Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Seventy4Blazer, Apr 29, 2002.
what years did they change the D44 spindals?
are any bearings interchangeable?
This is from Wes That K30 guy
GM has two different types of axles: the "first design" and the "second design". For those who dont know the difference, the "first" goes from 73-76. The "second" goes from 77 to 91. Some differences are:
1. Backing plates are ALL diffferent. Both 1/2 and 3/4 ton for both designs are NOT the same thing. 3/4 tons are larger diameter than the 1/2 tons. There are currently 6 different types of backing plates. The 1/2 ton has the 73-76, 77-80, and 81-91. 3/4 ton is the same years, but only bigger around.
2. Bearing hub and rotors are different. There are 4 types. 73-76 use a smaller wheel bearing on both the 1/2 and 3/4 ton. The 1/2 ton bearing hub is an internal drive. 3/4 tons were available in both the internal and external drives. 77 and newer bearing hubs are the same size wheel bearing. 1/2 and 3/4 tons are all internal drives. The differences in the rotor diameter is the fact that the 3/4 tons are larger around than the 1/2 tons. This is why the backing plates are larger around than the 1/2 tons. If you use a 1/2 ton backing plate on a 3/4 ton rotor, the caliper will NOT even align up with the bolts. If the 1/2 ton rotor is used with the 3/4 ton backing plates, the caliper will NOT have enough pad contact with the rotor.
3. Spindles. 73-76 are one type only. They are "first design" small bearings. 1/2 and 3/4 ton spindles are interchangable. 77-91 spindles are "second design" and all interchangable between 1/2 and 3/4 tons. You cannot use a first design spindle with a second design bearing hub & rotor. The hub will wobble in place. If the second design spindle is used with a first design bearing hub, the hub will not even go on at all.
4. D44 and 10B axle shafts are not interchangable. The D44 shafts measure: right - 36.13"
left - 18.31"
10B shafts measure: right - 35.46"
left - 19.15"
5. Steering knuckles. D44's have the infamous "flat top" knuckles on the passenger side. These are good for the crossover steering for where the steering arm is mounted on top of the knuckle after machine work and drilling has been done. The 10B knuckles have NO flat surface whatsoever. Machine work would be excessive to make the crossover work and therefore would be easier and cheaper to locate the correct knuckle off a D44.
All in all, when doing a swap like this, try to round up the parts off one truck to use on the other. Such parts to swap over would be: backing plates, spindles, bearing hub & rotors, and if desired for crossover steering, the knuckles.
The knuckles do NOT need to be changed if you do not plan on the crossover steering.
It all boils down to this: D44 and 10B parts ARE interchangable from the knuckles out. Anything else from the knuckles in is NOT interchangable.
ALL calipers on both D44 and 10B are compatible with either axle. Even the first and second design axles are compatible with BOTH 1/2 and 3/4 ton calipers. So, whatever swap you plan on doing, you can retain your stock calipers.
When stepping up to the big D60, this is a whole different ball game. Nothing is interchangable from the D44 and 10B to the D60
Info provided by ThatK30guy to me a few months back.
i can always count on wes to have a long winded yet VERY informative post. thanks. and i just printed it up to put in my binder.
once again thanks A LOT for re=posting that.
I will agree with everything up there except I think it is rather vague as to just when the change in spindle design occured. Other sources claim 78, some say mid-78
I cannot say for sure, and am not disputing what was posted, but I would say use caution. Make sur you know what you are buying regardless of the year, but ESPECIALLY if it is 77 or 78. Keep in mind too, that anything can be swapped. My 74 Dana 44 got the big spindles from my 83 10 bolt and vise-versa. Caveat Emptor!
Ok, sorry, no more Latin for me this week /forums/images/icons/smile.gif
That's true Chris
I have seen 77's with both style spindles and 79's with 10 bolts and D44's
Those were the tweener years and it is kind of a crap shoot as to what ya will find under a rig.
My 78 had the 2nd design spindles, now it has the 1st design.
Don't forget the sucky pre-73 D44's
They had small u-joints and pre-71 had drum brakes /forums/images/icons/frown.gif
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