a N/A 300 manual gearbox is identical to a TT gearbox?

i.e is it the same or is the TT box an uprated item....?:confused:

cheers Jon...

I believe that the manual gearbox is the same on all models, but on an NA the final drive ratio (differential) is 4.083:1 vs 3.69:1 on the TT.

I vaguely remember someone mentioning that the TT gearbox was made of a stronger metal, it may be worth investigating as im not 100% sure.

The autobox is definitely different ...

In the service manual there are 3 different boxes listed - 2 manual and 1 auto so I presume there is a different box for the NA

There only seems to be one manual box listed :-

http://www.300zx.co.uk/tech/manual/manual/mt/035.gif

 

But there are two autos :-

http://www.300zx.co.uk/tech/manual/manual/at/187.gif

 

 

Originally posted by ChrisC

In the service manual there are 3 different boxes listed - 2 manual and 1 auto so I presume there is a different box for the NA

Can someone explain why an auto's 4th is a higher gear than a manuals 5th? Never made sense to me...

Originally posted by Robtor

Can someone explain why an auto's 4th is a higher gear than a manuals 5th? Never made sense to me...

 

Final drive ratio is longer/higher on a TT by quite a bit - so if you take that into account I suspect the ratio of the whole drivetrain in 5th on a TT is longer than 4th on an auto. Also remember it's not usually til several k revs in a viscous coupling that input and output will spin at the same speed. (Does the Z have a lockup on the coupling?)

 

I can't find the bookmark I had with gear ratios on... so someone else will have to do the math!

Think its 25.7mph per 1000rpm in an manual TT versus 28ish mph per 1000rpm in an auto.

 

Remember the auto has a lock up clutch but when you desire moderate acceleration short of the box changing down or kicking down the lock up drops out and the torque converter allows the rpm per mph to increase. In effect using torque multiplication gearing effect to increase torque to the axle and give acceleration. So it makes sense to have a high mph/rpm just because you can and still retain driveability - In a manual this would result in loss of driveability and responsiveness.

 

In Auto 3rd locked up / OD locked out the ratio is the same as in a manual in 4th - ie. the gearbox is straight through input speed = output speed.