Saab Stories

I recently heard from another user of the Motor Sport Services conversion kit for the Weber 40DCNF carburetor. He has acquired a car with the kit and asked MSS if they could send him the instructions; he was told that they have sold so few of them that the instruction document has been misplaced! (It’s an excellent conversion; can’t imagine why more people don’t have them.)

Anyway, I still had my original instruction sheet, and a follow-up email from Jack Lawrence with some additional setup advice, so I have scanned and saved it as a PDF file which you can download here.

I’ve been dodging the issue for more than a year, but there was no getting around the fact that my Sonett needed new tires. Sure, the ones on the car — Korean ‘Jupiter’ brand, 165-15 size — still had plenty of tread. But they’re too big for the car.

The fronts rubbed on the fender lips in even moderately sharp turns, and the backs would scrape the inner fenders when I hit bumps at highway speed. Putting up with this made the car feel junky and clunky, to the point where I sometimes was ashamed to drive it.

But as anybody who’s tried it recently knows, buying new tires for a Sonett isn’t as simple as just walking up to the counter in a tire store and flashing plastic. Contrary to what some mail-list pundits and online calculators will tell you, you can’t just assume that any tire of size X will fit perfectly. Individual tire models, even of the same size spec such as 165-15, will have slightly different shapes and exterior dimensions. Given a Sonett’s tight wheel wells, those minor differences can be crucial.

That’s probably why, for example, I had no rubbing problems with the 155-15 BFG Radial T/As I used to have on the car — while my Vredestein Snow+ tires, in the same 155-15 size, do rub on the front fender lips in sharp turns.

And because of car-to-car differences — in body clearance, spring sag, even driver weight — somebody else’s Sonett might be just fine with a tire that rubs on my car. So ‘crowdsourcing’ an answer isn’t necessarily 100% reliable either.

Meanwhile, there’s the issue that the selection of tires available in 155-15 (the original stock size) and 165-15 (a common in-period replacement) isn’t exactly broad. Back in the day, these sizes were stock on everything from VW Bugs to Porsche 911s, and tires in budget, touring, and performance flavors were easy to find. Now that ‘back in the day’ was four decades ago, your choice of stock-size Sonett shoes often comes down to balancing ‘what’s going to fit?’ and ‘what can I get?’

In this type of dilemma the best play often is to consult an expert, and my go-to expert for all things SAABish is Chip Lamb of specialist vendor West of Sweden SAAB. Chip had an answer: the 175-65×15 size. This tire size, he said, should fit; isn’t too wide for the Sonett’s skinny 4-1/2-inch rim width; and is close enough in diameter to the originals that speedometer readings and axle ratios won’t be wildly off. And thanks to the popularity of the BMW Mini, which uses 175-65×15 as a standard, tires in this size are available from several manufacturers in several performance profiles.

With this info in hand, it was just a matter of waiting until I had enough money and then selecting what tire to buy. There were a couple of European brands classified in Tire Rack’s ‘performance’ and ‘high performance’ categories, but they were pretty expensive. A few months later, though, a new tire appeared from Yokohama: it had a silly name, ‘ENVigor,’ but the specs and price were what I wanted. I ordered a set, crossing my fingers and hoping that Chip was right about the fit.

He was, of course. In spite of their slightly wider ‘section width’ (175mm vs 165mm) the Yokos’ lower profile means they stay away from the fender lips at both ends of the car. (If you don’t know how to read tire size numbers, there’s a tutorial on the Tire Rack website.) And their overall diameter is pretty close. I’ve got a VDO digital ‘cyclometer’ (bicycling computer) that I can program for actual wheel circumference, giving me true-speed readings for different tire sizes. According to this, an indicated speed of 70mph on the Sonett’s dash speedo is a true speed of 67mph; that’s as close as most cars’.

So now I can drive my Sonett without dreading sharp turns, and on modern tires in a readily-available size. Next time I meet a Mini driver, I’ll say ‘Thanks!’

Old (top) vs. new — no change in the overall stance.

The 165 tires (top) dragged on the fender lips at full lock — see circled area. The 175s (below) clear it, although just by a finger…

Chip Lamb, the brain and sinew behind parts supplier West of Sweden SAAB, is an unusually good guy even by the rather lofty standards of the vintage SAAB community.

For a recent example, my recent disaster-fest began with trying to fix the Sonett’s backup lights and ended up with a huge hole in the floor, an exploded rear hatch, glass shards lacerating my elbow, and various other hair-raising horrors. Just when I thought I had wrestled all those into submission and that the Sonett was ready to start being a car again, I discovered that stepping on the clutch pedal did… nothing whatsoever. The proximate cause became evident when I examined the clutch fluid reservoir and discovered that it didn’t contain anything except atmosphere.

Well, I told myself, maybe I had left the bleed nipple loose when I changed the clutch fluid, and it all simply escaped. I refilled the reservoir, bled the clutch, made sure the nipple was tight, and found clutch action had been restored.

Next day, though, I was clutchless again — and the trail of hydraulic fluid eddying along the passenger-compartment floor and forming little pools under the shifter and seats told me that the clutch master cylinder seal had gone.

I also found a bit of fluid leaking out of the business end of the clutch slave cylinder — and since this eventually would find its way onto the clutch disc and do it no good, I figured that both ends needed to be redone.

I contacted the aforementioned Chip Lamb and asked him what parts were available. He had new slave cylinders, so no problem there. New or rebuilt replacement master cylinders, though, aren’t available, he said. He did have a rebuild kit with new seals for them — but warned me that most Sonett master cylinders by now are scored or pitted after 30-odd years of generally-neglected service, and should be re-sleeved, not just re-sealed, for best results.

(Re-sleeving involves boring out the cylinder to remove all the pits and scores that would wear out the new seals prematurely, and inserting a sleeve of new metal to provide a smooth sealing surface.)

I was fed up with dumping money into the car, though, and decided to ignore this advice. I ordered just the rebuild kit. While waiting for it to arrive, though, I started having second thoughts. I really didn’t want to have to do this job again, after all the other trauma I’d been through. When I got the rebuild kit and realized that it wasn’t the right part, I contacted Chip again and told him I had decided to do it the right way: when I sent back the part, I’d also send along my cylinder; he could take a look at it and re-sleeve it if he thought it necessary. The price of the re-sleeving service seemed reasonable enough, and I had no qualms about doing it if it would make the seals last longer.

With most mechanical service providers, that would have been the end of the story. After all, if the customer tells you to do X and he’ll pay for it, you do X and let him give you his money, right? Well, that’s not how they do business at West of Sweden, and in a couple of days I had another email from Chip, saying the bore of my master cylinder was one of the nicest he had ever seen from a Sonett, and it would be kind of a shame to re-sleeve it when it didn’t really need it. He proposed that he could save me some money by simply installing the new seals and cleaning it up.

Saving money sounded like a good idea at this stage, so I took him up on the proposition. A few days later I received a refurbished clutch master cylinder so pretty I almost hated to put it into my ratty old car. I did put it in, though, and now once again I have a clutch that clutches and de-clutches.

Thanks, Chip!

Update: Chip also reminds me that when he got the master cylinder apart, he discovered that someone, in the deeps of historical time, had rebuilt it with the seal mounted backwards. The upshot of this, he explains, is that once the very edge of the seal begins to wear, the cylinder will leak. I had been driving it that way for nine years… I guess now I know why the floor was always a little, uh, moist.

Chip says:

Diagram in the shop book is no help. Just remember in all cases that the cup of the seal goes towards the fluid, the flat surface goes towards the piston head.

I should have thought of that myself: when you push the piston inward, pressure of the fluid into the cup expands the seal, helping it seal more tightly. When the piston moves outward, the pressure eases, letting the seal contract a bit so it can slide more freely and with less wear. So it makes perfect sense when you think about it. Apparently, sometime in the past, somebody didn’t think about it…

Here are some photos of the stars of our show…

My new clutch slave cylinder (top) and rehabbed clutch master cylinder from West of Sweden SAAB

The slave cylinder installed easily... although I discovered the mounting hole in its end was about two threads (roughly0.08") less deep than the original. That meant the bolt wouldn't go in as far, leaving the cylinder loose. A couple of washers under the bolt head (not shown) solved that.

The master cylinder also went in easily enough. What, you say yours isn't this easy to reach? That's because you aren't using the C.I.A. (Corrosion-Induced Access) port. This port evolves spontaneously over the years, as spilled brake fluid runs down the fender well and removes the paint, causing rust that eventually eats right through the metal and creates a handy hole through which the cylinders are easy to reach. When I repaired this hole several years ago, I covered it with a screwed-on plate rather than welding in a patch, preserving the easy access.

Congratulations, you’ve found the new home of my collection of pictures and text documenting my various incompetent attempts to fix, improve, and resurrect my 1974 Saab Sonett III.

At this stage most of the content is still exactly the same as that on the old SaabStories website, but the spiffy new blog-style format may make it easier to update if I can ever bring myself to confront the car’s many foibles.

Use the Archive links down the right side of the page to visit your favorite picture-and-text pages from the old site. Remember, on most pages you can click any picture to see it at a larger size.