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Registered
Join Date: Jun 2000
Location: bottom left corner of the world
Posts: 22,770
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Understanding syncros
I have a '92 Toyota Corolla with a gearbox that graunches badly when cold. It's particuarly bad for the first few minutes then it's fine after 10 minutes of driving. I changed the gearbox oil to Castrol VMX and it still does it. I added "gear-up" additive to the oil and it still does it.
At first I thought it was a clutch problem, but a clutch place said it was fine and that the syncros were a bit worn and it needs THINER oil. The reason for this is the gearbox works fine when it has warmed up and the oil thined. I thought when syncros were worn you used a thicker, less slippery oil to make them grip and work quicker - I don't know. If I do need a thinner slippery oil would Redline synthetic lightweight gear oil be a good bet? Or do you have some other ideas? Thanks, Bill. |
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Author of "101 Projects"
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It's worth a try. There are several different designs for transmissions - the slip-synchro one used in the Porsches may be different than the one in your Toyota. The transmission depends upon friction to spin up the gears. If the oil is really, really thick, it could be acting like too much of a bearing surface, kindof like the way it does in the engine along the mainshaft bearings...
-Wayne
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Wayne R. Dempsey, Founder, Pelican Parts Inc., and Author of: 101 Projects for Your BMW 3-Series • 101 Projects for Your Porsche 911 • How to Rebuild & Modify Porsche 911 Engines • 101 Projects for Your Porsche Boxster & Cayman • 101 Projects for Your Porsche 996 / 997 • SPEED READ: Porsche 911 Check out our new site: Dempsey Motorsports |
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Thanks Wayne. A chap at work said try Autotmatic transmission fluid. He said it is very thin and will get the metal to metal, that the Jap syncos need, to work better. It may ultimately knacker the gearbox but if I can get a few years out of it, it's worth a go.
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Author of "101 Projects"
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Uhh, I would get a 2nd opinion on that. AutoTranny fluid is designed to work both as a lubricant, a coolant, and a hyrdraulic agent. I wouldn't use it in a manual transmission if I were you...
-Wayne
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Wayne R. Dempsey, Founder, Pelican Parts Inc., and Author of: 101 Projects for Your BMW 3-Series • 101 Projects for Your Porsche 911 • How to Rebuild & Modify Porsche 911 Engines • 101 Projects for Your Porsche Boxster & Cayman • 101 Projects for Your Porsche 996 / 997 • SPEED READ: Porsche 911 Check out our new site: Dempsey Motorsports |
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Administrator
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Second that. I'd use lighter-weight MTL, possibly something like the Redline synthetic. Second pref to that, a motor oil. ATF would be about my last choice...
--DD
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Pelican Parts 914 Tech Support A few pics of my car: http://www.pelicanparts.com/gallery/Dave_Darling |
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Join Date: Feb 2002
Posts: 53
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I'll third that. I'd use old cooking oil before ATF - sounds like a hack.
Seriously, the Swepco stuff is what I swear by - I think that they have different weights - let me check... Yes, check here: http://www.drivewerks.com/catalog/car_care/Swepco.htm |
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In the shop at Pelican
Join Date: Aug 2002
Location: Los Angeles, CA
Posts: 10,459
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DO NOT, I repeat DO NOT run ATF in a manual gearbox. this is a bad thing. You will almost instantly burn it all up, and then you will have a nice big glop of sulphides floating around your gearbox, causing all sorts of corrosion, not to mention higher temperatures, as well as the general inability of ATF to provide any sort of lubrication for manual transmission gears.
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Ok, four people whose opinions I respect say NO. No it is.
I'll source out some Redline Lightwieght oil. Thanks Guys. |
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Author of "101 Projects"
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I would try the Swepco first...
-Wayne
__________________
Wayne R. Dempsey, Founder, Pelican Parts Inc., and Author of: 101 Projects for Your BMW 3-Series • 101 Projects for Your Porsche 911 • How to Rebuild & Modify Porsche 911 Engines • 101 Projects for Your Porsche Boxster & Cayman • 101 Projects for Your Porsche 996 / 997 • SPEED READ: Porsche 911 Check out our new site: Dempsey Motorsports |
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Quote:
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1995 C2 w/Tiptronic, Stongard, HID's |
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In the shop at Pelican
Join Date: Aug 2002
Location: Los Angeles, CA
Posts: 10,459
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Sounds like typical Ford engineering.
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F-O-R-D...means...
Fix-Or-Repair-Daily...
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1995 C2 w/Tiptronic, Stongard, HID's |
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