1 piece or 2 ? (AMC 20) - JeepForum.com

LinkBack Thread Tools
post #1 of 9 Old 05-20-2015, 11:04 PM Thread Starter
Registered User
1983 CJ7 
Join Date: Oct 2013
Location: Abita Springs
Posts: 5
1 piece or 2 ? (AMC 20)

Since axle seal is leaking. I've been told to change from 2 to 1 piece axle's (running a stock 304). Are the 1 piece that much stronger ? Also, where can I find ring/ pinion backlash specs and manual.

herb812 is offline  
Sponsored Links
post #2 of 9 Old 05-21-2015, 12:23 AM
Web Wheeler
holliewood61's Avatar
1981 CJ7 
Join Date: May 2013
Location: Peterstown
Posts: 1,569
Yes they are that much stronger. Backlash is 0.006"-0.010". You can find a fsm on ebay or there are downloadable versions online

08 WK bone stock
00 WJ daily driver
99 TJ mostly stock 97 TJ cheap jeep
81 CJ7 very little stock
60 CJ5 tore down
holliewood61 is offline  
post #3 of 9 Old 05-21-2015, 03:17 AM
Registered User
1981 CJ7 
Join Date: Jul 2009
Location: Bali
Posts: 5,568
They are stronger but as with all things Jeep, you should question whether it is "necessary" or just received wisdom and whether your epensive hobby could use that money on something else.

2 piece axle shafts can happily last 30 years behind a 304. The problem comes when for some reason the torque on the Axle Nut starts to slacken and the parts start to move and fret, sudden failure often resulting. This can be brought on by big tyres (37" plus) which put a a lot of leverage on the flange. If you have 2 piece axle shafts which are fine, do you have to replace them for the axle seal? Is it the seal which has worn out or something more dramatic that requires new axle shafts?

If I was having to replace the 2 peice axle shafts, say because one had spun its flange, I would strongly consider single piece axle shafts. I didn't last time due to cost and delivery times.

BagusJeep lives in Bali.

1981 CJ7 258ci - Bagusjeep
1984 CJ7 258ci - Puthijeep
1981 J20 258ci - Gladys
1951 Willys CJ3A/MB/M38 - Little Willy
1995 Cherokee 4.0 - CHEROKEE
BagusJeep is offline  
post #4 of 9 Old 05-21-2015, 08:45 AM
Registered User
1977 CJ7 
Join Date: Mar 2011
Posts: 3,937
If the two piece axles are damaged, I'd definitely go with one piece replacements. Otherwise, what Bagus said.

I'd rather be lost on the trails than found at home!

Phoenix Rising- A Flame Off Restoration?
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
WindKnot is offline  
post #5 of 9 Old 05-22-2015, 01:17 PM
Registered User
1983 CJ7 
Join Date: Aug 2010
Location: Memphis, TN
Posts: 793
I've owned my '83 since 2006 with no axle problems.

I'm more concerned about the AMC 20 unit itself and plan to weld and brace the tubes.

If and when I have issues with the axles I'll definitely upgrade to one-piece units.

"We are all of us in the gutter...
Some of us are looking at the stars."
~ Oscar Wilde via Chrissie Hynde
Colt44 is offline  
post #6 of 9 Old 05-22-2015, 05:10 PM
Registered User
1977 CJ7 
Join Date: Sep 2012
Location: Prineville
Posts: 91
Bagus is correct I just last year replaced my 2 piece because of seals and bearings were shot. They never spun with 31 inch tires with over 200K miles on them. About half if not more where mostly on forest service roads. They also spent about 5K miles behind a turned up cummins 4bt and 33s. When I replaced them it was only 30 bucks more for moser one piece axles (they were on sale).

So you cant go wrong with 2 piece axles unless you don't torque them down fully. Yes one piece axles are worth the money if they are not much more. The piece of mind is very nice.

1977 CJ7. 3.9 Cummins 4BT, ZF5, Dana 300, SOA
ctorj is offline  
post #7 of 9 Old 05-26-2015, 01:51 PM Thread Starter
Registered User
1983 CJ7 
Join Date: Oct 2013
Location: Abita Springs
Posts: 5
Going to stick with 2 piece (for now). And replace seals. Thanks
herb812 is offline  
post #8 of 9 Old 05-26-2015, 02:05 PM
Registered User
1974 CJ6 
Join Date: Dec 2007
Location: Illinois
Posts: 1,438
Be sure to get the 250+ ft/lbs of torque on the axle nut when reassembling or you will be buying 1 piece axles sooner than later.

80 CJ-5, 74 CJ-6, 56 CJ-5
Fourtrail is online now  
post #9 of 9 Old 05-26-2015, 04:19 PM
Jeep. There's Only One
keith460's Avatar
1984 CJ7 
Join Date: Jan 2007
Location: Doylestown, PA
Posts: 6,762
Originally Posted by Fourtrail
Be sure to get the 250+ ft/lbs of torque on the axle nut when reassembling or you will be buying 1 piece axles sooner than later.
And I might add, when tightening the nut, make sure you have the tire on. I made the mistake of fabricating a tool to hold the axle flange from turning during the nut tightening procedure and bent my flange. Had to replace with a new one and made sure the tire was on as spelled out in the FSM.

Sent from my iPhone using JeepForum

1984 CJ-7 Renegade
keith460 is offline  

Quick Reply

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome