4 Speed Z Trannies - How strong?

[Ron Earp]

The 260Z Jeff and I bought came with a LOT of spares. Cranks, rear ends, etc. and it came with 2 transmissions. How strong are these things? We're not going to be dragging these to the tracks with us so I thought to sell them. If the one in the car breaks then we're packing it in, to take it home and have it rebuilt. So, do I realistically need to keep these around? They seem common on Ebay too.

Thanks,
Ron

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Ron Earp
NC Region
Ford Lightning Tow Beast
RF GT40 Replica
Jensen-Healey ITS
1/2 a 260Z ITS - Zero

[irondragon]

Ron:
The Z-car 4 speeds are a bit more durable than the 5 speeds because they lack the rather delicate 5th/Rev idler assembly.
ALL of the trannies suffer from undersized roll pins which attach the shifter forks to the shift rods. I have had a number of 4 and 5 speeds fail at the track. One involved the 5th gear idler, all others were roll pins shearing.
It is cheap and easy insurance to replace these pins and to add a smaller one inside the stock pin. Very easy to do when the gearbox is out of the car.
Bill Miskoe

[dspillrat]

Originally posted by rlearp:
The 260Z ? We're not going to be dragging these to the tracks with us so I thought to sell them.
Thanks,
Ron

Ron, I wouldn't go far from home without a spare tranny in the trailer....
1 1/2 hour tops to swap alone. Cheap insurance. Stand it up on end back in the corner of the trailer out of the way....
david

[kthomas]

We used 4mm bolt stock for roll pins since my ham fisted drivers managed to fatigue the 280ZX style double pins as well as the Nissan Comp double pins. Did have one of them ring all the teeth off 3rd gear once too, but generally the roll pins are the weak link on the 4 speeds. Put one in the trailer. 20 minute swap if you don't stop for lunch like dspillrat.

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katman

[x-ring]

So Ron, if you still want to sell one or both of those spares drop me a line. No need to pay an Ebay listing fee.


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Ty Till
#16 ITS
Rocky Mountain Division

[Tom Donnelly]

Ron,

I have 3 transmissions. I swap them out all the time. Always for the roll pins. I use a smalller roll pin within a roll pin. I tried katman's fix but I can be so indelicate that the solid pin didn't break but a brass synchro did. And I broke a shift fork once as well. So I stick to breaking the cheaper part. A tranny is easy to pull and rebuild. I've tried shifting "like its an egg" but there are those momentary laspes of reason that get in the way.

Tom
ITS 1970 240z

[Ron Earp]

Ty,

We've got one we'll sell, everyone has talked us into keeping the other.

good tranny, good splines, good shaft, all it needs is a lever that you can use from your existing tranny. Turns free. PO told us they came from running Zs that had been killed in accidents.

Make a reasonable offer and it is yours, probably cost about $25-$30 to ship to you.

Ron

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Ron Earp
NC Region
Ford Lightning Tow Beast
RF GT40 Replica
Jensen-Healey ITS
1/2 a 260Z ITS - Zero

[x-ring]

Ron -

How do I contact you?

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Ty Till
#16 ITS
Rocky Mountain Division

[powerslide91]

So does anyone have any details on which roll pins need to be replaced and how to do the proceedure. My trans has held up for 3 years of hard racing with no issues, so now that I have jinked myself, I better prep my spare...

Thanks,
Jeff

[Ron Earp]

[email protected]

You know, I just checked my profile by clicking on it on this thread and it says email not available. I clearly have an email in my profile though - what gives?

R

[This message has been edited by rlearp (edited March 16, 2005).]

[x-ring]

I don't know. That feature has not worked in the 3 years or so that I've been hanging out here.

You've got mail.

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Ty Till
#16 ITS
Rocky Mountain Division

[bobpink]

Whatever happened to Mr. Reckert?

Originally posted by kthomas:
We used 4mm bolt stock for roll pins since my ham fisted drivers managed to fatigue the 280ZX style double pins as well as the Nissan Comp double pins.

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Bob Pinkowski
Atlanta Region SCCA
ITS Honda Prelude

[wburstein]

Jeff,

If you go to the trouble of replacing one the roll pins, you may as well do all of them. Often, when I do ours, I find that some of the roll pins are damaged, but had not yet failed.

Over the years, these $.10 parts have been our highest failure item and have cost us a number of races. We now use two transmissions and get about half a season out of each by using a double roll pin.

That said, by properly servicing the synchros, balk rings, T-bars and springs, you can make shifting much easier and reduce the load on the roll pins. Of course, that is much more expensive than using old transmissions and just replacing the roll pins on a routine basis ;-)

And if we could just get our ham-fisted driver to take it easy on the shifter...

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Wayne Burstein
WDC Region, ITS #10, Datsun 240Z
www.mountainmotorsports.net

[kthomas]

Originally posted by bobpink:
Whatever happened to Mr. Reckert?

Ah, he'll be pleased to know you remember him by that description. He's unhappily retired from racing but passing time by hotrodding his dad's fishing boat, terrorizing the local ricers in his 560hp 300ZXTT, and keeping F-22's rolling out the door of the bomber plant.

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katman

[bobpink]

Just brought back some memories of the "old" days and poking a little bit a fun, but have the utmost respect for Paul and his abilities as a race car driver. He greatly accelerated my learning curve as a driver with his teaching and insights. Glad to hear he continues to have some "go fast" in him :-)

Originally posted by kthomas:
Ah, he'll be pleased to know you remember him by that description.

[Shant Saroukhanian]

Jeff,

Hey there, glad to hear the trans is still ticking, I believe I double pinned second and third gear only on that trans. I'd pull it apart at this point and just rplace them, You can get a bag of them from nissan for a few bucks and just replac ethem all, as far as the double pinning part, just go to a HW store and buy a smaller set to fit inside the oum nissan ones. they should just slide in with a small rift and ball peen. How's the rest of the motor and car holding up?

Shant

I still have the same email if you want to email me off line...