The CJ3A Page CJ3B.info

Author Topic: Oil Pump Question  (Read 2139 times)

0 Members and 1 Guest are viewing this topic.

Offline PaulS

  • Willys Guru
  • ****
  • Posts: 271
  • Karma: +0/-0
  • Still Plays With Jeeps
    • View Profile
Oil Pump Question
« on: July 27, 2016, 03:42:29 PM »

I just assembled my oil pump with a new gasket (home cut from gasket paper).

Two questions:

1.  There is 0.003 inches of end play.  Too much, not enough, or just right?  (It's in the range in the manual, but this isn't either of the types shown in the manual--it's the one with the two intermeshing gears.)
2.  When I rotate the shaft, I can feel the teeth engaging and disengaging--it doesn't feel smooth.  Is that normal or a problem?  (If it's a problem, how can I fix it?)

I'm making another Walcks order in the next couple of days, and I need to know if I have to include an oil pump on that list, or if there's a simple fix, or if it's fine as-is.

Thanks,

-Paul

Offline Gunslinger

  • Flatfender Master
  • *****
  • Posts: 942
  • Karma: +0/-0
  • Cj3a, M38A1,
    • View Profile
Re: Oil Pump Question
« Reply #1 on: August 02, 2016, 06:48:13 PM »
Hi Paul,
I rebuilt a motor for my 3a, we used a gasket from Felpro, I don't know the thickness, but I think it was too thin or maybe it shrunk under heat. Anyway I drove about 3 miles after the install and the oil pump locked up, tore out three teeth in the gear and I had to tow it home. I was lucky I didn't loose the cam shaft.  I pulled the pump apart, and after just loosening the screws a little the pump spun freely.  I tell you this because this is no casual affair.  My suggestion would be to call Midwest Military and talk to John, he has NOS oil pump gaskets, I put one of those in and have had no problem in 4000 miles. for some reason the head space between the pump gear and the end plate is critical and the material of the gasket and the thickness seem to be critical as well.  Just my 2 cents.
Gun.
Climbs trees, hides in the long grass, hangs out with wet dogs...

Offline PaulS

  • Willys Guru
  • ****
  • Posts: 271
  • Karma: +0/-0
  • Still Plays With Jeeps
    • View Profile
Re: Oil Pump Question
« Reply #2 on: August 04, 2016, 06:24:47 PM »
Gunslinger:  I don't suppose you noted what your shaft play was on that pump when you installed it?

-Paul

Offline Gunslinger

  • Flatfender Master
  • *****
  • Posts: 942
  • Karma: +0/-0
  • Cj3a, M38A1,
    • View Profile
Re: Oil Pump Question
« Reply #3 on: August 07, 2016, 12:49:11 PM »
No I didn't sorry
It was a really weird deal, when the pump and motor were cool, and the gasket dry the pump turned fine.  As soon as it got hot, it locked up and we had to loosen the bolts on the pump head just a quarter turn and it freed up.  I do have a post out here somewhere that goes into the details and I may have recorded the end play in that post, it was couple years a go now and I just don't remember.
on top of all of that it was the third time I pulled that motor apart that summer, so I was pretty frosted... :-X
Climbs trees, hides in the long grass, hangs out with wet dogs...