Front Wheel cylinder issues - Front Axle ID

[hkopp]

I own a 60 K10, 20 yrs ago after losing another rear axle in the 10 bolt eaton I found another 60's (so I was told) 4x4 that had the right width, front dana 44 with the same knuckles, etc). I exchanged the axles and drove the truck for another 3 years then parked it until this year. Since its been sitting so long I bought all new brake shoes, rubber lines, and wheel cylinders. Thats where my problem lies.

The front wheel cylinders I removed are narrower than the replacements by about half an inch, and they will not fit between the upper shoe brackets. Also the line is bigger on the old ones. The backing bolts are aligned on the old and new ones, I've looked at other years and see the attaching bolts are offset. With this info I started looking for numbers on the front and rear axle housings to find out what exactly I installed 20 years earlier. If anyone has any info on this pls let me know. Thanks!!

[hkopp]

Here is the rear end out of the same donor vehicle (cab and bed were gone), It is a 12 bolt but I do not know how to decipher codes to see what year it may be. Obviously it has the panhard bar mount, and I recall cutting off the old mounts and welding on leaf perches. HA is a 3.73 gearset from what I have read, and idea on the other digits?

[Captainfab]

In that last pic, there appears to be a crack in the casting. Or is that just an optical illusion?

I believe that 12 bolt may be a '67? The easiest way to determine the year of a differential is to pull the cover and look for the date stamped on the ring gear. After 20 years those differentials could certainly use an oil change anyway.

[hkopp]

I did change the oil in them when I did the swap, but understand sitting is still nearly as bad as them running, if not worse.

I thought it was a crack too when I reviewed the photos, I went back and double checked - its a grease separation.

Whats making you think its a 67? I'm really good with Ford date and casting codes, just learning GM. Thanks!

['63GENIII]

I think what CF is asking is if you changed the oil, you can do a visual of the gears and get the ring gear tooth count to figure out what the ratio is. Im not sure what a grease separation is but that pic looks like there is a crack in the casting to me. I would not be running something like that if it is a crack. Stuff like that scares the crap out of me.

[61K10]

looks like the ft axle is a 63 or late 63 and up to 67 or 68. as the brakes are different. If both axles from the donor tk the panhard bar mounting changed in 65? my 61 had the off-set wheel cyl's (bolt holes) and had the old jeep style adjusters. looks like yours have the star wheel to adj. and self adjusters.

pic of my 61 backing plate. putting disc on mine.

[Captainfab]

Looking at the 02 07. I really don't pay any attention to casting codes and such on differentials as it really doesn't matter that much to me. If it's a 12 bolt, it's a 12 bolt. I'll open it up, check the gears and overall condition, if all is good, button it up, fill it up with gear oil and run it.

With a GM you don't have to know exact dates and what plant a unit was built in like you do with a Ford.

Originally Posted by hkopp

I did change the oil in them when I did the swap, but understand sitting is still nearly as bad as them running, if not worse.

I thought it was a crack too when I reviewed the photos, I went back and double checked - its a grease separation.

Whats making you think its a 67? I'm really good with Ford date and casting codes, just learning GM. Thanks!

[hkopp]

Originally Posted by 61K10

looks like the ft axle is a 63 or late 63 and up to 67 or 68. as the brakes are different. If both axles from the donor tk the panhard bar mounting changed in 65? my 61 had the off-set wheel cyl's (bolt holes) and had the old jeep style adjusters. looks like yours have the star wheel to adj. and self adjusters.

pic of my 61 backing plate. putting disc on mine.

Thank you for the photos and info! I'm not a numbers chaser (at least not on this truck, I've built a few #'s cars with one being a low 6 figure one - what a pain), I was just hoping those numbers would help id the year so I can buy brake and other parts for the right application. I bought a spring kit for a 67 and it had mostly the right stuff in it, my front does not have the bar separating both shoes with the springs like some I have seen.

The axles I removed from this truck which are original to it dont have the wheel cylinder bolt holes offset like yours - they are both on top. The rear is the eaton 10 bolt, I removed both after losing another rear axle (and watching the rear tire pass me up) so I removed the cursed rear and so far the 12 bolt is working fine.

So looking at the panhard bar mount, would it be 65 and newer, or older?

Thanks everyone!

[61K10]

What brand and part # for your new cyl's? do they have 3/8 hole for the brake line as the ones you need have a 7/16.. I had a problem finding the cross bolt style one so i re-drilled and re-taped to 7/16. Rockauto shows the right ones for a 67 axle. the cross bar is for the rear only, for the E-brake. about the panhard bar, a 4x4 doesn't use one as they have leaf springs. So i don't know if the mount came on all rears or just coils.

[hkopp]

I used my front originals, once I got them off I found they were not pitted and were gm originals so I honed and kitted them. I had bought all 4 from Rockauto along with new lines - they sent 7/16 lines but 3/8 cylinders, smart. The rears worked just fine. The self adjusters were missing on the rear, ordered those and they will be here in the morning. One side had the longer shoe in the front...the other in the rear. Some people shouldnt turn wrenches.

Time sitting really does ruin vehicles...