AkumaNoZeta Posted September 21, 2008 Author Share Posted September 21, 2008 I ripped apart and reassembled a 4T60 transaxle in school, but that's an automatic not a manual. In an automatic transaxle I think the only bet you have is to replace the planetary gear system with something to work with the diffs, probably has to be custom made. I want a manual though, for me driving an automatic is so boring that it literally makes me fall asleep Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted September 21, 2008 Share Posted September 21, 2008 I like autos with cruise control for long distance trips along straight or gently curving roads. just set the speed and watch the scenery go by... Manuals are for thrashing round gnarly roads having fun Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted September 21, 2008 Share Posted September 21, 2008 A little Google work, shows a simplified FWD transaxle having the output shaft of the gearbox driving a diff, the only significant difference is that unlike a RWD diff having a crown gear and a angled drive gear, this has a flat gear that engages another flat faced gear on the shaft, just like two gears on different shafts inside the gearbox. http://www.procarcare.com/includes/content/resourcecenter/encyclopedia/ch20/20Fig14.html Quote Link to comment Share on other sites More sharing options...
AkumaNoZeta Posted September 21, 2008 Author Share Posted September 21, 2008 I uploaded a drawing of how a FWD transaxle is like from my text book. As you can see there is a final drive that's like the ring and spider assembly of a differential (circled in red). The only thing I can think of is to replace the gears with similiar sized ones with teet on it so you can hook a chain around them, transfer cases are done that way in big V8 trucks so it should be able to handle all the torque a little 2.0 litre, or less, can ever dish out. Sorry for the blurry photo, my scanner is all packed up so I used my camera instead and I don't have much of a steady hand. I'm 19 but feel 80, lol. Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted September 21, 2008 Share Posted September 21, 2008 If it's possible to turn that gear down and have it re-cut and re-tempered at a gear place, then re-install it, then maybe a pair of smaller gears working like the Edelbrook timing gear set would do the job? imagine them as 4 nearly equal sized gears, one the output shaft of the GBox, one the Diff gear, and the two driver gears between them. The question is how the drive gear for that diff is applied, if it's bolted to the back of the spider gear carrier housing, then unbolting it and reducing it then re-bolting on again would work. if it's cut into the edge of the carrier housing, nothing will really work. Quote Link to comment Share on other sites More sharing options...
AkumaNoZeta Posted September 21, 2008 Author Share Posted September 21, 2008 The problem with that idea is that you'll probably have to drill more holes in the casing in order to have the gears on shafts to rotate which would make rebuilding a little more difficult. And wouldn't having it run through more gears make more power lost through the drivetrain? Then again, if the chain idea is done then the smaller gear would have to be cut down considerably as well so the chain wouldn't rub against the case which might make that gear more prone to breakage. There's no easy solution, but that's what makes the discussion fun. Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted September 21, 2008 Share Posted September 21, 2008 you're already losing power through 2 diffs rather than one... whats a little more parasitical loss Quote Link to comment Share on other sites More sharing options...
AkumaNoZeta Posted September 21, 2008 Author Share Posted September 21, 2008 You do have a point. But that could be taken two ways, 1.) there's already more loss so what's a little more? or 2.) We already added more loss so let's try to limit any more to be taken. I'm just trying to think of what would be the most efficient and allow future maintenance to be a little simpler. Knowing how the human brain works, we'll probably get off the computer and 5 hours later a random thought will hit us and we'll be "THAT'S IT!!! IT'S PERFECT!!!" Quote Link to comment Share on other sites More sharing options...
AkumaNoZeta Posted September 21, 2008 Author Share Posted September 21, 2008 I found this image if it helps any http://www.davidandjemma.com/mazda/images/G25/J2-004.gif Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted September 21, 2008 Share Posted September 21, 2008 I've been thinking along the lines of a viscous coupling... fit a driveshaft with a 1:1 connection between the final gearbox output shaft and the driveshaft. and a R200 VSLD carrier such as from the Nissan Serena with the crown gear turned off flush with the outer face of the carrier assembly. the driveshaft splines into the carrier and the shaft out to the front flange is in the other end of the carrier... I'll try and find a photo and photoshop it. Quote Link to comment Share on other sites More sharing options...
AkumaNoZeta Posted September 21, 2008 Author Share Posted September 21, 2008 I like that idea. Axle splines do spline into a viscous coupling the same as a spool would doesn't it? I would like to see a photoshop though, maybe even just a drawing made in MS Paint. I'm still thinking along the lines of changing the transaxle. Here's what I think. Cut off the part of the casing that holds the final drive and cast two peices that would be used for holding the final drive but extended outwards to fit in a gear assembly like the Edelbrock one you were talking about and have it designed so that the two peices bolt together and then that whole thing bolts back on the rest of the case so that whenever you have to rebuild the transaxle it would be easier to do so than when it was in factory trim and you will get that 1:1 ratio to boot. Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted September 21, 2008 Share Posted September 21, 2008 http://www.zrelated.com/VLSD_files/pic55.JPG if it's like my Hilux diff I had out and sitting in the workshop this weekend as I replaced the CV joint seals and re-greased everything, the side shafts are splined and just poke straight into the carrier sides. I think one side is cut into the carrier, the other is run by the spider gears, or the VLSD in this case. so if you have just the carrier, and cut off the crown gear, with power being applied from one shaft, then the cut down VLSD will act as a viscous coupling to turn the other shaft. do you get what I am trying to say? My photoshop sucked, so I gave up If you put this between the gearbox drive, and the front diff, you will have a rear drive biased AWD, putt it between the gearbox drive and the rear diff and you will have front biased AWD I think... any engineers see any problems? Quote Link to comment Share on other sites More sharing options...
AkumaNoZeta Posted September 21, 2008 Author Share Posted September 21, 2008 So are you saying to put the VLSD in place of the final drive? That's what I'm getting out of it. If so you still need a way to get the power from the engine to rotate the assembly. That would pretty much have the VLSD locked up the whole time the vehicle is being driven wouldn't it? Would that cause the fluids inside the coupling to burn up a lot quicker than normally? Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted September 21, 2008 Share Posted September 21, 2008 in post #30, "fit a driveshaft with a 1:1 connection between the final gearbox output shaft and the driveshaft" then the suggestion of a viscous coupling turned down from a VLSD. like below: fix one side's shaft to the carrier if it's not already, and let the VLSD's viscosity do the work of turning the other shaft. Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted September 21, 2008 Share Posted September 21, 2008 no, since the rear is fixed, the gears turn the driveshaft to the rears, at most times the rear wheels rolling along will make the fronts turn anyway... it's only if both rears spin out that there should be sufficient speed difference between the front and rears to make the modified VLSD lock up and start spinning the fronts. edit: unless you fit funny car style mini front wheels and want to do front wheel burnouts constantly while the rears do the driving Quote Link to comment Share on other sites More sharing options...
AkumaNoZeta Posted September 21, 2008 Author Share Posted September 21, 2008 Oh, I think I see now. It's like adding a second center LSD into the mix. If I were to do it that way I would first make the two gears from your drawing into an overdrive to cancel out the reduction from the transaxle's final drive. I would also weld up the spider gears in the final drive so that all the power get transfered to the driveshafts. I'm still worried about the lifespan of the VLSD's fluid since it would be locked pretty much the whole time. I like that because it's adding another part instead of doing complicated modifications to an different part Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted September 21, 2008 Share Posted September 21, 2008 I'd just cut out the diff and run a longer driveshaft through where the diff was, and use gears to hook that up to the output shaft of the gearbox. hang on and I'll do another MSPaint job of what I mean Quote Link to comment Share on other sites More sharing options...
AkumaNoZeta Posted September 21, 2008 Author Share Posted September 21, 2008 Isn't the center differential on a Subaru Impreza a viscous coupling? It would be the same at that. Or if it's bothering you that much, could just make a special housing for a helical gear or clutch type LSD so it would be torque sensing instead of speed sensing. Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted September 21, 2008 Share Posted September 21, 2008 Old setup new setup Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted September 21, 2008 Share Posted September 21, 2008 that make more sense of what I am thinking about? make the gear replacing the diff such as the driveshaft is 1:1 with the gearbox, and final drive reduction is in the diffs at each end of the car? the 1:1 gears could be chain type, gears, V belt... whatever needs to go to make it work and what the engineer can manage Quote Link to comment Share on other sites More sharing options...
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