Arrhh, it's really starting to drive me nuts. It feels like just about every second set of traffic lights I pull up at, there's a WRX (invariably with the usual mods) that loudly blasts its way off into the distance. And there I am in my decrepit Liberty RS dawdling off the line, short-changing every cog and barely staying up with the flow of traffic - when I should be up there running door-handle-to-door handle to the tearaway Rex. It's such a sad state of affairs it makes me want to hold my head and cry...
But that's the way life is after the car's fourth major gearbox failure in around two years - I'm literally too scared to turn the boost up to 15 psi or rev the throbbing flat-four beyond about 5 grand. Mainly because my cardboard box full of broken Subaru gearbox bits couldn't hack the weight of any more stripped teeth without the bottom of it falling out...
So what's the cause of this appalling gearbox track record?
Buggered if I really know. But it seems that just about any constant 4WD car with boosted power - and a clutch that won't slip - has a very hard time keeping gearboxes together. TX3s, GSRs, GT-4s, WRXs - they can all munch 'em up. However, with the number of modified Aussie GSRs and WRXs now running such scintillatingly fast quarter mile times, I figured that there must have been some progress in that area of late. I jumped on the blower to Sydney to find out...
I chatted to Vince Rigoli (of V&E Rigoli Racing) and he certainly had some interesting things to say about a couple of cult hi-po cars. He's had one customer - the owner of an early model WRX - who's come in for around ten gearbox fixes. Yes, that's right, ten! Many others have had about four complete re-builds - with breakages including 1st, 2nd, 3rd driven gears and the long, flimsy input shaft. Of course, then there's worn sychros that add to the tally as well.
But Vince, who's recently been working on a 500+ horsepower Rexy, says he knows of a guy (Sam) in Sydney who's solved the dreaded Subaru gearbox woes. For around $3800 you can get a Stage 1 full synchro 'box packed with billet gears and shafts - and that's apparently the bees-knees for most street driven Rexes. But for those that are pushing the leading edge of WRX performance, there's a Stage 2 Race Box option - that sells for $5500 - and comes with fatter billet gears than in Stage 1 as well as dog engagement on first and second. Obviously, though, a dog-box isn't ideal for street use.
Furthermore, Vince told me that the standard MY99-onward WRX comes equipped with a stronger gearbox. It's reputedly got slightly beefier teeth and revised synchos over the older models, but Vince also suggested it wasn't really all that much better in a high-powered car. A Stage 1 or 2 "Sam's Box" is a much stronger unit.
On the other hand, Mitsubishi's Lancer GSR turbo is said to only have problems with breaking gear selector forks - a hassle that's reputedly easily fixed by installing a VR4 item. And Vince should know - he's got a quite a few customers with mega-quick street-driven Lancers. The only other driveline trauma he's noted is accelerated wear of the front CV joints. But that's nothing anywhere near as spectacular as a Subaru gearbox let-go! A little more digging around has revealed that the GSR's transfer case is also a bit of a dodgy item - but I'm not 100% sure on this. Can anyone else shed some more light?
So what's the go here? Are nearly all tweaked constant 4WD turbos on earth destined to spend eternity receiving gearbox rebuilds? Probably not - but then... From what I've been able to work out, many of the hot all-wheel-drive turbo cars experiencing 'box problems have already had an up-rated clutch put in. Of course, no clutch slip = bulk strain on driveline components. That's when things are more likely to go "bang".
To give you an example, I'll tell you about my 3-inch exhaust'd, intake'd and boost'd Liberty RS. While under the ownership of AutoSpeed's Editor, Julian Edgar, the car never had any gear breakage problems with the standard clutch in place. Even after being subjected to performance testing (ie 0-100s etc) and more abuse than I've ever dished out (honestly!) all was pretty much okay. However - in the earlier days of Julian's ownership - it did experience synchro and bearing hassles, which have never re-appeared since these items have been replaced/modified.
At the time, the standard Subaru clutches always came out for replacement looking severely glazed and, given the amount of slip that sometimes occurred, that was no surprise. The friction heat build-up must have been fierce. Julian recalls that when the clutch was in good, unglazed condition, the RS was good for about three full-bore launches before slip put an end to the enjoyment.
Since moving to a full-faced Kevlar clutch with a massively up-rated pressure plate (about 1200kg), I can guarantee there has never been a trace of slip whatsoever. Wear is also a non-issue. The problem now lies in gearbox strength - which, I might add, is much more expensive to endure than a slippery clutch! I've stripped (on separate occasions) two first gears, a second gear (which kindly went on to trash the entire gearbox) and a couple of teeth off the input shaft - just for good measure.
After shotpeening first gear after the second mishap, there was no such re-occurring problems - until second gear let go. In the next (the third) rebuild, every forward driven gear was 'peened. First through to fifth. But what unexpectedly cried enough next was a couple of (stronger looking) teeth on the input shaft... arrhhh.
If I could start all-over, (given my style of driving and the everyday role of the car) I'd probably just have everything shotpeened to begin with and fit a slightly up-rated clutch and pressure plate. That way, the gearbox should be protected by the added strength (apparently) achieved through shotpeening and a clutch plate that'll slip a bit before something breaks - but not quite as much as the standard clutch.
Even then, I suppose, there's no guarantee that the gearbox would last any longer than a $10 Rolex...
Oh, and just a final word on imported Japanese Subaru RS/WRX gearboxes...
Based on my experiences, the Japanese gearbox can come with a different front diff ratio to our Aussie 'boxes. However, it's lucky that the Aussie diff plonks straight in its place to prevent any potentially destructive driveline wind-up caused by mismatched front/rear diff ratios. In addition to this, some of the internal coggery in the Japanese gearbox is different too. The ratio formed between the input shaft and some of the driven gears varies slightly to the local gearboxes - which I only found out when my Japanese 'box broke some teeth off its input shaft. It turns out that the Japanese input shaft had a different number of teeth on it to the Aussie part - which meant only a Japanese inter-locking gear (second gear) could be used in conjunction with it. It physically wasn't possible to team a new Australian-spec input shaft with the Japanese second gear. The only solution was to create a matched set of gears by purchasing a new second gear and to use with a spare input shaft I had lying around - both of the Australian spec variety.
So be warned - don't assume that imported Japanese and our local 'boxes are exactly the same!
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