Rear axle "alignment" and rear tire wear

Re: Rear axle "alignment" and rear tire wear

Postby pmou [OP] » January 20th 2021, 4:36am

Since installed, the axle has slipped. Granted, i did go into a ditch at one point when i went off the road in a snowstorm.. but I think I'd like things more solid than they seem to be at this moment.. The DS seems to have not moved but the PS slipped backwards so that the centering pin is resting against the back of the clamshell centering hole.

Guess that means it's time to try out the plate / u-bolt upgrade. I ordered a couple parts from ruffstuff specialties: ubolts -- UB275, and plates (3", to clear the perch) -- 3F-UPLT .. also ordered some isolators/pads -- energy 3.6112G to install at the same time. I'm a little concerned about the clearance of the u-bolts to the "frame" rails in the body, but I'm not sure I have too many other options so going to give it a shot. Should have all the parts and time in the next couple of weeks here.
Original Poster [OP]
pmou
Firing on 2 Cylinders (L1)
Firing on 2 Cylinders (L1)
Posts: 216
Topics: 8
Joined: June 2020
Location: Colorado Front Range
Gender: Male
Alias (AKA): Paul
Van Model Year: 2003
Van Make/Model: GMC Safari
Extra Info: AWD 3.73 3in JOR

  • Similar topics
    Replies
    Views
    Author

Re: Rear axle "alignment" and rear tire wear

Postby Mmusicman » January 20th 2021, 2:30pm

pmou wrote:..the PS slipped backwards so that the centering pin is resting against the back of the clamshell centering hole..

This was discussed way back on page 1. The center-pin bolt on mine was installed upside-down (with threads sticking up). I found a perfect sized "centering spacer" solution.. a socket from a cheap 3/8 ratchet set that fit the bolt as well as inside the clamshell opening perfectly. This was also fastened in place so it's permanent. My axle absolutely can no longer "shift" around on the springs, and has worked for me ever since.

Photo from page 1:

Image

The clamshell is a poor design (with issues..especially if you modify anything)
None the less.. the upgraded plate and u-bolts should be the best solution.
Image
2000 Astro LS 4x4 | NP233 | 31" LT265/70R17 Tires | 8" LIFT | 10" TOTAL
92 Chevy Astro Cargo Shorty | V8-350
http://www.CruisinSouthFlorida.com
User avatar
Mmusicman
V8 Swap Achievement
V8 Swap Achievement
Firing on 8 Cylinders (L5)
Firing on 8 Cylinders (L5)
Years of Membership: Mmusicman has been a member for 7 full yearsMmusicman has been a member for 7 full yearsMmusicman has been a member for 7 full yearsMmusicman has been a member for 7 full yearsMmusicman has been a member for 7 full yearsMmusicman has been a member for 7 full yearsMmusicman has been a member for 7 full years
Posts: 4958
Topics: 73
Images: 59
Joined: June 2013
Location: Ft. Lauderdale, Florida
Gender: Male
Alias (AKA): Scott
Van Model Year: 2000
Van Make/Model: Chevrolet Astro
Extra Info: 2000 4x4 - 92 V8-350

Re: Rear axle "alignment" and rear tire wear

Postby dcsleeper » January 20th 2021, 3:01pm

does your rear have 3" perches or is that assumed by a post from a member with the old FG leafs?
Please update your User Control Panel to include your location!!! it's in the upper right!
Profile | Edit signature

RandomInternetUser wrote:I blame stupidly-written 1970s and 1980s TV shows.
User avatar
dcsleeper
Firing on 4 Cylinders (L1)
Firing on 4 Cylinders (L1)
Years of Membership: dcsleeper has been a member for 1 full year
Posts: 490
Topics: 21
Images: 79
Joined: April 2020
Location: North Carolina
Gender: Male
Alias (AKA): DC
Van Model Year: 2004
Van Make/Model: Chevrolet Astro
Extra Info: I have 2 1AWD 1RWD

Re: Rear axle "alignment" and rear tire wear

Postby pmou [OP] » January 20th 2021, 4:19pm

ohh!! mmusicman -- sorry, i think i originally misunderstood. I did use a socket to align the pins, which i thought was what you were suggesting. I didn't realize you left them in place to hold it all solid. Thats a good solution! I don't think at the moment i have a socket i'd like to sacrifice, and as you've said the U-bolts will be about as solid as i can get, which is sounding pretty good right about now.

dcsleeper wrote:does your rear have 3" perches or is that assumed by a post from a member with the old FG leafs?


So my van has steel springs and I would assume the narrower perches as far as these vans go. However, in my measuring it looked like i would still need a 3" plate to be able to clear the perch. It looks like the perch is a bit wider than the 2.5" spring.. i was debating trying a 2.75" wide plate however the perch seems to "flare" a bit as it goes down and i wasn't confident that a narrower plat would allow the bots to actually clear. I am planning to destroy the one non-ubolt side of the perch in order to accomodate the 2x u-bolts. even still, i think 3" will be just wide enough. I intended to order the same items referenced part way down here: https://www.astrosafari.com/viewtopic.php?f=41&t=127346

Here's a few pics of me roughly measuring the width:

PXL_20210120_142947222.MP.jpg


PXL_20210120_142923454.jpg


PXL_20210120_142838178.jpg


You'll have to trust me a little bit that these measurements on the calipers line up with what you are seeing, i couldn't really fit my calipers all the way in to measure with everything still bolted together. Anyway, you can see that 2.5" and likely even 2.75" would be too narrow. I think 2.75" could maybe work with some minor trimming, hard to say. decided to play it safe. Also looking at that pics in that thread i referenced, it doesn't look like they had 1/4" on their 3" plates to spare.
Original Poster [OP]
pmou
Firing on 2 Cylinders (L1)
Firing on 2 Cylinders (L1)
Posts: 216
Topics: 8
Joined: June 2020
Location: Colorado Front Range
Gender: Male
Alias (AKA): Paul
Van Model Year: 2003
Van Make/Model: GMC Safari
Extra Info: AWD 3.73 3in JOR

Re: Rear axle "alignment" and rear tire wear

Postby MI_Ghost » January 25th 2021, 8:03am

Here is a different approach to doing the U bolts.

Downward Facing Square U-Bolt Option for Rear Springs
https://www.astrosafari.com/viewtopic.php?f=40&t=145188
~Ghost
Ast' Cargo: 2001 Astro Cargo
Beauty: 2009 Impala LT
User avatar
MI_Ghost
Firing on 3 Cylinders (L2)
Firing on 3 Cylinders (L2)
Years of Membership: MI_Ghost has been a member for 5 full yearsMI_Ghost has been a member for 5 full yearsMI_Ghost has been a member for 5 full yearsMI_Ghost has been a member for 5 full yearsMI_Ghost has been a member for 5 full years
Posts: 1364
Topics: 7
Images: 107
Joined: November 2015
Location: On The road Again! Great Lakes Based.
Gender: Male
Alias (AKA): Ghost
Van Model Year: 2001
Van Make/Model: Chevrolet Astro
Extra Info: Big White RWD Box

Re: Rear axle "alignment" and rear tire wear

Postby pmou [OP] » January 25th 2021, 4:53pm

MI_Ghost wrote:Here is a different approach to doing the U bolts.

Downward Facing Square U-Bolt Option for Rear Springs
https://www.astrosafari.com/viewtopic.php?f=40&t=145188



Dang, i actually like that option a lot better. It's a little more work.. but it doesn't seem like a huge difference really. I had been concerned about the U-bolts hitting the frame..

My order hasn't shipped yet so I'm going to see if I can cancel it. If so, I'm going to start looking into collecting the pieces for this conversion instead.
Original Poster [OP]
pmou
Firing on 2 Cylinders (L1)
Firing on 2 Cylinders (L1)
Posts: 216
Topics: 8
Joined: June 2020
Location: Colorado Front Range
Gender: Male
Alias (AKA): Paul
Van Model Year: 2003
Van Make/Model: GMC Safari
Extra Info: AWD 3.73 3in JOR

Re: Rear axle "alignment" and rear tire wear

Postby pmou [OP] » January 25th 2021, 6:08pm

okay, i was able to cancel that order. My housemate will be at a JY in a few days, i'm going to ask him to grab the extra bottom plates from a random van there. I think i'm going to go with the idea shown in there of re-purposing the clamshell top to act as a leaf spring top plate. I had bought different isolators as I thought I was going to be using a flat top plate.. I think it may end up working out better to re-use the rubber isolators that were on the van as they are shaped to the clamshell a bit and were in decent shape. Let you know how it all works out. Given that this is likely now a bit of a longer term thing, I think I'm going to re-set the rear axle to be square and see if I can get it to stick that way for any reasonable amount of time.
Original Poster [OP]
pmou
Firing on 2 Cylinders (L1)
Firing on 2 Cylinders (L1)
Posts: 216
Topics: 8
Joined: June 2020
Location: Colorado Front Range
Gender: Male
Alias (AKA): Paul
Van Model Year: 2003
Van Make/Model: GMC Safari
Extra Info: AWD 3.73 3in JOR

Re: Rear axle "alignment" and rear tire wear

Postby pmou [OP] » January 27th 2021, 5:06pm

OK so based looking through that other thread, I've had a hard time tracking down anything that anyone else used for the square U bolts. After some searching I came across these options:

5/8" (grade 8 "equivalent") https://store.uboltsdirect.com/5/8-u-bo ... side-width
1/2" (grade 5 "equivalent") https://store.uboltsdirect.com/1/2-u-bo ... side-width
3/8 (grade 5 "equivalent") https://store.uboltsdirect.com/3/8-u-bo ... side-width

There are some price differences, and the 3/8 is only offered up to 8 5/16" long which may rule that one out. If so, then i would think it would come down mainly to what size holes I would be able to use, and what grade would be acceptable. I am leaning towards 5/8, as they are grade 8 but am also wondering if the little clamps that would form the bottom of this could accept a 5/8" hole. It looks to me like other folks used 1/2" and possibly not even something officially graded. Based on the pictures from dit / sportsboy, i believe a 5/8" hole would be okay in those perches (of course i don't have a bit that big...).

Anyone have any thoughts? or any other sources for this sort of bolt?
Original Poster [OP]
pmou
Firing on 2 Cylinders (L1)
Firing on 2 Cylinders (L1)
Posts: 216
Topics: 8
Joined: June 2020
Location: Colorado Front Range
Gender: Male
Alias (AKA): Paul
Van Model Year: 2003
Van Make/Model: GMC Safari
Extra Info: AWD 3.73 3in JOR

Re: Rear axle "alignment" and rear tire wear

Postby pmou [OP] » January 27th 2021, 7:14pm

Okay, actually maybe this will be the determining factor:

https://www.uboltsdirect.com/torque-specs.html

I believe if I'm remembering correctly that the original clamshell torque was around 70 ft/lb -- so I believe i would want to go at least that high if not higher. According to their torque recommendations, that would mean 1/2" would barely make it, and 5/8" would probably be the safe bet.
Original Poster [OP]
pmou
Firing on 2 Cylinders (L1)
Firing on 2 Cylinders (L1)
Posts: 216
Topics: 8
Joined: June 2020
Location: Colorado Front Range
Gender: Male
Alias (AKA): Paul
Van Model Year: 2003
Van Make/Model: GMC Safari
Extra Info: AWD 3.73 3in JOR

Re: Rear axle "alignment" and rear tire wear

Postby pmou [OP] » January 28th 2021, 5:13pm

I ended up ordering 9/16 x 3" x 7 1/8" (a little extra long) + their hardware (nuts + washers) for $66 shipped. much cheaper than bolts and plates as well. Still need to obtain the extra brackets from the JY, that may happen this weekend.

I talked with someone on the phone about their product, they seem like a good company. That said, i would strongly recommend paypal payment on their aging website if anyone else buys from them.
Original Poster [OP]
pmou
Firing on 2 Cylinders (L1)
Firing on 2 Cylinders (L1)
Posts: 216
Topics: 8
Joined: June 2020
Location: Colorado Front Range
Gender: Male
Alias (AKA): Paul
Van Model Year: 2003
Van Make/Model: GMC Safari
Extra Info: AWD 3.73 3in JOR

Re: Rear axle "alignment" and rear tire wear

Postby pmou [OP] » February 4th 2021, 6:53pm

Just re-positioned the rear axle for the time being -- getting the studs out of those brackets is not for the faint of heart. I would really probably only attempt that again with a plasma cutter or drill press. I may try to grab some brackets off of a Dodge 2500/3500 this weekend -- they are 3" wide. Or i'm just going to hold off on the square ubolts for now.

anyhow, noticed the passenger side leaf bushing looking a bit odd when i was under there -- these are new as of a few weeks probably like 1100mi at most. rear didn't look like that.

PXL_20210203_235548729.jpg


maybe it's nothing, but figured i'd share for armchair consideration.

I re-torqued the bolts to 80ft lb all around, 6ft higher than last time / recommended torque. on the DS where i didn't loosen anything i probably got 1/2-3/4 turn out of it to hit 80ft/lb. we'll see if it's more solid
Original Poster [OP]
pmou
Firing on 2 Cylinders (L1)
Firing on 2 Cylinders (L1)
Posts: 216
Topics: 8
Joined: June 2020
Location: Colorado Front Range
Gender: Male
Alias (AKA): Paul
Van Model Year: 2003
Van Make/Model: GMC Safari
Extra Info: AWD 3.73 3in JOR

Re: Rear axle "alignment" and rear tire wear

Postby WoodButcher » February 4th 2021, 7:43pm

Did the bushing slide on the sleeve?
User avatar
WoodButcher
V8 Swap Achievement
V8 Swap Achievement
Firing on 5 Cylinders (L6)
Firing on 5 Cylinders (L6)
Years of Membership: WoodButcher has been a member for 10 full yearsWoodButcher has been a member for 10 full yearsWoodButcher has been a member for 10 full yearsWoodButcher has been a member for 10 full yearsWoodButcher has been a member for 10 full yearsWoodButcher has been a member for 10 full yearsWoodButcher has been a member for 10 full yearsWoodButcher has been a member for 10 full yearsWoodButcher has been a member for 10 full yearsWoodButcher has been a member for 10 full years
Posts: 5578
Topics: 30
Images: 514
Joined: October 2010
Location: Woodbury CT
Gender: Male
Alias (AKA): Bruce
Van Model Year: 1993
Van Make/Model: GMC Safari
Extra Info: 5.7L RWD

Re: Rear axle "alignment" and rear tire wear

Postby pmou [OP] » February 4th 2021, 7:44pm

WoodButcher wrote:Did the bushing slide on the sleeve?


That is certainly what it looks like to me, although i thought that shouldn't really be possible as I thought they would be bonded to each other in some way? And the bushing should occupy the full width (3") of the opening?
Original Poster [OP]
pmou
Firing on 2 Cylinders (L1)
Firing on 2 Cylinders (L1)
Posts: 216
Topics: 8
Joined: June 2020
Location: Colorado Front Range
Gender: Male
Alias (AKA): Paul
Van Model Year: 2003
Van Make/Model: GMC Safari
Extra Info: AWD 3.73 3in JOR

Re: Rear axle "alignment" and rear tire wear

Postby pmou [OP] » February 5th 2021, 4:44pm

U bolts arrived, look good to me. 9/16 x 18tpi

PXL_20210205_152707609.jpg


and their quality control is top notch

PXL_20210205_152723855.jpg


going to be at a JY this weekend to look into grabbing plates from a dodge truck, see if these can end up being used with that.
Original Poster [OP]
pmou
Firing on 2 Cylinders (L1)
Firing on 2 Cylinders (L1)
Posts: 216
Topics: 8
Joined: June 2020
Location: Colorado Front Range
Gender: Male
Alias (AKA): Paul
Van Model Year: 2003
Van Make/Model: GMC Safari
Extra Info: AWD 3.73 3in JOR

Re: Rear axle "alignment" and rear tire wear

Postby pmou [OP] » February 5th 2021, 4:49pm

Oh, i also got new tires .. just had to happen the ones i was running were garbage craigslist dried out tires. wow what a difference first of all. the alignment report again said thrust angle at about +0.36deg.. i decided to do some maths last night and i measured the center pins to be 49.5" apart. based on that, i came up with the tan(0.36) * 24.75 is 0.155" or about 5/32" -- so if this alignment is to be trusted, and this is what was causing the wear, to make the thrust angle 0 i would need to scoot the PS wheel forward 5/32" and the DS wheel back 5/32" .. which seems incredibly minor.. i'm almost inclined to think the dynamic nature of highway driving would practically negate a difference that small. anyone else have any thoughts?

edit: now for consideration, you could say the tire is possibly +12" wider at it's widest point from the center pin.. so that would work out to 1/4" at the tire. or for arguments sake, assume 24" wider (per side) -- that would be 0.3".. still seems quite small.
Original Poster [OP]
pmou
Firing on 2 Cylinders (L1)
Firing on 2 Cylinders (L1)
Posts: 216
Topics: 8
Joined: June 2020
Location: Colorado Front Range
Gender: Male
Alias (AKA): Paul
Van Model Year: 2003
Van Make/Model: GMC Safari
Extra Info: AWD 3.73 3in JOR

Previous

 
  • Related topics
    Replies
    Views
    Last post

Return to Lifted Suspension

It is currently April 21st 2021, 9:57am

Lifted Suspension Forum
Lifted SuspensionLifted Suspension, 4x4, Leaf Springs, Lift Kits, Coils, Gas Shocks, Suspension Lift, Body Lift, Sport Utility, Off-Roading.
Moderator: chevy57bert
To create a new topic in Lifted Suspension, click this button:
Previous topic Next topic
Recent Image Attachments
Attached by:
Attached by: LumaWJ
LumaWJ
in Lifted Suspension
Views: 195
Comments: 5
Date: Apr 18 '21
Time: 6:45am
» Read last comment
Attached by:
fe2o3
in Lifted Suspension
Views: 195
Comments: 5
Date: Apr 12 '21
Time: 5:58pm
» Read last comment
Views: 291
Comments: 11
Date: Mar 25 '21
Time: 11:48pm
» Read last comment
Attached by:
Attached by: SportsBoy
SportsBoy
in Lifted Suspension
Views: 1056
Comments: 28
Date: Feb 15 '21
Time: 3:20am
» Read last comment
Attached by:
Attached by: SportsBoy
SportsBoy
in Lifted Suspension
Views: 1056
Comments: 28
Date: Feb 08 '21
Time: 2:46pm
» Read last comment
Sponsors

Who is online

Users browsing this forum: No registered users and 1 guest