Page Index Toggle Pages: 1 Print
Normal Topic Bell housing dowel bolts (Read 2232 times)
 
Gunslinger
Flatfender Master
Owner Member 2012
*****
Offline


Cj3a, M38A1,

Posts: 942
Location: Minneapolis
Joined: 02/06/11
Gender: Male
Bell housing dowel bolts
11/13/11 at 18:24:18
Print Post  
I'm getting ready to put the motor back into Triple X, I read that I should be using dowel bolts to make sure the alignment is correct, so I picked up a couple.  I've got a 3A block its a later version, and an early bell housing.  There are two heavy boss bolt hoels at the top of the bellhousing/motor and two at the bottom.  The side holes seem to be for the bell housing cover plate, the starter motor and the security cable.  My question is "which set of holes should the dowel bolts go into, top, bottom or do I split them diagonally top and bottom.  I'm assuming all I need is two, correct?

Todd
  

Climbs trees, hides in the long grass, hangs out with wet dogs...
Back to top
 
IP Logged
 
Carls_jeep
Flatfender Master
Owner Member 2012
*****
Offline


...

Posts: 1746
Location: Taylorsville Ky
Joined: 10/18/10
Gender: Male
Re: Bell housing dowel bolts
Reply #1 - 11/13/11 at 23:22:05
Print Post  
As best I remember they go in the bottom holes. I will suggest that when you put the dowel bolts in that you also dial indicate the bell housing to the flywheel to be sure that is is as close to .000" as you can get it. On the CJ2A site there was a long discussion about it and someone said the factory spec was .006" but Sean said the CJ2 and 3's didn't have a spec for it. The poster said he found it in a 1965 Jeep manual.

Given the slop that is in the input bearing and the pilot bearing, and all bearings have to have some slop to work, .006" would work because that is only .003" to each side. However, I prefer to get it as close as possible.

On the other hand, if with the dowel bolts in it is within the .006" runout you should be ok.

The thing is, DON'T ASSUME it is in spec when you put the dowel bolts in. You said the engine and bell housing didn't start out as a factory assembly and there is no guarantee that any bell housing will bolt up and be within tolerance.
  
Back to top
 
IP Logged
 
calvinhunt
Flatfender Master
Owner Member 2012
*****
Offline


Let's keep these great
American icons alive!

Posts: 1000
Location: Santa Clara, Utah
Joined: 08/02/09
Gender: Male
Re: Bell housing dowel bolts
Reply #2 - 11/14/11 at 10:24:15
Print Post  
Hello Todd,
 Bell housing dowel bolts?  You said you picked up a couple.  They have been hard to find in the past.  They must be more readily available now.
 Carl is right.  They go in the two lower positions.  Those holes have the closely machined fit.  Carl mentioned dialing the bell housing to the flywheel.  This is a good idea and many experienced machinists, like Carl, can perform this process without difficulty.  The rest of us lean on experienced members like Carl.  They help a lot, as you have already seen on this site. The question is, if you don't find the results you want what do you do about it?  One option is switch out bell housings till you find one that fits, but I had only two to choose from during my restoration.  
 This topic was discussed at length (with good info coming to the surface) back on the old forum.  In case you haven't been to it before you can find it at: http://cj3apage.proboards.com   You don't have to log in or register.  A guest can perform a search on that forum.  Just click "Search" in the blue bar just under the pic of the Jeep on the page that comes up when you enter the site.  When the search pages comes up just fill in the boxes (info) requested. Search for, Engine to bellhouse alignment bolts. When you get to "Posted within the last:", enter 900 days (The topic was started more than 2 years ago on Oct 4, 2009). Lots of good information there.  
« Last Edit: 11/14/11 at 10:28:18 by calvinhunt »  

Calvin
Santa Clara, Utah
Back to top
 
IP Logged
 
Gunslinger
Flatfender Master
Owner Member 2012
*****
Offline


Cj3a, M38A1,

Posts: 942
Location: Minneapolis
Joined: 02/06/11
Gender: Male
Re: Bell housing dowel bolts
Reply #3 - 11/14/11 at 11:23:12
Print Post  
Thanks guys,
Actually I think I started the thread on the 2A site just recently as there was some discussion on this topic there, I think Carl brought it up.

I'm kind of stuck on dialing it in.  I'm doing this with the body on and I don't know how to use a dial indicator to get these readings. 
Carl do you have any suggestions?  The jeep ran out pretty smoothly before the rebuild with this same configuration, I can only think the Dowel bolts will help an already ok situation, but I'd like your thoguhts.

Calvin, I got the bolts from Midwest Military, they are used but they mic out at .374 at the shoulder.
  

Climbs trees, hides in the long grass, hangs out with wet dogs...
Back to top
 
IP Logged
 
Carls_jeep
Flatfender Master
Owner Member 2012
*****
Offline


...

Posts: 1746
Location: Taylorsville Ky
Joined: 10/18/10
Gender: Male
Re: Bell housing dowel bolts
Reply #4 - 11/14/11 at 21:42:52
Print Post  
If you can borrow a dial indicator with a magnetic base put the bell housing on temporarily with the dowel bolts and a few others just snugged up. Put the mag base on the flywheel where the clutch would be with the plunger of the indicator in the bore where the tranny goes. Then have some one turn the engine over BY HAND, DO NOT USE THE STARTER. Start at 12 O'clock and set it to "0". go to 3 O clock and mark what the indicator says on the face of the bell housing. Do this at 6 O clock and 9 O clock. The runout should be within the recommended .006". That is, .000" at 12 O clock and no more than .006" at 6 o clock and the readings at 3 and 9 O clock should not exceed .003" on each side for a total of .006". The .006" could be on one side or the other or even .003" on each side.

I hope that's not to confusing.

You are replacing the pilot bearing, throwout (clutch release) bearing and clutch I hope.  
« Last Edit: 11/14/11 at 21:46:02 by Carls_jeep »  
Back to top
 
IP Logged
 
Gunslinger
Flatfender Master
Owner Member 2012
*****
Offline


Cj3a, M38A1,

Posts: 942
Location: Minneapolis
Joined: 02/06/11
Gender: Male
Re: Bell housing dowel bolts
Reply #5 - 11/15/11 at 08:49:36
Print Post  
Thanks Carl, but not exactly,
The transmission is in the vehicle, bell housing bolted to it, throw out bearing and carrier are all in place, next step is to drop the motor in and connect it to the bell housing, with this method I don't have access to the flywheel to measure anything.  Any suggestions?
  

Climbs trees, hides in the long grass, hangs out with wet dogs...
Back to top
 
IP Logged
 
Carls_jeep
Flatfender Master
Owner Member 2012
*****
Offline


...

Posts: 1746
Location: Taylorsville Ky
Joined: 10/18/10
Gender: Male
Re: Bell housing dowel bolts
Reply #6 - 11/15/11 at 12:35:51
Print Post  
All you can do is assume the bellhousing and engine will line up within the alleged .006". I think if it is within .010" it would be ok but as I said it's best to be as close as possible.

Did you replace the pilot bearing in the flywheel?
  
Back to top
 
IP Logged
 
Gunslinger
Flatfender Master
Owner Member 2012
*****
Offline


Cj3a, M38A1,

Posts: 942
Location: Minneapolis
Joined: 02/06/11
Gender: Male
Re: Bell housing dowel bolts
Reply #7 - 11/15/11 at 18:21:29
Print Post  
Thanks Carl,
Yes the pilot bushing is new, so is the throw out bearing, carrier and return spring.  Appreciate the help, I'll let you knw how it comes out.
Todd
  

Climbs trees, hides in the long grass, hangs out with wet dogs...
Back to top
 
IP Logged
 
Page Index Toggle Pages: 1
Print
Bookmarks: Facebook Google Google+ Linked in Twitter Yahoo