help on gearbox removal

Post by **wedgenut** » Tue Nov 01, 2005 4:35 am

Yep, buy a new gearbox LOL

I know exactly what you mean on the 5th-4th, mine is so sloppy it is easy to come too far back and make all sorts of noises as it wants reverse, I've taken al the play out of the lever and fork so I figure the problem is internal. I'm going to look at the detent springs and balls to see if they are causing the problem but I suspect it will more likely be the forks themselves being worn. I'm probably going to do a box change and then open up the sloppy one to see what I can find and figure out if the forks can be built up to reduce the amount of play. Until i do that though i don't really have any other ideas. In the meantime keep stirring the pot and i'll let you know how I get on.

GeminiCoupe · Post by **GeminiCoupe** » Tue Nov 01, 2005 9:54 am

Ah great, because im made of money. LOL

This car apparently had the box replaced not long ago and was supposed to be better then the one that was in there. First time i drove it i was missing gears left right and centre - used to the BMW where you have to force the shifter across the gates into 3rd etc [bloody oversprung Germans, no offence Chris] - The Piazza didnt want to hear about it. 5000rpm in 2nd went to flatshift 3rd and...well..erm...yeah, lets say she dont accelerate too well in 5th. lol

Do you mean the forks inside the box or just on the shifter forks? An easy way to check if its the box or not is just to bolt a Gemini shifter in place. Having no linkages means direct into the box - if its still sloppy then its definately the box. Funny thing that too - not sure what you blokes think, but even having driven R33 Skylines, the BMW, and numerous other cars, to me the Gemini still has one of the best shift feels [despite the odd-ball position]. Same thing with a mates 240K C110 Skyline - old school boxes ROCK! Gotta love the clicj-click as it slips between gears

Better end the rant now.

Nick-

Bugle · Post by **Bugle** » Tue Nov 01, 2005 12:49 pm

Yea the Gemini has a nice solid feel to the shifter without the remote thing the Piazza has..

It's probably unlikely the box is worn if it feels sloppy. My Gemini is on its original box with 270,000km's and its still as tight as new.It's most likely the plastic pivot ball in the remote shifter.

I think the 5th-4th thing is standard with the remote shifter both boxes i've had in my Piazza did it.. Gemini doesn't do it.

GeminiCoupe · Post by **GeminiCoupe** » Tue Nov 01, 2005 12:55 pm

Yeah thats a common thing in the old datsun boxes. Theres a plastic/nylon bush that gets sandwhiched inbetween the shifter and the box, when that goes trying to find gears is like using an extension bar in a concrete mixer. 1st is over here, second is somewhere in the back seat, third is anyones guess and fourth forget about it...

Any pictures/diagams of the pivot ball Bugle? I wonder what it could possibly be re-made out of to cure it, maybe turn a complete one down on a lathe? Thatd be nice...

Nick-

Bugle · Post by **Bugle** » Tue Nov 01, 2005 6:28 pm

Nah haven't got any pics of the ball, could turn a new ball out of steel or something I guess. Or a new nylon one would work ok too.

mcmuthafart · Post by **mcmuthafart** » Tue Nov 01, 2005 6:28 pm

ok the 1 thats is hard to get in gear half the time 4 cant be found without grindin reverse and the rest a just hard to get in gear.. also so feels real sloppy

Rodeobob · Post by **Rodeobob** » Tue Nov 01, 2005 7:15 pm

mcmuthafart wrote:ok the 1 thats is hard to get in gear half the time 4 cant be found without grindin reverse and the rest a just hard to get in gear.. also so feels real sloppy

If its got all the gears you could try building one box out of the two. Put some new bearings in at the same time.

Rodeo has the same setup as the Gem. You could fit onw of them sticks in a Piazza. Youd have to loose the stereo and the equalizer and make a hole. lol.

Im going to toy with the selector lid off a column shift box. Make up a remote linkage shifter, should be able to make it tight with close gates. Should be easy enough to mod the lengths of the levers, they come out of the housing easy enough. Heres what one looks like.

Notice how the breather is in the lid and not in the rear housing, instead theres a rubber gromet.
Thats the 1.8L Shuttle/G200 Rodeo box on the left and the 2L shuttle box on the right. Different output shafts.

It could be that the TF Rodeo shifter has the nylon ball as well. If i get a chance i will have a look.

Cheers. Bob

Post by **wedgenut** » Tue Nov 01, 2005 8:15 pm

Can you not fit the Piazza remote linkage into the top of these boxes? the attachment point looks the same?
Regarding the ball, not sure what the material is but it is harder than nylon I think and nylon is a pain to machine at times. If I had to make one I would use "Ertalyte" thats a trade name for a PET-P material. It is extremely hard wearing and good surface hardness so it is nice to machine accurately. It is resistant to oil and non hygroscopic as well. I have used it instead of bronze for industrial bushes, wet bearings and conveyor rollers etc. and it is primo stuff. It is expensive compared to nylon but for such a small piece it would be negligable cost difference. It comes in all shapes including round bar so check it out with your local plastics company. I think Dotmar in Victoria have it or will know where to get some.

Rodeobob · Post by **Rodeobob** » Tue Nov 01, 2005 11:58 pm

wedgenut wrote:Can you not fit the Piazza remote linkage into the top of these boxes? the attachment point looks the same?

Yeah you can and it is the same. Exatly the same boxes.

Point was i rekon i could make a tighter more accurate short throw shifter with the remote shift selector lid as the basis. Lever ratios and piviot lengths etc.
Plus the Piazza shifter isnt easy to come by, it happens to fit in a Gemini nicely. The TF Rodeo remote shifter is shorter and not terribly precise. Make my own i say.

Cheers. Bob.

Bugle · Post by **Bugle** » Wed Nov 02, 2005 12:19 am

The rear case is a slightly different casting between the 1.8 shuttle/Gemini box and the 4ZC1 Shuttle/Piazza box the 2 holes at the back of the case are further forward in the 4ZC1 box so only one of the holes on the shifter will line up to the other box. This is how mine is attached and it still works ok.

mcmuthafart · Post by **mcmuthafart** » Thu Nov 03, 2005 6:20 pm

can a gem 5 speed fit in a piazza? whats has to be done?

Rodeobob · Post by **Rodeobob** » Thu Nov 03, 2005 9:29 pm

mcmuthafart wrote:can a gem 5 speed fit in a piazza? whats has to be done?

What Bugle said above is right. If you look at the picture above you will see that the box on the left has a smaller output shaft. Thats the same box as the Gemini and early Rodeos. The one on the right is the same as the Piazza and KB29 Rodeo and 2L Shuttle.

So you have to get the right yolk and have it mated to the front of your tailshaft. I doubt you will be able to get a uni to do it, How did you do it bugle????

bob.

Bugle · Post by **Bugle** » Fri Nov 04, 2005 12:03 am

I bought the 117 coupe box (Gemini 10 spline) and it came with the yolk same design as the original tailshaft and asked em if it would go onto my tailshaft they said yes but when I took it to a tailshaft place they said the joints cant be rebuilt grr..
So I had to get the front tailshaft chopped and had a Gemini uni joint welded to it. That cost about $200 all up..

Rodeobob · Post by **Rodeobob** » Fri Nov 04, 2005 12:56 am

Bugle wrote:I bought the 117 coupe box (Gemini 10 spline) and it came with the yolk same design as the original tailshaft and asked em if it would go onto my tailshaft they said yes but when I took it to a tailshaft place they said the joints cant be rebuilt grr..
So I had to get the front tailshaft chopped and had a Gemini uni joint welded to it. That cost about $200 all up..

So it was one of the pressed in type unis??? ive got two shuttle small output fine spline shafts here like that. Im in need of a couple of yolks to fit the boxes ive got so i can use them. In my case it might be possible to get the yolk off the shaft and have the hole machined out if the uni im putting in is a tad larger.

Bob

Bugle · Post by **Bugle** » Fri Nov 04, 2005 1:10 am

Yeah had the caps just pressed in, both the original Piazza one and he 117 coupe one.. Tailshaft place reckons theres no way they can centre them properly.

Not hard to find a yolk with the fine spline. Geminis supposed to be the same.. Also at the wreckers I checked some late model Commodore tailshafts and they had the same spline count but idnd't check the diameters.