Dana 27 on my 1961 CJ5

[oblvnnwtnjhn]

I came across some data indicating via a Willys Service Bulletin from Nov 1960 that the 27 was used and seems to indicate it was not common until it became standard in 1966.

"The Dana Model 25 was initially used as the front axle, however according to Willys service news of Nov. 1960, the Dana Model 27 axle entered production with serial # 57548 - 121248"

Other info I read says it wasn't used in mass production until 1966.

I seem to recall one of the members here is a retired Dana Spicer employee. Hoping they'll chime in and share their knowledge.

[bmorgil]

Suddenly, I feel old.

The Dana 27 appeared as a "Production" axle in Jeeps in 1966. Meaning at that time the O.E.'s officially made it a factory standard installed part. The 27 was used well into the 70's. The 27 became the 30. The 27 has a smaller carrier assembly than the 25 but always came with the Cardan style joint. The 25 could use one of three wheel joint types. With the standardization of the Cardan style joint, the 27 became the "Standard" in 1966 in Jeeps making the Cardan style wheel joints "Standard".

So if you know LarrBeard's "Rules of Jeep", it is very possible you could find a model 27 in a Jeep as early as 1960. The 27 was used by International Harvester on the Scout starting in 1961. So the axle was available to the O.E.'s for production. The Jeep had established the 25 because it had three different wheel joint options installed and it was very available, as the wheel joint assembly was the "hardest" component to keep stocked. The 27 only came with Cardan style wheel joints. However, enter production volume issues. To maintain production, since 1960 Willys used the Model 27 for CJ-3B's, CJ5's, and CJ-6's. From early 1960 Willys used both the Model 25 and Model 27 axles for CJ models. The Model 27 was used in the Jeep Wagoneer, CJ-5 and CJ-6. So officially, the model 27 was introduced in 1966. Unofficially, it could show up as early as 1959 simply because it was available and bolted right in.

Record keeping at Willys in the 50's and 60's was not very thorough. A lot of information is lost. A lot of people nowadays are used to the computer age and the massive amount of data that we keep. It just wasn't always that important in the early years of automotive. I have seen some published serial numbers indicating which Jeeps had the 27 but, I would take that with the knowledge that Willys was definitely "mixing" the 27 in to production from about 1960 through 1975. I would say you have what you have, if it looks like it was always in there it probably was!

[oblvnnwtnjhn]

Suddenly, I feel old.

The Dana 27 appeared as a "Production" axle in Jeeps in 1966. Meaning at that time the O.E.'s officially made it a factory standard installed part. The 27 was used well into the 70's. The 27 became the 30. The 27 has a smaller carrier assembly than the 25 but always came with the Cardan style joint. The 25 could use one of three wheel joint types. With the standardization of the Cardan style joint, the 27 became the "Standard" in 1966 in Jeeps making the Cardan style wheel joints "Standard".

So if you know LarrBeard's "Rules of Jeep", it is very possible you could find a model 27 in a Jeep as early as 1960. The 27 was used by International Harvester on the Scout starting in 1961. So the axle was available to the O.E.'s for production. The Jeep had established the 25 because it had three different wheel joint options installed and it was very available, as the wheel joint assembly was the "hardest" component to keep stocked. The 27 only came with Cardan style wheel joints. However, enter production volume issues. To maintain production, since 1960 Willys used the Model 27 for CJ-3B's, CJ5's, and CJ-6's. From early 1960 Willys used both the Model 25 and Model 27 axles for CJ models. The Model 27 was used in the Jeep Wagoneer, CJ-5 and CJ-6. So officially, the model 27 was introduced in 1966. Unofficially, it could show up as early as 1959 simply because it was available and bolted right in.

Record keeping at Willys in the 50's and 60's was not very thorough. A lot of information is lost. A lot of people nowadays are used to the computer age and the massive amount of data that we keep. It just wasn't always that important in the early years of automotive. I have seen some published serial numbers indicating which Jeeps had the 27 but, I would take that with the knowledge that Willys was definitely "mixing" the 27 in to production from about 1960 through 1975. I would say you have what you have, if it looks like it was always in there it probably was!

Very informative and fascinating, thank you for sharing your knowledge!

[test1328]

My 61 CJ5 has the 25 in it! As they say, who knows what Willys used unless you actually see it.

[davide]

Bob, thank you for the very detailed history of the Dana 27, fascinating! And kudos to oblvnnwtnjhn for digging up an old Willys TSB.

I think this data would be a great addition to the TechLibrary