5 speed in a 4 speed question

[e_racer1999]

Khatru z, One additional thing to consider.....with a 5spd from a ZX, you will likely want to change the gearing in your differential to 3.90 gears. (this gearing is what the ZX tranny is matched to for best overall gearing on the street). Many guys just swap out their R180 diff to an R200 diff to get that gearing, as the a naturally asperated ZX comes with an R200 w/3.90 gearing. All the info is in the archives and if not there, visit the HybridZ site.

Tom

true. i'm still running the OG 240Z r180 and i wouldn't mind some better accel. i'm switching out to the R200 once i gather all the pieces. however, with the nicely tuned stock L28 (F54 w/ N47) it still pulls like mad

[Carl Beck]

Hi Dave:

Since you have a 72 240-Z - you just use the shift lever off the 4 spd. for the 5sp.

If all you are changing is the transmission - no need to worry about the Clutch Assembly {Pressure Plate and Clutch Disc} .... However - you will want to take the Throw-out bearing collar off your 4spd.. and put it on your 5spd. Since this is the first time you have done this - BE CAREFUL NOT to get the two confused... don't hold them up together to look at them!......Take the throw-out bearing collar off the 5spd. and set it far aside - out of the way. Then take the throw-out bearing collar off the 4spd. and put it directly on the 5spd.

If you retain the stock rear gear - you'll have to swap the speedometer drive gear from the 4spd. to the 5spd. {one bolt to take out, and the carrier and gear will lift out}. This will keep your Speedo accurate.

Before you do any of the above -

a) order a new throw out bearing from Nissan {cheap insurance}

order new shift lever bushing for the 83 5spd. There are three of them. Two go in the sides of the shift lever at the tranny - and one goes on the bottom of the shift lever. Two different Part Numbers {cheap insurance - these always wear out}

c) depending on the type of exhaust system you have - you may need to get and exhaust manifold to exhaust header pipe gasket. If the car is still stock - you have to loosen the exhaust header pipe to move the exhaust system aside - to get the tranny in/out. I also recommend that you order new nuts for the exhaust header pipe while your at it. You may or may not need them.. but better to have them on hand and again cheap insurance.

As for changing the rear end ratio - I didn't. I'm perfectly happy with the slightly taller gearing in town.. all stop and go traffic can be easily handled in 1st and 2nd... Likewise on the highway - the taller gearing is GREAT....much lower engine RPM and a more quite ride...

If you like drag racing from stop light to stop light - yep... you'll need the 3.9. If you put an L28 in front of that 5spd. - you'll have enough additional HP/Torque to easily pull the 3.3... and you wouldn't want to go much lower then a 3.7.

FWIW,

Carl B.

[khatru z]

Thanks for the info Carl..I don't race my Z like I did when I was young. I have put over 200.000 miles on it and I want it to last . I have had a lot of cars and own 11 now but I will never sell my Z...

Dave...HLS 3069220

[240ZX]

Carl,

I certainly respect your opinions but, the 3.90 gearing was the stock set-up for the ZX 5spd (N/A cars) and no by means drag race gears. Many have done this swap without changing the diff gears and most all have complained of too high of gearing....eventually they wind up going with the 3.90.

Tom

[sblake01]

That would depend on how you drive your car. 'Drag racing' and 'drag racing from stoplight to stoplight' (neither of which I do anymore) are two different things. First year ZXs (79) had 3.70 rear ends like the 810s. The 3.90 came in the 80-83. I have the stock 3.54 in my 78 w/an 83 5 speed and for the way I drive, it's fine.

[ktm]

I have a 3.54 in my car with a 260z 4-speed (3.592 first gear). The overall gearing ratios are close to running a '72 4-speed with a theoretical 3.70 differential. I love it. The car turns around 3000 rpm at 70 mph and pulls in damn near any gear at any speed.

[Marty Rogan]

That would depend on how you drive your car. 'Drag racing' and 'drag racing from stoplight to stoplight' (neither of which I do anymore) are two different things. First year ZXs (79) had 3.70 rear ends like the 810s. The 3.90 came in the 80-83. I have the stock 3.54 in my 78 w/an 83 5 speed and for the way I drive, it's fine.

Hey Stephan,

Is the 3.54 from the '78 an R180 or R200? Did it come with the splined connection to the half shafts? I picked up one of those last year, but have not had a chance to install it. The guy I bought it from said it was an R180. I was hoping to stay with an R180 so I didn't have to change the moustasch bar, etc.

Marty

[ktm]

Marty, I have a 3.545 R-180 differential. The half shaft connections are not splined but use 4 bolts. See the following link that shows pictures of my diffy:

http://www.classiczcars.com/forums/showthread.php?t=24461

[Marty Rogan]

Marty, I have a 3.545 R-180 differential. The half shaft connections are not splined but use 4 bolts. See the following link that shows pictures of my diffy:

http://www.classiczcars.com/forums/showthread.php?t=24461

The one I picked up looks just like yours and does not look big enough to be an R200. I does however have the splined connection. I was hoping to use my current half shafts since I just replaced the U-joints with Spicers.

What I would really rather do is replace the diffy with R-180 LSD in 3.9, 4.11 or 3.7 ratio, but I haven't found one yet. That would really help wake up the L28, ZX 5speed combo. If I can't find one, I guess I will pop in the 3.54.

Marty

[Duffman]

Marty, other than having to change the moustache bar, etc, doesn't it make more sense to go with the R200, rather than the R180? Was always told the R200 is more durable, etc, and was a desired swap for those going from a 4 speed to a 5 speed tranny. Your thoughts?

[sblake01]

The 78 280Zs came with a R200 if they were a manual trans and a R180 if they were an automatic.

[Marty Rogan]

Marty, other than having to change the moustache bar, etc, doesn't it make more sense to go with the R200, rather than the R180? Was always told the R200 is more durable, etc, and was a desired swap for those going from a 4 speed to a 5 speed tranny. Your thoughts?

There are a number of reasons that I don't really want to use an R200. This is a track car, so:

1) I don't want to add any un-necessary weight.

2) My engine isn't that powerful that the R180 won't hold up.

3) The R200 has a non-symetrical shape to it. It is fatter on the drivers's side. In hard cornering, the half shaft can bottom out and cause handling problems. This is my biggest concern.

Marty