[h018871]

Does anyone know if the ZL1 & SS input shafts have the same number of gear teeth? Not splines for the disks.
Asking another way, are the shafts interchangeable?

They do have different part numbers, curious if it is a meteorological or gear ratio difference.

Thx in advance

[bishopts]

Originally Posted by h018871

Does anyone know if the ZL1 & SS input shafts have the same number of gear teeth? Not splines for the disks.
Asking another way, are the shafts interchangeable?

They do have different part numbers, curious if it is a meteorological or gear ratio difference.

Thx in advance

They are different
MJK is the non 1LE Zl1 trans
MM6 is the non 1LE ss trans
Both are TR6060 but they run different gear ratios.

[bishopts]

Quick search on the internet says the zl1 uses 33 tooth gear and some SS models do too but some use 31 tooth gear depending on the year. But the bearing is different.

[h018871]

Correct, the transmission ratios are different for ZL1, ZLE and SS.
All 6th Gen TR6060 have the same clutch spline count, from my research anyway.

My question is in regards to the gear on the input shaft that drives the counter shaft, highlighted by the green arrows in the drawing and picture of the full gear set.
Note in the picture that the input shaft is not shown, only the input gear. The upper shaft is the main shaft and lower shaft is the counter shaft.
The output to the driveshaft is from the main shaft on the right of the picture.

For info purposes, the gear order front to back, left to right in picture is
input gear, 3, 2, 1, 6, 5, reverse, 4th locks the input and main shafts together
When the clutch is engaged and the engine is running both the input and counter shafts spin.

The reason for my question about the input shaft tooth count is that I plan to change both 5th gears, drive and driven. If the input gear tooth count is different between ZL1/ZLE and SS, then the overall 5th gear ratio will be different...........
I want to be sure I get my desired ratio.
If you've made it this far, thank you.

[bishopts]

Originally Posted by h018871

Correct, the transmission ratios are different for ZL1, ZLE and SS.
All 6th Gen TR6060 have the same clutch spline count, from my research anyway.

My question is in regards to the gear on the input shaft that drives the counter shaft, highlighted by the green arrows in the drawing and picture of the full gear set.
Note in the picture that the input shaft is not shown, only the input gear. The upper shaft is the main shaft and lower shaft is the counter shaft.
The output to the driveshaft is from the main shaft on the right of the picture.

For info purposes, the gear order front to back, left to right in picture is
input gear, 3, 2, 1, 6, 5, reverse, 4th locks the input and main shafts together
When the clutch is engaged and the engine is running both the input and counter shafts spin.

The reason for my question about the input shaft tooth count is that I plan to change both 5th gears, drive and driven. If the input gear tooth count is different between ZL1/ZLE and SS, then the overall 5th gear ratio will be different...........
I want to be sure I get my desired ratio.
If you've made it this far, thank you.

I would think your going to need to swap both (which is part of the cluster gear)in order to achieve what you're wanting. But the "wrench in the gears" of the idea might be the different bearing for the input shaft.
I doubt your going to be able to take a 31 tooth gear out and simply replace it with a 33 tooth gear without a mesh issue.

[h018871]

Originally Posted by bishopts

I would think your going to need to swap both (which is part of the cluster gear)in order to achieve what you're wanting. But the "wrench in the gears" of the idea might be the different bearing for the input shaft.
I doubt your going to be able to take a 31 tooth gear out and simply replace it with a 33 tooth gear without a mesh issue.

I agree, the gears have to match or mesh. I do appreciate your input
I do not plan to swap the input shaft. My goal is to swap only the 5th gear set from 0.74 to 0.82. The rub is that the final ratio, 0.82, is also dependent on the ratio of the input shaft to the counter shaft. I have the ZL1 5th gear set and know the number of teeth on them, 41 & 27. That doesn't come out to 0.82. You can back calculate the input/counter shaft ratio, but it is only for the ZL1 trans.
In a round about way I can determine if the ZL1 0.82 gear set will "act" like 0.82 if the input shaft gears have the same number of teeth between the SS and ZL1. I don't have the parts to count them, just curios if anyone had a transmission or two down and would count them for me.......or even better knew if they were the same or not.

Tomorrow I plan to call up Tx drivetrain performance, tremec and tick performance and see if I'm on the right track or if I'm way out in left field. They for sure ought to know.

I know that this is a very specific question that only a handful of people would know and even fewer are interested. Sever folks are swapping complete MJK or MH3 transmissions into SS cars, I don't want to do that because I do a fair amount of highway driving and want to keep the 0.50 6th gear

[bishopts]

Originally Posted by h018871

I agree, the gears have to match or mesh. I do appreciate your input
I do not plan to swap the input shaft. My goal is to swap only the 5th gear set from 0.74 to 0.82. The rub is that the final ratio, 0.82, is also dependent on the ratio of the input shaft to the counter shaft. I have the ZL1 5th gear set and know the number of teeth on them, 41 & 27. That doesn't come out to 0.82. You can back calculate the input/counter shaft ratio, but it is only for the ZL1 trans.
In a round about way I can determine if the ZL1 0.82 gear set will "act" like 0.82 if the input shaft gears have the same number of teeth between the SS and ZL1. I don't have the parts to count them, just curios if anyone had a transmission or two down and would count them for me.......or even better knew if they were the same or not.

Tomorrow I plan to call up Tx drivetrain performance, tremec and tick performance and see if I'm on the right track or if I'm way out in left field. They for sure ought to know.

I know that this is a very specific question that only a handful of people would know and even fewer are interested. Sever folks are swapping complete MJK or MH3 transmissions into SS cars, I don't want to do that because I do a fair amount of highway driving and want to keep the 0.50 6th gear

Where do you even use 5th gear? On throttle it's like 140mph+ and highway cruise you just go to 6th.

[h018871]

Originally Posted by bishopts

Where do you even use 5th gear? On throttle it's like 140mph+ and highway cruise you just go to 6th.

High speed tracks like Watkins Glen, also when open road racing on 19” tires.

[h018871]

Ok, first off........as I tell my wife "I'm slow, but I do eventually get there", bishopts knows what he's talking about

SS input shaft has 31 gear teeth, counter shaft has 36 teeth
ZL1/ZLE has 33 teeth, 41 teeth

putting the ZL1/ZLE 5th gear, 0.82 (27/41) in the SS will make an overall ratio of 0.76, not desirable
Tremec makes a 37/54 set that makes a ratio of 0.80, much better

So, the answer to my question(s):
the gears are different on the input shafts
the shafts are not interchangeable
the shafts may or may not have metallurgical differences
there is definitely a difference in the tooth count

good explainer on the ratios in the TR6060

[bishopts]

so input shaft is 4th gear drive gear . the cluster gear is 4th, 3rd, 2nd, 1st driven gears.
the cluster and input shaft have nothing to do with 5th or 6th swapping. 5th 6th and reverse are in the extension housing which is the rear of the transmission.
ive built t56 before but not tr6060, but i just looked through the parts breakdown to confirm.
its probably why there is a difference between zl1 and zl1 1le on 6th gear only. because both of those are easily swapped without having to change out a cluster gear and 4 other gears that drive it.