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Posted by: McMark Feb 19 2010, 02:05 PM

I'm now offering this speedo drive gear modification to help seal one of the more persistent leaks on the 914 transmission. By adding a second, lower o-ring to this part it not only gains a second barrier again leaking, but also helps reduce the vibration that can wear the clearances and cause further leaking.

This part sits inside the transmission tail cone and the angle drive screws into it, then the cable attaches to the angle drive.


The new internal seal is noticeably smaller on the ID. This means more sealing pressure against the gear shaft, and therefore better sealing against oil leaks.


http://shop.914rubber.com/Speedo-Drive-Bushing-Double-Seal-NO-LEAKS-90131824312-901318243.htm

This member (Thanks Eric!) had a significant leak at the speedometer, even while parked. After this modification was done... ZERO LEAKS! Read his story http://www.914world.com/bbs2/index.php?showtopic=104875.

Posted by: SirAndy Feb 19 2010, 02:53 PM

Great idea!
After years of abuse, the case often is slightly oval allowing for oil to seep by.


A second o-ring should take care of that ...
Andy

Posted by: 9146986 Feb 19 2010, 05:26 PM

VERY COOL!!! You get a gold star McMark!!!!

Posted by: whatabout1 Feb 19 2010, 05:54 PM

PM sent

Posted by: ConeDodger Feb 19 2010, 07:11 PM

This looks cool. Mine doesn't leak that I know of but I will keep it in mind...

Posted by: Sleepin Feb 19 2010, 10:14 PM

Awesome!

Posted by: McMark Mar 9 2010, 11:26 PM

These are now available only as complete rebuilds, all new o-rings, a new internal seal, and a new sealing washer. No compromise, no second guessing, no leaks.

Posted by: eyecolor Mar 16 2010, 07:16 AM

Count me in

Tell me how to pay and where to send the core

thanks

George

Posted by: McMark Mar 16 2010, 11:46 AM

PayPal: $65 to mark@originalcustoms.com

Core: Original Customs
19660 Eighth St East
Sonoma, CA 95476

Posted by: McMark Mar 24 2010, 12:32 PM

Sleepin' posted his experience with the speedo modification. Read about it http://www.914world.com/bbs2/index.php?showtopic=104875.

Posted by: jflash914 May 31 2010, 02:39 PM

McMark,
Besides removing the set screw what else is needed to remove the speedo drive?? Do you have to remove the back plate of the trans to get the drive shaft out?
Thanks,
Jack

Posted by: BKLA May 31 2010, 06:00 PM

When I removed my speedo drive for my track day car, I machined a plug with two 0 rings with a centered trans temperature probe. Seemed the prudent thing to do.

No leaks!

I never thought of offering a simple modification like this on the speedo drive. Great Idea!

Posted by: McMark May 31 2010, 09:22 PM

Jack, once the set screw is removed the speedo drive just pulls out. They can get quite stuck sometimes though. Leaving the angle adapter in place will help give you a place to grab.

Make sure the transmission is drained, or the rear end is HIGH up or the gear oil will drain out all over.

Posted by: jflash914 Jun 1 2010, 08:20 AM

Thanks McMark

Posted by: Kevins911 Jun 25 2010, 12:41 PM

Hi Mark, just wondering if you are still making these? I sent you a pm.

Cheers
Kevin

Posted by: McMark Jun 25 2010, 01:17 PM

Yes I am. I'm waiting on more seals from Porsche, but as soon as they come in more will be ready to ship.

Posted by: Ericv1 Jul 1 2010, 07:21 AM

What's the turn around time? I just degreased my transmission (in the middle of a six conversion) and found it is leaking at the angle drive. Do I need to send the drive gear as well as the housing? Thanks.

Posted by: McMark Nov 10 2010, 03:33 PM

Turn around time is one day. The only piece I need sent is the piece pictured at the top of this thread. Not the angle drive, not the geared shaft.

Posted by: SUNAB914 Dec 24 2010, 06:51 AM

Hey I will order one as soon as I get settled in on my move. Be contacting you in Jan.

Posted by: McMark Mar 29 2011, 04:04 PM

Gear seal kits are now available with the speedo drive for a completely leak free transmission. Seal kits are only $17.50.

Posted by: pktzygt Mar 21 2012, 03:56 PM

Are the drive gear mod and the gear weal kits currently avaliable?

How much $$$ for both if I don't send you my core until after I install the new one?

Posted by: McMark Mar 21 2012, 04:19 PM

Speedo gear mod can go out tomorrow.

Trigger wheels kits are on backorder until I can get the next shipment of trigger wheels.

Posted by: john_g Feb 5 2013, 10:23 PM

Mark,
Sorry I'm coming in so late, but I just inherited the problem and did a google search to discover this thread. I had a look underneath today to remove the speedo drive, but I don't see a set screw anywhere? (side shifter). Where is it?

Posted by: euro911 Feb 6 2013, 01:54 AM

Great mod ... you won't regret doing it

Posted by: McMark Feb 6 2013, 09:37 AM

Thanks Mark! Didn't even think of using that picture.

Posted by: john_g Feb 6 2013, 03:18 PM

Thanks - got it now! It was so full of grease and crud I had to clean the area up to find it.

Posted by: euro911 Feb 6 2013, 03:23 PM

I'm good for something every now 'n then ... but you may notice that my MS Paint skills are somewhat lacking

THOMAS did this mod to mine before he went back to Germany, and it hasn't leaked a drop since

Posted by: john_g Feb 6 2013, 03:35 PM

McMark,
Are you still selling the modified drive gear (w/ the seal, o-rings, and washer)?

Posted by: McMark Feb 6 2013, 03:38 PM

Yup. Available at http://www.originalcustoms.com/store/.

Posted by: john_g Feb 7 2013, 11:06 PM

I'm having great difficulties ordering from the store. Please see my PM.

Posted by: no1uno Feb 12 2013, 02:38 PM

Just ordered speedo drive gear upgrade using webstore. Thanks

Posted by: HalfMoon Jan 2 2014, 12:51 PM

Order sent!
Great lil fix, thanks!
David
Btw, Can I assume core return instructions will be sent along with my part?
TY
D

Posted by: maf914 Jan 7 2014, 07:17 AM

Mark, I placed an order for your speedo drive gear upgrade via your website this morning. Thanks for offering your products to us.

Posted by: 914_3.0 Feb 10 2014, 10:42 AM

Just what I need. Off to your store.