16 replies to this topic

[CityEPete]

Sorry for the Morris content in advance but you guys know a series engines well! It's a 1098 a series and I think my distributor drive is noisy under light throttle, I've fitted a new distributor and I think it has upset it's position to where it was run in for many many years, I'm hoping it might mesh itself together but I'd like to inspect it and the cam gear (I've got a boroscope), can I extract it without removing the cam?

Thanks.

[panky]

There's a threaded hole in the end of the dizzy drive so you can screw a bolt in and pull it out. Can't remember the tread size unfortunately.

Are you sure it's the drive and not the new dizzy?

[Cooperman]

After removing the distributor you need a long (about 4") 5/16" UNF bolt. This screws into the top of the distributor drive and the drive shaft can then be pulled out, turning slightly as it does. Once out you can inspect the cam gear with a boroscope.

When re-fitting, note the orientation of the top of the shaft as it needs to be correct and in accordance with the workshop manual.

It is a bit unusual for the distributor to camshaft gears to be noisy and I would check in other areas first.

[Spider]

Careful when pulling the drive out or refitting it.

 

It can fall in.

[CityEPete]

Thanks guys, it could be the new dizzy but I think I could hear it at a lower volume with the other dizzy at high revs because I took some readings with my timing light just in case I needed to put the old one back in.

The peg on the new one is more substantial and it has no wear in the shaft so I'm thinking it's altered the way things are sitting there?

I think it 'might' be getting quieter as it runs in.

[gazza82]

Careful when pulling the drive out or refitting it.

 

It can fall in.

 

At least with Minor you can drop the sump! But they aren't as easy to reach as a Mini! I've got an A35 and they are hard to read down into the engine bay when you are "vertically challenged"!

[Ethel]

The key through the dizzy that is driven by the gear is off centre, it is possible to fit them together 180 degrees out. Another possibility is that the dizzy is too too long, or otherwise pressing on the gear. 

[CityEPete]

I fitted it by putting the rotor to cylinder one on the old one before extracting it then putting the new one on the same position but it could certainly be longer, the square peg bit is definitely bigger. Hhhmmm

[CityEPete]

Just checked and the drive peg offset is correct, I can wobble it around a bit with my finger though?

[carbon]

Thanks guys, it could be the new dizzy but I think I could hear it at a lower volume with the other dizzy at high revs because I took some readings with my timing light just in case I needed to put the old one back in.

The peg on the new one is more substantial and it has no wear in the shaft so I'm thinking it's altered the way things are sitting there?

I think it 'might' be getting quieter as it runs in.

Pete,

 

You must have a really quiet engine, I have never managed to hear any distributor noises above the rest of the background engine chatter...

 

But some of the comments I have seen about recent cheap replacement 'Lucas' distributors would make me suspicious about the fit between the distributor drive shaft in the engine and the base 'dog' on the replacement distributor.

[CityEPete]

It is quiet to be fair, valve clearances just done too, should I be able to wiggle the shaft at all? Could it be wobbling around in the hole rather than wear on the splines/cam?

[Ethel]

Not sure what your wobbling, the rotor arm end should turn against the centrifugal advance mech.

[CityEPete]

No with the dizzy out I can poke my finger down the hole and wiggle the dog drive is it called?

[retired]

No with the dizzy out I can poke my finger down the hole and wiggle the dog drive is it called?

 

Quite normal, the top part of the drive shaft (dog) is unsupported until the spigot end at the bottom of the dizzy engages into the middle bit of it. Its top flange is quite a bit smaller than the hole in the block and the only other support (before the dizzy is in) is way back/below at the cam end of it.

[CityEPete]

I'll have to try putting the old dizzy back in and seeing if the noise goes then! Thanks guys.