5 Spd to 6 Spd Conversion DIY

[Bluevitz-rs]

This is a DIY on how to convert the stock C150 5-Spd (Echo) to the close ratio C160 6-Spd.

Detail on this conversion would still apply to the Yaris transmission.

Unfortunately the C160 I purchased does not have the optional LSD, but the price was right, so I got it. There is also a possibility of swapping the lower ratio .815 5th gear out of the 5-Spd in place of the 6th gear's .725 in the 6-Spd. This would make the RPM even higher in 6th and would only be recommended for racing purposes only. The stock gearing in the 6-Spd has increased RPMs @ 100km/h from 2600 to 2950.

You need to make slight modifications to the frame in order to clear the end of the transmission, as it's longer for the extra gear and an extra bearing, though the modifications to the frame of the Yaris might be different, or not needed at all. I don't have a Yaris, so I can't be sure. This was relatively simple to do with a cutoff wheel on my angle grinder and MIG welder.

Here is a graph to illustrate the speed differences between the two transmissions.



The Main Gear Housing
I'll start with a side by side comparison shot.
The Echo's C150 on Left and the C160 on Right.


Inside the C150


Inside the C160
Notice the extra gusseting under 1st gear.


Slight differences in the top of the cases. There's an extra hole on the top of the C160. Its only and oil fill hole, but the shifter mechanism is slightly longer.




The Bell Housing
C160 on Left and C150 on Right
The only swap needed is to the reverse gear arms and shaft. All of the bearings are the same size. I measured both input and output shafts and they're identical.


The C160.
The only noticeable difference is the notch for oil flow to the reverse gear idler shaft hole.


The C150


The End Cover

There are major differences here. It's much longer because it contains an extra gear and bearing support.
Also, you NEED the Puller B Set from Toyota in order to properly pull the gears off, plus a steering wheel puller and studs for the No.3 clutch assy.


My Clutch after 70,000Km. Looking really good


My Fidanza Flywheel and Celica GTS clutch and cover
Also note the frame before modification.

[Bluevitz-rs]

Frame Modification

Here you can see what needs to be done to the frame.


After cutting, hammer the frame back together and Weld.


And the "D" shaped piece that was cut out.


Frame welded and some white primer (that wouldn't spray LOL).
After welding, I sprayed the inside of the frame heavily with oil rustproofing.
The outside of the weld was prepped with rust neutralizer, primer and I finished it off with black asphalt undercoating. (not pictured)


Assembling the Transmission
All of the gears need to be pulled from the Case and placed into the Bell Housing.
The reverse idler gear shaft needs to be unbolted from the case and oriented into the bell housing for reassembly once the case is put back on.
(Sorry, no pictures of this procedure)

Fully Assembled

(Not pictured is the Neutral Idler Arm)
The neutral idler arm became and bend and fit process until the proper travel was achieved for the shifter inside the car. Unfortunately the arm was already bent when I opened the box after delivery, so I don't know if a stock arm would have worked or not.








Gear Shift Return Spring

There's a neutral return spring that needs to be removed and/or modified for proper shifting.

I'm sure the same thing would need to be done in the Yaris.



I did all modifications myself, in my garage. The hardest part of the whole precess is getting the transmission up and back onto the motor. That requires the help of someone else. The transmission weighs about 60-70lbs, so lifting it into place is nearly impossible to do on your back.

One thing I would recommend when buying a used transmission with unknown millage is a COMPLETE teardown. I'm kicking myself now for not doing this as there's a slight click going into 4th and slight vibration in the shifter. I just switched from cheap break-in oil back to Castroil Full Synthetic 75W-90. The cheap oil was used to clean out the crud and was only used for 100km. It came out pretty dark, so it did it's job. Gear 5 and 6 and their synchronizers were both wiped clean while they were off and shift like butter.

If you have any Q's that need A's, post up.

Bluevitz.

Update: I did a bit more tweaking to the bottom of the shifter so it doesn't pull back as far for gears 2-4-6. I just pulled the lever out and bent the bottom with the torch. I also put a couple of bends into the Neutral Return Spring. It centres between 3-4 with more authority now. If left stock (the spring is normally straight) it fights the transmission to pull the lever in between 1-2. It worked fine without the spring, but feels better with it in.

[ddongbap]

I was just thinking about this today. So this probably means the 2zz needs the same frame notch. Probably.

Btw, you're insane. Gj.

[Kaotic Lazagna]

Wow. Awesome!

[Betrivent]

Damn you're in ontario, I'd totally pay you to do this for me :P

[rob323]

Good stuff . I have about a million questions for you, but here's a couple to start off with:
1 Are the mounts in the same place on the C160?
2 Any mods required to the shifter cable ends or to the throw of the cables to prevent over selecting etc?
3 Why do you remove the neutral return spring?
4 When you change gear at redline in 1st, what revs does it drop to in 2nd?
5 Do you re-use the factory echo driveshafts?
6 Is the C160 diff an 8 bolt diff?
7 Did you have to re-shim anything?
8 Did you use any of the C150 bellhousing or casings or is it all C160 that's in there?

I'll stop there for now.

Cheers,
Rob.

[Bluevitz-rs]

Originally Posted by Betrivent

Damn you're in ontario, I'd totally pay you to do this for me :P

I've driven from Calgary back home, and it's a far enough drive. LOL, at least 3 days from Richmond

[Bluevitz-rs]

Originally Posted by rob323

Good stuff . I have about a million questions for you, but here's a couple to start off with:
1 Are the mounts in the same place on the C160?
2 Any mods required to the shifter cable ends or to the throw of the cables to prevent over selecting etc?
3 Why do you remove the neutral return spring?
4 When you change gear at redline in 1st, what revs does it drop to in 2nd?
5 Do you re-use the factory echo driveshafts?
6 Is the C160 diff an 8 bolt diff?
7 Did you have to re-shim anything?
8 Did you use any of the C150 bellhousing or casings or is it all C160 that's in there?

I'll stop there for now.

Cheers,
Rob.

1. Yeah, the mounts are all in stock locations.
2. You don't have to modify the cables, but you do need to play around with the angle at which neutral arm is on the transmission in order to be able to select all the gears. R is beside 1st.
3. Because of where neutral naturally fall between 3rd and 4th. With the spring in there it wants to pull neutral between 1st and 2nd. Not good when you pull out of 5th looking for 4th and you get 2nd instead.
4. I haven't really checked yet, but it somewhere in the area of 4600-4800. (I'm eventually going to make a video pulling onto the hyw so I can see what the RPMs are actually doing.)
5. Yes.
6. Yes. Prime for various LSDs.
7. No.
8. Yes, the entire C150 Bell Housing is used. The only swap is to the reverse arm and shafts pictured. The rest is C160. They both mate together perfectly with locating dowels.

I think this would be killer in the rally car. But you'd definitely want to find one with an LSD.

[rob323]

That's what I'm thinking. I already have this sitting at home waiting for the right gearbox to put it in.

[Bluevitz-rs]

Will that one for the Echo's axles?

Do you know what model car it was intended for?

[rob323]

TRD Part No. 41301-AW004
Suits Vitz, Starlets, Corollas, Levins etc.
Suits 8 bolt ring gears.
http://trdparts.jp/english/parts_lsd_mechanical.html

[Bluevitz-rs]

Ah yes. It would fit.

[rob323]

Originally Posted by Bluevitz-rs

7. No.
8. Yes, the entire C150 Bell Housing is used.

Once you swapped it over onto the C150 bell housing, did you recheck the preloads?

[Bluevitz-rs]

Originally Posted by rob323

Once you swapped it over onto the C150 bell housing, did you recheck the preloads?

No i didn't. I probably should have but nothing is whining or making any noise, so I think I'm ok.

I was kinda pressed for time as I needed my car. The only problem there seems to be is with 4th gear when the transmission is still cold. I think the syncro is a little rooted. Once it warms up it shifts much better. Also, it doesn't grind or anything, even when shifting hard @ redline. It just has a click when you pull it into gear and a slight vibration in the shifter.

But in your case, if you have the time to work on both transmissions out of the car it would be a really good idea to go over EVERYTHING, like a rebuild should be done.

[thebarber]

amazing. very nice work.

[zachryboles]

yah i was thinking if anyone would actually do this lately and its nice to see its being considered. All we need to see now is that matched with the 2zz motor.

[Bluevitz-rs]

Originally Posted by zachryboles

yah i was thinking if anyone would actually do this lately and its nice to see its being considered. All we need to see now is that matched with the 2zz motor.

I shouldn't be all that hard. The 2ZZ uses a single pulley with one huge belt to run all the accessories, but the whole motor (from the surface the transmission bolts to) is wider by about 1". So on the echo at least, you'd need to cut about .5" thick portion of the frame away to clear the pulley and belt. Then you'd need the C60 and C160 transmissions to swap bell housings like as if you were doing it to the 1NZ in order for the axles to fit. Or just have custom inner CV joints put on the stock axles and use the C60. Which is probably cheaper.

Then I'm not sure if you'd need a custom header fabbed up and custom exhaust. One plus on the Yaris is that it uses electric PS, so you wouldn't need to worry about plumbing the PS pump and could delete it from the motor. Next, plumbing the A/C is optional but shouldn't present any issues.

Last, wire it all up. Chances are the most of the Yaris wiring will plug in, but if you're going to all the trouble of installing this engine you might as well use the 2ZZ harness.

[Bluevitz-rs]

Here's a Video uploaded to YouTube.

Enjoy