International Full Size Jeep Association
Home Forums Reader's Rigs Tech Library Trail Stories FSJ-List
International Full Size Jeep Association  

Go Back   International Full Size Jeep Association > Tire Kickin' > General FSJ Tech

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 10-05-2011, 02:28 PM
jbentley's Avatar
jbentley jbentley is offline
Member
 
Join Date: Feb 28, 2008
Location: texas
Posts: 155
Axle Swap/Upgrade

OK, so I recently had a post about a jerry rig solution to an axle problem...

Short version:
Factory AMC 20 NT got replaced with a WT, tires rubbed fenders, so a poor man's lift solution was created.....

Bottom line, I'm going to need to ditch the WT and put a proper length Axle in place, which leaves me three options:
A. Return to factory AMC 20 NT
B. Upgrade the axle, say a Dana 44 (though the AMC 20 is said to be equivical), but if I'm swapping out the axle, why not put in something more common/modern? Maybe swipe one from another vehicle with disc brakes perhaps, the skies the limit....
C. Upgrade the axle with a newer unit that has a trackbar for better stability and towing. See, I really like this idea here, because my 82 doesn't have a trac-bar and I think that would a be a snappy feature, not to mention safer...

So, I know nadda of axles or swaps... I don't want to break the bank on this project, $200-$300 tops, I don't want to alter Drive shafts.... I can make shock perches or brackets and weld 'em on if required, but I just don't know what'll work on these things. The last thing I want to do is run out, get a new axle and find that it's too long, narrow, the differential doesn't line up with the drive shaft, you know, those kind of gotchas that make you feel like you just dropped the pry bar on your crotch...

Maybe sticking with a factory NT is best given the budget, but I don't want to do it and find out later that I could have put in an 84 rear axle with trac-bar for the same $$ and had a rig with more modern features.
__________________
'82 limited edition Jeep Wagoneer
"The Stock Beast"
Reply With Quote
  #2  
Old 10-05-2011, 02:34 PM
addicted's Avatar
addicted addicted is offline
Big Meanie
 
Join Date: Dec 11, 2004
Location: Byron, MI
Posts: 4,876
If you can weld up shock tabs and stuff then making track bar mount shouldn't be heard either. Find a NT that's the same ratio as yours and swap it in. If it doesn't have a track bar mount make one, you'll have to make one for the frame side anyway.
__________________
Quote:
Originally posted by Ristow
i bet it was Simon....
he's such big meanie that way...
please don't tell him i said that....
Reply With Quote
  #3  
Old 10-05-2011, 02:38 PM
jbentley's Avatar
jbentley jbentley is offline
Member
 
Join Date: Feb 28, 2008
Location: texas
Posts: 155
Nice! So I don't have to have a newer axle then eh? Just snag an existing trac-bar from a new FSJ with the AMC 20 and build my own axle/frame mounts?

Sweet!

BTW, to my knowledge, the gear ration hasn't been touched, so if the cover differential bell stamp isn't lying, the "circled A" character means it is a 3.34, so that should be easy enough to matching NT. Now, I just need to find one 'round Dallas/Lewisville.
__________________
'82 limited edition Jeep Wagoneer
"The Stock Beast"
Reply With Quote
  #4  
Old 10-05-2011, 03:11 PM
addicted's Avatar
addicted addicted is offline
Big Meanie
 
Join Date: Dec 11, 2004
Location: Byron, MI
Posts: 4,876
Are you talking about the piece of tin between two of the cover bolts? If you are then that should be the gear ratio. The best way to tell is to pull the cover off and find the ratio stamped into the edge of the ring gear or count the teeth on the gears. I should also point out that you want one from '80-'91. The majority of them from the mid 70's to '79 will have an offset to the pass side for the Qtrac case they used.
__________________
Quote:
Originally posted by Ristow
i bet it was Simon....
he's such big meanie that way...
please don't tell him i said that....
Reply With Quote
  #5  
Old 10-05-2011, 03:32 PM
derf's Avatar
derf derf is offline
360 AMC
 
Join Date: Jul 12, 2001
Location: Littleton, CO
Posts: 3,403
Quote:
Originally Posted by jbentley
Nice! So I don't have to have a newer axle then eh? Just snag an existing trac-bar from a new FSJ with the AMC 20 and build my own axle/frame mounts?

Sweet!

BTW, to my knowledge, the gear ration hasn't been touched, so if the cover differential bell stamp isn't lying, the "circled A" character means it is a 3.34, so that should be easy enough to matching NT. Now, I just need to find one 'round Dallas/Lewisville.

Back when I lived in DFW I remember finding a few FSJs in junk yards around the mid cities area. I grabbed a few parts out of one that still had it's axles probably 10 years ago. It's probably been crushed by now. But I'm sure if you call around you can find something. If push came to shove and you can't find an axle with 3.31 gears, just find an 80's wag and grab both axles so you have matching ratios. They'll probably be 2.73 gears. Grab the speedo gear out of the t-case while you're at it so your speedo reads right.
__________________
Try out my gear ratio calculator

My Jeeps: Truck Norris and Grimm Jeeper

Truck Norris doesn't need a brow. He has fists.
Reply With Quote
  #6  
Old 10-05-2011, 03:37 PM
joe joe is offline
 
Join Date: Apr 28, 2000
Location: PNWet, USA
Posts: 22,392
I have no clue what a circled A means. All 1980-91 Wags and Chero's only had two factory options. Standard were 2.73's and the optional towing pack included 3.31's.
The 80-mid86 years used an AMC 20 rear axle. Late 86-91 used D44's I agree AMC20 or D44 similar in strength. The ratio code on an AMC20 axle is stamped into the flat boss next to the dowel hole on the pass side of the differential. "D" = 2.73, "B" = 3.31 On a D44 the ratio is on a tag between two cover bolts. No letter code just the tooth count. 2.73's would show a number like 41 15 I would go with either flavor NT axle so long as the ratio is the same and it's from an 80 or later with the centered differential. Price varies with location but around here you could find either axle for $150. So doing a stock 80-91axle swap is well within your $300 budget
__________________
joe
"Don't mind me. I'm just here for the alibi"
Reply With Quote
  #7  
Old 10-05-2011, 03:43 PM
Tad's Avatar
Tad Tad is offline
 
Join Date: Nov 30, 2001
Location: Out West
Posts: 17,617
If you can't find a 80-91 NT rear with 3.31's then grab the cheapest NT you can find.
I have 3.31's for D44 and AMC20 (complete, pulled w/carriers) I'd send over for the price of shipping. They are dirty and dusty from sitting but quite useable.
You would need install kits, I have not priced those in a long time so you'd have to figure that into the equation.
__________________
2000 Infinity QX4, 3.3L, MPFI, 4 speed auto, 2 speed Nissan tcase, Unibody, IFS front, 4 link rear solid axle with 255-70/16s

IFSJA WMS PROJECT
EARLY WAG LIFT SEARCH

Quote:
...Pay no attention to these heathen barbarians with their cutting torches and 8" lift kits!...

Self Inflicted Flesh Wound
Reply With Quote
  #8  
Old 10-05-2011, 05:13 PM
78J-10's Avatar
78J-10 78J-10 is offline
Gear Head
 
Join Date: Apr 15, 2008
Location: Lima,Oh
Posts: 583
If you up for a little fabbing. You could go with a ford 8.8 31 spline axles and 98+ had disk brakes. come in 3.31 to 4.10 gear raitos with LSDs

I have on in my 95 YJ and i beat the snot out of it with no issues.
__________________
78 J-10: 258 w/2100,D20,HD44,14 Bolt,36's (SOLD )
79 J20: 360 T18 D20 33s 36k: current state:
88 Waggy: 360/727/Quad All stock rusty roof 78k :
Tow Rig: 2013 CCLB 4x4 w/ 6.7L Cummins





Reply With Quote
  #9  
Old 10-05-2011, 05:58 PM
addicted's Avatar
addicted addicted is offline
Big Meanie
 
Join Date: Dec 11, 2004
Location: Byron, MI
Posts: 4,876
Quote:
Originally Posted by 78J-10
If you up for a little fabbing. You could go with a ford 8.8 31 spline axles and 98+ had disk brakes. come in 3.31 to 4.10 gear raitos with LSDs

I have on in my 95 YJ and i beat the snot out of it with no issues.

He'll need to do some serious work to that axle to make it work. The bearing ends will need to be replaced with 9" big bearing ends and have custom shafts made for the 5.5" bolt pattern. The stock flanges aren't big enough for anything bigger than the 4.5" pattern.
__________________
Quote:
Originally posted by Ristow
i bet it was Simon....
he's such big meanie that way...
please don't tell him i said that....
Reply With Quote
  #10  
Old 10-06-2011, 01:21 AM
78J-10's Avatar
78J-10 78J-10 is offline
Gear Head
 
Join Date: Apr 15, 2008
Location: Lima,Oh
Posts: 583
Why you you have to replace the bearing with 9" ones? Aftermarket shafts with 5.5 bolt pattern can be had for a decent price and there stronger. I have friends with 8.8 behind V8s and run 38s on 5.13 gears and its on stock shafts and bearings.
__________________
78 J-10: 258 w/2100,D20,HD44,14 Bolt,36's (SOLD )
79 J20: 360 T18 D20 33s 36k: current state:
88 Waggy: 360/727/Quad All stock rusty roof 78k :
Tow Rig: 2013 CCLB 4x4 w/ 6.7L Cummins





Reply With Quote
  #11  
Old 10-06-2011, 04:28 AM
jeeping1974's Avatar
jeeping1974 jeeping1974 is offline
FSJ Maniac
 
Join Date: Jun 17, 2007
Location: Manchester, NH
Posts: 3,066
If you still have the stock NT axle, just swap that back in. The ring gear is a little larger than the D44. Only thing you need to watch for are the axle tubes spinning in the diff. Easy fix is to weld the tubes to the diff housing. Same bolt pattern, no drive shaft mods needed and no welding required.

If you want disc brakes, do some research on what you need for calipers and rotors and get some weld on brackets.

As for a track bar, all it does is keep the axle from moving side to side (which your leaf springs can do). If you'll be tow with it, install a sway bar and links in the rear.
__________________
03 GMC 2500HD - DD/toy hauler
06 Street Glide - Cruiser

Last edited by jeeping1974 : 10-06-2011 at 04:31 AM.
Reply With Quote
  #12  
Old 10-06-2011, 06:19 AM
addicted's Avatar
addicted addicted is offline
Big Meanie
 
Join Date: Dec 11, 2004
Location: Byron, MI
Posts: 4,876
Quote:
Originally Posted by 78J-10
Why you you have to replace the bearing with 9" ones? Aftermarket shafts with 5.5 bolt pattern can be had for a decent price and there stronger. I have friends with 8.8 behind V8s and run 38s on 5.13 gears and its on stock shafts and bearings.

I called or visited several shops in my area that do axle work/custom off-road fab and they all told me that a 5.5" bolt pattern weather it's 5 or 6 lug will require a custom shaft and different bearing end. One shop even called 3 axle suppliers in front of me and was told the same by all 3. Currie and Yukon were 2 of them the other was either Moser or Superior.
__________________
Quote:
Originally posted by Ristow
i bet it was Simon....
he's such big meanie that way...
please don't tell him i said that....
Reply With Quote
  #13  
Old 10-06-2011, 07:14 AM
jbentley's Avatar
jbentley jbentley is offline
Member
 
Join Date: Feb 28, 2008
Location: texas
Posts: 155
Thanks all!

I'm really excited about this project.. It doesn't seem nearly as daunting as before now. I appreciate all the great input.
__________________
'82 limited edition Jeep Wagoneer
"The Stock Beast"
Reply With Quote
  #14  
Old 10-06-2011, 11:44 AM
bshoke's Avatar
bshoke bshoke is offline
Member
 
Join Date: Jan 21, 2011
Location: South Texas
Posts: 29
I use www.car-part.com to hunt down some parts, I usually use the distance search, and follow up call to the yard to make sure they still have the part. Never used it for rear ends though.
__________________
1982 Wagoneer, 360, cs-144, AC, 2 wheel drive soon to have a np219 like it started life with.

1981 Wagoneer, 360, np208, starts rolls around the yard in the process of getting back to running, stock tape player works radio tuning knob does not.
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Break for a Dana 60-2 Marcus Fox Off-Road FSJ Tech 8 11-19-2011 06:36 PM
RPM, tire size, and axle ratio questions twmattox General FSJ Tech 11 03-07-2009 01:00 PM
Axle seal/bearing update cajunKen General FSJ Tech 1 09-29-2008 03:26 AM
Looks like a bad axle bearing...... cajunKen General FSJ Tech 14 08-22-2008 09:23 PM
Different Ways to Relocate Rear Axle viscacha Off-Road FSJ Tech 16 04-01-2005 07:04 AM


All times are GMT -6. The time now is 07:15 AM.


Powered by vBulletin Version 3.5.4
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
corner corner