Need Help on GMC:

[conoverbandit]

Hello,

I have a 71 GMC 3/4 ton truck,2wheel drive, and I need to replace the upper a-arm bushings.THey are kinda like a "big nut"? i guess that screws off ,at least that's how tha one's they gave me at the parts house look, but no one around here can tell me how to put them on.My question is this, do you jack the truck up to take the weight off the a-arm and then take them out,or do you leave the truck on the ground and do it that way? I hope it's just the bushings and not the a frame it's self, on the pass. side the wheel assy. will move foreward and back a good bit.I think this is what it does when I go around a curve to the left. When I do it get a really bad vibration. Thanks,

[Gee_Emm]

You have to take the a arm off to replace them, the ends screw off, I can't remember if they are threaded opposite, put one end in a vise and find a wrench big enough to fit on the other end.

[conoverbandit]

ok,
I was under the impression that they just screw off with out taking the whole thing apart, hmmmm, sounds like a big project. The parts I got just look like two big nuts that screw over each end...............................But thanks for the reply.

[OhioDan]

The parts should have come as a kit? Both nuts and the cross-shaft. Remove upper arm, and chuck it up in a vice, Remove both nuts and cross-shaft. The new shaft must be centered in between the new nuts, and not so tight as to bind. That's how the arm pivots. Start the nut on one side, and then start the other. Tighten them up the same amount, until the nuts are seated. They'll also be screwing onto the shaft at the same time. If you install one side completely, you stand a good chance of binding the shaft inside the nuts, and possible destroying your new parts? hope this helps?

[conoverbandit]

ooooohhhhhh,

So you DO have to take the A-frame completly off the truck? ok how do I keep that big ol' spring from comming out to get me? Never done this if ya can't tell, heard of at least 3 different ways of doing this.(1) have truck high enough so that when you let the jack down the lower frame down the spring just "falls" out. (2) bind the spring with a good chain, and then let the lower a-frame loose and it will fall out.(3) use a coil spring compressor and the lower the a-frame.............Need help here Don't want to kill my self messing with a loaded spring,on the bright side my wife is taking emt training so i'd have "medical" attention but still
Thanks,

[cwilli84]

Ifd you have lifted it by the lower arm it should be trapped by the bracket between the uppeer and lower. The spring should not be pressing on the upper arm at all. I would recommend getting a complete setup from somebody like mothertruckers or whoever that has the complete upper arm and shaft. I did this build up with the truck still functioning until it was time to swap the arm. The shock may need to be replaced at the same time and this is easy while your under there anyway. Just my .02.

[conoverbandit]

I can relate to that, this truck serves as my hauling rig, and to tow my trailer for my lawn service.and it's getting full swing. Thanks for the reply's y'all.Keep'em comming

[Blue_71]

hey man! long time no see. i cant help with your problem but...

i think the big nut is the one sitting behind the steering wheel, it's already loose

[conoverbandit]

BIG 10-4 on that loose nut behind the wheel:p You think that's the problem????

How ya been? sent ya a pm,