Transmission Upgrades on pre '72 Z's?

[Dave N]

Has anyone with a '70 or '71 Z changed to a 4 or 5 speed transmission from a '72 or later Z? I have a '71 Z restoration/project car where the previous owner replaced the original 4 speed with what appears to be a '72 or later 4 speed. Due to the different locations of the shifters, he cut the center console by the ashtray (and the ashtray itself also) to eliminate the interference problem with the later transmission.

I thought this could be remedied by changing to a '72 center console - but after getting one from a junk yard to check the fit, I found that the shifter is not centered in the opening of the '72 console. When I put the transmission in 1st or 3rd gear, the lever comes very close to hitting the forward edge of the opening. I remember that the lever was centered in the opening on my previous '72.

Either the previous owner installed the wrong 4 speed (could it be a 510 or similar transmission?), or does the '71 and '72 dash differ slightly where it meets the center console and my '71 dash is not letting the '72 console sit in the proper location?

I would greatly appreciate comments and advice from anyone who has encountered this problem before.

Thanks!

Dave N.

'71 240Z (restoration in progress), '90 Z32 TT (to hold me over until the '71 is finished), '78 280Z (parts car - but possible autox'r candidate).

[240ZX]

Yes, a 5 speed (I'm using a 5 speed from a 82 ZX in my 1970 240Z) will bolt right into your early Z car. However, the shifter will be located 2.25" forward of the original 4 speed shifter. You can read articals on various ways to make this a functioning swap, but the bottom line is modifying the shifter to exit where the original one did! Now I'm no genious, but here is basically what I did. I purchased a length of 0.625 x 0.095 DOM steel tubing and used a tubing bender to put an almost 90 degree bend in it. Now knowing that the new lever must be back 2.25", I layed the original 5 speed lever on a flat surface so the main part of the shaft near the pivot was vertical. Now lay the 5/8 tube over the it so as to replicate the angle of the original lever, but positioned back 2.25". I drew this on paper, to scale, for a more precise calculation!!! Where the original lever and 5/8 tube intersect is where you will want to cut both pieces. The cut should run from one exstreme of the intersection to the other, providing maximum weld area. ( Roughly speaking, you will have an angled cut of about 45 degees on each piece). Before welding the two pieces together, double check it in the car for proper position. Note: Be sure to leave enough of the original shaft, above the pivot, to accomodate the boot on the transmission!!! Once you are satisfied with the location of the new lever, have it TIG welded together by an experienced welder. You might ask why I choose 5/8" tube for the lever!? Well, it just so happen that the shifter knob I purchased has a 5/8" lever hole. In the event you want to use an original shifter knob, weld a threaded peice to the end of the new lever. Of course you will still have to come up with a method to seal the trans tunnel opening. And yes you will have to open up the front side of the trans tunnel opening. I opened mine up approximately 2" and have plenty of clearance. With this lever modification, you have the luxury of making your shifter as long or short as you wish. I hope this information may help you out.

One Man's Opinion,

240ZX

[frumon]

I have a 1970 Z with the original 4-speed. I did purchase a 1982 five speed but after considering the changes that installation would require decided to stick with the 4 speed. I have heard the original 4 speed was a stronger transmission but really don't know.