel sleeve that essentially binds the hub assembly together, then presses that sleeve into the assembly. Once in there, both the inner and outer portion of the sleeve gets fully welded to assure a very solid input that will hopefully never break. He also sent along a replacement gear and one of the main shaft bearings that was needed. The new freewheel hub looks dramatically different… just like my bank account!
Back home, I took apart the funky Sonett III gearbox shift linkage. It was all covered in grime and corrosion, so that wasn’t going to work. Some quality time with a wire wheel cleaned those up, but the smallest part ended up being the biggest pain. There is a small boot that helps protect one of the linkage joints, but I could not find it anywhere! After looking at several different dust boots online, I decided to take a chance with one designed for an International Harvester… wish I was making this up…! This boot looked reasonably close, but not perfect. The opening needed to increase to 5/8″ of an inch, so my step drill made short work of that. Next, it needed to be shortened. A few minutes later, this part seemed to fit better than stock! And certainly better than the 45 year old boot that had literally fallen off on its own…
The bellhousing needed some major cleanup work too. After scrubbing it all down, I took my die grinder with a scotchbrite-style abrasive “cookie” to clean up all the sealing surfaces. After another dose of “environmentally-friendly” cleaner, I picked up yet another POR-15 product called Detail Paint. This product is available in a few different styles (Cast Iron, Cast Aluminum, etc) and is designed to duplicate the original OEM casting look while still providing even coverage and corrosion resistance. I went with the Cast Aluminum look, and gave the bellhousing a few coats on the exterior. Looks like new! The gearbox linkage cover also got the cookie treatment, and a coat of Detail Paint too.
Ready for reassembly, I popped the fresh clutch release arm back in using a new tension pin (3/16″ x 1″). The linkage bracket got put back on the gearbox cover along with the freshly wire brushed linkage shaft and a dab of synthetic grease. There are a couple of bushings inside the bracket, but thankfully they were in great shape with no excess shaft play. I feel like there is an Anthony Weiner joke in that last sentence somewhere…? In any event, I tied the cleaned up linkage shaft back onto the gearbox cover along with my International Harvester dust boot. A zip tie provided temporary hold-together duty for the cover and bracket until is was time to go back on the gearbox itself. The before and after is pretty crazy!
After completing my mission, I brought the parts over to Roger’s house, where he was installing virtually all new bearings and seals in my fully rebuilt gearbox. He topped it off with my refurbished bellhousing and gave the rest of the gearbox a coat of Detail Paint as well. Redline’s synthetic fluid went in now, just to make sure I didn’t put it in the car and forget the fluid…! Because unlike Skyrim, even if you complete the mission, you still might get to do it all over again anyway!