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Posted by: mepstein May 27 2021, 06:14 PM

Please remind me how to tell the difference between a four and six transmission case. Thanks!

Posted by: 76-914 May 27 2021, 06:21 PM

$2500

Posted by: IronHillRestorations May 27 2021, 06:28 PM

They have a threaded hole for the throttle pivots shaft, and the shift mechanism at the tail isn’t like the 4cyl

Posted by: mepstein May 27 2021, 06:38 PM

I think the early fours also have the pivot hole.
What is the difference on the model number?
I just need to identify a bare case.

Posted by: Retroracer May 27 2021, 07:15 PM

As I recall the casting is different along the centerline underneath - there should be an extra lump on -6 version, as well as a different part number?

Also, as @http://www.914world.com/bbs2/index.php?showuser=9964 points out, $2500.

- Tony

Posted by: davep May 27 2021, 08:16 PM

Three things that I look for are the serial # which is a 7xxxxxx # for a six, The serial is either stamped along the bottom rib or off to the side on a flat made especially for it, and the bell housing usually has a protrusion on the right side low down (perhaps a cable guide).

Posted by: mepstein May 27 2021, 08:39 PM

Perfect. Thanks!

Posted by: Cairo94507 May 27 2021, 09:06 PM

Here is what is should look like on a Six:

Posted by: davep May 28 2021, 10:28 PM

Not all, but I would like to narrow the range down (a lot) from between 7500215 to 7501454; up to 215 I have photos of the serial along the rib as is usual for a 914 trans. I just need serial photos of many more six trans.
The feature on the case is also present on the early version:

These were 911 trans cases albeit with the breather vent relocated.

Posted by: ClayPerrine May 28 2021, 10:44 PM

That "Feature" on the trans bell housing on the sixes, and the loop on the side cover, are there because Porsche was using the same case on the 70 and 71 911, with the 225mm pull type clutch. That is the anchor for the end of the 911 clutch cable and the loop is the cable guide.

The ones on the fours were a Porsche design from 69, that was built by VW. And they have the markings to prove it. If you look in the bell housing on a 914-6 transmission, the pad that the ball stud is in is oval shaped. The clutch arm pivot on the 70-71 911 was mounted in a slightly different place.

You can combine a 70-71 911 trans with the pull type 225mm clutch with 914 side shifter parts and make a transmission that will work on anything up to a 3.2 engine using factory parts. The drawback is you have to use the 70-71 911 pressure plate and release bearing. And the release bearing is well over $300.00 for a new one.

But you do get a 914 that doesn't need a pulley on the side of the transmission. So the clutch tube in the chassis has no stress on it and is just a guide tube.

Yes, I know this works. I have one that I took out of my car still attached to a 73 2.4 MFI motor sitting on a dolly in my garage. I used a 76 911 clutch cable to hook it up.

Posted by: mlindner May 29 2021, 07:51 AM

Not to go off topic of Identification but are gears and final drive the same. Thanks, Mark

Posted by: ClayPerrine May 29 2021, 07:54 AM

The six has a GA second gear and a Z fifth gear.

The four has a F second gear and a ZD fifth gear.


Clay

Posted by: mepstein May 29 2021, 11:23 AM

Found one in my stash. Is this a six case or a converted 911 trans?


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Posted by: gms May 29 2021, 12:26 PM

911

Posted by: mepstein May 29 2021, 01:16 PM

Thought so. Thanks

Posted by: gandalf_025 May 29 2021, 01:28 PM

This, from my car.... # 619

Posted by: 914werke May 30 2021, 09:33 AM

isnt the shatf hole on the intermediate plate?

Posted by: fixer34 May 30 2021, 05:00 PM

Took these today while I was pulling all the calipers to send in for a PMB rebuild.
March '70, 0836. Mine has a small V notch on the casting extension, not the circle.

Posted by: davep May 30 2021, 06:58 PM

Thanks very much for those images of the trans #'s. That pulls the start of the reinforced case back much earlier. Interesting about the V-notch. That feature is not used on the 914/6, correct?

Posted by: fixer34 May 30 2021, 07:07 PM

I don't believe there was anything ever attached there and I've had mine over 40yrs.

Posted by: gms May 31 2021, 07:08 AM

Pete don't you own 0826?

Posted by: gandalf_025 May 31 2021, 08:33 AM

Forgot to post this..
This is from 7500630

Posted by: fixer34 May 31 2021, 09:08 AM

Yes, thank you. I shouldn't post after spending all day wrenching... 9140430826

Posted by: ClayPerrine May 31 2021, 09:42 AM

No, it is not used on the 914-6. The 914-6 used the same transmission cases as the 70-71 911, and that used the tab on the bell housing to anchor the clutch cable. The v-notch was there because Hans never machined out the boss for the 911 clutch cable.

Clay

Posted by: mepstein Jun 1 2021, 01:20 PM

I found one in the stash. Also has a v notch


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