vtirocz

Like the title states, I'd like to get the 1-3 gearing of the M12, but want to keep the 0.50 M6 6th gear ratio. My question is this:

1. Can the 1-3 gears from the M12 be swapped onto the M6? OR
2. Can the 5/6 gear from the M6 be swapped onto the M12?

Thanks!

thesource

iTrader: (60)

You can't retain the .50 6th gear ratio with the 2.97 1st gear.

vtirocz

Thanks for the info. Would you mind elaborating on why not? I thought as long as both 5 and 6 were changed, it could be done. Interested to hear why it's not possible. Thanks!

jmd

iTrader: (4)

The 2.97 MN12 boxes have different 4th gear tooth count / countershaft gear tooth counts.
4th gear (input) to countershaft ratio impacts all gears except 4th.
This is because power is transmitted from the input to the counter, and then from the counter back to (6th) gear.

vtirocz

Thanks JMD! Just to be clear, theres no alternate 5/6 gearset that could give me a lower (numerically) ratio than 0.57 in the MN12?

vtirocz

On Tremecs website http://www.ttcautomotive.com/english...s/t-56.asp#Car, part number TNET1077 has the 2.97 first gear and 0.50 6th gear. Is that a typo?

calhoon

iTrader: (6)

That is not a typo. That is a different 2.97 gearset.

thesource

iTrader: (60)

Not sure what that unit consist of. It appears to be an after market unit. I've seen all kinds of crazy T56 units floating around out there. Tremec supplied the unit in different configurations to all kinds of models and offered a few in strictly after market applications.

gectek

iTrader: (2)

If you can disassemble the main shaft and the counter shaft and pull the gears off, then why can you NOT swap 5/6 drive and drive gears to get that ratio? These are not like standard 4 spd or 5 spd gear boxes where the counter shaft has all the gears cast into it and they are not removable. You can disassemble the entire counter shaft and restack.

thesource

iTrader: (60)

Not sure what that unit consist of. It appears to be an after market unit. I've seen all kinds of crazy T56 units floating around out there. Tremec supplied the unit in different configurations to all kinds of models and offered a few in strictly after market applications.

vtirocz

This seems to make sense, but JDM mentioned that 4th gear tooth count was different between the two gear sets (M12 set & M6 set) so maybe that's where the problem lies.

Could one of the experts chime in again to respond to Gectek's post? I'd like to get your opinion.

85MikeTPI

iTrader: (9)

This thread may help to explain some of what you're asking:

https://ls1tech.com/forums/manual-tr...gear-swap.html

I think the TNET1077 is an aftermarket Ford T56. Some of the ford units have separate 5 and 6 gearing (2 pc driven gear) and wouldn't be interchangable with GM units.

thesource

iTrader: (60)

The 03-04 Cobra and the Aston Martin are the only two I know of with the 2 piece 5-6 cluster gear. The TNET1077 could be an after market Ford unit but I've never heard of or seen it. The 1396-xx-011 and 012 I believe are the Ford units for the 5.0 and 4.6 engines.