What is my type 911/0X transmission where “X” is “0” with superimposed “1”?

[blee]

The tranny is out of a 1970T. I was told by the PO that it had a 5-spd. 915 with a 2.4. Upon closer inspection, it seems to be a "911" rather than a "915", and possibly a 4-spd? The serial number is 7000563 and the type is 911/00 with a "1" superimposed over the last zero. As for the motor, I have no idea what it is. Take a look:











I've already had some discussions with Grady Clay, who by the way is very helpful and knowledgeable on the topic. Here's what he had to say:

"It is a 901 (sorta). The proper designation is a type 911 transmission. Next to the transmission number on the bottom rib, you should see the type 911/00. Note that the casting numbers are also 911.xxx.xxx.xR and not 901.xxx.xxx.xR.

In general all the internal parts interchange between a type 901 and type 911, both ways. There are some subtle differences that can cause a problem.

In most ways, a type 914 transmission is interchangable with type 911 and 901 transmissions. The 914 parts were of slightly less quality than their 914-6 and 911 counterparts.

VERY few parts interchange between the 901/911/914 and the 915. It is about the same lack-of-interchange as between the 915 and 930.

Most notable difference between 901 and 911 is the 1st and 2nd gears that are 0.8 mm wider with the type 911. This isn't a problem with 1st gear but there is a change in the intermediate plate bearing clamping plate and bolts to clear the wider type 911 2nd gear.

The big advantage of the type 911 transmission is it is situated to use the larger 225 mm pull-type clutch (compared to the smaller 215 mm push-type clutch common to all type 901 transmissions).

The differential bearings and differential are larger (same LSD as a 930). Naturally the magnesiun castings are lighter weight than the earlier aluminum counterparts.

There are two distinctly different type 911 main castings. The undocumented change occures in early '71 models. An easy way to spot the difference is the early version has the numbers stamped on the ridge under the differential where the later version has a rectangular boss cast under the differential for the numbers. The later version has notable reinforcements.

Another piece of trivia; don't confuse the late '69 type 901 transmission with the magnesium castings with the type 911. They are the same as the earlerier type 901 aluminum versions but were the first generation magnesium. The type 911 is notably different."
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"Please email me a picture of the transmission number and type number on the rectangular boss. I suspect the main casting may have been replaced at some point with a later spare part and the 1970 numbers transferred.

I guess you should now look inside the transmission. You will want to do this in any event. Even if you decide on a 915 and go to sell the 911, you will have a better sale knowing what you have. The buyer can pay more knowing what he is buying.

All the gears and castings have a date-of-manufacture cast/stamped in them. Looking at the consistency among these dates (all pre-dating the assembly of the transmission) should offer some insight.

You need to determine if the transmission is a 4-speed type 911/00 as the numbers indicate or converted to a 5-speed type 911/01 with the “1” added through the “0”. Looking inside will tell. Same to tell if the differential is ‘open’ or a LSD.

Take a picture of the cast ‘loop’ on the differential side cover. That is a wear item and needs inspection.

How complete is the transmission? Send many pictures of everything. Measure the length of the clutch release (TO) bearing guide tube."

[Shoepop]

I own 2 911 type both are stamped 911/01, serial # is 7102876 the other 7113522 both are 5 speeds. I'm sure the splines for clutch '225 mm' are two year only 70/71 as is the T/O bearing and T/O bearing fork as well as the guide tube. I 'THINK' you can use a later pressure plate to 1986 but not certain since it's been a long time. Maybe Grady will shed some light on it.

[Grady Clay]

WOW.
This is getting more interesting all the time.

Those appear to be Factory numbers stamped for the transmission. The transmission number is inconsistent with the later casting as is the strikeover on the type number. The lack of engine number only adds to the mystery.

This is worthy of the (expensive - $100) Porsche ‘Certificate of Authenticity’ (CoA) to try and see what happened here. How are the VIN on the chassis?

Clearly this is the late ’71 casting regardless of the early transmission number – good.

It appears that the cast ‘loop’ support on the differential side-cover for the clutch cable Bowden tube is in acceptable condition – good.

You need to find the proper Bowden tube support piece to replace the homemade wire.

We should discuss the speedometer drive rehab.

We need to confirm the clutch release (TO) bearing guide tube is the correct length.

We need to see that the clutch release arm pivot has been up-dated.

The transmission axle flanges need facing to rid them of sealant. Probably same with mating CV joints.

Most important, you need to confirm that the ‘simplified differential’ has the up-date.

More coming.

Best,
Grady

[djpateman]

It would appear that a teardown is the only way to really know what you have. The 911 transmission is anything but a 915 type. It appears the engine was rebuilt using a replacement case, so the internals could be anything.

[Matt Monson]

I'm going to go with the simplest explanation of what is going on here. The serial number is clearly for a 1970 4 speed gearbox. There's no mistaking that. The 1970 4 speeds run from 700 0001 to 700 0691. This gearbox is in that range.

A gearbox with that serial number should be a 911/00 type. This gearbox is stamped with that. Sure, it's got a light "1" stamped the same place, but my money is on that being a mistake made on the assembly line.

I bet it's a 4 speed with A, Hb, S, Za ratios. I wouldn't bother with a COA. Just pull the tailcone off and you'll see immediately whether or not it's a 4sped. If there's only reverse out there it's 4spd. If there's a first gear there it's a 5spd and warrants exploring deeper.

Regards,

Matt Monson
Guard Transmission LLC

[ddubois]

+1 on not wasting your money on a COA for this. I just got one for my 71T and they could not provide the trans number.

[Grady Clay]

Brian,

The pictures offer more clues.

Note the ‘paint-stick’ markings on the transmission (red arrow below). That is a salvage yard method
of identifying parts. Perhaps this is an indication that the transmission (at least) was in a salvage yard.

It also appears that everything was painted black at some time. That paint should be removed
and a light coat of 'Tectyl' applied.

There is supposed to be a hose clamp support at the yellow zig-zag. That long rubber oil
hose tends to flop about a lot - both from road vibration and from the pulse nature of
the oil-air mix pumped through the hose.

Check the condition of the bore of the Bowden tube support ring (green arrow).

IMG





What are the date codes on all the transmission castings?


You will want the proper Bowden tube support to replace this wire (red arrow below).

The ‘loop’ is missing from the end of the throttle rod (green arrows). This is a VERY important
part as it must perfectly fit the groove in the transmission bell crank. Anything other than perfect
can cause a sticky throttle. This is also a wear part (both pieces).

Check that there are two aluminum spacers between the transmission and mount (yellow arrow).

IMG



Is there a type number on the engine (red arrow below)? I suspect not, given no engine number (green arrow).
What are the casting numbers and date codes on each half of the engine crankcase?

Apparently the engine has been molested in a VW shop. The M6 slotted screws (yellow arrows)
are common to early VW (and 356) where all 911s use hex-head.

IMG




Please post more engine images. Perhaps we can offer insight as to what it is.

Best,
Grady

[blee]

Lots of good information...
I'll give the motor/trans a hose-down and post more pictures this week. Appreciate the help.

[blee]

Didn't get to the tranny but found some pictures of the motor. Any insight from these angles?

[Jagshund]

CoA is hit or miss, but when I received the one for my '68 (in 2006) it did include the tranny #- and it actually matched the one I had removed from the car.