Distributor Gear Wear

['76mintgrün'02]

I have been thinking about the used distributor gears I have and how they may be contributing to a sloppy spark.  There was a Bosch unit from a 74 on eBay this week, which sold for 'best offer' at a $40 asking price.  Anyway, it is from that ad that I stole this photo of the gear coming through the housing, because it looks about like mine, in terms of wear.

What I am wondering is whether it would be STUPID to add a shim 'under' the distributor, to lift in a tenth of an inch, or so; to utilize a different place on the gear.  It hits right in the center of the gear, as installed, but it appears as though there may be room to lift it up and use 'new meat'.  

 

There are timing anomalies that I see under the light, on the engine, which I do not see on the sun machine.  I think the gear probably plays into the bouncing BB.  I know the chain slop can affect accuracy as well and I do get a slappy noise up there sometimes, although that could also be the oil pump chain....  I am ignOring that symptom.

 

A new gear would make sense, but they want money for them.  A homemade aluminum shim-washer would be free, essentially.  Silly idea?

 

Tom

[TobyB]

Don't move it.

 

There are lots of horror stories about what happens when the thrust axes are moved.

 

I'll post more in a bit, but a mis- mesh here is messy and expensive.  On FJ60 engines, it can kill cam gears, covers, etc.

 

edit.  Ok, I thought about it some more, and it's probably not so bad on a 2002.  The issue on engines where

the dizzy also drives the oil pump is that if the gear's too high or too low, it puts end loading on the

camshaft.  The cam's not designed to take much constant end load, so it wears, starts to move, wears more,

moves farther, and then the gear starts to get chewed up.  I think on the FJ's it's made worse by gear metallurgy.

 

On the 2002, the distributor's not loaded at all, so...

 

Of all the people to try it, Tom, I think you should.  BUT keep an eye on it to make sure nothing goes wrong.

 

Other than the thrust 'issue', it seems like it'd work...

t

 

https://forum.ih8mud.com/threads/how-does-this-even-happen.959904/#post-10679711

Edited November 20, 2016 by TobyB
engaged brain.