A friend of mine bought a 260Z that was in a storage locker for 40 years. A real barn find! It was heavily modified for racing back in the 1970's and then went into storage. We pulled the engine and transmission out today and can't figure out what the transmission is. We thought it was from a roadster but it has a zcar bell housing. Here are some pics. Any information, comments or suggestions are appreciated. Thank you. -Mike

 

With the '71A gearbox, it was fitted to the U20 engine in the SR(L)311 roadster, and also fitted to the early S30, but the bell housing was different, as the starter is on the other side. As the North American market didn't get the 5 speed from the factory until at some point with the 280z (whilst other countries did from the start of the S30 production run) someone was just joined the rear roadster 71A rear and front Z bell housing. My take on it.

Datsun Competition in the USA used to supply a 'kit' to convert an FS5C71-A 'Roadster 5-speed' for use in the Z. The transmission you ask about may be an example of this. Datsun Competition supplied various close ratio gear kits for them too.

However, the FS5C71-A Servo Synchro 5-speed overdrive transmission was fitted as standard equipment for the S30-series Z range everywhere except the North American market. They were also used on Skyline, Cedric and Gloria models in the Japanese market.

Parts (especially the steel Servo-patent synchros) are now hard to find and therefore they can be expensive to refurbish. I have the FS5C71-A on three of my cars and I personally like them, but they have a somewhat undeserved bad reputation which mostly comes from worn out examples.        

16 hours ago, HS30-H said:

Datsun Competition in the USA used to supply a 'kit' to convert an FS5C71-A 'Roadster 5-speed' for use in the Z. The transmission you ask about may be an example of this. Datsun Competition supplied various close ratio gear kits for them too.

However, the FS5C71-A Servo Synchro 5-speed overdrive transmission was fitted as standard equipment for the S30-series Z range everywhere except the North American market. They were also used on Skyline, Cedric and Gloria models in the Japanese market.

Parts (especially the steel Servo-patent synchros) are now hard to find and therefore they can be expensive to refurbish. I have the FS5C71-A on three of my cars and I personally like them, but they have a somewhat undeserved bad reputation which mostly comes from worn out examples.        

We were able to contact the original owner of the car today and he independently confirmed it was a Datsun Competition conversion and even has the receipts to prove it. So mystery solved. I'm guessing it needs total refurbishment so if you have any sources for the rare parts let me know.

Thank you for your help. You were right on, as usual! 

What makes you think it needs a total refurbishment?

3 minutes ago, Patcon said:

What makes you think it needs a total refurbishment?

Just a wild guess, I guess. Because the owner said it slips out of 5th gear and goes into a neutral and that he found metal in the oil when he drained it.

2 hours ago, Consigli said:

Just a wild guess, I guess. Because the owner said it slips out of 5th gear and goes into a neutral and that he found metal in the oil when he drained it.

It's possible but these transmissions will still function well even after abuse. Many times they come out of gear because of interference at the shifter lever. On the transmission I rebuilt that long ago. The only damaged part I really found was the reverse idler gear. It had chipped teeth. Maybe Siteunseen will chime in...

9 hours ago, Consigli said:

it slips out of 5th gear and goes into a neutral

In the main plate (between the 2 halves) are two springs behind short bolts (or one i don't remember) and it's got to short.. best to install a new one or as i ones did. you can make the spring longer again with a side cutting set of pliers.. just pinch the spring with the wirecutter between the windings. (translationproblems haha. hope you understand what i'm saying/meaning to say!)

Measure the length before and after, ad some 3-4mm i think..guess.. (1/8 inch!)

Also.. watch out behind the spring is a ball bearing ball! leave it in! Don't loose it! 🙂  (Adding:  this spring is holding your 5th speed in position and it no longer jumps out of gear..  Also, if you have balance trouble in your powertrain (shaking stick..)  it's also a cause for falling out of gear. Then you have some extra work to do.. )