Hitchcocks Forum

Hi all, today's head-scratcher is oil all around my points. I presume that the oil seal behind the spring weights has given up so my question is ...

"How hard is it to switch that seal?"

Can it be done without taking the timing covers off and is it a straight-forward pry out the old one and push in the new?

Let me know your experiences of doing this and how often do these seals need replacing?

Ta

Stuart

That, or someone has been over-enthusiastic with a grease gun. I don't find a whole lot of oll gets up that far.

You'd need to detach the drive gear on the timing side to take the shaft out (but it does pull out from the points side of the housing) , so yes, timing cover removal required.

Check if your distributor has iron bushes or ball bearings. They use different size seals. In theory later 350s and 500s have the ball bearing one but my late 350 is testament to the fact they don't always.

Ah - so the seal is accessed from the timing case end? I was hoping it sat just behind the adv/ret unit and could be swapped easily. Bugger! Still - you've saved me starting from the wrong end.

I think it is the seal as it's runny oil not thick. Once it hits the spinning parts it coats everything then runs out of the ignition cap.

Thanks for the warning about irregular parts - I'll pull it apart before I order the spares.

Stuart

As I recall, the seal is on the points side but to get at the seal, you'll need to remove the shaft which is mushroomed on the points side and has a sprocket bolted onto a taper at the timing side. Once the sprocket is pulled off the taper, you can pull the shaft out from the points end.

You will need a pulling tool of some sort. This was not ideal but does work.


Umm. Yeah, looks like you can then pull the whole shaft with the points cam and auto-advance unit still attached. Couldn't remember but this picture seems to confirm that.

Hi, if you remove the points housing, then undo the bolt holding the cam and bobweights . Tap the cam gently sideways will normally break the taper free. the seal will then be visible. The seal can be removed quite easily but the problem is when it comes to fitting the new one they tend to catch and deform on the shaft. Overall its quicker to do as others have stated , remove shaft , fit seal them reinsert shaft and reassemble. Vince

All clear

Sounds like a good plan to buy more than 1 seal as insurance!

Thanks again for everyone’s help

Stuart

I think 350s had a bush rather than a bearing. Certainly my 2008 had.

I fitted a 500 unit with the bearings in place of the 350 bushed one on asbo 30

Expensive if it's just a seal gone but worth doing if there's any play in the bushings

Take care all Dai

PeteF wrote: ↑

Sun Apr 26, 2020 7:37 am

I think 350s had a bush rather than a bearing. Certainly my 2008 had.

So did my 2007.

It seems "later" ones went to bearings then the "last ditch final imports" went back to a bushing again. I get the feeling they were scraping the bottom of the parts bins with the very last ones.

Does anyone know the life expectancy of the bushes? Should I be looking to replace them while it's apart?