1975 axle swap

[alaska nix]

I have a '75 4 cyl 4 speed w/3.72 disk brake axles and a '72 6cyl 3 speed 4.27 axles with drum brakes. I want the 4.27 axles on the '75 scout II. Can the drum brakes work on a scout with disk brakes setup or can I take the drum brakes off and replaced with the disk brakes and then swap the axles?

[Baradium]

the '75 has a dana 44 front. You'd rather have a dana 44 front....

You can convert to discs on the '72 stuff. But the '75 axle is stronger. So be aware if you do the swap you'll lose some strength.

[Scout SS II]

If you end up converting to drum one other thing to note is that the brake proportioning valve has a different allocation designed into it to determine the split of braking power between the front and rear brakes. Also, if I remember correctly from swapping in a newer disc brake axle into an older drum brake chassis many, many years ago, the brake line to the front will be a different size due to Disc needing more volume. Which also brings up the fact that the master cylinders are different. Disc brakes needed the larger resevoir but in your case of going the other way that would be ok, except you have to adapt to the different brake line size somewhere.

Not that it can't be done but there are a few things to consider.

Personally, I would stick with the Dana 44 front for the durability but depending on how you use the truck that may not be an issue. That would mean you would need to locate anther 4.27 R&P which I believe are no longer available but many people have them laying around.

If you convert from drum to disc or vise versa you will need to separate the front housing at the ball joints. The drum brake units are a 6-bolt spindle with a smaller inner bearing than the disc brake 8-bolt spindle.

U-Joint sizes also changed between 72 & 75 within the Dana 44 series. The early Dana 44's shared the same u-joint size as the Dana 30, but sometime during 1974 the Dana 44's were upgraded to the larger 5-297x vs the smaller 5-260x Spicer joint.

That should give you some good info as to how you should proceed.

Any further questions, you can try me at home at:
scoutsupply@tds.net

Good Luck, Dan

[Scout SS II]

After re-reading your post I noticed that your 75 is a 4 cyl. With that engine it is possible that it only came with a Dana 30 front axle even in 1975, so I guess you may not be sacrificing any strentgh after all. If so, go for the swap but convert the older axle to disc you will be happier in the long run.
Dan

[Baradium]

Originally posted by Scout SS II
After re-reading your post I noticed that your 75 is a 4 cyl. With that engine it is possible that it only came with a Dana 30 front axle even in 1975, so I guess you may not be sacrificing any strentgh after all. If so, go for the swap but convert the older axle to disc you will be happier in the long run.
Dan

As far as I'm aware they didn't make any changes based on what motors you had. Maybe if it was a leftover axle, but even then I don't see why why would have specifically waited to put it on a 4cyl.

[alaska nix]

Thanks for the input. Sounds like it's easier to leave it alone! :D
How about this. Will the 4 speed tranny on the 4 cyl engine bolt behind a 6 cyl with a 3 speed manual tranny?

[Baradium]

Originally posted by alaska nix
Thanks for the input. Sounds like it's easier to leave it alone! :D
How about this. Will the 4 speed tranny on the 4 cyl engine bolt behind a 6 cyl with a 3 speed manual tranny?

If you get a correct bellhousing... I don't know if the 3 and 4spds used the same bell housing or not.

[Scout SS II]

The Dana 30's were still used after the Dana 44 was introduced, exactly why, I can't say. Could be due to a purchase agreement with Dana/Spicer, Cost issue to keep the 'basic' Scout lower priced, etc. We have had Scouts that originally came with Dana 30 FA's after model year 1974. The Dana/Spicer Application book lists them out as being used through 1978.

As for the bellhousing issue: The 3spd & 4spd have a different bolt pattern and the early 3spd bellhousings only accomodated the 3spd smaller pattern. The newer ones were made with a dual set of bolt holes. The exact cut-over I can not say, but I have had that issue come up already with someone getting parts and his '72 only had the single set of holes, while the '74 parts truck I have had both so he had to change it to put in the 4spd. What was the '73 like?? I don't know, don't have one.
Dan

[Baradium]

They were just using the rest of the dana 30 stock in '75... there is no rhyme or reason to what scouts got a dana 30 instead of the 44 other than when they came down the line.

No scouts after '75 got the dana 30, and most '75s got the 44.