Welcome to the CJ-3B Bulletin Board, the discussion forums section of the website CJ3B.info. Everyone is invited to view the postings here, but you must register as a member in order to post messages. The moderator reserves the right to remove items posted. Items may be archived in the Tech Tips section of the website. If you post a tech problem, please follow up by posting the solution when it is found, as it may be useful to other readers. For forums covering other Jeep models, see the bottom of this page.
Search for keywords or phrases anywhere in the CJ-3B Bulletin Board using Google. Enter key words here.
| You're currently viewing the forums as a guest. This means there are some features you can't use. If you register, you'll be able to post messages and use member-only features such as customizing your profile and sending personal messages. Registration is simple and free. Join the CJ-3B Bulletin Board! If you're already a member please log in to your account to access all of our features: |
- Pages:
- 1
- 2
| Rod Side Play; Out of spec. side clearance | |
|---|---|
| Tweet Topic Started: Sep 4 2013, 01:54 PM (2,282 Views) | |
| Motiv8 | Sep 8 2013, 04:56 PM Post #16 |
|
Member
![]() ![]()
|
Gentlemen, My 1st amateur post. Top ring gap should go to major thrust side ,the right side of engine. 90 deg to wrist pin. 2nd ring gap to minor side,180 deg from top ring. There are various types of oil control ring packs tried thru the years. Never place any gaps in the wrist pin quadrant. Rings will stay put and not rotate much. The biggest cause of migration is rod twist or bend. When a bent rod passes thru each revolution it causes a left and right twist of the piston. Rings and cyl wall finish isn't understood by many. References to Ra finish, brushing , plateaus are totally variable to the particular eng AND its intended use. A CK10 or many of those machines are overrated. Just because a shop has impressive eqpt doesn't guarantee a proper job. Loving this site. David |
![]() |
|
| Motiv8 | Sep 10 2013, 06:07 PM Post #17 |
|
Member
![]() ![]()
|
Mr Moonraker, .015 is of no concern. assemble it. David |
![]() |
|
| Motiv8 | Sep 10 2013, 06:24 PM Post #18 |
|
Member
![]() ![]()
|
How can a rear seal be defective? I'd sooner believe it was installed by an DIYer. I've seen this happening for 60+yrs. There's a correct procedure requiring finesse. I will add a crankshaft regrind should verify concentricity of the seal area. David |
![]() |
|
| oldtime | Sep 10 2013, 06:36 PM Post #19 |
![]()
MODERATOR
![]() ![]()
|
David, Welcome to the CJ-3B Bulletin Board !It's a known fact that most if not all of the NRS neoprene type rear crankshaft seals for 134 Willys engines are defectively manufactured. This has been a real concern for about 15 years now. Use the Google search option and you'll find old topics like: http://z4.invisionfree.com/CJ3B_Bulletin_B...?showtopic=3985 |
|
Currently building my final F-134 powered 3B . Rock Crawler using factory parts from the Willys Motors era (1953-1963) http://s4.zetaboards.com/CJ3B_Bulletin_Board/topic/30228766/1/#new | |
![]() |
|
| Motiv8 | Sep 11 2013, 05:07 AM Post #20 |
|
Member
![]() ![]()
|
Oldtime, Thanks for rear seal tip. Haven't done one of those engines since the '50s. I've just gotten to the point of building a CJ like I enjoyed so many yrs ago. David |
![]() |
|
| Motiv8 | Sep 11 2013, 05:37 AM Post #21 |
|
Member
![]() ![]()
|
Oldtime, Something I've done for yrs on many brands of older engs is to turn a steel disc .010" smaller than the crank's seal area diameter.First, verify all main brg clearances w/ no seal installed. The seal would give false readings. Soak a rope seal a couple or more days in light oil.. Use the disc to "seat" the seal halves in block and cap. With the disc still seated, use a razor type blade to trim the excess rope flush w/ cap to block surface.I like to use a .010/.015 feeler under razor while trimming to make a good seal at butt ends. Be very careful that no ragged edges get sandwiched between cap and block or brg clearance won't be correct. Install lightly lubed brgs and torqued main caps. The crank should turn by hand w/ a slight resistance. Remove the rear cap and turn crank again by hand and feel if the resistance is half your first test. This will help determine if one or the other seal is / isn't concentric to shaft's seal area. The best Gasket folks have some good items. Their products have made my life a little easier. David |
![]() |
|
| MoonRaker | Sep 11 2013, 04:58 PM Post #22 |
|
Member
![]() ![]()
|
Back to the rear main seal issue, which has been expensive. The first seal to weld the rear main bearing to the crank was a Best Gasket neoprene 2 piece. The next seal was an original JV-687 circa 1970's. Same thing, 1.5 miles from the house, crank locked up rear main welded to crankshaft. Then I found AERA Technical Bulletin (TB -2025). Wonderful reading, this simple two page document described the failures and the cure. I think Dave has a good idea about the disk check. I had talked to one of the machinist at work about making a Go-No Go gauge for the rear main seal. He said it wouldn't be to tough to do, we just never got around too it. The block in the 53 that caused all of this is probably the one from the factory. This block was sent to Ohio Crankshaft and was align honed. The rear cap was found egged after cooking 2 cranks. Like Ken says, and I say too, I've got a large box of Crown 2 piece late model rear main seals. None of the Crown seals fit, even playing mix and match. This time I'm doing rope, got them from Brent Mullins. Later Dennis |
![]() |
|
| Motiv8 | Sep 11 2013, 05:29 PM Post #23 |
|
Member
![]() ![]()
|
Moonraker, I am not a fan of line honing. It is highly inaccurate. People buy these expensive machines and must justify their cost with tales of how great the results will be. It's all bull. A colossal ripoff. They are rather useless and cause more harm than any so-called good. I wouldn't use one if it was free. Believe me. Could be the cause of your problems. Find another shop. David |
![]() |
|
| oldtime | Sep 11 2013, 06:31 PM Post #24 |
![]()
MODERATOR
![]() ![]()
|
Well I have had 100% luck to date on all of my rebuilt engines. To date I've always used the neoprene type seals. If it's rough at all I don't hesitate to have the rear seal journal turned to .004 - .010 undersize. Normally when a crankshaft is turned the seal journal is never touched. It takes a special narrow stone to grind on the seal journal. The commonly avialable undersized rear main seals occasionally work O.K. on undersized seal journals. I always test the rear main seal for fit and lube it with synthetic grease. As mentioned there should only be a slight detectable drag to rotate the crankshaft without pistons being attached. No inch pound torque reading required. Just feel the amount of drag. A stiff drag will heat the seal journal at high RPM. At the extreme I found some rear main seals to be so tight that one can't turn the crankshaft by hand. |
|
Currently building my final F-134 powered 3B . Rock Crawler using factory parts from the Willys Motors era (1953-1963) http://s4.zetaboards.com/CJ3B_Bulletin_Board/topic/30228766/1/#new | |
![]() |
|
| « Previous Topic · CJ-3B Posts · Next Topic » |
- Pages:
- 1
- 2



![]](http://z4.ifrm.com/static/1/pip_r.png)




7:24 PM Jul 10