Speedometercable on Gearbox 250GTE

[Besters]

I've bought a "new" gearbox for my GTE, but the bellhousing was different, so I changed it and the "old one fits". the Gearbox is now build in.
BUT: The Speedometercable doesn't fit !!!
The hole for it is a bit wider than it was on my "old" Gearbox.

Foto 12-1.JPG (179.49 KiB) Viewed 11164 times

My questions: There where two different diameters ? Is this correct ? Or where there MORE THAN two different diameters for the speedometercabel ?
Who can tell me the diameter ? is the gear at the end of the Cable-input the same on both types ? And at last ... where to get the fitting one from ?

Thank for any answer

No doubt: The "new" gearbox is only for driving while overhouling the (matching) original one.

[250GT]

Not the bell housing is different but also the backbody (Glöcke in Germany)
this GB was designed to get the donut( hardy disk) just behind the GB this is a late 330GT Gearbox you bought.
all GTE and PF- I think-has them donut on the rear
an other difference is the schwitch for the OD.
this is placed on the late 330GB on the top deck
and not in the bell housing- 250gt- see below
the diameter for 250gt GB for the tacho drive is 23.75 mm
the adopter- tacho- can has a standard speed cable connection
look at lancia/ Alfa cars of the period ,for replacement available in all lengths
I dont have a 330gt GB as spare to measure up.
but if these have an wider opening I would place an Alu tube inside with fixation bolt.
so you can use the old one

C.

[250GT]

Markus,
this inscription should be on the right bell housing for 1959-1963 with OD

C.

[250GT]

If there is a difference in the diameter for the speed drive adaptor
it must have to do with the back body " glocke "
I found an early 330gt in he garage.
Some themes its helpful for me to write here than I learn whats down stairs !
The diameter is however the same as on my 250 gt boxes
but it has the SAME back housing as 250gt.

C.

[Besters]

Thank you, Cornelis, for zhe Info.

BUT: The End with the donut is quite similar and the OD-Switch is NOT in the Bell, but out of it at the same place of the 250-GB.
see picture attached. I will see, if the diameter is 23,75mm or different.
But IF the diameter is wrong for the 250 AND the GB fits, can I then use the seedometer-Cable from a 330 ?

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[Besters]

The GB-Type is 508E , my 250GT-GB is 508F, like you posted, Cornelis.

But also my 508F GB has the OD switch NOT inside the Bell, but at the same place, the 508E GB has it now (at the end to the Donat).

So the new question to the 330-owners-fraction: what diameter has the speedometercable at the 330 GT ?

Type 508 E

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[250GT]

Markus
in the gearbox sits the 1. tachodrive then comes 2. a . 90 degree litle GB see my frist pic
than comes 3. a speedocable to the dashboard
you mix up two things I think.
I understand from the first post that the opening for tachodrive diameter is smaller on the org GB.

C.

P.S.
I think all speedocables are identical a mass product used on many Italiencars.

[Besters]

OK, that´s true.

I was talking about the first part, the "thing" that fits into the GB, the 90DEG-Angle and the cable are the things that fit and that I can use further ... I hope

[Besters]

The "tachodrive" is the problem.

a drive from a 330GT-GB should (normaly) fit ?

[250GT]

The GB-Type is 508E , my 250GT-GB is 508F, like you posted, Cornelis.

But also my 508F GB has the OD switch NOT inside the Bell, but at the same place, the 508E GB has it now (at the end to the Donat).

So the new question to the 330-owners-fraction: what diameter has the speedometercable at the 330 GT ?

Foto 5.JPG

NO,NO Markus
sorry
The switch to the end of the donut is the reverse light switch !
The switch for the OD must have contact to the 4th gear axle.
The Ferrari OD works only on the top gear.
The englisch cars like Jag, TR has them on all gears.

C.

[Besters]

pardon, my mistake. It´s the switch on the upside, you can see on the picture with the two Gearboxes, I´ve posted today.

This is exakt the position the switch has had on the old GB. We changed also the cover withe the 6 screws.

[250GT]

pardon, my mistake. It´s the switch on the upside, you can see on the picture with the two Gearboxes, I´ve posted today.

This is exakt the position the switch has had on the old GB. We changed also the cover withe the 6 screws.

Youre lucky Markus, that I did for me just 2 Gearboxes a few weeks ago.
And I made some pics.
When you change the toplid is OK but the 4th gear must have this groove.
see pic below
other wise you can wait very long
Maybe it makes Fun to let works the OD on the revers gear......... 2 gears backwards !
Put the OD electric on the Ceam reverslight switch.
I can image this will work , when I understand my hobybusiness correct.

c.

[Besters]

Yes, the switch location looks exactly like this on your picture. At both GBs, the "old" one (508F) and the "new" one (508E).

So, the only thing I need is a "adapter" (aluminium tube) for the tachdrive or a complete tachdrive for the 508E GB...

[Besters]

I've scaled the Tachodrive hole again.
At the 508F it is 23,25 mm diameter
At the 508E it is 26,6 mm diameter

the garage told me, there are also two versions: one with 15 teeth and one with 16 teeth. I don't know, wich number of teeth the "big one" has.
Who can help ?

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Nummer2.jpg (188.75 KiB) Viewed 10981 times

[Besters]

Update:

Yesterday my spedometerdrive complete with angledrive and 16-teeth-gear arrvied from GTO Engineering !

It hopefully fits the Overdrive... IF it will fit, I will have all parts so foar to complete the partial restauration (Part 9 ).
Next week she will be transported to the paintshop ... I hope ...