'79 K20 Steering Box Rebuild Issues

[zac]

1979 K20 Camper Special, 400 sb, TH400, NP203, 14FF, 10 bolt front. Ordered the correct kit off Rockauto for box 7802644, which is on my truck. Apparently they also installed a 7802644L that year as well. The bearing, seal and dust seal that came in the kit for the stub shaft are much too small. The stub shaft where the bearing rides on my box is 7/8". Sometimes with the Camper Special things get a little crossed up when finding parts, so I checked out what the kit for a K30 would be. Same part number. I'm afraid if I send the kit back they will just send me the same kit again. And I will probably get the wrong one from Autozone etc as well. Just wondering if anybody else has run into this and can save me some time and aggravation.

[SunSoaked]

Take the old seal and bearing to Napa and match them up.

[KrazyRay]

1979 was about the time GM changed from the compression style steering box to the O ring style. I'm not sure if that affects the other components.

[tucsonjwt]

For my 83 C20, I just got a steering box from AutoZone and it was a good fit. I have had it in the truck for the past 15 years with no issues. The core value was very high, so I was only out something like $20 for the new box.

[zac]

Here's what I got so far. Once again proves the point you can't really figure anything out just by looking on the internet.

But I did spend a lot of time on the internet, and at the Pull and Pay, and digging through all my stuff. The bottom line is that I have now looked at 5 truck Saginaw gears in the last 36 hours and they are all casting number 7802644. But they are not all the same. One came off a 2wd truck. One was off a '78 K10, one off a '70 K10 suburban and one off a '72 K10 suburban. the 2wd box obviously had a different sector shaft, but it was also different internally. Smaller sector shaft gear teeth with different pitch, worm shaft very different with 22 recirculating balls instead of 24. I don't know what the burb boxes look like internally, but externally they are identical to my '79. I'm assuming the sector shaft where the pitman arm goes on is the same. It looks like it is. The '78 box was supposed to be a direct interchange, but it has the smaller stub shaft. It would work I guess with the proper rag joint. So most if not all interchange stuff I found was useless, and the part numbers and cross references on Rockauto, Autozone, etc appear to be meaningless--at least so far. I'm going to try the '72 box on my Camper Special and see what happens. So far it seems to be simpler and more complicated than you would think at the same time. It's a 2wd or 4wd box, and it either has a small or large stub shaft. But I'm sure there's more to it that I will run into shortly. As long as these have been around you'd think someone would have cracked the code by now. To me it's been like the DaVinci code. And I'm still not sure how to order the proper rebuild kit. I've heard West Texas Offroad is the only place that knows much about these boxes...

[zac]

So the '72 box is not the same as the '79, although they are the same casting number. But the differences are very slight--the sector gear area on the '72 box is about 3/16" larger, etc.--but the main difference is the pad on the box for the front upper bolt has to be be opened up a bit to account for differences between the frames. The dimple on the square frame is much more pronounced. After that ten minute mod the box bolted right on, the pitman arm slipped right on, as did the rag joint. I drove it and it was fine and predictable, thank god, unlike the box I took off, which had some internal damage. I don't necessarily recommend doing this, I only did it because I had the '72 box and I wanted to do something to advance redneck science. But mostly because I wanted to move the truck so I could mow the grass next to the barn.

It occurred to me that I have no idea if the box I took off my '79 is the original. For that matter, I have no idea if the "72" box I put on is actually that. I bought it off eBay about 15 years ago and never used it. All these boxes have the same number cast into them, so unless you bought the vehicle new there's no way to tell where the steering box came from. With all the differences I have noticed, there's no way I would ever try to mix and match internals and cases. Either use the whole unit or chuck it. Also, I have little confidence that the rebuilt box you can buy from any vendor is actually "correct." I suspect it's like the reman quadrajet you buy. It will bolt on and work, but you don't know where it came from. But I could be wrong. Maybe their quality control is better than I think.

[Fishermen0105]

Just went through this. Ended up buying a reman unit for $100. I guess time will tell.