WTB 915 gearbox (early)

[Ashbaxter]

Just dropped that car off to have the engine put in and after grabbing the gearbox I have from storage, mechanic informs me is a later one for electronic speedo (yet another something new learnt by me).

Does anyone have an early one with mechanical speedo drive they are willing to part with


Cheers
Ash

[HughH]

ash
do you need a complete gearbox or just the nosecone that has the speedo drive in it? I am not certain but I think that you may be able to just swap the nose. You should talk to your mechanic to see if that is possible before you shell out for a whole new gearbox. Nosecones with mechanical speedo drives are available - i saw a couple for sale on early S a little while ago for a couple of hundred dollars each - much cheaper than a full gearbox if it will work
also IF it is a later one do you know what final drive it has in it, and what ratios? It may have a 8:31 and thus be quite a different internal format to an early one and may require recalibration of the speedo as well

[Fishcop]

Depending on how original you want to be... I had an electronic speedo rebuilt by NHS to appear identical to the early cable speedo - all you have to do is run a pair of wires from the dash to the rear coupler cover inside the tunnel. A much cheaper and easier option.

[Fishcop]

Just reading Hugh's response. Nope - the speedo gear drive is missing from the pinion shaft on later cars...

[HughH]

and i just read johns response and THAT is a MUCH easier option

[Ashbaxter]

Thanks John that sounds like the answer and means work can continue

[9er]

I have a transmission if you decide to go that way.

[Ashbaxter]

What year speedo am I looking for to have NHS do their magic on

[Fishcop]

What year speedo am I looking for to have NHS do their magic on

Any electronic 911 speedo - it will say 'VDO electronic' on the face in a small font. Preferably you'll use a Kph version, but NHS can convert a Mph to Kph pretty easily and they can re-do or improve the face artwork to whatever extent you like. Here's mine - all 5 were completely refurbed. P2270296.jpgP2270294.jpg

[Fishcop]

Ash, I should probably give you some perspective...

If you use an electronic set up you will need to ensure you have the pick-up on the gearbox - it is the round puck with two wires located on the outside near the diff housing. Two wires run from this sensor to the speedometer - but you will also need to pick up 12v from somewhere behind the dash to "power" the speedo and its lights. The electronic speedos have a trip reset button on the front as opposed to the turn-knob under the speedo on earlier/cable speedos - this will lose you concours points and anoraks will cry...

NHS replace the later speedo's needle for the early capped version and replace the face for a perfect facsimile of the early version. This may make it look different/better than the rest of your gauges and you'll want to get them all done. I actually recommend this as NHS overhaul them all (and remember they're all 40+ years old and tired). NHS polish the glass, repaint the needles, fix the known problems such as the trip meter's plastic cog and can reset the odometer to anything you want (I chose zero based on my full resto ), they also 'chipped' my tacho so it never bounces and is compatible with MSD and other electronic ignitions, and they set my clock up to always tell the correct time! The other really nice thing they did was to add the studs on the back for <69 dash mounting using the thumbscrews.

You could take the path of locating an earlier gearbox with the cable drive (as Chris has offered), but if you know and are happy with the history of the one you have, the speedo conversion will be less immediate hassle.

[Ashbaxter]

A the wealth of information as usual thanks john
As I'm impatient I will go with the speedo option as the transmission I have has been rebuilt (thanks Christ for the offer) and get a speedo modified
From the originality perspective shouldn't I get it done on in miles?

[Ashbaxter]

Apologies for the grammar above, damn autocorrect
what does this it think it is correcting anyway

[9er]

The later transmission that you have will also have a different drive ratio, 8:31 as opposed to the 7:31 of the earlier 915.

[Fishcop]

The later transmission that you have will also have a different drive ratio, 8:31 as opposed to the 7:31 of the earlier 915.

True. What size engine are you running Ash?

I have thoroughly enjoyed my later 915 behind my 2.7 - I have the 8:31 diff and I added the tall TL 5th gear from an early 915 (replacing the standard SM 5th... I like lazy ratios

[Fishcop]

Chris, do you have one of the rocking-horse sh!t rare mag cased, 7:31 diffed, cable driven, one year only ('77) 915s? Couldn't find one of those for love or money when I was sourcing my stuff...