1973 240z 3 speed auto swap to 4 speed maxima

[ez73]

I am thinking about swapping my 3 speed auto to a maxima 4 speed I know guys that have done this,but I need all the info thats required.The tranny I have is a 3n71b,the 83-84 maxima/84-89 z31 uses a 4n71b. I think the guy that did this from group z used a 82 maxima---is this a 4n71b? I think all he had to change was a shortened drive shaft. I heard a drive shaft out of a z31 will work. I am compiling information and checking into parts need some advice

[Montezuma]

I wanted to do that too. It takes an 82 Maxima with the electronic over drive. I know that you have to change drive shafts as well. Do a search on this site, I think you will fi.nd the info you need.

[ez73]

I did the search but not finding all the reference material I need ,Are the 82-84 maxima trannys all the same ? the fourth gear is the electronic over drive? Found a couple of 4N71B trannys in Ridgecrest $250/$275 don't know what kind of shape they are in .It looks like the rebuilt ones go for $700-1200. still no definitive word on the Z31 drive shaft. still need more info thanks

[hr369]

I've wanted to do this swap also but haven't had the time. This is what ive archived for future reference. most of what ive seen is converting the zx but this person over on hybridz.org, username "HizAndHerz" did the conversion on a 76 which is not that much different than your 73.

the zx may be different, im not sure. If you really want to do this conversion you might send him a pm. The post was dated 2006.

To clarify: the L4N71B 4-speed OD automatic transmission from a Maxima will bolt up to the L-series engine, but it is quite a bit longer than the 3-speed auto or a manual transmission. New brackets need to be fabricated and either welded or bolted up into the transmission tunnel a few inches back from where the standard crossmember mounts.

From what I've seen and read, the L4N71B overdrive automatic came on late '82 through '84 Maxima's and some early 200SX's. The version from the 200SX has a different bellhousing. The 300ZX and 240SX had the electronic version of the transmission (E4N71B). The electronic version can't be easily used on a first generation Z.

I'm in the middle of this swap on my wife's '76 280Z. I'd been looking for a Maxima to show up at the junkyard for two years when two of them came in the same week. Only one, the '83, had the 4-speed overdrive tranny. Finding a strong transmission is key. I've since found a couple in 200SX's that were burned up (they have the wrong bellhousing anyway).

TransStar has rebuild kits available. Rebuilt torque converters are anywhere from $85 to $300. I was suprised that my local O'Reilly could have one to me in 24 hours for less than $100. I don't think I need one, but its nice to know if mine is bad or goes out.

Our costs so far:

L4N71B 4-speed OD transmission from PnP: $130

Flex plate including crank shaft spacers: $20

Auto shift lever from 1975 280Z: $18

Kickdown switch and mounting bracket from 280ZX: $3.50

Brake pedal: $3

Refresh items (filter, seals, modulator): $32

Hard fluid lines from 3-speed 280Z: $9

Fluid hoses: $10

Driveshaft shortened, rebuilt, balanced: $165

New rear transmission mount: $25

Hardware (bolts, nuts, metal spacers): $15

[ez73]

Thanks for the info. Is the text info from hizandherz at hybrid z? I went back to 2006 and could not find the post .whats the post heading,date of post,.started by hisandherz? can I use my existing flex plate? brake pedal $3?