Gearbox Not Selecting Gears?

[RLY240]

So what was the problem?

[Dionysus]

So what was the problem?

 

I know right!!!

Here I was thinking forums were about sharing knowledge.

 

Issue like this are what's interesting and I'm currently looking for an excuse to not do work..

[YosemiteZed]

Hi

I think it's ironic that you put a post to the general forum for help and when you get the solution to your problem you don't share the answer so it can help other people who might run into the problem

I did not know that the forum had an secret inner sanctum society

Cheers

Phil

[C.A.R.]

In essence the gearbox was hydraulicing itself...

The cause was so unusual that neither Les nor Stewie at SW Motorsport had ever encountered it before.
Because the gearbox in James Zed is a hybrid of sorts, the likelihood of anyone ever encountering this particular problem would be more than a 1000 to 1.
It's just not worth explaining...
 

 

 

 

 

And yes Phil there is a secret inner sanctum to the forum - we even have our own handshake...

Edited June 21, 2016 by Lurch ™

[YosemiteZed]

Hi

Everything is worth explaining

Especially if it is a 1000-1 as these are unique if your explanation is is relative to a hybrid box

Thanks for your reply

Cheers

Phil

[PB260Z]

And yes Phil there is a secret inner sanctum to the forum - we even have our own handshake...

I hope you wash your hands first

Edited June 21, 2016 by PB260Z

[dat2kman]

Hydraulicing? As in how, ?, the cavity inside the front cover where the selector rods slip into, not draining/blocked?

I have seen excess silicon sealant cause isues.

Also had the top rod baulking, as the hole drilled into hell, at 16mm wasnt relieved with a bit of emery, the rd at 16mm was galling

( L bell conversion to SR/RB)

[JIM71Z]

I had this problem a few years ago when I replaced the std Porsche type syncros with brass type [280zx] in my 260Z std C/R gearbox. The problem would occur when I would try to get reverse but be baulked out, so would let out the clutch to spin the box, depress clutch select first to stop the box again and select reverse. If it went into reverse BINGO 2 gears. Selector in neutral, gearbox in first.

From memory, I put the 280 selector forks and rods to go with the hubs in the 260Z housing. Where the selector rods go into the front housing on the std 260 rods have flats ground on them to stop hydraulic action. The later 280 rods are round and oil trapped behind them in the early case.  

So what happens is when you select first gear it draws oil in as the rod pulls back out of the front case and when neutral is selected some oil remains behind the rod and when you select reverse, rod forward, it hydraulics the first gear rod back into gear.  The way the selector detents work this can happen. 

THE FIX    linish flats on the ends of the rods so they can't hydraulic.

PS if it happens and you need to get going quickly, jack up drivers side of car, remove filler plug and you can pluck it out of first while gear stick is held over 5 reverse.  You can do this and still make the race!!!

Its a great gearbox now and been raced for 10 years

Hope this helps. It drove me nuts for a while. Missed out on 2nd row start at Bathurst because of it.

I hope you like my explination

James

[d3c0y]

Wow that's really interesting that it will totally jam the selector fork. I take it this fork is submerged and there for the oil can't just drain away?

I wonder how long it took the factory to figure out it needed to make that modification when they were testing it haha.

[dat2kman]

Looking at various L, RB and SR, along with FJ front cover plates, the ones inside front of bell, quite a few have no ability to drain any built up oil, and, as above, the ones that do, can be eadily blocked with gobs f sealant that does get squeezed into the drain recess.

Jim71Z suggestion f a milled flat ( not mch!) is a good solution.

 

When drilling the 16mm hole for RB/asR into L bell, i wrap a bit f emery tape around a drill bit, and "hone" the hole in the bell out a touch, as the top rod can baulk/cock and make shifting difficult.