C20 Upper Control Arm Shaft Studs

[HotRodPC]

I've gone out took another look. Noway to leave anything welded to the front, and not much room to get in there and cut it off. The upper A arm swings right in front of the studs and clears by very little. I might even just try to find a nut put on it just to catch a few threads, then weld that nut. That leaves hardly any room for the tightening nut to come forward, but it will give at least a couple turns and hope it's not needed any further. So I'm not done with this weld a bolt or nut on the front idea as of yet. But....

 

[HotRodPC]

.... I"m looking at this LMC diagram. It appears to me these knurled studs are in this bracket and not the frame. If this is the case, I can take that bracket off the frame, and go get that same bracket off the 85C20 with the bent frame out at my dads place. Or, get this bracket off and then weld these studs in place on the bench, then bolt it back on. I hope it's all bolt anyway. I might have to take the whole friggin A frame assembly off to do it, but so be it. I want this done, and done right. It's a major safety factor and needs to be right.

See bracket #12, and then studs #13.

 

[HotRodPC]

Well, this is going to be a shitton of work. Just to check that bracket out. It does bolt on to the frame rail. But then it's riveted to the, I guess called cradle or main assembly that hold the upper and lower A arms, springs and all that. So I'd have to grind the rivets off, then use hardened bolts to put it back on. To get to the bolt holes, they go up inside the spring cavity. So I'd have to pull the whole A frame, upper and lower, and spring out to change this bracket. But, while under there figuring this out, I noticed that front stud is bent almost to a J now. It looks like it could snap any second, so welding it in, or any other alternative is out at this point. IT MUST BE replaced, either another OEM type stud or hardened bolt. No saving that one. MutherFugger !!! This is exactly why I've not got motivated on this truck. I get this fixed, I'll be rockin on getting things done to it.

 

[bucket]

Hmm, just torch the whole deal out of there and install a set of leaf springs. Big block 4x4's are awesome.

 

[HotRodPC]

NO, Wait !!! According the LMC diagram, those 3 holes where the bracket would bolt are NOT in the spring cavity. Looks like I should be able to get to those holes around the lower A arm shaft doesn't it? I'm talking about taking out rivets then replacing them with what would be part #s 25,26 and 27, into those 3 holes shown on the shaded part of the diagram. Does that seem right to everyone else or am I seeing the diagram wrong???

 

[HotRodPC]

Hmm, just torch the whole deal out of there and install a set of leaf springs. Big block 4x4's are awesome.

Not !! Although, this 454 is planned to be in the K10. This is the truck I want to put the Olds 455 in. Having 3.21s running a Th400, having plenty of low end torque from the Olds 455, and Olds not being a big fan of high rpm, the 3.21's will work out great for that project.

 

[bucket]

I'll go out a take a look at mine in a few.

 

[HotRodPC]

Probably what I need to do is, get out to my dads, grind those rivets off the bent frame 85C20, get that bracket with good studs already in it, and I'll have it figured out for sure by then, and have the parts here to tear into it and not have to leave my truck in the driveway with the A frame tore off of it for the city jack with me. Not like I'm gonna hurt the bent frame truck. As soon as I get the cab off that frame, the 14B SF axle, fuel tanks and brackets and the 3/4 ton springs for the K10 to K20 conversion, that frame and truck is going over the scale, so I can rob all the C20 front suspension parts I need off of it including the new shocks.

 

[Guardian]

Looks right, but I think it is riveted or bolted to the support bracket that is behind it (#17).

 

[HotRodPC]

Looks right, but I think it is riveted or bolted to the support bracket that is behind it (#17).

Yes, you are exactly right. That #17 is inside the frame rail and bolts thru the frame rail to this other bracket on the outside of the frame rail. I've also now figured out why my welds aren't sticking. If you notice bracket #17 makes the studs recessed through the frame and into the outter bracket #12, so I'm not even hitting the studs. I'm losing my welds inbetween the brackets in the recessed area.

 

[Guardian]

Sounds right, with the support bracket there you can't access it. Looks like you are going to have to remove the a-frame either way it goes. If you can get it off you can tack the studs from the front side.

 

[HotRodPC]

Well NO, I was wrong. There are 4 rivets that to use bolts will go up inside the spring cavity. The 3 bolts shown in the diagram is where the frame rail bolts down to the crosssection that the A frames bolt to and cradle the engine. So, to clear all this up. I have some pics. Now, I know what's what FOR SURE.

Here is the outter bracket (#12 in the diagram) that holds the 2 studs that the Upper A control arm bolt to the frame rail. Notice the studs are in the bracket itself and NOT the frame rail at all. The frame has two big circles cut out for access to changing those studs from the bracket. The studs don't even touch the frame rail at all. Just knurled studs just like wheel studs but much bigger.

Here you see the inner bracket (#17 in the diagram) that sits inside the frame rail. You also see the 3 bolts that bolt the rail to the cross section, 2 of which are in the inner bracket too.

 

[HotRodPC]

SOOOOOOOOOOOOOOOOO, I drove the 70 miles East today and got my dad's generator for the barn, and drug out to the pasture so I'd have power for the 4in grinder. To no avail. The bracket is not shaped where you can use an angle grinder. I was able to use some drill bits and drill holes thru the rivets, then with a chisel and 2 lb short handle hammer, beat the damn rivets off. Wished I had an air hose long enough but the trucks are about a 1/4 mile from his barn.

Now you get an idea of how that bracket is attached to the frame. This was taken off of my 85C20 bent frame truck that has the awesome cab that's going on the 84C20 burnt cab truck. No motor in the way, no fender well, no fender, no hood etc, so I'm going to dread getting the cut off of the 84C20 I'm repairing that has a motor in it and all it's body parts. Being I don't have to worry about damaging the bracket, I hope to hell and air hammer will do the job in minutes and make easy work of it. Then I'll have to drop the spring out also to get up in that cavity with the hardened bolts, washers, and nuts that I'll also be using super grade locktite on in place of the large frame rivets.

Here's the beautiful donor bracket with beautiful studs and nuts.

And here is the backside of the bracket showing where the studs are installed in the bracket.

 

[HotRodPC]

So, I've got a bit of daylight left and need to run to Lowe's to get the hardened hardware I'll need. I think I got this guys. Finally, once in for all, forward progress on this rig and it's going to be done right and I"ll have a safe vehicle once again. Gotta run, Be back in a bit.

Add Edit: Just got back from Lowe's with 4 Grade 8 7/16 bolts 1 1/4in long, 4 Grade 8 flat and 4 Grade 8 lock washers, and of course 4 Grade 8 nuts. All for just over $6. Out of daylight now, which never stops me, but I got that damn fuggin baby next door that being outside in the driveway pounding on rivets, I'd have that fat lard ass bitch running outside asking me if I was High, so I'll wait til in the morning to start tearing the truck down and have it completed tomorrow I hope. Working the night shift for awhile so I'll in the day time.

 

[smurph20]

Id put a bead of weld on those studs before you put that new bracket in.