Ok, so I am going to preface this with "I have never opened up a transmission in my life".
I have a w58 Toyota transmission. I would like to someday regear it for the final drive and engine power band. Ultimately, it would be really cool to make it a six speed (5spd now). Is this something possible? Is it a grassroots level difficulty?
Second option, regear 1-4 as track gears and have fifth be my long cruising gear for road trips.
Not an option: "adapting a 6spd transmission to your bellhousing". Why? Because I just spent my bank account on items adapting this one to my v8! The clutch and throw out assembly alone are a PITA, plus my custom one piece driveshaft. So not going that route.
The question is really, is there an advantage to changing gears that often that an extra gear would be worth it?
Most V8's are very torquey and don't typically need the extra gear unless you're trying to improve economy or top speed.
That said, altering gear ratios to suit the primary use of the vehicle and the engine's power output makes complete sense, but there's almost an artform to it.
Turning a typical 5-speed manual into a 6-speed is approximately as complicated as turning a V6 into a V8.
Replacing 5th gear with a higher ratio may be possible, it depends a lot on how the transmission was built and what options there were from the factory.
All good things to know. Thanks. Fortunately, the W series has plenty of variations. So I don't think finding suitable gearing alternatives will be hard. I figured adding an extra gear would be ridiculous, since I never hear of people doing it.
Isn't the w series an aisin transmission? Off to search the googles...
When I put an Aisin J160 (JDM Altezza 6-speed) in my AE86, I ended up finding out that a lot of what I needed to make it fit was available Stateside as W58 parts. I ended up using a W58 speedo drive, Supra W58 rubber mount, W58 yoke on the front of my custom driveshaft, and a modified W58 clutch disc...and the stuff bolted right up. This leads me to believe that Toyota may have designed that six-speed transmission to fit where a W58 once fit.
Since I put it where a T50 once fit, I can't confirm that details like length from input to output, and shifter location match the W58. I'm also not sure what you had to do to the W58 for your 1UZ, but it could be an option worth looking into.
Possible yes, grassroots no. You'd need to add another shift rail, so basically you'd need heavy case modification.
Most 5 to 6 speed conversions I have seen were only on transmissions that already had four gates, like Volkswagen 020 and 02A/02J. Then it's just a matter of sticking another gear pair on the end and a little shift rod tweaking.
Hmmmmmmm... brainfart - would it be possible to add an electric engaging overdrive (aka Volvo's M40+ electric O/D)
In reply to oldeskewltoy:
Gear Vendors overdrive, not cheap but if they can't hang one off whatever trans you have I think they make a divorced unit.
And by the time you buy a GV, make room for it under the car (no small task), have new driveshafts made, etc... you'd have been money far ahead to find a bolt in 6 speed solution and use that.
Knurled wrote:
Most 5 to 6 speed conversions I have seen were only on transmissions that already had four gates, like Volkswagen 020 and 02A/02J. Then it's just a matter of sticking another gear pair on the end and a little shift rod tweaking.
This is what I was thinking, and even these are expensive if you don't have a donor trans to steal parts from. Other common 5-6spd conversions are Honda Element and the f35 trans used in the Ion Redline/Cobalt SS/Saab whatever/etc.
In reply to Trackmouse:
Stalker at all of the autox's we did setting up the mumpkin only ran second gear on course. Seriously, TCM was set up so in D, it ran through all 4 gears in the 4lxe, but pull it back into 2, and it never left second. It was fast too. Bone stock 6L Ls from a GTO with auto trans. First gear according them was "worthless" car was too light, engine had too much to give. Just a thought for the 6th gear is over rated vote.
Ok. Ok. Cool. I have heard the j160 trans has similarities. I'll look into it.
I only know of the Honda Element 5 to 6 speed conversion with a few Acura TSX parts.
This will be cool to see what you find out.
Trackmouse wrote:
I figured adding an extra gear would be ridiculous, since I never hear of people doing it.
Put a ramp truck electric overdrive on it.
If there were different versions of the trans with different ratios, you may be able to change out gear pairs to get the ratio spacing closer to what you want, but adding a gear can be a challenge. You're also limited on what you can do by clearance for the gear diameter, the centerline spacing, and pitch/tooth profile/tooth number requirements unless you don't care if you have a hunting gearset or have a lot of whine, etc.
