8/70 240z transmission question

[ZcarFanMan]

I came across a 240z dated 8/70 vin HLS30008992 with A/C. It looks like it was converted from A/T to 4sp. Would it be worth it to swap back to A/T? I'm not looking for performance gains or anything. I just want to get it back to an original state.

I've never driven an AT z before, are they gutless? Should I just keep the manual and move on?

Opinions please.

Thanks

[Arne]

8/70 would have been a very early automatic. What changes do you see that make you think it was converted?

[ZcarFanMan]

There's oil cooler lines coming from the bottom of the radiator that are capped off at some metal plate. I'm just going by description of what my friend gave me. The car is still in reno, on my next run reno in a few weeks i'll pick it up. Lucky for me i'm an auto transporter so it'll be a breeze. Hmm, I read that it was mid A/T production era. Maybe it's a true 4 speed.
Thanks!

[djwarner]

According to Carl Beck, the first AT was SN 08942, so it may very well have been in the first batch of AT's produced. Mine has a oil lines running from the AT to the oil cooler built into the radiator. The automatic transmissions were the same for all the S30s as well as several other cars from the era.

Finding the AT console and shift lever mechanism may be harder to find than the transmission itself.

As for performance, what are you driving intentions? Mine is a daily driver in a suburban environment. 4 speeds can get tiresome in an urban environment.

[ZcarFanMan]

Looking at a pic he sent me and his description of the console I think it's just missing the outer shifter boot for the stick. Maybe?
Here's a pic, not too good but you can see what I mean.

My intentions are weekend driving, occasional trips to vegas with the wife (250 miles one way). Nothing that requires a led foot.
How's the get up and go factor with the AT compared to the manual? kick down for passing as opposed to down shifting etc..

thanks
Jim

[nix240z]

There are a few little things different on auto and manual cars that you can look at.
the console was cut for the auto shifter.
3 hole brake and fuel line insulators vs 4 hole for the clutch line.
no bracket on right side of the transmission tunnel for the clutch slave hose
no clutch stopper bracket or pad on the inside drivers side firewall.
fire wall insulator will not be notched out for clutch stopper bracket
plus other little things.

steve

[ZcarFanMan]

Thanks!

[jfa.series1]

Perhaps the radiator was swapped out at some point with an AT version - possibly from a salvage yard?

[djwarner]

A quick snap of my console showing the automatic shift lever assembly.




To be honest, for your driving intentions, converting back to an automatic would be low on my priority list. Yes, a three speed automatic without a lock-up style torque converter will not be as peppy as a 4 speed. It will kick down from a vacuum switch or from a kick down switch when the throttle is mashed to the floor. Differentials are also different ratio 3.54 for an AT, 3.9 for a MT.

[Arne]

You could look at the write up I did years ago on a similar vintage auto-to-4-speed swap. Imagine doing the opposite. The article also outlines some of the differences between the auto and manual body shells.

http://www.classiczcars.com/forums/t...peed-swap.html

In the end, unless the car is a really nice time warp car that might benefit in value to being 100% original, I doubt that I'd go to the effort to swap back to the auto. The automatics don't totally ruin the car, the little six has enough torque to make it work. But the effort to go back might be considerable, and parts to do so could be hard to come by.

[ZcarFanMan]

Finally picked her up yesterday. Here's a few pics of the lines from the radiator that are plugged and the tranny.

[Arne]

As a guess, I'd say yes, it used to be an automatic. Post a picture of the left front fender well in the engine compartment, showing the ignition coil and the area below and in front of the coil. That should pin it down for certain.

[Stanley]

Car and Driver ran a favorable review of the Z with AT. It's not gutless if you shift it like a stick. You can also downshift, but it's not recommended over 70mph or so according to the owner's manual, so not good for a road race where you need to downshift for a 90mph curve. Can't burn rubber unless the tires are crappy. With a 2 1/4" exhaust you can get very close to the 1/4 mile time that C&D got with the stick (launching at 6000 rpm with the borrowed car). 119mph top speed compared to 124mph with stick. Read somewhere it's good for autocross where you leave it in first and just drive.

I like it for the quick 60 to 90 mph which is handy on the freeway. Worth it to swap, I don't know.

[Zed Head]

I would go all the way and put a bench seat and column shifter in there. Then you can cruise with an arm free for your passenger. Haha.

The residual hoses attached to the radiator imply that it's the stock radiator unless someone was getting fancy with oil cooling. Looks like it was a factory auto car.

The typical mod for autos were called "shift kits". I searched the Google and found a few links.

Shift kits for auto Zeds

Technical Information Page ..... Transmission

Jatco Valve Body Shift Kit Installation 3N71B & 4N71B Datsun 240Z VL Turbo - DragTimes.com

[Stanley]

Thanks for the links about the Shift kits. I'm interested, of course, especially since it doesn't sound very expensive.

[EuroDat]

Thanks for the links about the Shift kits. I'm interested, of course, especially since it doesn't sound very expensive.

A little bit of subject, but maybe interesting for some with auto transmissions.

If you want these kits, you should google "Holden VL commadore nissan transmission shifter kit"

In Australia Holden was using the Nissan RB3.0E engines and the 4N71B auto or the 5-speed manual transmissions in the late 85 through to 1988 Holden commadore until the Buik engine plant was ready for production.
The VL was with the Ford Falcon one of the most popular cars in those years. All the auto transmission shops were doing these mods back in those days.

See link in Gumtree. Kind of Craigslist in aussie land.

VL Turbo Commodore Nissan Datsun Jatco Automatic Shift Kit Servic | Engine, Engine Parts & Transmission | Gumtree Australia Gladstone City - Gladstone | 1021151782

Chas

[Zed Head]

Here's another thread on shift kits that I just came across. Not that a shift kit is necessary, just posting because automatic transmission threads are few. I think it's the same guy.

DIY Stage III Shift Kit Installation for S30 and S130 Jatco Autos - Drivetrain - HybridZ

[hr369]

A turbo zx auto with a lockup torque converter and one of these shift kits would make a nice desert highway cruiser.