AMC 20 Gear Build Thread - Page 6 - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > AMC 20 Gear Build Thread

Labor Day Sale!FS: 2007-2013 Jeep Wrangler "HALO" Angel Eye KitEngo winches available at www.rockridge4wd.com! Free shipp

Reply
Unread 04-16-2009, 12:03 PM   #76
kufd
Registered User
1982 CJ7 
 
Join Date: Dec 2008
Location: Hawaii
Posts: 48
that was a very good write up on gear installation for amc 20, I just completed my gear swap last week, im now running 4.56 and (from previous 3.54) the hardest part to me was crushing the sleeve, and going back and forth 100 of times getting the correct shim/backlash. all good, the final reading of my backlash was .oo7 and my ideal target was going to be .006 but I could not achieve it with the shims I had. also the aussie locker was so ez to install.

kufd is offline   Reply With Quote
Unread 08-11-2009, 08:50 PM   #77
80cj
Web Wheeler
 
80cj's Avatar
1980 CJ5 
 
Join Date: May 2002
Location: Hawaii
Posts: 5,786
Every once in a while some one gets a bare axle housing with no gears or old bearings installed. In a situation like that, the question of how thick a pinion depth starter shim pack to start with comes up. I was browsing Randy's Ring and Pinion's web site one evening and came across this chart in one of their old news letters that gives pinion depth starter shim thicknesses for different rearends. A good reference to stash some place.
http://www.ringpinion.com/Content/Do...4_04_April.pdf
80cj is online now   Reply With Quote
Unread 08-18-2009, 10:07 PM   #78
Totallymetal
Registered User
2007 JK Wrangler 
 
Join Date: Jun 2007
Location: Colorado
Posts: 458
This write up is great so far, I am just tearing down my AMC 20 to replace old gears (3.54) with 4.56 from Precision Gear. After doing my front axle I feel pretty confident that the 20 is going to be a cinch. Just a quick question.

The pinion has no marking to tell me (such as +2, -4). Should I assume that it means 0. Anyone experience this?
__________________

2007 JK Rubicon
5.5 Rock Krawler X-factor lift w/37 x 12.5 x 17 BFG KM2s, 5.13 Superior gears
Warn Powerplant HD

Totallymetal is offline   Reply With Quote
Unread 08-18-2009, 10:32 PM   #79
80cj
Web Wheeler
 
80cj's Avatar
1980 CJ5 
 
Join Date: May 2002
Location: Hawaii
Posts: 5,786
Quote:
Originally Posted by Totallymetal View Post
This write up is great so far, I am just tearing down my AMC 20 to replace old gears (3.54) with 4.56 from Precision Gear. After doing my front axle I feel pretty confident that the 20 is going to be a cinch. Just a quick question.

The pinion has no marking to tell me (such as +2, -4). Should I assume that it means 0. Anyone experience this?
Is there something like 2.547 or a number close to that? If so, that would be the depth setting dimension.
80cj is online now   Reply With Quote
Unread 08-19-2009, 08:02 AM   #80
Totallymetal
Registered User
2007 JK Wrangler 
 
Join Date: Jun 2007
Location: Colorado
Posts: 458
Quote:
Originally Posted by 80cj View Post
Is there something like 2.547 or a number close to that? If so, that would be the depth setting dimension.
No, there is nothing on the new gear, except serial number and tooth count on the shaft. The old gear has a +4 scribed on it. I am going to give Precision Gear a call later today.
__________________

2007 JK Rubicon
5.5 Rock Krawler X-factor lift w/37 x 12.5 x 17 BFG KM2s, 5.13 Superior gears
Warn Powerplant HD

Totallymetal is offline   Reply With Quote
Unread 08-29-2009, 01:28 PM   #81
CJman77
Registered User
1977 CJ7 
 
Join Date: Nov 2003
Location: Nokomis, Florida
Posts: 726
I have a quick question. I took the yoke off to replace the seal and as it turns out I don't need to tear the unit apart. So Can I just put the yoke back on and torque it down and not have to worry about setting backlash etc etc etc....?
CJman77 is offline   Reply With Quote
Unread 08-29-2009, 01:49 PM   #82
mcmud
Web Wheeler
1983 CJ8 
 
Join Date: May 2008
Location: N.E. Alabama
Posts: 2,650
Well.......the backlash will be the result left after you attempt to restore proper torque to the nut.

One should read the rotational torque (force needed to rotate)of the pinion, ring and axles prior to loosening/removing the nut. That amount of force would then have been the target to reach with the new nut. Unless you did this your guess will be as good as anyone else.

Once the rollover of the crush sleeve (which is tough) is achieved in it's install the nut torque quickly diminishes as you approach the preload spec.

Someone else may offer up to you their best guess as to how much torque to apply.

Hope it works out for you.
mcmud is offline   Reply With Quote
Unread 09-02-2009, 06:10 PM   #83
CJman77
Registered User
1977 CJ7 
 
Join Date: Nov 2003
Location: Nokomis, Florida
Posts: 726
Quote:
Originally Posted by mcmud View Post
Well.......the backlash will be the result left after you attempt to restore proper torque to the nut.

One should read the rotational torque (force needed to rotate)of the pinion, ring and axles prior to loosening/removing the nut. That amount of force would then have been the target to reach with the new nut. Unless you did this your guess will be as good as anyone else.

Once the rollover of the crush sleeve (which is tough) is achieved in it's install the nut torque quickly diminishes as you approach the preload spec.

Someone else may offer up to you their best guess as to how much torque to apply.

Hope it works out for you.
Well what should I do? What would you do in my position?
CJman77 is offline   Reply With Quote
Unread 09-02-2009, 08:23 PM   #84
mcmud
Web Wheeler
1983 CJ8 
 
Join Date: May 2008
Location: N.E. Alabama
Posts: 2,650
Tough one to answer here. I had hoped that someone would pick this one up.

I have made the attempt with a purchased cj which had a leak, nut was loose, yoke had seal ring wear. Didn't last more than a year, with a new yoke installed.

Here is my best guess, in the event you do not want to pull the axles/carrier/pinion to install a new crush sleeve. Inspect for a wear groove on yoke replace it if necessary. Remove the tires/wheels. Be certain that the brake drums have no additional drag on the axles, or even remove the drums. Install seal into a clean housing and lube its sealing surface, lube the yoke and use a new nut (normally sold in a seal and nut kit). You will feel the yoke bottom out to the sleeve. Then tighten the nut very gradual until a rotational torque of the yoke/pinion, ring and the free spinning axles have a reading of say.....20-25 inch pounds of rotational torque. If you find that the rotational torque is decreasing with a slight tightening of the nut after say 15-18 in pounds, stop. And drive on like there is no tomorrow.

If you don't want the likelihood of doing it again, a good bit of work is ahead.
mcmud is offline   Reply With Quote
Unread 09-02-2009, 09:00 PM   #85
Fjguercio
Web Wheeler
1978 CJ7 
 
Join Date: Dec 2007
Location: Burnsville, MN
Posts: 2,814
Quote:
Originally Posted by CJman77 View Post
I have a quick question. I took the yoke off to replace the seal and as it turns out I don't need to tear the unit apart. So Can I just put the yoke back on and torque it down and not have to worry about setting backlash etc etc etc....?
To set the pinion preload you will need a dial torque wrench. The values for new and used bearings are on post #3 if you would like to read some.

I think the values McMud quoted are too large for a used bearing set up. Please read the post.

Fred
Fjguercio is offline   Reply With Quote
Unread 09-02-2009, 10:13 PM   #86
80cj
Web Wheeler
 
80cj's Avatar
1980 CJ5 
 
Join Date: May 2002
Location: Hawaii
Posts: 5,786
Since you removed the pinion nut with out first checking the rotating torque, you're in a quandry as to what value to use for tightening your new nut down. Realistically, the absolute proper way to do it is to remove the carrier and set the pinion up again using new bearings, crush sleeve and resetting the gears. But that is just a major PIA and expensive, since you'll probably have to get an experienced person to do it.

In the high mileage rearends I've disassembled, I've found that on many of them, pinion preload is practically undetectable with an in lb. torque wrench with the axles removed. What I've seen done, and I'm not saying that it's the correct thing to do, is to figure on no more than 5 in lbs rotating torque plus another 5 in lbs for the new seal. So tighten your new nut down so that you get no more than 10 in lbs rotating torque. I'm going to cover my butt again by saying that this is not the way described in the FSM but I've seen it work several times.
80cj is online now   Reply With Quote
Unread 09-03-2009, 05:38 AM   #87
bdmonist
WTF is that?
 
bdmonist's Avatar
1984 CJ7 
 
Join Date: May 2006
Location: Brandon, MS
Posts: 1,441
Quote:
Originally Posted by Fjguercio View Post

I think the values McMud quoted are too large for a used bearing set up. Please read the post.

Fred
I wouldn't think so, he still has the axles and ring gear installed, remember.
__________________
1984 CJ 7, SBC 350TBI, 700R4, D 300, AMC 20, D30, 35" Mickeys, 3.54 Gears, 4" susp. Lift, 2" body lift.

AMC 20 Write Up
In Progress - 4.56 gears, Aussie Rear Locker, Moser 1 Piece Axles
Coming Soon - CV Shafts, Welded Tubes, trusses
bdmonist is offline   Reply With Quote
Unread 09-09-2009, 11:30 AM   #88
CJman77
Registered User
1977 CJ7 
 
Join Date: Nov 2003
Location: Nokomis, Florida
Posts: 726
Quote:
Originally Posted by bdmonist View Post
I wouldn't think so, he still has the axles and ring gear installed, remember.

The axles are out
CJman77 is offline   Reply With Quote
Unread 09-09-2009, 09:14 PM   #89
sbcranger
Registered User
1985 CJ7 
 
Join Date: Mar 2009
Location: long island
Posts: 309
okay one more with the whole removing yoke gig-

im replacing my yoke because i had a u-joint explode and broke a bolt off in the yolk and dont want to waste time trying to drill the damn bolt out so...ended up getting a new yolk and its the U-Bolt style rather than the strap style. do i go about this all the same way as just changing the seal?

i checked the rolling resistance(rotational torque) and got a whopping 6 in/lbs. i stopped there to just double check with anyone who may have done this.

after i pull the yolk and replace the seal, i install the new yolk and tighten and check rolling resistance and repeat as necessary.

so at the end of the day when everything is all said and done, im looking for a rolling resistance of 11 in/lbs right?
sbcranger is offline   Reply With Quote
Unread 09-10-2009, 12:28 AM   #90
80cj
Web Wheeler
 
80cj's Avatar
1980 CJ5 
 
Join Date: May 2002
Location: Hawaii
Posts: 5,786
Quote:
Originally Posted by sbcranger View Post
okay one more with the whole removing yoke gig-

im replacing my yoke because i had a u-joint explode and broke a bolt off in the yolk and dont want to waste time trying to drill the damn bolt out so...ended up getting a new yolk and its the U-Bolt style rather than the strap style. do i go about this all the same way as just changing the seal?

i checked the rolling resistance(rotational torque) and got a whopping 6 in/lbs. i stopped there to just double check with anyone who may have done this.

after i pull the yolk and replace the seal, i install the new yolk and tighten and check rolling resistance and repeat as necessary.

so at the end of the day when everything is all said and done, im looking for a rolling resistance of 11 in/lbs right?
You got it. Add 5 in lbs torque for the new seal.
80cj is online now   Reply With Quote
Reply
Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.