Rear Trailing Arms

['68 C-20]

I am going to start my first large repair on the 68 C20 soon. Thanks to this board I have located the new trailing arms and am planning to replace them myself. I am in pretty good shape for tools. Have 3/4 drive socket sets, die grinder with cutting wheels, various nut busters, heat etc., so I don't think any hardware will be an issue.

I am planning on pulling the bed to do the job. I think it will be easier to expose the entire rear frame to do the job. That will give me a chance to inspect everything, clean off any rust and re-paint the frame (Rustoleum), rear-end, springs etc. I don't have a sand blaster; I should be able to clean it up with flap wheels and 3M De-burring wheels. It still has some factory paint on the frame.

I will replace the shocks, exhaust hangers and most likely the spring cups depending on what they look like.

I am planning on leaving the wood floor in the bed when I remove it, it should stay in place OK. It is in good shape. I plan on taking the wood out and running it through a planer next year to clean it up. It has been painted every few years for the last 40 years. Has so much paint on the wood you cannot see the grain!

Before I start, any advice, cautions, or watch out for's?

[LockDoc]

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I try to save all of the parts when I remove a rear end. I start by dousing all of the threads with a good penetrating oil (I like PB Blaster) and letting it set for a couple of hours. I then use a wire brush or wire wheel to clean the rust from the threads as much as possible. The cleaner you can get them the easier it will come apart. Usually the shock bolts will come off with no problem but the track bar, U bolt, and trailing arm nuts will need some heat. I use my acetylene torch to heat the nuts and the 3/4" breaker bar and socket to break them loose, then switch to the 3/4" rachet to finish taking them off. Spraying with lots of penetrating oil during the process.

Yes, it is a lot of work, and new U bolts are only 30 bucks but that is 30 bucks I can spend on something I can't save or rebuild. Ten things I can save at 30 dollars each is 300 dollars and it all adds up....quick!

LockDoc

[68chevy68]

Those flap disk wear out pretty fast. I like a 4.5" grinder with a wire wheel. It works really good and will not bite into the steel.

[GREASEMONKEY72]

PB blaster and what he said

[Luvlegs]

When you try to re-install the front end of the trailing arms, the new bushings may make it VERY tight (mine were) - I put a piece of all thread through the bracket holes with a large washer and nut for each side. I "spread" the mounting bracket open just enough to get the arm started down into position and then took out the "spreader" - worked very well, no BFH and didn't beat up my fresh paint.

[casterbuster]

I am a professional mechanic, on Industrial Engines, I have used every type of pentrating oil there is including PB Blaster and Kroils oil. The absolute best stuff I have ever used is GM Heat Valve Lubricant. This stuff is absolutly amazing. You can get it in the parts department of your local Chevrolet house. It is a little pricey about 8.50 a can, but worth every penny.

['68 C-20]

Thanks a bunch! All great tips.

LockDoc: I agree, everything I do is on a shoestring too. That is part of the reason why I bought a truck that does not need a lot of work. Not a lot of time and darn little money to invest in the project. Plus I have not had a truck to work on in decades, literally, I need to ease back into it. I often work a lot longer than I should attempting to salvage something like a U-Bolt, But if push comes to shove and it begins to distort, out comes the artillery!

I have used Kroil and PB for some time, both excellent (IMHO). I will check out the GM Heat Valve Lubricant. Never heard of it.

68Chevy68. I do use flap wheels, but I should have been a bit more specific, actually I use a relatively new product from 3M, it is a Brushlon Disc. They are a carbide impregnated rubberized plastic sort of bristle. That and their Scotch-Brite Radial Bristle Brush. These work really well and do not eat the original metal. Sorry to sound like a commercial, but I sell Industrial Supplies for a living and I am pretty familiar with such products. I also have two wheels that I use that I have not seen for sale in a while, they are a wheel with fairly thick wires (about 20 gauge) . Each wire is attached in a loop so they swing independently. Beats the devil out of rust and scale, but bounce off of metal.

Luvlegs, is "all thread " another name for Threaded Rod? If so, I think I can picture what you are referring to. Have a piece of 7/16 Rod in stock...

Thanks again all for the tips, I will try to get some photos posted, It rained all last weekend, this truck is pretty sweet, I am anxious to show it off...

[Luvlegs]

yep - All thread = threaded rod (at least to me) - here's a quick pic - made it MUCH easier!

[casterbuster]

GM rust penetrant and heat valve lubricant #1052627