1971 Chevy C20 Trailing Arm Suspension

[jbwolfe]

Hi all, this is my first post to this site, I've been reading different threads for a few days, and really like the site, and have found the threads very helpful.

I have a 1971 Chevy CST/20 3/4 ton pickup with trailing arm coil spring suspension in the rear. About three months ago, after hauling a large load of firewood, the trailing arms broke near clean off near the springs. I've attached pictures of the suspension.

So I want to fix the truck as cheaply as possible. I've been calling junk yards in the area, but no one seems to have the trailing arms. They all seem to have leaf springs though. Would it be possible to replace the coil spring suspension with leaf springs?

I found after market trailing arms online, they are quite a bit cheaper than LMC, anyone have any input on these:

http://www.carpartsdiscount.com/auto...ml?3593=128189

I would really appreciate some input on this. This is my first Chevy, I love this truck, and I really want to keep it!

Thanks in advance!

[black_sheep454]

That sucks. Try looking through the for sale ads on here for one or become a supporting member and post a want to buy ad.
Posted via Mobile Device

[Sicklajoie]

This is for a pair:
http://www.manestruckparts.com/store...&Category_ID=6

[notsolo]

Originally Posted by jbwolfe

Hi all, this is my first post to this site, I've been reading different threads for a few days, and really like the site, and have found the threads very helpful.

I have a 1971 Chevy CST/20 3/4 ton pickup with trailing arm coil spring suspension in the rear. About three months ago, after hauling a large load of firewood, the trailing arms broke near clean off near the springs. I've attached pictures of the suspension.

So I want to fix the truck as cheaply as possible. I've been calling junk yards in the area, but no one seems to have the trailing arms. They all seem to have leaf springs though. Would it be possible to replace the coil spring suspension with leaf springs?

I found after market trailing arms online, they are quite a bit cheaper than LMC, anyone have any input on these:

http://www.carpartsdiscount.com/auto...ml?3593=128189

I would really appreciate some input on this. This is my first Chevy, I love this truck, and I really want to keep it!

Thanks in advance!

Nice used trailing arms show up here or on Ebay from time to time, I found a nice set of 3/4 ton from California a few years ago came off a 1964 3/4 ton....The difference between 1/2 and 3/4 ton is a flat strap welded top and bottom to reinforce for heavier load.

[jbwolfe]

Originally Posted by notsolo

Nice used trailing arms show up here or on Ebay from time to time, I found a nice set of 3/4 ton from California a few years ago came off a 1964 3/4 ton....The difference between 1/2 and 3/4 ton is a flat strap welded top and bottom to reinforce for heavier load.

If I were to find a pair of 1/2 ton trailing arms, would I be able to weld on a similar metal plate for re-enforcement?

Originally Posted by Sicklajoie

This is for a pair:
http://www.manestruckparts.com/store...&Category_ID=6

That looks like a good price, I will definitely bookmark that site.

Does anyone have any thoughts about the idea of replacing the current suspension with leaf springs? A couple junk yards in the area have sets of leaf springs for under $100.

Originally Posted by black_sheep454

That sucks. Try looking through the for sale ads on here for one or become a supporting member and post a want to buy ad.
Posted via Mobile Device

What exactly does it mean to become a supporting member?

[black_sheep454]

It cost $25 per year to become a supporting member. It allows you to post for sale and want to buy ads. Supporting members like myself have blue names instead of pink.
Posted via Mobile Device

[desertnick69]

Hello i have a 1969 C-20 that has been in the family for 42 yr got totaled last April it has good trailing arms if interested let me know

[Indyuke]

I notice you're up north of Bellingham. There is a really good yard in Arlington, about 65 miles south of you. I was there last week and noticed they had two of our trucks each with trailing arm suspension intact. There's another sister yard in Lynnwood about 80 miles from you that currently has four of our trucks. You might give them a try.

[jbwolfe]

Originally Posted by desertnick69

Hello i have a 1969 C-20 that has been in the family for 42 yr got totaled last April it has good trailing arms if interested let me know

I will keep it in mind, and let you know what I decide.

Originally Posted by Indyuke

I notice you're up north of Bellingham. There is a really good yard in Arlington, about 65 miles south of you. I was there last week and noticed they had two of our trucks each with trailing arm suspension intact. There's another sister yard in Lynnwood about 80 miles from you that currently has four of our trucks. You might give them a try.

You don't happen to remember the names of the scrap yards do you? That would be great to find them locally!

[Sequoyah]

Looks like it was due to rust? I don't have anything for sale, but I have a 1/2 ton and welded some flat stock to the top and bottom before I even knew about this. It just seemed like the thing to do to make it stronger.

[Indyuke]

They're called Pick N Pull.

http://www.picknpull.com/locations.aspx

[jbwolfe]

Originally Posted by Sequoyah

Looks like it was due to rust? I don't have anything for sale, but I have a 1/2 ton and welded some flat stock to the top and bottom before I even knew about this. It just seemed like the thing to do to make it stronger.

Yeah it was rust. This truck started life in a more salty environment. The whole truck is pretty rusty, the rocker panels are nearly completely missing on one side. I think when I get new trailing arms, I'm going to re-enforce them, sand them down and paint them.

Originally Posted by Indyuke

They're called Pick N Pull.

http://www.picknpull.com/locations.aspx

Cool! If I don't find a pair close to home, I will definitely check them out.

[68 TT]

Here are some pics of the 3/4-ton arms I was going to put on my stepside. A little dirty but in pretty good shape.

[jbwolfe]

Well I think I'm going to find a good condition pair of 3/4 trailing arms and just replace the ones I have. Any words of wisdom as far as actually replacing them?

[k2rm]

Mine were almost that bad when I replaced them. Here are some tips.

Replace the trailing arms one at a time.

Detach the ebrake cable from the trailing arm.

Jack up the truck with the jack under the axle. Once it gets high enough, place a jackstand under the frame on both sides and remove the wheel. Slowly lower the axle until the spring is relaxed and place a jackstand under the the axle

You won't beable to remove the bolt holding the retainer cup to the lower part of the coil to the arm. The rust will have completely fused the bolt to the trailing arm. Hopefully you won't have an issue on the upper retainer cups so just loosen the upper retaining cups.

Remove the pivot bolt at the cross member and remove the trailing arm with the spring still attached. A big breaker bar comes in handy here.

Cut the retaining cup so you can remove the spring. You will need to find some new retaining cups. ECE and others sell them.

When reinstalling, I first attached the trailing arm to the cross member and then attached the coils.

[Shaky]

Mine were starting to go that way. It may have made more sense to look for replacements, but here's what I ended up doing:

[Sequoyah]

You can see what I did (or rather have my friend who can weld do) lol

[jbwolfe]

Originally Posted by k2rm

Mine were almost that bad when I replaced them. Here are some tips.

Replace the trailing arms one at a time.

Detach the ebrake cable from the trailing arm.

Jack up the truck with the jack under the axle. Once it gets high enough, place a jackstand under the frame on both sides and remove the wheel. Slowly lower the axle until the spring is relaxed and place a jackstand under the the axle

You won't beable to remove the bolt holding the retainer cup to the lower part of the coil to the arm. The rust will have completely fused the bolt to the trailing arm. Hopefully you won't have an issue on the upper retainer cups so just loosen the upper retaining cups.

Remove the pivot bolt at the cross member and remove the trailing arm with the spring still attached. A big breaker bar comes in handy here.

Cut the retaining cup so you can remove the spring. You will need to find some new retaining cups. ECE and others sell them.

When reinstalling, I first attached the trailing arm to the cross member and then attached the coils.

What about the shocks?

Originally Posted by Shaky

Mine were starting to go that way. It may have made more sense to look for replacements, but here's what I ended up doing:

I'm strongly considering doing some re-enforcements on my new trailing arms.

Originally Posted by Sequoyah

You can see what I did (or rather have my friend who can weld do) lol

The arms I'm getting are 3/4 ton arms, so they have the metal strip running along the top and bottom, preventing splitting. I'm not sure from your picture, but did you also add metal strips along the sides of the arms? I was thinking about doing that as well.

[Sequoyah]

Originally Posted by jbwolfe

I'm not sure from your picture, but did you also add metal strips along the sides of the arms? I was thinking about doing that as well.

No, just strips on the top and bottom.

[k2rm]

Originally Posted by jbwolfe

What about the shocks?

Yup, forgot about the shocks and u-bolts. The shocks can be removed once the suspension is relaxes.

On mine, I was able to remove the u-bolt nuts and the lower shock mounting plate, but the shafts were also rusted to the trailing arm. So, I had to cut the u-bolts above the axle.

[jbwolfe]

Thanks for all the help everybody! I've found a set of 3/4 ton trailing arms, just have to get them shipped to my house. A friend of mine who is a mechanic is going to help me replace them. I'll be sure to post updates on how its going.

Anyone have any recommendation on a good paint to use on the new trailing arms once I take a wire brush to them?

[gysgtc]

POR-15 to paint them with. The stuff is as hard as beavers teeth.

[jbwolfe]

Well I got my new trailing arms today! They are 3/4 trailing arms, great shape, just need cleaned up and painted.

Heres my question: the 3/4 ton trailing arms have the metal re-enforcement strip spot welded to them. I'm thinking about having a friend with an arc welder weld the strips of metal solid all the way around. Does that sound like a good idea?

[chopped68]

that is what I did with mine.the trailing arms had the plates spot welded on but I took them off to make sure they had no heavy rust underneath the plates,welded the 2 halves together and plated them all the way around with 12 gauge steel.I also z'd them 3 inches at the axle pad.

ken

[jbwolfe]

Someone mentioned to me the other day that if the trailing arms are heat treated, welding them wouldn't be a good idea.

Anyone know anything about that?