Help needed to Identify the Differential Model

diesel_maniac · 7th September 2009, 19:23

Hello All,

I have come across this rear differential belonging to an earlier generation Jeep. It has a peculiar bulge on the crown gear cover unlike what I have seen on various 3Bs. As I have very little knowledge on actual technicalities like different Gearboxes, T/cases, Differential that came with various Jeep models. I would request all the seniors to share their knowledge on this one.

Here are the two pictures of the differential. They are not very good but I hope you people will be able to make out the details.
regards

U.B.Singh · 9th September 2009, 02:31

Hello Jasvinder,
Wow !
that is a beauty. A rare Dana 41 from the rear of the early CJ2As and 3As.
At first I was very happy seeing the 41, but was sad to notice closely that it has been converted to a 4X2 setup.
The left side spring seat has been replaced with a later CJ3B (boat) type which comes commonly in a Dana 44. The previous user has removed the top side bracket which sits between the U bolts and takes the dump from the rubber dumpers bolted to the chassis.

Just for academic interest, I shall post a few differences between the Dana 41 and the famous Dana 44 (from a CJ3B), which are equal in track and the axles are same, so are the hubs and wheel bearings. Even the tube dia. is same.

1. 41 has a bigger dia. crown pinion and the tail is bigger too at the teeths. They also
came with 43/8 teeth count but not interchangeable with 44.
2. The diff cover is round, and is fitted with 3/8 in bolts as opposed to 5/16 as in the 44.
3. Since 41 was made for the rear only, the diff body does not have a built-in seat to
take the centre bolt's head as we see in the front of the 44.
4. The spring seats are like the Dana 25 or 27(that we see in the early WWII and only in
the front of the 2As and 3As and pre 1956 CJ3Bs jeeps), with
a dump absorbing bracket welded on top again like 25/27.
The Dana 44 has a boat like spring seat.
5. Unlike 44, there is only one set available for ratio alteration, and that is 45/11 out of
a later Studebaker car. The early Studys came with 41/10 which could fix in the 25s
or Dana27s as a straight fit.
6. ........... To be filled in by experts.

I would have believed it as original from a 4X2 DJ3A, if only there were four bolts on
the hubs, and seat not altered.
Whatever it is - it is diamond, so be happy and proud.
90% of the CJ2As and 3As restored in India have replaced the rear with Dana 44s.
All the best,
with you always...................... UBS

Ignazio · 9th September 2009, 03:13

Hi Mate,
I have a beautiful book about differential identification, repair and restoration, that will be for sure of help.
It happen only that I'm on business travel in France and will be UK tomorrow, I won't be home before Friday.
I will certainly check and let you know what I can, if anyone else doesn't give you an answer.

Ciao

Ignazio

diesel_maniac · 9th September 2009, 09:08

@ UB Singh: Thanks Kaka for the detailed information. This information will be of great importance when the vehicle is put up for actual restoration. Is it possible to find the original seat for this Dana 41. More over the wheel studs have also been changed to later model CJ3B type, which have regular direction thread as opposed to earlier model Jeep which used to have opposite thread pattern for the left hand side front and rear wheels.

@ignazio: Looking forward to hear from you mate, hope to have more insight on this one.

Ignazio · 12th September 2009, 01:38

Hi!
yes is definitely a Dana41.
I will make a scan of my book and send you a PM, book is copyrighted and I do not want troubles!

Ciao

Ignazio

SirAlec · 13th September 2009, 00:39

Axle Identification Chart

DANA 25/27
These Danas are indistinguishable in appearance. The military Model 25 has a thick, cast cover, while the 27 and civilian-model 25s have a thinner cover, will accept taller gears, and backed V-6s.

DANA 30
The Model 30, with a 7 1/8-inch-diameter ring gear, was the standard front differential in some 1972-75 CJ-5s and all 1975-and-later CJ-5s and CJ-7s. It is still used in the front of Cherokees and Comanches, and will probably appear in the front of the Grand Cherokee.

DANA 35
This axle, with a 7.56-inch ring gear, is the fronted for 4.0-liter Ford Rangers and Explorers/Mazda Navajos. The 35C version is found in the rear of Cherokees and Comanches.

DANA 41
The 41, which has a ring gear size similar to the Dana 44, came in early CJ-2As. The spiders are the same as a 44's, but the carrier and gears aren't. It is almost universally swapped out in favor of a Dana 44.

DANA 44
All domestic manufacturers have used Dana axles, and the 44, with its 8 1/2-inch ring gear, is likely to be a step up on anything smaller than a 1/2-ton. A narrowed 44 could be the hot ticket for vehicles smaller than a full-size sport-utility. It was standard under the front of pre-1976 Chevy Blazers and 1/2-tons, solid front-axled F-150s and Broncos, and Jeep J-10/J-20s and Grand Wagoneers.

DANA 44-IF
The Ford-version Dana 44 Twin-Traction-Beam setup is similar to other 44s (ring gear diameters are identical), but there are no axle tubes and the "cover" is actually the suspension arm. It's standard in the front of any TTB-equipped Ford except the 1987 and newer F-250HD, which uses a Dana 50.

DANA 60
A Dana 60 looks deceptively similar to a Dana 44, but the 60's 9 3/4-inch ring gear diameter is a major factor in strength. It can be found in many 3/4-ton pickup and van rear ends.

DANA 70
Almost identical in appearance to a Dana 60, the Dana 70 is standard in heavy Dodge pickups and GM duallies. The large 10.54-inch ring gear diameter will tolerate much torque, and is suitable for diesel power and/or big tires.

FORD 7.5-INCH
The small Ford rear end, which sometimes uses a fiberglass cover, is found in Bronco IIs and non-4.0-liter-powered Rangers. For bigger tires and/or engines, it's usually swapped for a Ford 9-inch.

FORD 8.8-INCH
The 8.8-inch debuted in 1983 Broncos and F-150s, and is now found also in 4.0-liter Rangers and Explorers/Navajos. It is easily distinguished from a 9-inch by having a cover on the back.

FORD 9-INCH
The venerable Ford 9-inch is both readily available and strong. Later models have bigger axle tubes and stronger housings. It was standard under 1966-88 F-150s and Broncos. It also came on many vans and the Lincoln Versailles (a popular axle for swapping because of the Lincoln version's disc brakes with parking brake).

FORD 10.25-INCH
Ford's biggest axle comes with semi-floating shafts in 1983-and-newer F-250s, and as a full-floater in F-250HDs and F-350s. Applications are similar to the big GM 14-bolt and the Dana 70.

GM CORPORATE 10-BOLT
The GM 10-bolt is named for the number of bolts on the cover; ring gear diameter is 7 1/2 inches. Variations of this can be found in the rear of GM S-trucks and some Isuzus, and in the front of S-trucks.

GM CORPORATE 10-BOLT
This 10-bolt, with a larger 8 1/2-inch ring gear diameter, replaced the Dana 44 that was used in the front of some pre-1977 GMs. It can also be found in the back of 1983-91 1/2-tons and in the front of 1983-87 1/2-tons.

GM CORPORATE 12-BOLT
The stronger 12-bolt, with an 8 7/8-inch-diameter ring gear, can be found in various 1964-82 GM 1/2- and 3/4-ton rearends.

GM CORPORATE 14-BOLT
The "small" GM 14-bolt has a 9 1/2-inch ring gear diameter. It was used in the rear of 1964-and-later GM pickups, and in the rear of 1984-91 3/4-ton Suburbans.

GM CORPORATE 14-BOLT
With a 10 1/2-inch-diameter ring gear, the biggest 14-bolt GM rearend looks much like a Dana 70, and is but a few thousandths of an inch shorter in ring gear diameter. This axle is commonly used with big engines and/or overly large tires. It was used under 1973-87 3/4-tons.

AMC MODEL 20
Used in 1976-and-later Jeep CJs, the Model 20 rearend is both strong and weak. An 8 3/4-inch-diameter ring gear provides strength; weaknesses are the housing itself and the axle-to-hub retaining method. Converting to one-piece axles or full-floaters gives this axle better stamina.

CHRYSLER 9 1/4-INCH
Mopar's 9 1/4-inch rearend can put a stop (notice the octagonal stop sign cover shape) to rearend woes on many lesser-equipped vehicles. Chrysler has used these since 1969, on 1/2- and 3/4-tons.

Source:
fourwheeler.com

SirAlec · 13th September 2009, 00:56

You may find this useful too if you are disassembling and assembling it again.

Help needed to Identify the Differential Model-dana-41-exploded.jpg

Help needed to Identify the Differential Model-desc.jpg

diesel_maniac · 13th September 2009, 23:11

Thanks Ignazio and Sir alec for the guidance and help on this one. Sir Alec the guide that you posted will be of great help for me and many more to come. Ignazio I am awaiting your PM. Thanks once again !!

7th September 2009, 19:23	#1
diesel_maniac BHPian Join Date: Jun 2007 Location: Delhi Posts: 170 Thanked: 3 Times	Help needed to Identify the Differential Model Hello All, I have come across this rear differential belonging to an earlier generation Jeep. It has a peculiar bulge on the crown gear cover unlike what I have seen on various 3Bs. As I have very little knowledge on actual technicalities like different Gearboxes, T/cases, Differential that came with various Jeep models. I would request all the seniors to share their knowledge on this one. Here are the two pictures of the differential. They are not very good but I hope you people will be able to make out the details. regards Attached Thumbnails
	() Thanks

9th September 2009, 02:31	#2
U.B.Singh BHPian Join Date: Oct 2004 Location: 266/D G.T.Road(N), Liluah, Howrah. W.B. Posts: 43 Thanked: 17 Times	Hello Jasvinder, Wow ! that is a beauty. A rare Dana 41 from the rear of the early CJ2As and 3As. At first I was very happy seeing the 41, but was sad to notice closely that it has been converted to a 4X2 setup. The left side spring seat has been replaced with a later CJ3B (boat) type which comes commonly in a Dana 44. The previous user has removed the top side bracket which sits between the U bolts and takes the dump from the rubber dumpers bolted to the chassis. Just for academic interest, I shall post a few differences between the Dana 41 and the famous Dana 44 (from a CJ3B), which are equal in track and the axles are same, so are the hubs and wheel bearings. Even the tube dia. is same. 1. 41 has a bigger dia. crown pinion and the tail is bigger too at the teeths. They also came with 43/8 teeth count but not interchangeable with 44. 2. The diff cover is round, and is fitted with 3/8 in bolts as opposed to 5/16 as in the 44. 3. Since 41 was made for the rear only, the diff body does not have a built-in seat to take the centre bolt's head as we see in the front of the 44. 4. The spring seats are like the Dana 25 or 27(that we see in the early WWII and only in the front of the 2As and 3As and pre 1956 CJ3Bs jeeps), with a dump absorbing bracket welded on top again like 25/27. The Dana 44 has a boat like spring seat. 5. Unlike 44, there is only one set available for ratio alteration, and that is 45/11 out of a later Studebaker car. The early Studys came with 41/10 which could fix in the 25s or Dana27s as a straight fit. 6. ........... To be filled in by experts. I would have believed it as original from a 4X2 DJ3A, if only there were four bolts on the hubs, and seat not altered. Whatever it is - it is diamond, so be happy and proud. 90% of the CJ2As and 3As restored in India have replaced the rear with Dana 44s. All the best, with you always...................... UBS
	() Thanks

9th September 2009, 03:13	#3
Ignazio BHPian Join Date: Feb 2008 Location: Turin-Italy Posts: 128 Thanked: 3 Times	Hi Mate, I have a beautiful book about differential identification, repair and restoration, that will be for sure of help. It happen only that I'm on business travel in France and will be UK tomorrow, I won't be home before Friday. I will certainly check and let you know what I can, if anyone else doesn't give you an answer. Ciao Ignazio
	() Thanks

9th September 2009, 09:08	#4
diesel_maniac BHPian Join Date: Jun 2007 Location: Delhi Posts: 170 Thanked: 3 Times	@ UB Singh: Thanks Kaka for the detailed information. This information will be of great importance when the vehicle is put up for actual restoration. Is it possible to find the original seat for this Dana 41. More over the wheel studs have also been changed to later model CJ3B type, which have regular direction thread as opposed to earlier model Jeep which used to have opposite thread pattern for the left hand side front and rear wheels. @ignazio: Looking forward to hear from you mate, hope to have more insight on this one.
	() Thanks

12th September 2009, 01:38	#5
Ignazio BHPian Join Date: Feb 2008 Location: Turin-Italy Posts: 128 Thanked: 3 Times	Hi! yes is definitely a Dana41. I will make a scan of my book and send you a PM, book is copyrighted and I do not want troubles! Ciao Ignazio
	() Thanks

13th September 2009, 00:39	#6
SirAlec Senior - BHPian Join Date: Sep 2006 Location: zxc Posts: 3,393 Thanked: 726 Times	Axle Identification Chart DANA 25/27 These Danas are indistinguishable in appearance. The military Model 25 has a thick, cast cover, while the 27 and civilian-model 25s have a thinner cover, will accept taller gears, and backed V-6s. DANA 30 The Model 30, with a 7 1/8-inch-diameter ring gear, was the standard front differential in some 1972-75 CJ-5s and all 1975-and-later CJ-5s and CJ-7s. It is still used in the front of Cherokees and Comanches, and will probably appear in the front of the Grand Cherokee. DANA 35 This axle, with a 7.56-inch ring gear, is the fronted for 4.0-liter Ford Rangers and Explorers/Mazda Navajos. The 35C version is found in the rear of Cherokees and Comanches. DANA 41 The 41, which has a ring gear size similar to the Dana 44, came in early CJ-2As. The spiders are the same as a 44's, but the carrier and gears aren't. It is almost universally swapped out in favor of a Dana 44. DANA 44 All domestic manufacturers have used Dana axles, and the 44, with its 8 1/2-inch ring gear, is likely to be a step up on anything smaller than a 1/2-ton. A narrowed 44 could be the hot ticket for vehicles smaller than a full-size sport-utility. It was standard under the front of pre-1976 Chevy Blazers and 1/2-tons, solid front-axled F-150s and Broncos, and Jeep J-10/J-20s and Grand Wagoneers. DANA 44-IF The Ford-version Dana 44 Twin-Traction-Beam setup is similar to other 44s (ring gear diameters are identical), but there are no axle tubes and the "cover" is actually the suspension arm. It's standard in the front of any TTB-equipped Ford except the 1987 and newer F-250HD, which uses a Dana 50. DANA 60 A Dana 60 looks deceptively similar to a Dana 44, but the 60's 9 3/4-inch ring gear diameter is a major factor in strength. It can be found in many 3/4-ton pickup and van rear ends. DANA 70 Almost identical in appearance to a Dana 60, the Dana 70 is standard in heavy Dodge pickups and GM duallies. The large 10.54-inch ring gear diameter will tolerate much torque, and is suitable for diesel power and/or big tires. FORD 7.5-INCH The small Ford rear end, which sometimes uses a fiberglass cover, is found in Bronco IIs and non-4.0-liter-powered Rangers. For bigger tires and/or engines, it's usually swapped for a Ford 9-inch. *FORD 8.8-INCH* The 8.8-inch debuted in 1983 Broncos and F-150s, and is now found also in 4.0-liter Rangers and Explorers/Navajos. It is easily distinguished from a 9-inch by having a cover on the back. FORD 9-INCH The venerable Ford 9-inch is both readily available and strong. Later models have bigger axle tubes and stronger housings. It was standard under 1966-88 F-150s and Broncos. It also came on many vans and the Lincoln Versailles (a popular axle for swapping because of the Lincoln version's disc brakes with parking brake). FORD 10.25-INCH Ford's biggest axle comes with semi-floating shafts in 1983-and-newer F-250s, and as a full-floater in F-250HDs and F-350s. Applications are similar to the big GM 14-bolt and the Dana 70. GM CORPORATE 10-BOLT The GM 10-bolt is named for the number of bolts on the cover; ring gear diameter is 7 1/2 inches. Variations of this can be found in the rear of GM S-trucks and some Isuzus, and in the front of S-trucks. GM CORPORATE 10-BOLT This 10-bolt, with a larger 8 1/2-inch ring gear diameter, replaced the Dana 44 that was used in the front of some pre-1977 GMs. It can also be found in the back of 1983-91 1/2-tons and in the front of 1983-87 1/2-tons. GM CORPORATE 12-BOLT The stronger 12-bolt, with an 8 7/8-inch-diameter ring gear, can be found in various 1964-82 GM 1/2- and 3/4-ton rearends. GM CORPORATE 14-BOLT The "small" GM 14-bolt has a 9 1/2-inch ring gear diameter. It was used in the rear of 1964-and-later GM pickups, and in the rear of 1984-91 3/4-ton Suburbans. *GM CORPORATE 14-BOLT* With a 10 1/2-inch-diameter ring gear, the biggest 14-bolt GM rearend looks much like a Dana 70, and is but a few thousandths of an inch shorter in ring gear diameter. This axle is commonly used with big engines and/or overly large tires. It was used under 1973-87 3/4-tons. *AMC MODEL 20* Used in 1976-and-later Jeep CJs, the Model 20 rearend is both strong and weak. An 8 3/4-inch-diameter ring gear provides strength; weaknesses are the housing itself and the axle-to-hub retaining method. Converting to one-piece axles or full-floaters gives this axle better stamina. CHRYSLER 9 1/4-INCH Mopar's 9 1/4-inch rearend can put a stop (notice the octagonal stop sign cover shape) to rearend woes on many lesser-equipped vehicles. Chrysler has used these since 1969, on 1/2- and 3/4-tons. Source: fourwheeler.com Last edited by SirAlec : 13th September 2009 at 00:40.
	() Thanks

13th September 2009, 00:56	#7
SirAlec Senior - BHPian Join Date: Sep 2006 Location: zxc Posts: 3,393 Thanked: 726 Times	You may find this useful too if you are disassembling and assembling it again.
	() Thanks

13th September 2009, 23:11	#8
diesel_maniac BHPian Join Date: Jun 2007 Location: Delhi Posts: 170 Thanked: 3 Times	Thanks Ignazio and Sir alec for the guidance and help on this one. Sir Alec the guide that you posted will be of great help for me and many more to come. Ignazio I am awaiting your PM. Thanks once again !!
	() Thanks