My caster mod (with pictures)

[HO455]

Here is a link to my Burban thread page on my front bag installation. I did have to reposition the bag on the upper plate to get the bag to sit straighter.
You didn't mention what make and model of bags your installing. If your using the SS7 bags I used, your plan with the control arms should work well. I haven't done it yet but I am planning to cut my lower cups down to get a higher pressure at ride height.

http://67-72chevytrucks.com/vboard/s...698377&page=10

[Slowguy]

All I have are the cheap 2600# airbags that came with the truck. I assume they are mostly the same? If not, it's not a big deal for me to change to a different brand right now.

[HO455]

Those bags are what I replaced. They gave me the same ride height but required higher air pressure to do it on my Burban. I can't really give you a good ride comparison between the two as the entire suspension was worn out with the old bags and the new bags are part of the total suspension rebuild. They are also smaller in diameter so you will have more room for misalignments in the top and bottom mounts as the suspension moves.

[crakarjax]

Originally Posted by Slowguy

I didn’t even know about this mod until reading a build thread on “green Gus” since I have everything apart for my nut and bolt build I figured I had better do this now or I may regret it.

Anyway, you were one of the only ones to mention bags. I too am using air and wondered how well you solved the issue of the crooked bag?

Did you purchase those cups somewhere? I think I'm going to want to cup my LCAs also.

Anyway for posterity here, it's best to keep the bag centered on the LCA to evenly distribute load to the LCA bushings.

[Slowguy]

Originally Posted by crakarjax

Did you purchase those cups somewhere? I think I'm going to want to cup my LCAs also.

Anyway for posterity here, it's best to keep the bag centered on the LCA to evenly distribute load to the LCA bushings.

Yeah. It took me a bit to find these just because of the name needed to search for. I kept looking for “cups” and even if you search their website you can’t find them with that search term. It wasn’t until I used “pocket” that I actually found what is was looking for.

I bought them here : http://www.bcfab.com/Front-Drop-Pock...10_p_1263.html

I could have fabbed something myself but I figured for the amount of time saved searching for the correct sized steel, cutting and welding, etc...I’d be better off just spending the money on these. They went in pretty easy and I think I’ll be glad I did it once everything is all back together. It will allow the front to drop quite a bit more.

[HO455]

For what it is worth from what I have done on mine I would recommend going with a smaller diameter bag like the 2600 as opposed to the Slam SS7 that I used. It will be easier to set up the bag at ride height so it won't touch the pocket.

[BMERDOC]

Have you put air in them (cycled them) to see if they settled out correctly?

[69gmcc10]

got myself my new Moog (part# k6147) lower shafts in the mail today! When I set them up against the old shafts I noticed something was not right!

The old shafts are longer than the new shafts!

[69gmcc10]

New shafts

[69gmcc10]

Old Shafts

[69gmcc10]

And side by side...

[69gmcc10]

In the photos yo will notice the overall length of the shafts themselves are the same, bot with and without the caps on. When comparing the end of just the shafts, not the knurling or lip but over all length of the entire rod, the index hole on both shafts are the same. It appears that there was a redesign to the new shafts at some point and they decreased the length of the large diameter (by 3/8" on each end to be exact) and used a longer rubber grommet to cover the distance. This is why we are getting different dimensions when comparing old shafts to new shafts, they are designed slightly differently, but keep and maintain the same geometry as the old shafts.

One of the biggest telling factors are the rubber seals/grommets used, there is a large difference between the old and new.

[The Rocknrod]

Can you just buy those new grommets somewhere?

[69gmcc10]

I don't know, I haven't looked, sorry.

[Ezzz]

About to give this mod a go this weekend. One thing I'm wondering is why it's necessary to remove and replace the original riveted stud on the saddle that serves to locate the shaft? If we're drilling the same size locating hole on the shaft won't the same locator work?

[jjzepplin]

I reused it.

[racecougar]

I left the saddles in place with the stock rivets as well. Not certain why the OP removed them only to reinstall with socketheads.

[chevyrestoguy]

It wasn't really a requirement to knock out the rivets on the saddles. I just wanted maximum engagement on all four points. I machined the new spotfaces in the shafts .005" over the diameter of the Grade 8 socket heads, and the added height of the sockethead (versus the height of the rivet) makes for a positive interaction where the shaft locks in to the saddle. With the rivet, you're only engaged at the height of the outer lip. It'll work fine, because that's all the factory required, but I tend to overkill when it comes to suspensions.

[Johnny_Lamebridge]

Hey guys, I moved my LCA's ahead by 3/4". They were original steel bushing style shafts.

I got an alignment done today. The caster reading was 5.5 degrees. Just an FYI...

[The Rocknrod]

I installed socket heads. One of the reasons is someone previously mounted the lower a-arms and didn't ensure they were seated properly, the locating pins were crushed some and I wanted to ensure they worked properly.

[crakarjax]

I think you'd have to twist one cap one way, the other cap the opposite -- otherwise you'd draw the caps in or move them out equally netting no caster gain. I'd be concerned about removing bearing surface on the one end of the shaft though, causing premature wearout since the caps are the actual friction surfaces.

[69gmcc10]

Originally Posted by crakarjax

I think you'd have to twist one cap one way, the other cap the opposite -- otherwise you'd draw the caps in or move them out equally netting no caster gain. I'd be concerned about removing bearing surface on the one end of the shaft though, causing premature wearout since the caps are the actual friction surfaces.

You are correct in tightening one and loosening the other when it comes to the caps, but since both ends are right hand turn when you twist a shaft already installed the shaft moves forward and backwards. It won't squeeze or push the ears of the control arm at all.

[ranger2339]

Ended up doing my arms, got the idea from Rob but decided to take a different approach I saw another member here took. I am on a tight budget so went this way, might brace them up a bit, we will see. I'm not the best fabricator, but I'm happy with them. Moved them over .75

Thanks to everybody.

[SCOTI]

Originally Posted by ranger2339

Ended up doing my arms, got the idea from Rob but decided to take a different approach I saw another member here took. I am on a tight budget so went this way, might brace them up a bit, we will see. I'm not the best fabricator, but I'm happy with them. Moved them over .75

Thanks to everybody.

Definitely..... plate & brace them.

[ranger2339]

Originally Posted by SCOTI

Definitely..... plate & brace them.

Anybody have any ideas on how to do this with this set up?