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Question on Sagging Trailing Arm...

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Old Dec 22, 2019 | 03:56 PM
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Default Question on Sagging Trailing Arm...

Well, got my goodies in from Vansteel last week and got around to tearing out the old rear suspension components. Old shocks are off, original leaf spring is out, strut rods out and BOOM, this is what I'm looking at:


Unless your blind, I guess you see the question/concern I have. Obviously the drivers side trailing arm is sitting on the frame. The passengers side is not. Please see close up of each side...

Drivers Side:


Passenger Side:



Prior to getting this far, I snapped a few photos in the event my amnesia kicks in and I forget where certain things went. Prior to removing spring and strut rods, everything looked alright...but surely this isnt right? When I tried to remove the drivers side strut rod, she was in a bind...had to jack up the hub just to take the pressure off to knock the rod out. Now I know why...And to be honest, before I go monkeying around with the trailing arm, I thought I'd drop back, punt and see what some of you more skilled guys have to say. Drive wise, prior to the overhaul, shes all original so I thought after 41 years, she'd like an upgrade. So I'm not sure if anything was off as its always ran the same(suspension wise) for the last 19 years that I've had it? As far as play...you can push up with ease on the drivers side to move the entire trailing arm with ease. Passenger side is pretty stiff but does move with some force...

Before pics...






Any ideas?

Last edited by austinseanchris; Dec 22, 2019 at 03:59 PM.
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Old Dec 22, 2019 | 04:33 PM
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Third photo, down from the top, has red circle:
Look to the right of the jackstand cradle. Does that frame appear to be coming apart? Looks like the welds are broken. Maybe not.

Anyway, sure like to see you add some extra jackstands forward. Or even some cement blocks. Anything! Just in case of a primary jackstand failure.
That car will crush you.
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Old Dec 22, 2019 | 04:33 PM
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Well it's kind of got to be either the u-joints or the T/A pivot and there's a lot of weight hanging on that pivot bolt, but for years the shocks kept it from going any farther so it's possible
I'm sure you looked but is there anything in the pocket possibly holding it up?

Try rotating the axle 90 degree and watch to see if the u-joints are binding
M
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Old Dec 22, 2019 | 04:46 PM
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I believe your over thinking this, I’d be looking at repairing the chassis , as pointed out a few posts back.
bfit
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Old Dec 22, 2019 | 05:04 PM
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I do alot of rear suspension rebuilds at work The front pivot bushing are seized to the bolt not letting the trailing arm drop. What did you get from Van Steel, are you replacing the trailing arms? I don"t see anything wrong with the frame.

Last edited by 71yellow454; Dec 22, 2019 at 05:07 PM.
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Old Dec 22, 2019 | 05:31 PM
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Alright...trying to touch on all the issues mentioned...
Most importantly, I apologize for the pics. When looking at them in the pics, the light does cast a shadow(with all the road grime) that the frame may in fact be cracked. So just to clarify, I went out and shot from a different angle with a different light to go ahead and rid that element:
Drivers Side:



Passenger Side(no shadow):



So the kit I ordered from Vansteel was the 78-79 Advanced Street & Slalom Suspension kit as pictured below:


Kit included:63-82 Advanced Street & Slalom Kit

VSD-01A
  • 360 lb Compostie Spring
  • Smart Struts
  • QA1 Front Single, 18 point Adjustable Semi-Coilovers w/550# Springs
  • QA1 Rear Single, 18 point Adjustable Shocks
  • Spanner Wrench
  • 1 1/8" Front Sway Bar
  • 3/4" Rear Sway Bar

Also ordered a rear bushing kit from Willcox:


REAR SUSPENSION MOUNTING AND HARDWARE COMBO KIT 78-79



To "71yellow454": So I wasnt planning on replacing the trailing arms...too cost prohibitive! Not to sound like a complete moron, but I'm assuming then that the trailing arm concern is actually in the passenger side? Which would mean its supposed to be sitting on the frame like the drivers side?

To "Mooser": So I see nothing in there, minus the shims of course...But if you look back through the pics, you can see the cotter pins on both sides as well as shims. If you look at the passenger side pics and most recently posted passenger side pic, you can see a shim wedged between the frame and I guess pivot bolt. Wondering if I raise the hub assembly and try turning the shim back towards the front if it will fall down and lay onto the frame? Drivers side shim is not like this...


Even more noticeable in original pic...:




P.S. To All: Extra Stands added

Last edited by austinseanchris; Dec 22, 2019 at 05:33 PM.
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Old Dec 22, 2019 | 05:54 PM
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Raise the arm and see if that (those) shims don't go up with it. likely bonded to the TA bushing on the molecular level and it's possible it'a what might be jamming it up.
M
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Old Dec 22, 2019 | 06:02 PM
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Look up ^^^^^^^ Frame welds are cracked. Inches to the right of the jackstand. But not likely having any effects of your question. Just concerning though.
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Old Dec 22, 2019 | 06:03 PM
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Originally Posted by Mooser
Raise the arm and see if that (those) shims don't go up with it. likely bonded to the TA bushing on the molecular level and it's possible it'a what might be jamming it up.
M
Yessir...just raised it up...I dont really know if the bracket that's sitting in there is supposed to be there? When you let the TA all the way down, the shim circled in red hits the frame not allowing it down anymore.




And, so the trailing arm is supposed to be resting on the frame then, correct? In other words, the problem is the passenger side, not the drivers as initially thought?
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Old Dec 22, 2019 | 06:13 PM
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Originally Posted by HeadsU.P.
Look up ^^^^^^^ Frame welds are cracked. Inches to the right of the jackstand. But not likely having any effects of your question. Just concerning though.
I guess if it were a snake, it would bite me b/c Im not seeing the cracks your referring to...Can you circle the area your referring to?
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Old Dec 22, 2019 | 06:16 PM
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Yes, the arm will drop down to touch the frame pocket. I used a set of wood blocks to hold mine up while working on the rear suspension



And then a set of ties (up to the frame) to hold the rear up in location when installing the shock etc until it was able to support itself


Not sure exactly where the frame issue is they are pointing out but certainly have a look and see if it's light/shadow or not
M

Last edited by Mooser; Dec 22, 2019 at 06:16 PM.
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Old Dec 22, 2019 | 06:21 PM
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I think the cracks he sees is just the frame end cap. Mine looked that way too.

Last edited by 69ttop502; Dec 22, 2019 at 06:25 PM.
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Old Dec 22, 2019 | 06:24 PM
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Originally Posted by Mooser
Yes, the arm will drop down to touch the frame pocket. I used a set of wood blocks to hold mine up while working on the rear suspension



And then a set of ties (up to the frame) to hold the rear up in location when installing the shock etc until it was able to support itself


Not sure exactly where the frame issue is they are pointing out but certainly have a look and see if it's light/shadow or not
M
Alright...minus pulling the cotter pin out, it looks like some jackleg may have added in a bracket or something of sorts on that inner side. When I lifted the drivers side, it looked like the normal shims that are supposed to be there. I think I'm gonna block it up like you did, remove that cotter pin and see what kinda dang crap this spacer is?

Yea, Im freaking out about this "crack"...I may be totally looking over it but they look the same on both sides and I dont see any cracks...fingers are crossed! If it is cracked, trailing arms will probably be the least of my concern...

Mooser, thank you sir...
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Old Dec 22, 2019 | 07:06 PM
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Your initial concern was having a TA lower than the other. Could it be that the real reason is that the u-joints/shafts are attached 90 degrees apart?
Try rotating them 90 degrees to see if the passenger side lowers......



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Old Dec 22, 2019 | 07:06 PM
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Originally Posted by austinseanchris
I guess if it were a snake, it would bite me b/c Im not seeing the cracks your referring to...Can you circle the area your referring to?
I believe that is a gusset in the frame that is separating. The welds are broke. Look behind the parking brake cable. Huge gap on passengers side.
Welded tight on drivers side.
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Old Dec 22, 2019 | 07:17 PM
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I always thought every rubber suspension bushing I worked on was kind of tight, and took more force to move the a-arm etc. than I expected. Because of the need to flex the rubber.
Now I assume a rubber bushed trailing arm would be like that also, but I have not had one of those apart.
Your suspension never droops this much during normal driving.
The long alignment shims are cotter pinned in place and should not move.
I would be concerned about the "loose" one. Maybe the 41 year old bushings are shot.
At any rate I would pull one or both trailing arms and inspect the bushings. At 41 years it's time.
Or at the very least inspect both arms for looseness or movement under pressure. (Big crowbar)

Duh! See post 14. It is usually the obvious!

Last edited by leigh1322; Dec 22, 2019 at 07:20 PM.
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Old Dec 22, 2019 | 07:25 PM
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Originally Posted by HeadsU.P.
I believe that is a gusset in the frame that is separating. The welds are broke. Look behind the parking brake cable. Huge gap on passengers side.
Welded tight on drivers side.
I tried sending you a PM...Can you circle what your referring to? Still think you may be seeing a shadow...
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Old Dec 22, 2019 | 07:26 PM
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Originally Posted by snoopykissedlucy
Your initial concern was having a TA lower than the other. Could it be that the real reason is that the u-joints/shafts are attached 90 degrees apart?
Try rotating them 90 degrees to see if the passenger side lowers......

Will do...just seeing this metal "shim" or whatever it is appears to be pushing down on the frame though not allowing the TA to settle on frame...
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Old Dec 22, 2019 | 07:32 PM
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Originally Posted by austinseanchris
Yessir...just raised it up...I dont really know if the bracket that's sitting in there is supposed to be there? When you let the TA all the way down, the shim circled in red hits the frame not allowing it down anymore.

And, so the trailing arm is supposed to be resting on the frame then, correct? In other words, the problem is the passenger side, not the drivers as initially thought?
Yes, with the shocks removed, the trailing arm will rest on the pocket, so the problem is on the passenger side, likely with your shims.

Perhaps some Kano Kroil will loosen up the shims enough to let you pull them out to replace them with stainless shims (you are doing the trailing arm bushings, right?)

Completely unrelated to your current issue, it looks like the kit from Van Steel comes with their high-arch spring. They also make a low-arch spring, similar to what VB&P used to sell. If it's not to late to contact them and swap (or confirm that you got the low-arch spring), you may save yourself some grief in the future.
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Old Dec 22, 2019 | 07:33 PM
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Originally Posted by leigh1322
I always thought every rubber suspension bushing I worked on was kind of tight, and took more force to move the a-arm etc. than I expected. Because of the need to flex the rubber.
Now I assume a rubber bushed trailing arm would be like that also, but I have not had one of those apart.
Your suspension never droops this much during normal driving.
The long alignment shims are cotter pinned in place and should not move.
I would be concerned about the "loose" one. Maybe the 41 year old bushings are shot.
At any rate I would pull one or both trailing arms and inspect the bushings. At 41 years it's time.
Or at the very least inspect both arms for looseness or movement under pressure. (Big crowbar)

Duh! See post 14. It is usually the obvious!
Yea, I need to probably pull them both and see whats going on. Was hoping not to have to with only one of me. Hopefully theres not a lot to screw up in there...Any ideas what the entire assembly weighs? Im guessing 100 lbs-ish? Its just one of me...
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