Which Trans For A '71?

[Richard McDonel]

After 10 years off and on with the restoration of my 240Z, I have discarded two bodies, and am left with HLS30 28726, which is now totally rust free and painted the proper shade of orange.   I have three transmissions, all of which are of the second generation pattern, that is to say the shift lever rises about 2 - 3 inches forward of the earlier ones, and the lever has an S bend.  Problem is, the hole in the tunnel is too far back.  So, I have to decide whether to cut a larger hole in the tunnel sheet metal and do everything necessary with the interior attachments, or find an old-style transmission.  I'm interested in hearing your thoughts.  Should I try to find an early transmission?  And of course that begs the question why did Datsun switch -- were there problems with the ratios, the shifting, or the durability of the older model?  Or do I just cut an inch or so off the tunnel sheet metal and worry about the interior when I get to that point?  

 

Here's a curious thing; two of the transmissions have part or serial numbers on the top of the bell housing (710380 and 7226602), but third is blank.  That last one has possibly had a number filed off, but with age it's hard to tell.

 

I appreciate any advice you can offer.

 

[EuroDat]

From what you are describing, you have a pre 09/71 240Z. The original transmission was a F4W71A. The transmissions you have are the F4W71B. The A would be more original, but they are getting harder to find in repairable condition.

Which one is better?? Going on availability, I would say the B would be the better option and you already have 3. Maybe other people have ervaring on this and can make a better judgement.

Those numbers on the casing are just casting numbers for warranty and quality control.

An alternative is to use the B transmission and install a competition S type shifter or cut and weld the existing shifter. There are drawing floating around on how to do this, but the main idea is to get the shifter about 60mm back from anchor point so it clears the tunnel in 1st and 3rd.

Chas

Edit: Just read your VIN. That puts it at around 4/71 I think.

Edited March 25, 2015 by EuroDat

[grannyknot]

Richard, when I replaced the original 4spd with a F4W71B 5spd in my early 240z I found I only had to remove about 5/8" on trans tunnel sheet metal on the forward most edge of the shifter hole for the the 5spd tranny to clear it. Then I added 5/8" on to the back of the shifter hole so I could re-use the stock shifter seal boot.

 

This is one of the most popular mods that are done to these cars so there should be lots of documentaion in the archives.

On the shifter console I found I only had to remover a semi circle notch to keep the shifter from hitting it in

1st, 3rd and 5th.

Chris

 

[EuroDat]

Chris' method would be the simplist and quickest way to fit the 71B, but if you don't want to cut the console you can consider this method. 

I found some photos on the web some time ago. You can see how he cut and rewelded the shifter rod.

A friend did this to his, but we welded it on the back position to make sure it had enough room above the shifter rod. You can see what I mean in the photos and the sketch we made.

 

A word of advice if you choose to do this: Cut the shifter rod off. Mount the bottom section back in the selector mechanism with the transmision in 2nd or 4th. Tack weld the shifter in place so it clears the striking rod guide. Then remove it and weld it fully..    

We found out the hard way. Its was hitting guide and wouldn't let it go all the way into 2nd and 4th. After cutting it off and rewelding it again at a slightly higher position on the ball the problem was solved.

This also makes the shifter shorter and the through is shorter.

 

Chris:  You made a slight error in the type transmission. "with a F4W71B 5spd" should be the FS5W71B.

A little bit of trivia: The 71B stands for the distance between the main shaft centre line and the cluster shaft centre line 71mm. The B is the version; A, B & C.

 

Chas

[grannyknot]

Chas, I'm still your student and make mistakes, you are the master

[EuroDat]

Chris. I have a long way to go before Ill be any sort of master. I make my fair share of mistakes.

btw. Thanks for posting photos of your mod to the console. I havs read about it, but never seen one done before.

Chas

[Richard McDonel]

Much thanks for this gents!

Not entirely sure which way I'll go, but I think I'll take a copy of the drawing Chas provided, along with a shift lever to my friendly local machinist and see if he can doe something like that.

Restoration?  No way.  We're going to be hot rodders!

 

Cheers,

Richard McDonel

[Diseazd]

Chris.....Just wondering......why not put a couple clips in the new cut out area to finish off your cut out more? I like both of your solutions......just find it hard to cut the console of a Series 1.

[pjoe]

The shifter in post #4 has not been cut and rewelded. I used an oxy/acetylene torch to heat it and bend it. Once I got it close I heated it up again and flattened it out on the top. I probably didn't need to trim the couple mm's of sheet metal and I did not modify the console at all. This method takes a little bit of patience. Heat it then bend it and test it the do it again and again. While your bending it, keep a bolt in the pin hole so it doesn't get distorted. I have put plenty of miles on it and never had a problem. It's not hard to do. You just need patience and a hot torch. Good luck.

Brian

[EuroDat]

Hi Brian, I can't remember where I found the photos, but I like the way it was done so I saved them. Nice to know it possible to modify without welding.

We opted to cut and weld to get the extra clearance. It had a new transmission mount which pushed is very close to the tunnel. He also had the guide with the extra long ears, which needed grinding down for clearance and described in the second sketch.

With some modification we managed to fit the rubber boot. It needed a cable tye to hold it on the guide flange, but it seals it well.

It worked well until he sold the car and the new owner rolled it into a ditch

Did you fit the rubber boot when you finished the modification?

Chas

[grannyknot]

Because the leather wouldn't stretch anymore, also I have the leather boot pulled way back to get the pic,

normally you can't even see that semi-circle cutout.

I had 3 consoles to choose from so cut up the worst one then spent far too much time making it look good again.

Chris

Chris.....Just wondering......why not put a couple clips in the new cut out area to finish off your cut out more? I like both of your solutions......just find it hard to cut the console of a Series 1.

[pjoe]

Chas, I was unable to get the original style boot to fit. I had to use the boot from a 73. The clearance is tight but in that picture the transmission is in 1st or 3rd. I didn't want to worry about my weld breaking if I did it that way. Good welders wouldn't have a problem though.