1800: Gear selector leak?

[Phid]

I'm looking for a little advice if possible. I have a leak from the back of the gearbox which appears to be coming from the selector box and dripping down over the prop UJ. Only leaks after a run out.

Is it likely that it is the selector box? Are there any likely culprits?

What is the best way to access - remove the UJ and prop and go in from underneath or through the transmission tunnel. From pictures it looks like there won't be much access from above.

Its a P1800 running a '69 B20B.

Many thanks
Philip

[Phid]

I should add that the rear g'box seal appears dry (oil is coming UJ side) and I have replaced the speedo cable angle drive as this was leaking.

[Phid]

Just looked again and does in fact seem to be coming from the angle drive. I wonder if it previously dripped off there and got flung upwards by the prop/UJ?

I have a new speedo cable angle drive from Brookhouse so had previously assumed it was OK. The drip is on corner of the angle drive but this is the lowest point of course.

It doesn't seem to be leaking from the gearbox end of the angle drive - but perhaps it is and running down? Is there an oil seal at that end - I can't find a diagram of this set up anywhere? There is a bit of play where the angle drive connects to the gearbox. Grub screw is tight.

[Ron Kwas]

Philip;

There should definitely be a seal at speedo drive, and it is easily checked for (or replaced, or installed if missing) by removing Right-Angle Drive...and RAD should not be loose...if it is, that is likely the source the source of oil, and once liberated, it is getting slung around to saturate everything in sight...

Good Hunting!

[Phid]

Thanks Ron

I've just had another look - there is a seal so I can remove and replace. Do you just removed the grub screw/bolt and pull out the threaded bit with the seal on it with a pair of pliers. Change seal and shove back in?

Another "new bit of car" for me so thanks for any advice.

Thanks

[Ron Kwas]

Philip;

It's been too long since I've been inside the Speedo drive for me to recall assembly details, and the factory exploded assembly diagrams are not so good on detail either...I see from "speedo angle drive" thread that this leak is sorted, so maybe you could post some usable notes, sketches or pix.

Cheers

[Phid]

Right I've now completed the job - a quick summary as requested.

I have attached a picture of the speedo drive that is inserted into the gearbox. It is held in place by means of the speedo drive housing. The outer o'ring seal you can see on the main body of the drive housing. The housing is held in place by a grub screw/bolt screwed through the body of the gearbox and into the hole you can see on the side of the housing.

The 'top hat' inner seal pushes onto the end of the speedo drive/housing - narrow end first. Once the housing and drive are back in the gearbox and secured by the grub screw, this seal is compressed by the nut on the end of the angle drive which screws onto the threaded end you can see in the picture.

The new o'ring outer seal I received was very hard rubber (much tougher than the old o'ring) - with that on I could not push the housing back into the gearbox. Possibly tapping in with a hammer would have worked but I wanted to avoid doing any damage. I have used the old seal - I'm fairly convinced my leak was from the inner seal. If not at least I know what I'm doing now!

[CLIVERALLY]

Very helpful.doing mine next week as its pis++,ng oil out

[paul staines]

Originally Posted by CLIVERALLY

Very helpful.doing mine next week as its pis++,ng oil out

Must be a common fault !