T5 speedo drive - bung?

seight · Post by **seight** » Sun Feb 06, 2011 10:49 pm

Before I make a big cock up, do I need to fit some kind of bung where the speedo cable used to fit?

I'm going to use an electronic speedo with a signal off the diff bolts so I don't need the gearbox speedo. When I bought the box there was no speedo cable on it just what I guess is the drive gear housing sticking out of the tail casing. Up to to day I have just shoved a rubber bung in it stop stop muck getting in without really knowing whether it needs sealing properly to stop the gearbox oil emptying out. There's no facility for bolting a clamp on either.

From a bit of googling it looks like there may be several variations on the way the speed cable attaches. It looks like this one could be something thats held in by an internal circlip but I'm not sure and haven't seen any examples.

Any ideas?

thanks
Mike

kiwicar · Post by **kiwicar** » Mon Feb 07, 2011 6:27 am

Yes I think a bung of some sort would be a good idea if only to keep you transmission tunnel free of a thin film of oil. A small ally bung in the same diamiter as the cable outer epoxied in would do it I would think.
Best regards
Mike

seight · Post by **seight** » Mon Feb 07, 2011 10:00 am

Yes I think I'll do something like that. At the moment this is what I can see sticking out:
http://cgi.ebay.co.uk/FORD-COSWORTH-T5- ... 0525577933

Mike

kiwicar · Post by **kiwicar** » Mon Feb 07, 2011 10:41 am

Hi
At the risk of stating the obvious, it would look even simpler to make up an ally bung the same size as the outer bit, with O ring and put that in missing out the drive bit all together and clamp it in with whatever normally holds the drive in place

.
Best regards
Mike

seight · Post by **seight** » Mon Feb 07, 2011 12:07 pm

You're probably right it looks like that's what TVR did as I've found a TVR site that has a bung listed:
http://www.thetvrsite.com/files/parts-m ... earbox.pdf

For some reason though I don't have the retainer !!

Never mind, yet another job to sort out.

Unless anyone knows where I can get one?

Mike

DEVONMAN · Post by **DEVONMAN** » Mon Feb 07, 2011 2:57 pm

seight wrote:You're probably right it looks like that's what TVR did as I've found a TVR site that has a bung listed:
http://www.thetvrsite.com/files/parts-m ... earbox.pdf

For some reason though I don't have the retainer !!

Never mind, yet another job to sort out.

Unless anyone knows where I can get one?

Mike

Hi Mike,
The Cosworth T5 speedo drive has an outside groove machined into it close to the speedo cable end and a small lug of flat metal fits into the groove and is held in place by a small cap head bolt. You should have a small threaded hole just below the speedo drive if it's a cosworth T5.
Theoretically no oil should leak through the speedo drive even if no cable is attached but if the tiny shaft seal is knackered it may do so. . The speedo cable attaches to the drive with an internal circlip, very fiddlely to do so that's one job you have avoided.

Regards Denis

seight · Post by **seight** » Mon Feb 07, 2011 4:26 pm

Thanks Denis,

That makes sense now. The box is in the car so it was difficult to see the speedo drive late last night. But I've found some photos I took of the gearbox on my PC and they match what you describe. I think I just need to make the clamp/tab to hold it in place. With a bit of effort I should be able to access it though the ally trans tunnel side panel.

Mike

richardpope50 · Post by **richardpope50** » Tue Feb 08, 2011 5:53 pm

My TVR T5 has a brass plug held in by a clamp & bolt as per items 15 & 16 in above mentioned link. It looks crude & simple.

kiwicar · Post by **kiwicar** » Tue Feb 08, 2011 7:28 pm

Brass bung in an ally case, oh how I miss TVR

Best regards
Mike

seight · Post by **seight** » Tue Feb 08, 2011 8:40 pm

If I make an entire bung rather than a cap of some sort does the whole drive body just pull out of the case?

Seems like I'll be buying my neighbour a bottle of vin rouge again to make something on his old Myford.

thanks
Mike

DEVONMAN · Post by **DEVONMAN** » Tue Feb 08, 2011 11:18 pm

seight wrote:If I make an entire bung rather than a cap of some sort does the whole drive body just pull out of the case?

Seems like I'll be buying my neighbour a bottle of vin rouge again to make something on his old Myford.

thanks
Mike

Yes, the whole body with cog just pulls out. (Complete with 2 Lt of oil)

Regards Denis