Comparing the Toyota C160 to the C60 | 6-Speed Transaxle Evolution

6-speed cases

This post is going to be similar to the comparison blog I created on the C150 vs C50, I believe the C160 is super rare so I jumped at the opportunity to document my findings. The first thing you will notice about the case is again, just a bit more width on the newer C60 version. You will see in this blog how slight changes in a few places results in that outcome. In the picture above we notice the cases are very different, on the outside. The bell housings have different starter locations since they are used on different engines. The center case is different due to the C160 being a 1/2 inch shorter, thus requiring a different upper mount. Then end cap for 5-6 seems to be the only compatible part.

Gears

1st gear

The C160 1st gear tooth width is 3mm narrower than the C60, and the overall gear with is 4mm less. That's a huge difference if you do any drag racing, The synchronizer seems to be the same part between the two.

2nd gear

The 2nd gear is a similar story to 1st gear, the C160 is 4mm narrower at the teeth and overall. The C60 has a superior 3-piece synchronizer as well, so that means the 1-2 shift hubs will be different.

1-2 shift hub

3rd gear

3-4 shift hub

The 3rd gear set is where things start to become close, at this point, there is roughly a 1mm difference between the two transmissions. The shift hubs are almost identical and the synchronizers are also the same size, you can use the 2000-2003 C60 synchros with the C160 3rd gear for an upgrade to bi-metal friction material! 

Just like the C150, the measurements of the 4th, 5th, and 6th gears are all the same. The only differences are the synchronizer and hub designs.

Shafts

input shaft

output shaft

Here you can see the C60 shafts are longer than the C160 by roughly 0.6 inch. The differences all occur between the clutch splines, pinion and bearing race, 1st, 2nd, 3rd, and 3-4 hub.

Bearings

bearings

The bearings have the exact same differences as the C150 did, 2mm less width. The good thing is I recently ordered a set of these bearings from Japan, so they are still available.

Differential

differential

This is really cool, the C160 actually came with a torsion LSD! The only downside to this is that it requires a 110mm ring gear, that means you can only use it with the C160, Yaris/xA C50, xB1 C50, or MR2 C52. All other gearboxes(except C150) require the 115mm ring gears and have fewer axle splines.

The differential bearings and seals are different, and so is the spacer in the bell housing. 

Conclusion...

The biggest takeaway here is that Toyota paid attention to what was failing and seriously beefed up those areas. The final drive, the bearings, 1st, 2nd, 3rd, the differential, and axles...the only thing unchanged was the ratios and the 4-5-6 gears. Too bad we still have a problem breaking 3rd and the final drive on stock 2zz's, its better but not a complete solution. I'm sure you know by now that Toyota doesn't even use the C60 in any modern cars, they all use the EC transmissions now like in the new Corrolas. This is why I recommend the WPC treatment on these weak points on all of my builds, and I haven't seen one break yet! Check out the comparison below: