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Axle strength questions

chrisja77

NAXJA Forum User
Location
Marion, AR
It is time for me to replace the D35 on the rear of my rig. I have found a couple of options and thought I would get you guys opinions! First, a little history. I have a 95 2 door XJ with an AX15, 4.0, 7" of lift, and 35" tires. I have found 2 different rears, I just don't know which would be best. First off is an 8.8 with 4.56 gears and factory LS and drum brakes for $100 bucks. Second, I found an 8.25 with 4.56 gears, Alloy shafts, and a Powertrax locker for $350. With the price difference, I could put a locker in the 8.8, but the 8.25 has the alloy shafts already and it's about 5 hours closer to the house! Would the 8.25 be stout enough to run the 35's and not have to worry about it? I'm honestly thinking about putting the 8.25 on my rig, and then reselling the 8.8 to make a little cash. What are your thoughts?
 
Yes the 8.25 would be plenty strong w/ 35s unless you got very stupid.
If the 8.25 is more plausable to go get then it sounds like a done deal to me.
 
That's kind of what I was hoping. Closer to home, geared the way I want it, and already locked. I didn't think I should have any problems with it with the alloy shafts.
 
Good axle info from pirate 4x4...
FRONT AXLES
D27 Front Axle:
Full Floating
Vehicles: '66-'71 CJ-5 and CJ-6; '63-'70 Wagoneer; '67-'71 C-101 Jeepster
Ring Gear: 7.2"
Stock Gearing:
Axleshaft Spline: 10
Axleshaft Diameter: 1.13"
Axle Joint: Spicer 260X
Knuckle: Closed
Brakes: Drum 10" 11"
Weakness: Weak axle for upgrades, low spline count, weak carrier
Width: 51" (CJ and Jeepster), 57.5" (Wagoneer)
Wheel Bolt: 5x5.5"
Max Recommended Tire Size: 31"

D30 Front Axle:
Full/Semi Floating
Vehicles: From ’72 CJ-5, CJ-6, CJ-7, CJ-8, YJ, TJ, XJ, ZJ, C104, WJ
Ring Gear: 7.125”, 7.33” (TJ/WJ Only)
Stock Gearing: 3.07, 3.54 (3.55), 3.73, 4.10 (4.11)
Axleshaft Spline: 27
Axleshaft Diameter: 1.16”, 1.193” (TJ/WJ Only)
Axle Joint: Spicer 260X (pre ’95.5), Spicer 297/760X (post ’95.5), CV & 760 U-Joint (TJ/WJ)
Knuckle: Open
Brakes: Drum 11” (pre ’76), Disc (post ’76)
Weakness: 260X U-joint; YJ Vacuum motor fails; standard CV problems
Width: 51” (’72-’75 CJ, C-104), 53” (’76-’81 CJ), 56” (’82-’86 CJ), 60.5” (TJ, YJ, XJ, WJ)
Wheel Bolt: 5x5.5” (CJ/C-104), 5x4.5” (others)
Max Recommended Tire Size: 35”

AAM 790 Front Axle
Semi Floating
Vehicles: '05 and later WK
Ring Gear: 7.87"
Stock Gearing:
Axleshaft Spline:
Axleshaft Diameter:
Axleshaft Joint: CV
Knuckle: Open
Brakes: Disc
Weakness: Limited modification ability, small ring gear
Width:
Wheel Bolt:
Max Recommended Tire Size: 32"

D44 Front Axle:
Full/Semi Floating
Vehicles: ’57-’65 FC-170; ’63-’70 Gladiator; '67-'79 1/2 & 3/4 Ton Ford Pickups; ’71-’87 J-Series; ’71-’91 Wagoneer; '72-'93 1/2 & 3/4 Ton Dodge Pickups; '73-'79 1/2 & 3/4 Ton Chevy Pickups; ’74-’83 Cherokee; ’03-’06 Rubicon
Ring Gear: 8.5”
Stock Gearing: Many
Axleshaft Spline: 19 (pre ’71), 30 (post ’71)
Axleshaft Diameter: 1.25” (19 spline), 1.31” (30 spline)
Axle Joint: Spicer 206X (pre ’73), Spicer 297/760C (post ’73)
Knuckle: Closed (pre ’73), Open (post ’73)
Brakes: Drum 11” (pre ’73), Disc (post ’73)
Weakness: 260X and 19 spline axleshafts
Width: 63” (FC-170), 57.5” (’71-’73 Wagoneer), 59” (’74 and later Wagoneer), 65.5” (J-Series), 60.5” (Rubicon), Full Width (Ford, Dodge, Chevy)
Wheel Bolt: (Varies)
Max Recommended Tire Size: 37”

D60 Front Axle:
Full Floating
Vehicles: ‘67-’69 Kaiser M-715; ‘72-‘93 3/4 & 1 Ton Dodge Pickups; ‘74-‘77 3/4 Ton Ford Pickups; ‘77-‘87 3/4 & 1 Ton Chevy Pickups; ‘78-‘79 1 Ton Ford Pickups
Ring Gear: 9.75”
Stock Gearing: 4.10, 4.56
Axleshaft Spline: 30
Axleshaft Diameter: 1.31”
Axle Joint: Unknown Spicer
Knuckle: Closed
Brakes: Drum 13”
Weakness: Metallurgically axleshafts inferior to modern metals
Width: 72.5” (M-715), Full Width (Ford, Dodge and Chevy)
Wheel Bolt: 6x8.25”
Max Recommended Tire Size: 42”


REAR AXLES
D35 Rear Axle:
Semi-floating (’85-’89), C-clip (’90 and later)
Vehicles: Most XJ; YJ; TJ (except Rubicon); ZJ; some WJ
Ring Gear: 7.562”
Stock Gearing: 3.07, 3.54 (3.55), 3.73, 4.10 (4.11)
Axleshaft Spline: 27
Axleshaft Diameter: 1.13”
Brakes: Drum 11”; Disc (later ZJ/WJ)
Weakness: Weak carrier & axleshafts
Width: 60.5”
Wheel Bolt: 5x4.5”
Max Recommended Tire Size: 33”

D44 Rear Axle:
Semi Floating
Vehicles (here we go…*long breath*): ’49-’65 6cyl Willy Wagons; ’49.5-’53 CJ-3A; ’53-’68 CJ-3B; ’50-’52 M-38; ’52-’57 M-38A1; ’53-’57 M-170; ’55-’75 CJ-5 & CJ-6; ’85.5-’86 CJ-7; ’58-’65 FC-150; ’57-’65 FC-170; ’63-’70 Wagoneer & Gladiator Pickup; ’67-’71 C-101 Jeepster; ’72-’73 C-104; ’71-’75 Wagoneer & ½-ton J-Series; ’74-’83 Cherokee; ’87-’91 Grand Wagoneer; Some ’86-’92 XJ and MJ; Some ’97-’06 TJ; ’99-’04 WJ; ’96-’98 ZJ
Ring Gear: 8.5”, 8.9” (WJ only )
Stock Gearing: Many, including 3.55, 3.73, 4.11
Axleshaft Spline: 10 (’49-’55), 19 (’56-’70.5), 30 (’70.5 and later)
Axleshaft Diameter: 1.193” (WJ/ZJ) 1.25” (10 and 19 Spline), 1.31 (30 Spline)
Brakes: Drum 9”, 10”, 11”; Disc (Rubicon, ZJ, WJ)
Weakness: 10 & 19 Spline, Some aluminum housings.
Width: 50.5” (up to ’75 CJ, FC, C-101, C-104), 54.5” (’85-’86 CJ), 57.5” (’63-’73 Wagoneer), 60.5” (XJ, MJ, TJ, ZJ, WJ), 65.5” (FSJ Cherokee, J-Series)
Wheel Bolt: Varies
Max Recommended Tire Size: 38"

D53 Rear Axle:
Semi Floating
Vehicles: '55-'65 Willys pickup; '63-'69 Gladiator; '57-'65 FC-170
Ring Gear: 9.25"
Stock Gearing:
Axleshaft Spline: 20
Axleshaft Diameter: 1.31"
Brakes: Drum 11"
Weakness: Hard to find parts, low spline
Width: 65.5" (Gladitaor), 63" (Others)
Wheel Bolt: 5x5.5"
Max Recommended Tire Size: 35"

D60 Rear Axle:
Semi/Full Floating
Vehicles: ‘67-‘69 1/2 & 3/4 Ton Ford Pickups; ’69-’87 J-2000/J-20; ‘72-‘93 3/4 Ton Dodge Pickups
Ring Gear: 9.75”
Stock Gearing 4.10, 4.56
Axleshaft Spline: 30
Axleshaft Diameter: 1.31”
Brakes: Drum 12”
Weakness:
Width: 65.5” (J-2000/J-20), Full Width (Ford, Dodge & Chevy)
Wheel Bolt: 8x6.5”
Max Recommended Tire Size: 42”

D70 Rear Axle:
Full Floating
Vehicles:’58-’68 FC-170 w/dual rear wheels; ’63-’68 J-3000 w/dual rear wheels; ’67-’69 M-715; CJ-10; '72-‘93 3/4 & 1 Ton Dodge Pickups; ‘76-‘77 3/4 Ton Ford Pickups; ‘77-‘87 1 Ton Chevrolet Pickups; ‘78-‘79 1 Ton Ford Pickups
Ring Gear: 10.5”
Stock Gearing: 4.10, 4.56
Axleshaft Spline: 23, 35
Axleshaft Diameter: 1.5”
Brakes: Drum 13”
Weakness: Poor parts availability
Width: 59” (FC & Pickup), 72” (M-715), Full Width (Ford, Dodge and Chevy)
Wheel Bolt: 6x7.25” (M-715), 8x6.5” (others)
Max Recommended Tire Size: 44”

AMC20 Rear Axle:
Semi Floating
Vehicles: ’76-’86 CJ; ’76-’91 Wagoneer and J-10
Ring Gear: 8.875”
Stock Gearing: 2.76, 3.07
Axleshaft Spline: 20
Axleshaft Diameter: 1.31”
Brakes: Drum 11”
Weakness: 2 piece axleshafts (CJ only), tubes spin, 20 spline
Width: 50.5” (’76-’81 CJ), 54.5” (’82-’86 CJ), 59” (Wagoneer), 65.5” (J-Series)
Wheel Bolt: 5x5.5” (CJ), 6x5.5” (Wagoneer and J-Series)
Max Recommended Tire Size: 33”-35”

Chrysler 8.25 Rear Axle:
C-clip
Vehicles: '91-'01 XJ
Ring Gear: 8.25”
Stock Gearing: 3.55, 3.73, 4.10
Axleshaft Spline: 27 ('91-'96), 29 ('96-'01)
Axleshaft Diameter: 1.17” (27 spline), 1.21 (29 spline)
Brakes: Drum 11”
Weakness: 27 spline, c-clip
Width: 60.5”
Wheel Bolt: 5x4.5”
Max Recommended Tire Size: 35”

Ford 8.8 Rear Axle
C-clip
Vehicles: Ford Explorer (Prefered Swap, information reflects Explorer only), Ford F-Series , Ford Ranger
Ring Gear: 8.8"
Stock Gearing: 3.08, 3.27, 3.55, 3.73, 4.10
Axleshaft Spline: 28, 31
Axleshaft Diameter: 1.320"
Brakes: Drum ('91-'94), Disc ('95-'01)
Weakness: C-clip, weak carrier
Width: 59.625" to 65.6"
Wheel Bolt: Most 5x4.5"
Max Recommended Tire Size: 40"

Ford 9 inch
vehicles: 57-'59 Ford station wagons, including Ranchero and sedan delivery
58-'90 F-100 and F-150 pickups
57-'67 Thunderbird
63-'69 Falcon and Comet
57-'64 Ford and Mercury full-size cars 63-'69 Fairlane (note: '67 Fairlanes had coil rear springs instead of leaf)
58-'60 Edsel
66-'77 Bronco (uses a larger five-on-51/2-inch wheel bolt pattern)
75-'78 Ford Granada and Mercury Monarch
71-'76 Torino, Ranchero and Mercury Montego
77-'81 Lincoln Versailles
70-'79 Lincoln and Continental
72-'86 E-250 Ford vans
65-'73 Mustang
67-'73 Cougar
Stock gearing:2.50,3.08, 3.27, 3.55, 3.73,4.11,4.30
Axleshaft Spline:28, 31
Axleshaft Diameter:
Brakes:
Width:
Wheel Bolt:
Max Recommended Tire Size:40"


AXLE STRENGHTS:
COT - Continuous Output Torque
MOT - Maximum Output Torque

Dana 35 ........................ COT: 870 MOT: 3480
AMC 20 .........................
Chrysler 8.25 .................
Dana 53 ........................
Dana 44 ........................ COT: 1100 MOT: 4460
Ford 8.8 28 spline ........... COT: 1250 MOT: 4600
Ford 8.8 31 spline ........... COT: 1360 MOT: 5100
Dana 60 semifloat ........... COT: 1500 MOT: 5500
Dana 70 ........................
Rockwell 2.5 Ton ............


IDENTIFICATION:
Tag Identification:
D30: “30” cast into back of diff casing on top right and left next to diff cover. Tag bolted on diff cover with axle ID and gear ratio.
D35: “35” cast into back of diff casing on top right and left next to diff cover. “C” next to “35” DOES NOT stand for c-clip, but “custom” (unfinished by Spicer). Tag bolted on diff cover with axle ID and gear ratio.
D44: In most cases “44” into back of diff casing on top right and left next to diff cover. Tag bolted on diff cover with axle ID and gear ratio.
D60: Similar looking casing to the D44, except the oil fill plug is elevated to provide more fluid for the larger gears.
Chrysler 8.25: Tag wrapped around passenger side tube with axle ID and gear ratio.
Ford 8.8: See Joe Dillard and T.Dome's writeup linked at the bottom of the page

Differential Cover Identification:
AMC 20: 12 cover bolts, round cover, fill plug not present
D27: 10 cover bolts, oval with straight sides, distinguished ring gear extension, low fill plug
D30: 10 cover bolts (five on top, five on bottom), oval cover w/flat sides, fill plug just below centerline
D35: 10 cover bolts, evenly spaced, oval "dome" shaped cover with low fill plug
D44: 10 cover bolts, hexagon shaped cover with very round edges, fill plug on centerline
D60: 10 cover bolts, hexagon shaped cover, fill plug on centerline
D70: 10 cover bolts, hexagon shaped cover, fill plug on centerline
Chrystler 8.25: 10 cover bolts, oval shaped cover, fill plug just below centerline
Ford 8.8: 10 cover bolts, square with very round edges, fill plug not present on cover




Gear Identification:
If the gears are unidentifiable from the tag or if the tag is missing, there are two methods to find the gear ratio.

1) Spin the tire one full rotation and watch how far the driveshaft rotates. Double the amount the driveshaft rotated, this gives you your gear ratio. Be sure you are spinning the tire forwards.

2) Count ring & pinion gears: Count the number of teeth on the ring and the pinion. Then divide the ring teeth by the pinion teeth to attain the gear ratio.


And thanks to:

Travis Waldher
Pirate4x4 Addict!

for some changes.

1) The AMC20 that came under the CJ is a different animal from the one that came under the waggie. A waggies pumpkin webbing is different, tubes are plug welded in to the housing, 29 spline. I think 2.21 was also a gear option -- I think. One perc to at least the waggie version is the massive pinion - the shaft is the same diameter as a D60.
 
I run a Dana 44 with 33's and it is nice having the peice of mind knowing that I have plenty of axle for the tires I run. I think you should give that 8.8 another look. Just look at its torque output numbers. Its a beast. You always want to make a change thinking about the future. If you get the 8.8 then you can go bigger and not worry about your axle. Might as well do it once right?
 
I run a 29 spline 8.25/alloy shafts/Detroit locker on 35's with no issues, its just as tough as the D-44 and much cheaper to replace.

Nothing at all wrong with the 8.8 though.
 
I run a Dana 44 with 33's and it is nice having the peice of mind knowing that I have plenty of axle for the tires I run. I think you should give that 8.8 another look. Just look at its torque output numbers. Its a beast. You always want to make a change thinking about the future. If you get the 8.8 then you can go bigger and not worry about your axle. Might as well do it once right?


I honestly can never see any reason to ever go larger than 35" tires for me.... 36 maybe, but I really doubt it. Too hard to find a quick replacement if you screw up. I'm not trying to build a monster of a jeep. A guy in my local club has an XJ on 39.5's, and I just don't see me going that route. I love my 7" of lift and 35's. Looks great, and does what I ask of it.
 
In that case you should just go with the 8.25. I am in the same boat as you except I am on 33's right now. I don't think I will go bigger than 35's so my d44 will always work for me.
 
8.25 all the way!!! im running the same setup in my 8.25 and its great. i use plenty of happy pedal and 35" claws. compared to the 8.8 ur lookin at, the 8.25 has better shafts and a true locker instead of a LS. newer 8.8's have disks, but since its an older one with drums, theres no brake advantage there and could very well be 28 spline. plus the 8.25 is closer
 
Well, I'm getting the 8.25! Picking it up next week and then working on the install...Can't wait! Next step will be regearing the front to match. It's gonna be AWESOME to get rid of the 3.07 gears with my 35" tires...LOL
 
I agree with the 8.25 as well. It is plenty strong, and its bolt in. You will have to have spring perches welded onto the 8.8 for it to fit, so that adds money and time right there.

I also don't agree with that axle chart from Pirate, I don't think I would trust an 8.8 on 40" tires.
 
my 8.25 is locked with 4.56 and i frequently have beat it, but only recently on 34s. (used to be just on 31s...) i'd say go for the 8.25, especially if it's that much closer. as said, it's even bolt-on. the disk brake conversions aren't that hard to come by either. i just got one for $100... if i do an axle swap that involves fab, it's going to be full width or nothing (for the rear) because i can safely run up to about 35s on the 8.25, but if i go to a 44 i might be able to run 37s... whereas if i throw a 60 in... hehe i can run 39s :D
 
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