915 code, once again

[Hoghead]

OK, I have searched the archives and have pieced together what I think is my 915 gearbox code 915 6112 718 5747

915 = 915 box
61 = 911 SC (ROW)
12 = LSD
718 = 1978
5747 = Serial number

R&P is a 8.31

Correct???

I bought this sight unseen as I am in Thailand, and was told that this is an 85 but it apparently not from the code and lack of an oil cooler.

I do not see any electrical connection other than a reverse light switch on the nosecone.
Where on earth is the speedo output?

Robert

[slodave]

Originally Posted by Hoghead

Where on earth is the speedo output?

Robert

The '85 has an electric speedo. It's gets the reading from sensors looking at the flywheel 'teeth' and ring gear on the pressure plate.

Dave

[Wayne 962]

Most 915s did not have a cooler, that was an option...

-Wayne

[Hoghead]

Do I have the gearbox code in that this is a 1978 box?

Looking at Pelican I see I need a speedo sensor 911-606-209-00-M100.
No problem and I now see where it goes but some cretin has installed a plug in the gearbox case!!!

There are also 2 plugged holes near the speedo output.
I dread to think what these are any why the same cretin has them plugged

[Bill Verburg]

Originally Posted by Hoghead

Do I have the gearbox code in that this is a 1978 box?

Looking at Pelican I see I need a speedo sensor 911-606-209-00-M100.
No problem and I now see where it goes but some cretin has installed a plug in the gearbox case!!!

There are also 2 plugged holes near the speedo output.
I dread to think what these are any why the same cretin has them plugged

yes, you have a trans from a 1978 911SC, w/ lsd. US and RoW were the for that model.

the MY84-86 915/67, 69 & 72 came oem w/ oil coolers. These were used on RoW 3.2 Carreras w/ 231hp leaded gas engines

The 2 plugs are on all 915s, they weren't there on 901/ or 911/ trans. They aren't used for anything that I know of.

[Hoghead]

Thanks Bill

I now am stumped on the speedo sensor as the hole is plugged. I understand that this box has an electric speedo, but what to do?

This plug looks a bit dirty like the rest of the box, and does not seem to be a pressed in "frost plug" type from the outside. OTOH who knows what has been done to it.

Nackered in Chaingami

[Bill Verburg]

Depends on what was done inside the case. The speedo may still work if the sender is installed. I dunno.

[Hoghead]

Is the speedo plug removable from outside the box - IE without dismantling?
I am a bit leery to start banging and prying just yet.

If so, then it is worth a try to remove it and see as I need the electric speedo output.

[Hoghead]

Here is a pic of the plugged speedo hole in a 78 - 915 box.

[Jim Sims]

The electronic speedometer pickup is an externally mounted sensor that goes in the recess just to the lower left of the output flange (the recess partially hidden in the above image). A series of permanent magnets on a disk mounted on the final drive inside the housing produce a pulsing magnetic field that passes through the back window of the recess triggering the sensor. The hex head bolts in the image are plugs for the shift rod detent passageways.

[Jim Sims]

Read this thread:

915 tranny electrical connections?

[Hoghead]

Jim

Thank you VERY much. I guess he was not a cretin after all.
The compass trick is a brilliant idea and I am off to give it a go.

Robert