Dana 44HD is a bunch of BS

[BobS]

Tradition, I suppose. There was a time when there were a lot of differences between GMC and Chevrolet trucks with the GMCs being built as more of a work truck. The two gradually became more and more similar as GM Corporate Headquarters increased their control over the individual divisions within the corporation, most likely to reduce production costs. The numbering system is about the only difference left.

Bob

[72longbed]

A 3/4 ton Dana 44 absolutely has considerably heavier Duty (HD) parts than a 1/2 ton Dana 44. Most of the differences start at the end of the axle shaft and out to the locking hub. Just look at the difference between a "small bearing" spindle and a "large bearing" spindle, there's some 'meat' on the large ones. Spindles, bearings, hubs, rotors, and locking hubs are all heavier duty than 1/2 ton.

My own personal opinion is that the 71/72 Dana 44 (it is different from the rest) factory 8 lug is one tough mother and should have been continued in that form until the end of its use.

72longbed

[WhiteWhale]

Zombie thread alert

Ive been searching for info on my 72 K20 suburbans Dana 44 front trying to get part numbers and such for inner/outer hub bearings and seals that need replacing so I can get her back on the road.

After all the reading for the past few days I think this is the break down


- 1960-1970 Closed knuckle drum brakes


- 1971-1977 Open knuckle disk brakes

1971-1972 "first series"
1973-1977 "second series"


1/2 ton small hub internal lock out
3/4 ton large hub external lock out


Series 1 has tapering axles that use a smaller u joint, smaller tubes with thicker wall thickness.

Series 2 has larger axles that use a larger u joint, larger tubes with thinner wall thickness

both Series 1 and 2 axles have 19 spline outers and use the same caliper.



Now here is where I get confused.

Series 1 has a thicker spindle, bigger bearings and seals for 3/4 ton (different than 1/2 ton)?

Series 2 has a smaller spindle, bearings and seals for the 3/4 ton (same as 1/2 ton)?

Lug size is different on the series 1 vs series 2?


Are the S1 parts that much weaker that I should forget about finding the bearings and seals and just look for S2 parts?

[WhiteWhale]

Here are a few parts sheets that clarify the break down a bit







73 and up 44 also shows 1st and 2nd design WTF??








To make things more confusing the 1972 2nd design is the same part number as the 73 up 1st design.

As far as the HD designation, the earlier parts catalogs show a D44HD referring to front brakes (possible largers shoes and drums?).

Now to get down to the sub to see what code is on the axle to see if there are any parts available.

[jeffahart]

1970 is an open knuckle drum. I have one in my garage I just pulled out of my k20.

[WhiteWhale]

Was finally able to get down to the burb and scrape 42 years of grease off the tube to get the numbers.

Looks like I have the 1st series axle after all #603352 8

Anyone know how to decode the other numbers? 1 10 2C4


For some reason I dont see a part number listing for the inner bearing for a K20



Luckily for me the inner bearing had the number still on it.


Inner bearing: 368A
Inner race: 362A
Inner seal: 6273949, 36366, 416273,
Outer bearing: 7451226, A35, SA35, BR35, SET45

I just ordered the above from Autozone (Timken) since no local stores had everything in stock for $80 with free shipping.



One more quick question, did all big external hubs come from the factory with Spicer selectors? I didnt realize I had Warn hubs on mine which look almost brand new inside. Any Warn hubs used from the factory or PO add upgrade?

[Orange Crate]

You can find a reference to a Dana 44HD here and also axle ident...


http://77cj.littlekeylime.com/web_rs44.html

[special-K]

Originally Posted by WhiteWhale

One more quick question, did all big external hubs come from the factory with Spicer selectors? I didnt realize I had Warn hubs on mine which look almost brand new inside. Any Warn hubs used from the factory or PO add upgrade?

GM only offered one optional hub,the Spicers. Many either upgraded to stronger aftermarket hubs or had to replace broken originals. Unless you are restoring to 100% correct,you are better off with the Warn hubs,and they are a commonly accepted era correct accessory for these 4wds.

[1972RedNeck]

Originally Posted by JIMs70GMC

Who put the HD on the dana44?

Dana - but not for GM. In the Ford world, there are HD Dana 44's. They made a Dana 44-6CF and a Dana 44-6CF HD - both are eight lug axles used under 3/4 tons.

['68OrangeSunshine]

Originally Posted by Superron21

why are 1 ton chevys k 30's when the same GMC is a 3500?

Inflation, I guess.
Why is the Jimmy a K/1500 and not a K/750, like the Blazer is a K/5 not a K/10? Arbitrary marketing/advertizing designations, with little relation to engineering.

[maxwoof]

I have a 62k20 with the original axles. The front is a dana 44 with closed knuckles. It uses tapered roller knuckle bearings. I can tell you that when searching for parts for the knuckles I came across listings for a "HD" version which used bushings instaead of roller bearings. I think that back then at least, the k10s and 20s both generally used the dana 44 and that the HD was an option. I am not aware of any other differences, except that the knuckles themselves may be larger as I know there is a larger wiper seal available too.

[BLAZERMAN]

Originally Posted by maxwoof

I have a 62k20 with the original axles. The front is a dana 44 with closed knuckles. It uses tapered roller knuckle bearings. I can tell you that when searching for parts for the knuckles I came across listings for a "HD" version which used bushings instaead of roller bearings. I think that back then at least, the k10s and 20s both generally used the dana 44 and that the HD was an option. I am not aware of any other differences, except that the knuckles themselves may be larger as I know there is a larger wiper seal available too.

I agree, all of my Spicer manuals show an HD version of the closed knuckle axles but no mention of it on the open.

[A1971Blazer]

Originally Posted by 1972RedNeck

Dana - but not for GM. In the Ford world, there are HD Dana 44's. They made a Dana 44-6CF and a Dana 44-6CF HD - both are eight lug axles used under 3/4 tons.

PLUS.........they went to "high-pinion" reverse cut R&P gears as well.
I have converted several of these to 5 lug for off road Jeeps.
Fairly tough, but no match for the high pinion Dana 60s....(at least not here in the mountains!)