Hello,

We just got our 1970 back on the road since switching the cruddy early 4-speed to a 1979 280ZX 5-speed. It works great and shifts extremely well....only one small problem. The speedo doesn't function now.

It worked great before with the original gearbox....do we just need to change the speedo gear or do we need a new cable? Our speedo is a very early one starting at 20 mph so we want to keep the gauge.

Anyone done this before? ...Frank I'm looking at you

Thanks,

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Currently Own - RED 70' 240Z, GREEN 72' 240Z

First Owned - New 72' GREEN 240Z
2nd Owned - Used BLUE 74' 260Z

Hi, Robbin ~ I'm lookin' right back atcha!

My Apr/70 240Z was returned to me with the old "71-A" 4-spd out, replaced by a 280ZX 5 spd. The 20mph Speedo works fine, altho I haven't tested it for accuracy yet. At the next opportunity, I will check the speedo gear color to zee what the PO had in there.

As an interesting side note, there has been much controversy over how much cutting and chopping is needed to allow the new 5spd stick to shift properly under the old 4-spd tunnel housing.

I put the tunnel housing from a 1971 240Z directly over my 'new' 5spd, and it *JUST* fits. 1st, 3rd and 5th gears just touch the housing, but not enough to prevent engagement or to knock them out of gear (so far).

*BTW ~ I saw your gorgeous car at Vinny's! What a beautiful job you guys are doing together!

Actually we had a later 240 shifter cut and welded to fit. Vinny then re-welded it and it works great with our original tunnel and console.

He said he won't tell us how he did it....we have to look under the car to find out !!!

Also we had no probelms with the old A-box 4 speed ...it just felt so sloppy and numb compared to 1972 B -box and the ZX 5-speed...so we felt compelled to do it. We still have the original tranny....maybe I'll put it over the fire place.

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Currently Own - RED 70' 240Z, GREEN 72' 240Z

First Owned - New 72' GREEN 240Z
2nd Owned - Used BLUE 74' 260Z

They were pretty good units, with only a few flaws ~ but those few were fatal for my car. The original "71-A" shift linkage involved a "cup" arrangement which held the bottom of the gearlever above the tailshaft. For some reason, that arrangement occasionally (once was enough) caused the whole box to lock-up, requiring complete disassembly of the box to fix it.

The '71-B' unit resolved that with a different shift linkage arrangement.

Anyway, I just had the chance to road test my old 240 with the ZX 5spd, and it's the way life was meant to be! The car always needed a 5th gear (something lower than the 1:1 direct drive of the old 4th gear), and it makes highway life SO much more pleasant! Reminds me of the overdrive units on my old Healeys!

My ZX 5spd is matched to a ZX R-200 differential, which was geared higher than my old R180. Did you leave the 180 in yours, or change it out?

Frank

The speedo gear color has to match the rear end used. I have the chart at home, but seems like you need to get the speedo gear that was in the 4 speed and swap it out. Also, shifter arms are different from Z to Z. For instance: if I put a 280z shifter on my 280zx, it will hit the tunnel. Just thought I'd throw that in. I also found out that a 240sx tranni, (not shure which one yet,) is even better than the 81-83 n/a tranni's and there is nothing wrong with using the R-180 rear diffy. They use them in racing and they do just fine, and lighter at that.

Actually we used a ZX shift lever...but we modified it to work with our early 240Z's tunnel.

We left the R-180 differential in.

Also we are going to try and get the speedo gear out of the our old 4 speed and see if that works.

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Currently Own - RED 70' 240Z, GREEN 72' 240Z

First Owned - New 72' GREEN 240Z
2nd Owned - Used BLUE 74' 260Z

Check on Bryan's ZGarage web site for a discussion of speedo cogs. There are at least two varieties, that on the surface appear to be identical, but they are offset slightly. I had the same issue when I swapped out the 5-speed in my 280zxt. The prior owner had been experimenting with speedo cogs in an attempt to get his digital speedo to read more then 85 mph. I remember having to notch the cog and rotate it 180 degrees before the cogs would mesh.

Phil

Phil & Frank T -

Thanks for the info. I just want to go on the record with you Frank - the car (1970) should have been born with a 5-speed. It is absolutely marvelous and just feels so right. Frank your words, as most often, were elegant and to the point with gobs of truth. The combination of a wonderfully operating motor and the 5-speed is an absolute pleasure. No wonder we all loved these cars when we were so young and were fortunate enough to have one.

I also want to thank and give a super recommendation to Vinny Bedini for his excellent work. This man is truly an early Z car wizard and he cares very much about his work. I honestly can't say enough about his knowledge and talent. I hope his engine project for the Datsun pick-up going for the world speed record at the Bonneville Salt Flats brings him the recognition he deserves.

I wish I had sent him my car long ago when he rebuilt our E31 head last year. We should have had him reinstall the head and motor because we not only would have saved big $$$ but we would have had the confidence in his work knowing that an expert put it all back together. Not to mention the fact that we would have been on the road this Spring!! I wish we could have been at his shop when he worked on her. I can't help but think that the guy who invented the saying "live and learn" owned an early Z or maybe his great, great grandson did (he could see the future!).

Anyway, I found Vin to be very honest and very fast with a very reasonable rate for club members. I sincerely hope he has been training an apprentice because I don't know what life with these cars would be like if he retired.

Thanks Frank, for the recommendation of Vin. And Vin, thanks again.

I would like to encourage any member to feel free to contact me for a reference on Vinny Bedini who is such an incredible asset of the CTZCC.



Robin Foote

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Currently Own - RED 70' 240Z, GREEN 72' 240Z

First Owned - New 72' GREEN 240Z
2nd Owned - Used BLUE 74' 260Z

Here's a post I made in 2002 regarding my speedo cog issue.

http://www.zcar.com/forums/read/1/387640

Here's the earlier post that lead me down the right path...

http://www.zcar.com/forums/read/1/351923/351923

Hope this helps. The keeper and bolt are either on the top or bottom and the cog has to be "adjusted" to correct the offset.

Phil

Oh MAN, Robin~ I will echo that. I can't sing Vinny's praises loud enough. I have known a lot of mechanics in my day, but this guy is a wizzard. He has forgotten more about the 240Z than I ever learned. He is new-tech savvy, but maintains an old-school approach to common-sense auto mechanics. I learn something new each time I visit his shop. (Latest example: Did you know that by leaving your Z in gear while towing it on a trailer, you run the risk of snapping the crankshaft? WHO KNEW? Well, after towing about 9,999 racecars over the years, Vinny knew, and he chewed me out thoroughly when I drove my Z up onto the trailer to bring it home and left it in gear).
Vinny has a lifetime of experience in daily street cars and full-comp racers. He has built countless engines and whole cars, and he presently owns a few race cars of his own, which he tries to spend time on when people leave him alone long enough. He has raced his own cars for many years, so he knows what's important for a car to do and NOT to do.
His dry humor cracks me up. Altho he was very conscientious about calling me frequently (2-3 times a week) with information updates about how my car was progressing (and all the problems he discovered), he would often leave a message that he "had decided to retire", and was "calling from Argentina to say goodbye". I believed it the first time he did it.
Nobody's going to replace Vinny Bedini. He is one of the last hands-on, personal repair mechanics I will ever know. We often laud the great guys at RDZ for their outstanding expertise in the new computer cars, and they deserve that praise. But Vinny has been working on Datsuns longer than any of the guys at RDZ have been alive (Sorry Vin ~ that's true!) and he has followed the evolution of the Datsun/Nissan cars for nearly 50 years. He really enjoys racing, and I suspect if it paid all the bills, that's what he'd rather do for a living. But somewhere along his lifeline, somebody discovered his extraordinary mechanical talent and started paying him to build THEIR winning cars, not his own. He's been at it ever since. Many big-name racers have won their reputations driving engines and cars prepared by Vinny Bedini.
There will always be an unquenchable need for professional mechanics like Vinny. We are the demand; he is the supply. Working alone in his familiar little shop, he limits his projects to only a few cars at a time, and works on them individually. He looks at a whole car, not just at one system of it. He's not pushy, but he makes sure the customer understands the total needs of their car as a complete driving system, and he won't skimp on safety items. He frequently offered to save me money on certain items or procedures, but never on a safety issue. If the car is leaving his shop, with his reputation behind it, it must be safe to HIS standards. I really respect that.
My only criticism about Vinny is that he lives at his shop too much. He pushes himself too hard sometimes, without taking a vacation to blow off steam occasionally. But when you need a master mechanic with a lifetime of personal, hands-on experience with the car you love, it's hard to criticize him for working too hard on it!
When my Z is finished (A/C hasn't come in yet), Vinny Bedini is going to get the biggest VENDOR RAVE I have ever written. This guy has become one of my personal heros, and I'm thrilled to have him as a member of the CTZCC.

Frank T
MbrshpDir/CTZCC
Satisfied Bedini customer

So I removed the carrier and cog from the orginal tranny and its black which means its for 3.545 geared R-180.

What I will do tonight is take the carrier and cog out of our current 5-speed and see what it looks like. Perhaps its no good or stripped. I'll also check to see if our 5-speed is from an early ZX or late ZX. Apparently the carriers are different between the two generaltions and are incompatible.

I'll also attach a drill to the speedo pinnion on the cable and see if it registers anything when I give it a spin.

Has anyone tested these cables before in a similar fashion? Has anyone had thier speedo cable fail...or are they pretty robust?

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Currently Own - RED 70' 240Z, GREEN 72' 240Z

First Owned - New 72' GREEN 240Z
2nd Owned - Used BLUE 74' 260Z

They fail. Mine never did, but two of my buddies had them break deep inside the sheath. Another guy I heard of had his break at the gearbox juncture. Use a low speed drill to start with.

So last night I disconnected the cable from the tranny and put a drill on it. I spun the cable which turned freely and nothing registered on the speedo. I did it counter clockwise...nothing, and then clockwise...nothing.


So I guess our speedo cable is kaput...so has anyone replaced one of these before...its seems like a pretty tough job?

I haven't pulled the carrier and cog assenbly on the tranny yet...because it seems that the cable is the issue. Kinda of strange since it worked fine a year ago when the car was last on the road...but I guess things just wear out sometimes.

Is there anyway its the speedo instument itself?

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Currently Own - RED 70' 240Z, GREEN 72' 240Z

First Owned - New 72' GREEN 240Z
2nd Owned - Used BLUE 74' 260Z

Only way to know that is to disconnect the speedometer cable from the speedometer and spin the cable with the drill again. Then, if you have consistent, hi speed spin at the speedometer end of the cable, you know it's the Speedo itself, not the cable. (If the speedo end spins sporatically, or is jerky, then the cable is bad).

A hint, in case you have to R&R the Speedo gauge:
These gauges have a series of colored lights plugged into the back of them, which are all connected to the same loom. They remind me of a string of Christmas tree lights. There is nothing on the back of the Speedo which tells you what color goes into which hole, and they'll all fit any hole.
When you pull the speedo out, take a felt tip marker and label each hole with the bulb color AS IT COMES OUT OF IT (G, R, "C" for clear, etc). Then, when you get the new speedo, re-copy those marks onto the back of it, so you can put the right color into the right hole.

Have fun standing on your head under the steering wheel! I hated that job and am planning to do it again very soon. Remove the front seat first or you're simply asking to die under there.


Frank

Wow, you guys have a whole different set of problemZ trying to decide what kind of a gearbox to put in the older Z-car than I did. I guess everything from the '77 280-Z to date (except some of the real new models w/a 6-speed) had 5-speeds, do I have that right?

Back in the day, July l974 is when the converZion was done on my '70, there were only two ways to go.

The first way was to find a wrecked or dilapidated SRL-311 (the 2-liter, 5-speed roadster that had way too much engine for its brakes) and to pull out all the stuff you needed and basically bolt it in. I think there were a few things you had to get if you went that route, the driveshaft comes to mind.....

The second way is the way I chose. That was to special order from the Datsun Competition Department the same 5-speed as was used in the race cars, a transmission mount, a short prop shaft, a speedo pinion, and I forgot what else. This gave a 0.864:1 ratio in 5th, but 1st gear wouldn't work with the original 3.36:1 differential unless you rode the clutch a lot, or chose a different set of gears to be installed in the trans at additional cost. My solution was to use the R200, 3.90:1 limited slip which killed the idea of an overdrive, but at least gave me the same final drive ratio as before, 3.36:1, since the 4-speed was direct drive in 4th. But what it really did was give me a better choice of RPM and torque in various situations. More than that, it gave a guy whose joy in driving centers largely around shifting his own gears, more opportunity to do so. As long as it was apart we also installed the 800kg clutch/pressure plate, roller bearing pilot bushing, and a couple of other things.

The only problem didn't appear during the installation. I forgot (this is 35 years later! ) whether it was 5th or reverse, but it would jump out of gear without warning. The fit of the gearshift thru the opening looked good, but would you believe that the thickness of the boot was just enough to apply enough pressure to pop it out of gear. As I recall, we just opened up the hole about 1/4" and it never did it again.

All Z Best, Kathy & Rick

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All Z Best,.......Kathy & Rick

1969 Z.CAR (#00013 10/69) 8/30/76
1969 ITSA.Z (#00171 11/69) 8/24/73
1970 OLD.Z (#06289 6/70) original owner
1971 510 2dr since 12/31/75
1969 1600 rdstr (our 160-Z)
1971 (#19851 1/71) sold
1975 75.Z (#01343 1/75)