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Posted by: porsche914_73 Jul 26 2018, 06:40 PM

Hi Guys!

I have a chance to get my hands on a speedo angle gear PN 91131802900 at a very good price.

Is it compatible with 914 speedo gear PN 91431802901?

Estetically, they look identical. Maybe it has different or reverse gearing?

Any thoughts?

Posted by: ClayPerrine Jul 26 2018, 07:19 PM

The 911 angle drive turns the opposite direction from the 914 angle drive.

BTDT.

Posted by: 914Sixer Jul 26 2018, 07:21 PM

Something is different but I do not remember. Maybe the good Dr Evil will chime in

Posted by: porsche914_73 Jul 26 2018, 07:36 PM

I imagined that much. Too bad. Also, there's an original speedo angle gear but has PN 90131802901. Is this for the 901 transmission therefore I assume compatible wiht a 914-4. Am I correct?

Posted by: bdstone914 Jul 27 2018, 07:21 AM

Only a 914 one will work. 914 318 029 01
911 318 029 00 is for 911's. Your car will go backwards if you use the 911 angle drive.
Actually it will break the speedo.

Posted by: morgan_harwell Jul 27 2018, 07:51 AM

Install the 911 angle drive, then you will have a Benjamin Button 914

Posted by: Mark Henry Jul 27 2018, 07:53 AM

I don't know if it would break the speedo, the needle isn't mechanically connected to the drive, it runs on magnets. My bug's 90mph speedo I've had 360* around and pinned back at 0 without issue.
My bug has a 901-911 transmission , 914 gearing, and a 180hp t4 conversion, scary at that speed but BTDT.

Of course this is moot, it won't work, unless you want to know how fast you're going in reverse.

Posted by: johnhora Jul 27 2018, 12:25 PM

there are some differences...even in the early 914 and later 914 ones...

they both turn either way so no problem with which way your engine is facing.

what's different is the size of the gear "head" ...where the teeth are...

I'll see if I have some pictures....

Posted by: johnhora Jul 27 2018, 01:18 PM

I think if you change just the angle part it would work...all of these show a 1:1 ratio.

some pictures for your viewing....and adds more to the fun

Posted by: johnhora Jul 27 2018, 01:20 PM

Posted by: ClayPerrine Jul 27 2018, 01:26 PM

The only angle drive listed for the 914 is 914-318-029-01. There was never a different angle drive for 914s.

The 911 uses 911-318-029-00.

If you look at the tail cone from a 911, you will see that the speedo drive connects to the input shaft on the top. The 914 speedo drive connects to the input shaft on the bottom. That makes them spin in opposite directions, and that accounts for the difference in the angle drives.

Posted by: johnhora Jul 27 2018, 01:57 PM

Clay...check the part numbers again on the pics....there is a 914-318-029-00 part number

Posted by: ClayPerrine Jul 27 2018, 09:16 PM

That number is not listed in PET.

Posted by: porsche914_73 Jul 27 2018, 09:49 PM

Thanks for the detailed reply!

Posted by: porschetub Jul 28 2018, 02:01 AM

Wow the info on here is amazing,remember testing my new to me metric speedo...didn't work till I turned it the right way with a drill .
Not like the correct drive is that expensive ,shop around ,even a used one with new seals will be fine.