xB final drive swap thread

[cali yaris]

I know this is posted in several threads, I figured those doing this swap could post in here, in one thread for this mod.

Besides the following parts, you'll need shims. There are about 12 part numbers for those, most shops would get a couple of each and work from there.

33321-52110, output shaft
41221-52270, ring gear
90105-11040, ring gear bolts (8)

Mine came in today:



I'll post more pics as this progresses.

[fnkngrv]

nice...what are your personal goals with this?

[Flipper_1938]

Final drive ratio changes from what to what?

[cali yaris]

what are your personal goals with this?

better acceleration. If I could be in the middle of 3rd instead of the bottom coming out of turns, I could be a lot faster.

[cali yaris]

I think these are correct.

2007 Yaris:

1st 3.54:1
2nd 1.90:1
3rd 1.31:1
4th 0.96:1
5th 0.81:1
Reverse 3.25:1
Final Drive 3.72:1

Scion xB 1st gen:

1st 3.54:1
2nd 1.90:1
3rd 1.31:1
4th 0.96:1
5th 0.81:1
Reverse 3.25:1
Final Drive 4.31:1

[netz2008]

"I could be faster" says the man with a 357 whp Yaris rofl
I'm actually really curious as to what this'll do for your car!

[CrankyOldMan]

Pardon the tangent, but...

I prefer to keep all three decimal places to avoid confusion with similar ratios available on variants of the C5* line. Yes, I've spent entirely too much time researching this. =)

Yaris (non Vitz RS) C50:
1st 3.545:1
2nd 1.904:1
3rd 1.310:1
4th 0.969:1
5th 0.815:1
Final 3.722:1

Vitz RS C56 close ratio:
1st 3.166:1
2nd 1.904:1
3rd 1.392:1
4th 1.301:1
5th 0.815:1
Final 4.312:1

My dream Frankensaxle:
1st 3.166:1
2nd 1.904:1
3rd 1.392:1
4th 1.031:1
5th 0.725:1
Final 4.312:1

Why go through the trouble? Well, because I hate getting stuck below the power band in second gear. The redline speed of 1st is very close to the stock, but because of the taller ratio the drop is only about 2400 rpm to second--instead of 2900. A rev-limit shift would in theory land you just over 4k, right in the sweet spot of the stock/NA torque curve. The internal ratio of 2nd is the same for all C5* series gearboxes, and the drive gear is integrated into the input shaft. Can't change it without customizing the whole shaft. The benefit here is from the shorter final drive ratio, as well as the shorter ratios in 3rd/4th. Sure, you give up a ton of theoretical top end speed, but if you don't ever plan on driving over 100mph, you'll never know it's gone.

The super-tall overdrive ratio in 5th is to compensate for highway cruising. When driving like I stole it, I don't get up into 5th anyway.

Anyway, really looking forward to see how this mod changes your corner exit speeds!

[cali yaris]

^ That's a great tangent, and totally belongs in the thread.

Now what about those tools I supposedly need?

[CrankyOldMan]

Tools. Yes, well. There are several opinions on this.

* Bluevitz-rs had access to a Toyo dealership and their task-specific "puller set B" tools, which made things much easier. This would be the most ideal route. Buying one will cost over $1500.

* A fellow with an older AE92 GT-S with a C52 transaxle bought just the SST's that apply to the C5* rebuild. Total cost at the time, $1200-ish. Not a bad option if you plan on rebuilding more than once, or offering rebuild services.

* One Celica owner that was adding a LSD to his C60 went the harborfreight route and had no issues to speak of.

NB - The single most expensive tool that a transaxle rebuild involving replacement of the LSD or its bearings is the torque wrench. To set the bearing preload, you need some seriously fine measurement. A 0-15 in-lbf is recommended, but you can probably get away with a 0-30. Yes, that's in-lbf. You'll know if you have one, because you would have paid upwards of $350 retail for it. There is no cheap alternative to this except perhaps getting a used one from ebay or borrowing one. Used is iffy unless you have a way to check the calibration on it. The smallest range I could find at work was a 0-50, and the graduations aren't fine enough--the needle is almost as thick as the gap between them. I have an alternative strategy planned, but it involves a force gauge and a custom tool for the output shaft, which is more expensive and complicated than a torque wrench, but I have access to the tools to do it.

[Bluevitz-rs]

I haven't read it anywhere but I know I've seen that some 6 speeds use the .815 gear as 6th, so that's why I thought 5th and 6th might actually be interchangeable.

Edit: The Corolla XRS (USA Model) uses the C64 and has the .815 6th gear. Maybe you could find part numbers and compare to the 5th gear .815, or see if a dealer will order them in for comparison.

http://en.wikipedia.org/wiki/Toyota_C_transmission#C64

[CrankyOldMan]

The 0.725:1 5th gear seems most common on Euro spec Toyota transmissions. I found a site that lists lots of info for the gears themselves including # of teeth and spiral direction. Many of the listings are incomplete, some seemingly halfway through data entry.

It looks on the surface that the 5th and 6th gear sets for 0.725 are opposite synchro spirals. That means that the individual gears can't be swapped, but the set could possibly be flipped over, assuming that the synchros and hub would mate properly, and the ID is the same.

Details:

5th gear 0.725:1

R40-NR30A29 {Drive Gear}
L29^N16A {Driven Gear}

6th gear 0.725:1

R40-NL30A28
L29^N

I'm not 100% on what the notations mean, but here's my best guess.

- R40: right-hand helix, 40 teeth
- NR30A: angled synchro teeth, right-hand slope?
- NL30A: angled synchro teeth, left-hand slope?
- 28/29: ID 28/29 mm??

- L29: left-hand helix, 29 teeth
- N16A: 16-tooth spline

- I think the gears have different IDs for their bearings. Perhaps this part should be broken off into another thread to prevent a total hijack?

[cali yaris]

I think it's useful info, although a general "gearing/trans" thread would probably be a good idea.

I think Art's going to attempt it with tools on hand, let's see how it goes. We can always take the wreckage to a good trans shop.

[CrankyOldMan]

Originally Posted by cali yaris

We can always take the wreckage to a good trans shop.

My brother-in-law has a sign in his garage:

Labor rates

• $50/hr if I do it myself
• $70/hr if you help
• $100/hr labor if you've worked on it before

[cali yaris]

good thing I won't be taking it to him, then...

[johnny_vitz]

I swapped out my echo transmission for the 1st gen xb (for the final drive), really picks up the acceleration. For the price of the used transmission, it wasn't worth pulling apart the transmission. I guess for the yaris, you probably have to though :(

[cali yaris]

I'm not opposed to swapping a whole trans if it's that hard to swap the final drive. I don't think it will be a major project, though.

[johnny_vitz]

How much are the parts from toyota? I didn't want to attempt to take it apart myself, would have went to the trans. shop. Boss wouldn't let me keep my car on the hoist long enough anyways :)

[cali yaris]

Three main parts are a bit over $400 from Toyota. Not including shims which should be pretty cheap.