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Rear axle reinstall

ClarKent

Full Member
Joined
Mar 30, 2021
Messages
10
Repair necessitated removal of my rear axle on our "02 Z71. Jiggling the pumpkin on a floor jack, I reinstalled every bar I'd removed with the nuts fingertight. Went flawlessly...right up until I had no idea the torque settings NOR THE ANGLE.

I can raise and lower the axle in a slight arc by pumping or slowly releasing my jack, and it appears to travel a good 18 inches up and down along this arc. I pre-measured nothing to establish reinstallation landmarks, feel like an idot, and dont know what to do short of sneaking on a used car lot to measure the distance from a stock 2002 pumkin, its axle, or those ginormous horizontal bars ...to the ground. (I'm way too old, fat, and broken to be pulling a stunt like that).

Second issue I can't figure, but feel as if I brought on myself: I replaced the stock Bilsteins (a 1.97"" cylinder) with Ranchos (2.27" cylinder) all the way around. On the front, the bracket with the bump stop prevents me from installing the shock upper bolt into the top shock mount. Clang. Clang. Clang. Can't even get it through the hole, much less centered in it. It's too late to return the shocks for Bilsteins. So the obvious quick fix is to shave away some inch or so of the bump stop bracket, using a cutting wheel and air hammer. But that doesn't explain why that bracket already had a rubbed-away indentation from the Bilsteins. Is it just some design oops by Chevy engineers, or does anyone out there know what part I might have damaged in some pothole a decade ago?

Thanks for any suggestions, dimensions, or torque specs you all might have lying around in the glovebox 🧐
 
The weight of the vehicle sitting on the springs on top of the axle determines the ride height unless you have some sort of load leveling option. The shocks keep the rear from dropping too far if you go over a rise too fast, or if you jack up the rear by the frame. Otherwise the axle goes up and down during normal driving. That's the purpose of a suspension. You may be overthinking it.
 
Hit my head a lot as a boy, so, probably under-thinking it actually 😉 ...plus, I own a definite lack of savvy under a truck.

Now, I can tell you what got me scratching my head on this:

The upper and lower control arms bolt into the frame on one end and bolt into the brackets welded onto the axle on the other end. My assumption (faulty assumption??) has previously been that I simply hunt down torque specs and lock these arms into place at whatever the factory angle is supposed to be. I have been worried about locking these steel bars into place at the wrong angle.

But looking at the control arms, following your reply, I see that each steel arm has monster holes on each end, inside of which is A BUSHING that I'm actually locking into place with the nuts and bolts.

What I'm hearing from you is that I have a misunderstanding of the mechanics involved with the control arms and their respective bushings.

I'm NOW guessing that I can run those bolts in on both control arms, with zero concern over whatever angle they're bolted at -- because these control arms (metal with holes on each end) will float up and down at every bump and dip, starting the moment I take this beast off the jack stands...while the bushing (poly or rubber) stays fast and tight in place??

That would make me feel pretty dumb, so tell me it ain't so?!?!
 
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Do you see anything that would allow you to adjust it?

Just slap her back together as said.

Holes are located on truck and axle and links made to specific dims to line everything up they way Chevy engineers wanted it.

Now if you cut stuff off and welded things back on... well that is different as you need to weld them back on in proper location and position
 
Now I just need to hunt down torque specs for the control arms, track bar, stabilizer bar and stabilizer link.

...Or I just dial my impact to "permanent fusion" and empty the compressor ???
 
I always just use a normal socket wrench and tighten 1 or 2 grunts.

Figure anymore I would never get undone or stretch bolt.

Torque for bolts in shear is just about keeping them from loosening up and falling out.

Even then Torque for bolts all depends on you using the thread lube Gm says to use else your torq is not the same due to different friction
 
I found that extensions, wobbles reducers, and even brand of torque wrench alters true spec. Now I know about the oil too! I think I'm going to go about 2 grunts, then triple my life insurance and go for a spin 🤪
 
I'm NOW guessing that I can run those bolts in on both control arms, with zero concern over whatever angle they're bolted at -- because these control arms (metal with holes on each end) will float up and down at every bump and dip, starting the moment I take this beast off the jack stands...while the bushing (poly or rubber) stays fast and tight in place??
Yep! Crank em down!
 
Tis done, but I haven't put it on the ground just yet because I can't figure out the front shock misalignment...but I thank all you guys for coaching me through it!
 
you can put pics in your MEDIA ALbum

Until you are full member they have to be approved by well me and other staff members (spam protection)
Then you can link to them in your post....

I doot understand your issue with front shocks.
 
Original owner.
2002 Chevy Avalanche 1500 Z71.
5.7L
No lift (until the 2.5" leveling kit I installed a month ago)
84K on it.

Story short: The front shocks I bought are too tall (I bought Rancho RS55371, which are supposed to fit a 1500 Avalanche 4WD that has a 1" to 2.5" lift in the front end) and they are 12.5% wider than the Bilsteins, so ...too tall & too wide for my ride.

I had 20 year-old Bilsteins all the way around. When tinkering with the truck to restore it to licensed roadworthiness, I inadvertently discovered that the right front shock was snapped in two pieces, right at about 1" below the upper shock mount. Bushings, washers, post and nut dangling from the top, and the rest of the stainless steel plunger lives down in my shock body.

Decided to replace all four, and simultaneously install a couple 2.5"-to-3" torsion keys on it (to finally keep my coffee from flipping off the seat onto my accelerator pedal).

Middle of the shock body clanks on the bump stop bracket that's welded onto my frame. Damn 2.27" wide Rancho is so much fatter than the 1.97" wide Bilstein that I can't even coax the shock's 3" tall threaded post to slip into the shock mount hole.

I chose to whittle away at the corner of the bump stock bracket (so the wide body Rancho would have clearance) instead of revert to thinner-bodied shocks. I wanted Ranchos since my Jeep envy adolescent years. Well, now I regret it.

So the Rancho shock width now clears...the truck's front bump stop bracket that I mutilated hides behind my new fat Rancho shock... I compress it... I slide it under tbe upper shock mount, I guide it to the center where the hole is (gleefully without a single clang)... I release the shock so that the 3" long threaded portion can rise up into the hole ...and bang, I start hating life because the s.o.b. is easily an inch short of being able to accommodate the Rancho's first washer, first bushing, upper shock mount, secong bushing, second washer, and cherry on top (nut).

Well... HOW IN THE HELL!??!

So I drop the torsion to zero -- literally took the bolts out of the keys-- and it made practically no difference in the relatinship between the Rancho's threaded head and the Avalanche's upper shock mount.

Called Shock Surplus, told them the shocks they recommended were both too wide and too short, and then they used the pictures I sent them as a defense: "YOU PAINTED THEM SAME COLOR AS TRUCK? WELL, PISS OFF, WE WON'T TAKE THEM BACK NOW."

C'mon man, it's so fresh that I could literally liquify and wipe that minimal amount of misted paint off with a rag dipped in paint thinner.

~ Anyway, that's off-track right now ~

Shock extenders for the new front shocks?

Pawn the new pair off on Craigslist and purchase longer shocks from someone with more business ethics? (Out with the RS55371 that are recommended for trucks with a 1"-to-2.5" lift, and in with another new pair...of Rancho RS55268 that are recommended for a 4" lift)?? Until the shorter pair of new shocks sell, I'm out another $125 for the right sized pair 🥺😡

And most importantly: why the hell did my right front Bilstein snap in the first place...why is the suspension refusing to accommodate a slightly beefier shock?

Did my kid drive my truck to circkle-K, hit a curb head-on, and some arm or joint under there? I don't even know how I'd go about learning if the stock front end is contorted so much that it broke a 2" bilstein and won't accept a 2.25" Rancho.

I'll go back, read your instructions, and then follow them to post a few pictures of all that aforementioned.

Thanks for replying to my wordy post.
 
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Hmm, there might actually be something to the kid hitting a curb really good. I think I'd take it to a reputable suspension shop for analysis
 
I need some pictures of what you speak to help me see it in my mind...

As for broken shock... it could have just froze up due to corrosion or something and you hit a bump and well she wont move so she breaks.
 
I loaded pictures in my gallery. I'm new to the site, so I guess it's necessary for moderators to ensure I'm not uploading clown porn or some such juvenile and inappropriate images. I'm actually so new that I don't know how to direct you to my gallery where the previously uploaded images are stored -- sorry.
 
Shock Saga . . .

I'm going to take a stab in the dark.

When you mount the shock to the lower bracket and attempt to install it in the upper mount, is the suspension at max height?
If yes, get another jack and put it under your lower control arm and slowly raise it up until the shock is up high enough to be secured.

Quite possibly with the suspension at it's max height and the lift, the suspension is too tall for the shock and needs a bit of compression to provide the right length for the shock.

Of course this doesn't explain why the other shock fit.
 
I loaded pictures in my gallery. I'm new to the site, so I guess it's necessary for moderators to ensure I'm not uploading clown porn or some such juvenile and inappropriate images. I'm actually so new that I don't know how to direct you to my gallery where the previously uploaded images are stored -- sorry.

Make a few more posts and the ability to directly post pictures will magically appear to you.

Look for the "Full Member" tag to appear under your forum name.

Looking forward to your pics.

:) (y)
 
TO see yours or anyones pics in their album:
1 - click their member name name in any post.
2- then you see in roughly middle the word MEDIA with a number underneath - CLICK THIS.

for you clark kent it takes you here to your media album:

Another way is to click media on top row of all web pages and then check out all the pictures available for your viewing.
Many ways to do things on this forum software and I am still learning so I just click stuff.
 
Shock Saga . . .

I'm going to take a stab in the dark.

When you mount the shock to the lower bracket and attempt to install it in the upper mount, is the suspension at max height?
If yes, get another jack and put it under your lower control arm and slowly raise it up until the shock is up high enough to be secured.

Quite possibly with the suspension at it's max height and the lift, the suspension is too tall for the shock and needs a bit of compression to provide the right length for the shock.

Of course this doesn't explain why the other shock fit.
I tried boosting the lower control arm with a spare 3-ton jack. IT LIFTED THE WHOLE TRUCK ...right off the 6-ton jack stands.

I gulped, then eased the jack down so the front end returned to its jack stands.

And we don't have to explain the old shock. It was in, but snapped in half (for years). Whatever is wrong there had apparently started wayyyy back when the stock shock snapped in two.
 
You could try to install the shock after the truck is lowered some. Maybe just use the jack and no stands. Raise the truck off the stands, remove them and slowly lower the truck down so the shock reaches. Secure and lower the jack all the way, then check for any issues of clearance and travel.

Whatever happened way way back maybe the cause of your frustrations today.
 
Hey...not a bad idea, sir.

I'll let you know how it goes.

( I am counting ten fingers before this...in case there's a discrepancy later ;)
 
in wonder if someone changed the torsion bar key or cranked on bar to raise the front end?

This would make it difficult to change shocks as the torsion bar torqs the lower arm downward so to lift truck up higher.
This would require more load to compress the normal truck and hence why it came off the stand since front axle load is pretty much fixed (engine,fenders, hood etc).

normally the trucks ride on the foam/rubber bump stops... kind a part of the suspension with normal empty truck the bump stop just kisses the lower arm.

did yours beforehand?
 
I added torsion keys. Leveled truck 2.5" by bringing up the front. When my new shock wouldn't stretch to the upper shock mount, I tweeked the torsion bars back down to zero again. However, the shock gap still wouldn't close. In fact, there was literally ZERO difference in the front height with the keys cranked up or cranked down. So glad I bought aftermarket torsion keys. So glad.

As for bump stops kissing: they'd be relegated to merely blowing their kiss long distance with the truck up in the air on jack stands. But I'm going to reinstall tires and drop it onto the ground this today just to see if the weight of the truck sandwiches this big chasm between upper and lower mounts.

Fingers crossed 🤞
 
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