Author Topic: Lister 12/2 Broken Teeth in Cam Gears  (Read 625 times)

Samo

  • Full Member
  • ***
  • Posts: 108
    • View Profile
Lister 12/2 Broken Teeth in Cam Gears
« on: June 16, 2017, 06:12:11 AM »
I've had the day off work today (rostered day off NOT sickie!) and have spent some time dismantling the 12/2 I got from the Bookham clearance sale. Majority of the engine is now apart, and plan today was removing cam then crank. However when I started looking to record the crank/cam position so I could get it back together the same, I noticed 2 of the gear wheels have missing teeth.

I didn't find them when I cleaned out the sump. Looks like I need more parts.... luckily there's not too much more!

Lister CS 12/2 & JKSON 10/1 Listeroid

dieselgman

  • Hero Member
  • *****
  • Posts: 2938
    • View Profile
    • Lister Parts
Re: Lister 12/2 Broken Teeth in Cam Gears
« Reply #1 on: June 16, 2017, 12:18:14 PM »
Pure luck that gear tooth damage did not also destroy the whole cam gear or worse... cast iron can be brittle and unforgiving of any foreign object flying around in there.

dieselgman
Ford Powerstroke, Caterpillar 3304, Cummins M11, Too many Listers to count...

Samo

  • Full Member
  • ***
  • Posts: 108
    • View Profile
Re: Lister 12/2 Broken Teeth in Cam Gears
« Reply #2 on: June 17, 2017, 07:21:11 AM »
Lucky the Crank teeth are ok Gary, like you said those teeth could have ended up anywhere. Three missing in total and eventually found them in the oil from the sump - I went looking through the goo.... Maybe it happened when it seized? Other than that got me buggered how 3 teeth can sheer like that. Drove the tapered pin out (after some hot/cold cycles) and removed the Camshaft. Everything else seems ok... Crank next.

Could be worse, I could be at work :)

Samo
Lister CS 12/2 & JKSON 10/1 Listeroid

38ac

  • Hero Member
  • *****
  • Posts: 1346
    • View Profile
Re: Lister 12/2 Broken Teeth in Cam Gears
« Reply #3 on: June 19, 2017, 01:19:54 PM »
Pheew! you were LUCKY! As Gary said there is usually more damage than a few teeth missing.  More often than not the cam gear gets all broken up when the gears have to eat broken off teeth,  it seems to be the weakest one of the three.  I see this often in the twins, both of Dursley and Indian origin.
Collector and horder of about anything diesel

Samo

  • Full Member
  • ***
  • Posts: 108
    • View Profile
Re: Lister 12/2 Broken Teeth in Cam Gears
« Reply #4 on: June 27, 2017, 11:07:58 AM »
Thanks All, so maybe my luck holds as I was able to find second hand Idler and Cam Gears... So I'll see how that works out when I put it back together.

I have now removed the Cam shaft and all the gears so there's only the crank to go to have the 12/2 completely stripped.

Regarding the crank I've got everything loose... crank bearings, removed the lock screws, broken the seals on the crank covers & got the bearings moving, filed (high spots), sanded and oiled the crank shaft ends, but I just can't seem to get it apart... everything moves left and right about 8mm or so but then clunk. Doesn't quite feel right.

So today I dismantled the oil pump, cleaned it, tested it, pumps clean oil really well, holds a vacuum too, stripped it again, painted (outside) & another part in the completed box!

Back to trawling the forum, at least it's a good read!

Samo
« Last Edit: June 27, 2017, 11:09:54 AM by Samo »
Lister CS 12/2 & JKSON 10/1 Listeroid

Samo

  • Full Member
  • ***
  • Posts: 108
    • View Profile
Re: Lister 12/2 Broken Teeth in Cam Gears
« Reply #5 on: July 09, 2017, 04:39:13 AM »
Just for the record, here's the junk from the sump....

The 3 Cam/Idler gear teeth, plus a piece of copper pipe from an oiler (though the ones I pulled out are ok) - one end is squashed so it may have been the cause of the knocked out teeth?

« Last Edit: July 09, 2017, 04:41:05 AM by Samo »
Lister CS 12/2 & JKSON 10/1 Listeroid