beefed up (factory) trailing arms ?

[sactoC10]

OK, so it has been reported that the 3/4 ton (?) trucks had reinforced trailing arms, with metal plates on the top and bottom? Is this correct? Was it a factory option, or standard on certain trucks? What's the deal, any pics?

[neonlarry]

IIRC they are std on ¾ton.

[bagged72blaz]

I've never heard of any regular trailing arms ever failing.

[rodnok1]

I guess they might help in twisting, but other than that I guess they had some extra steel laying around. I just welded the seams on mine completely shut instead of buying those aftermarket plates.

[Longhorn Man]

Come to the rust belt...plenty of trailinf arms fail.

[SCOTI]

Originally Posted by bagged72blaz

I've never heard of any regular trailing arms ever failing.

Longhorn Man Come to the rust belt...plenty of trailinf arms fail.

It's not just the rust belt where they fail. Years ago I had one snap on my swb 64 chevy during a 3K dump of the clutch w/4.11's. It split in half. I put 3/4 ton plated arms on that 64.

On my 67 & 68 I just put a small 1" weld about every 6" @ the seam & completely weld the rear (behind the u-bolt).

[da-burb]

This wasn't a big ol' heavy piece of reinforcement. It was a thin piece of flat steel tack welded to the top and bottoms of the trailing arms. It was more to prevent rust which forms between the 2 halves from seperating and breaking the welds that held them together. In the great icey North you can find trailing arms that have seperated 1/2" or more due to rust.

[SCOTI]

IIRC, the ones I put on my 64 that were plated had the same gauge metal as the arms themselves.

[72CSTC5]

That's what I did on my trailing arms was just weld four 1.5 inch stitches and they should be fine. I had heard that they may twist under horsepower so I did it just in case.

[Robert1970C20rstbukt]

Prevent rust, lol. The trailing arm on the driver's side of my truck has rust in between the plate and arms, and the rust is pushing the plate away from the trailing arms. Should I cut it off, treat the rust, then weld it back on? Not sure any kind of rust killer would get in between 'em. The one on the passenger side looks good though, kinda weird. Not trying to hijack the thread here, just need help from someone that's done this before.

[rodnok1]

I drilled out the rivets, blasted themand painted the insides and weled them back together. Crappy design the top just holds water and crud. I welded them solid top and bottom.

[special-K]

Don`t think the factory was thinking of rust prevention when using those plates.The rust came later.Were the plates just on 3/4Ts?

[4x4Poet]

I'm surprised the aftermarket has not made heavy duty trailing arms. Moreso than 3/4 ton arms, I mean. I've toyed with the idea of converting my C10 Sub to 4wd using the trailing arms flipped on top of the axles, but I've been leary of the arms' strength and the one, pass-or-fail, u-bolt. Good size u-bolt, though.

[68LSS1]

I'm pretty sure someone will be coming out with some real soon. Also I believe Ed @ Mothertruckers tried to get some people together to get a set made but didn't get enough interest. I wouldn't weld them up solid as they need some flex but do like SCOTI did and run some stitch welds. I am putting a 1/8" plate on top of mine where the axle sits.

[special-K]

Why do they need to flex?

[Bowtiefreak]

Early Classic Enterprises makes a trailing arm re-enforcement kit.

[N2TRUX]

Originally Posted by special-K

Why do they need to flex?

Actually they need to twist from torsional loading. They might "flex" some what on a hard launch, but twisting is something they do all day long....

[sactoC10]

So, they were 3/4 ton standard and 1/2 ton options from the factory. Just wondering because my truck had one of each on it when I got it, so I am thinking that one of them was replaced with the re-inforced version.

[68LSS1]

Originally Posted by N2TRUX

Actually they need to twist from torsional loading. They might "flex" some what on a hard launch, but twisting is something they do all day long....

One example would be cornering. The front of the trailing arm of course is secured by poly/rubber bushings for some flex there. The only other flex would be in the trailing arm as it would twist. The weight of the body is leaning to the outside of the corner. The inside rear tire will become lighter and want to lift. If the trailing arms are solid or some of that flex is taken away, the weight decrease will be even more. Sway bars counter act this but with these trucks we need all the help we can get. Leaving some flex there allows a little more to keep the inboard tire's (to the turn) weight up and the tire parallel to the ground. I thought that welding up my trailing arms would be a good idea also thinking along the lines of the goals for my truck but both Ed @ Mothertruckers and Steve (owner of Hot Rods to Hell) recommended that I didn't. Just do a few stitch welds to save as much flex as possible. These trailing arms are prety long so a few stitch welds shouldn't take away too much flex.

[sactoC10]

BUT...

To save flexibility AND keep the halves together, could some heavy duty bolts/nuts simply be used, say ten inches apart from one end of the arm to the other, fastened right through the middle, keeping the halves together?

OKAY, tell me how bad this idea is.

[68LSS1]

That would work but IMO wouldn't look too good. But I got this "it's got to look as good as it operates" hangup and that's just my opinion. A few stitch welds would be more than sufficient and keep the trailing arms together for hopefully another 35 years.