Viva La GMC!

Keep it clean, children may be present.

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Xelmon
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Location: LA or Portland, OR
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Re: Viva La GMC!

Post by Xelmon » Sat Jan 03, 2015 11:17 pm

I have to admit I have been falling a bit short on the "weekly washes" routine. I'll... Hm, I may take her down to the car wash tomorrow. Maybe.

The big mechanical update fer now is the fact that I've finally gotten around to inspecting the axles that I have aquired not too long ago!
WOooohooo, gogo 6-lug / 12 bolt!

I had to chop out the cross member to be able to get the diff cover off.

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Before we begin, this is a gem... Left rear drum, and I have to say, this is the most ruined drum I have seen thus far. That has not only exploded, someone also let it to sit forever and a day to get thoroughly rusted.

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On the other hand I managed to make a nice chip into one of the rare front drums all by myself, as I was trying to PB/torch/hammer the drum off. I had a bit of a moment to say the least. I'm pretty sure that that an be balanced out though, so I'm not too worried to be honest.

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The GM 12-bolt 8.875" rear differential, in all of its overexposed glory. One of the major objectives for cracking the diff cover to be able to see what the RPO was, as it could've been either 3.73 or 4.11

I counted the ring gear teeth which came out to 37. I didn't remember off the top of my head what the pinion was, and the ratio wasn't stamped into the ring gear either. With closer inspection I noticed that the pinion had "10 67 9 37" stamped into it. Huh. So this is likely the original 37:9 RPO, commonly known as 4.11:1

We'll see how much of an acceleration increase I will have once I hit the road with bigger tires compared to my current 3.06:1

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Condition wise it's a good axle, the inside surfaces are clean and free of rust and the ring gear has only minor surface rust. I'll first clean the axle out and drive it around to see what it does, as this is another "not too concerned" item.

Between the clean inside and heavily corroded outside it's safe to say that the van it came out of - '68 G20 in Ohio, thanks for the sale MC! - has been a life-long East coast van.

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Left axle shaft is in OK condition, it has some minor pitting on the outer edge. There isn't a deep grove per say, so it's not a dead axle. It'll definitely have to be replaced sometime eventually.

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Right axle shaft is A-OK though.

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These items actually had some good rust developing, had to scrape it off with some wood. They are the shims between the differential and the axle shaft gears. I have a feeling that all rust developed after the van has been parked, as this rust has not marked the differential or the axle shaft gears.

I'll be likely replacing these even though I scraped off the pertruding rust. I'd rather save a differential if I can help it.

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Mike Boell
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Re: Viva La GMC!

Post by Mike Boell » Sun Jan 04, 2015 8:44 am

What's with the bright light and dry pavement?
Looking good Adam.
Mike Boell
1975 FI Westy
Oregon City

SOME PEOPLE ARE LIKE SLINKIES - NOT REALLY GOOD FOR ANYTHING BUT THEY BRING A SMILE TO YOUR FACE WHEN THEY'RE PUSHED DOWN THE STAIRS.

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Xelmon
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Re: Viva La GMC!

Post by Xelmon » Mon Feb 23, 2015 12:48 am

Thank!

Since then I've been working on other projects too.

Such as nyah:

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At this point it has tires on it already, 215/75R15's... They are fairly massive compared to the 195's.

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Mike Boell
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Re: Viva La GMC!

Post by Mike Boell » Mon Feb 23, 2015 9:28 am

Looking good,
When are you in town next?
Mike Boell
1975 FI Westy
Oregon City

SOME PEOPLE ARE LIKE SLINKIES - NOT REALLY GOOD FOR ANYTHING BUT THEY BRING A SMILE TO YOUR FACE WHEN THEY'RE PUSHED DOWN THE STAIRS.

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Xelmon
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Re: Viva La GMC!

Post by Xelmon » Tue Feb 24, 2015 10:49 pm

This weekend, already booked too with the fam and such. =)

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Mike Boell
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Re: Viva La GMC!

Post by Mike Boell » Wed Feb 25, 2015 9:29 am

If you find time to squeeze in an adult beverage give me a call. :occasion5:
Mike Boell
1975 FI Westy
Oregon City

SOME PEOPLE ARE LIKE SLINKIES - NOT REALLY GOOD FOR ANYTHING BUT THEY BRING A SMILE TO YOUR FACE WHEN THEY'RE PUSHED DOWN THE STAIRS.

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Xelmon
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Re: Viva La GMC!

Post by Xelmon » Wed May 13, 2015 8:28 pm

In the recent months I've had to do all kinds of stuff to the van just to keep up with things getting old.
Now a while ago I manged to paint up a set of tires. Those rims? 15x8** smoothies with 215/75R15's. Them suckers turned out pretty big!

Another thing that needed immediate attention back in March/April were my leafs. As I was driving down one of the bumpy main drags my left front had this sinking feeling when I hit a bump. I was waiting for the rebound that didn't quite come.

So instead of wrenching on the axles - which BTW took forever! - I swapped my front leafs out.
I had to use 2 car lifts to get the van up straight as one-at-a-time was not stable at all. The jack stand wanted to rotate out from underneath the van.

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The leafs themselves! Woohoo!

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This time around the axle sat on the ground while I slipped in the new springs. Since I've swapped my front leafs for slightly less used leafs everything came apart easily.

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The U-bolts I got fit like a glove! Woohoo for quadruple measuring things!
On the other hand there are 2 things I did mess up. The new U's were freakishly long, and they are also one size smaller than what I could fit.

Eh, no big deal. I'll get beefier U's later. For now this will work just fine as the load bearing bolt is in the front.

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And everything back together!

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This was a slightly later occasion, I was curious why I had such a nasty oil leak... Well, a good coupe of drips, still irritating.
After I took off the fuel pump as it seemed to seep a lot I noticed that the gasket wasn't quite right.
That's right folks, that ghetto gasket was over a year old at this point of time. Tris made it when I was assembling the engine.
Whoops.

I also stripped one of the bolts when I was reassembling.
Double whoops.

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** 15" diameter, 8" rim outside width rims. This translates to a bead width of about 7".

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Xelmon
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6-Lug Samurai!

Post by Xelmon » Wed May 13, 2015 9:06 pm

And to double post things as they are that big... I finally swapped the axles.

So I swapped my axles on the GMC. I've thought of several names for this weekend.

The two top are 46 Hours Of Le Wrench and Operation Axle.

The ultimate start and finish of the Operation 11:30AM Saturday and 8:10AM Monday.
This includes moving everything into position, and attempting to pretty up some of the brake-fluid induced marks with acetone at clean-up.

It was also an operation as I had only the given time-frame of between work hours. This meant that by ~8-9AM Monday morning everything had to be gone.
The plan was straight forward too. Front axle first, then rear axle..... And that doesn't even begin to describe this undertaking.

Smaller side-notes are included with the pictures.

DAY 1

11:30AM
Setup wasn't too painful. I quickly figured out that sadly the lift-points are at the complete opposite ends of the van. That 2-post lift? Not as golden as I thought it was going to be, still made things a lot easier.

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Some of my tools and the previously mentioned wheels. Those are big guys! Of course I got a 4 + full spare as I didn't have any other option.

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2:30PM
Before I began disassembly I took off a brake hose. I checked online and it claimed that they were the same fitting size. I was pleased to note that this turned out to be true.

Front axle came apart like butter this is the 3rd servicing of the axle under my ownership. I ended up using the 2-post lift as a half-lift and I just left it neutral. Even if I wanted to no chalk would stay in place as the epoxy floor is somewhat slippery.

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This is how it my axle swaps went so that I didn't throw my back out and kept the floor somewhat scratch free. I still tore it up a bit though.
1. Raise chassis, lock lift
2. Push dolley under axle
3. Raise and remove tires
4. Lower dolley
5. Swap axles and perform steps in reverse

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Also had to go to Lous to pick up some T25 drivers as the fellow who put my palate together used T25-headed screws.

Assembly was just as fast, then the tires went on... They rubbed.
Options included 1/2" of body cut, cutting the leaf-pack center bolt, or making spacer blocks.
I even went to Lous again to see if they had Alu cutting disks, which they didn't. I ended up using Metal disks.

11:00PM
About 5 hours later I had finally fabbed up the four spacer blocks. This was the 1st major delay.
Far Left is original caster wedge. At first all I was going for was a spacer, thinking "Man, this tire rubbing into chassis is !!bad news!!".

The it was just a spacer, but it is flat and lets face it, that will fuck with caster and make it incorrect... What To Do?

I pirated some more scrap Al and started working on my own caster wedges... After not too long I gave up, too much effort.
So I just busted some notches in as I didn't find drill-bits big enough and bam, offset spacers are born.
Also, pizza. Pineapple BBQ chicken, yum.

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The axle went together just fine afterwards... Time to head home.

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DAY 2

Hopped on the bike and back into work. On the way to work I saw another orange van like mine, 108" model. =D

Noon...
Now it was time for the rear axle. The anchor ends, which are bushings with a 1/2" bolt through them, were a fucking bitch.
One anchor let go after a bit of impact wrench usage... The other one?
I wailed away at it for a good 3 minutes and got quite hot too. Finally *Paclick*, something hit my visor that I wore during grinding and under the van. It was a missing chunk out of the impact bit.

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After a lot of screwing around including going to Lous for the 3rd time, I cut the bolt head off then struggled to remove the bolt.

4PM
Extraction was a complete pain... This is how I extracted the bolt. I would've needed a 5-ton press if I wanted to just push it out it was so tight.
0. Clamp to prevent the flanges from widening.
1. Insert bolt from other side
2. Tighten bearing press
3. At full tension, rotate bolt working its way forward.
4. Repeat for an hour

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4:30
Half-way there... It's only a 3" bolt too!

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Finally loosened out... Mercy that took too long.

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7:30
It was time to focus on the 12-bolt axle... Mind you guys, this was Sunday, 7:30. By tomorrow morning the place was supposed to shine like I was never there.

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9:45
By this time I've finished off the fiddy bits on the 12-bolt and it was time to transfer over minor items from the 10-bolt. Of course nothing is ever easy, so I ended up having to skip parking brake cables for the time being.
It was pretty funny though, not only did I have the backing plates backwards I also had them upside down, and the wheel cylinders were also mirrored.

In the far right there's a spring still stuck on the axle. Those U-bolts did not want to let go, even with the impact wrench on them. This time I let the bit cool though, so I didn't break anything. Still, I was impressed how tightly they held on. Not surprising though, 40 years of 125 ft-lb's of torque is just enough to semi-permanently seize them together.
Let me repeat that, an impact wrench didn't cut it...

It finally occurred to me that I can just cut the suckers, and that's exactly what happened.

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Midnight, Sunday -> Monday
Finally the axle is prepped... Finally.

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Another I hitch I found is that my Grade 8 bolts were too short! Thank god I found some Grade 5 bolts that were the right size and length, threw some washers on there and used those.

By this time I've been working 11 hours that day, and 26 hours in total.

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DAY 2.5

Between midnight and 6AM I reconnected everything, torqued all the wheels, springs, and generally buttoned everything back up. I had little will to take shots at that time as it was a matter of just lining everything back up.

Unlike the front, the rear lined up more or less perfectly which I was very happy about. At this time it was also obvious that when the manual said 8.15x15 is the bigger tire size, that is really about the biggest tire you can fit in there.

At 6AM Monday I almost got everything together. Almost...
I was unable to bleed the brakes and gave up just in time to start the clean-up process. This meant cleaning up the mess I made in the main hall area, around the lift, and put everything away. I also returned all the tools and moved the van outside with an electric car mover. It was trippy moving an old school van through the studio.

One of the guys in the shop even helped me out an we finished up everything 8:10AM.

I hopped on the bike, went to the store, picked up a pair of jeans and shirt, took a shower in the locker room and went to work at 9AM.

Between the work and having to OT I clocked in my record of 37.5 hours awake. It was a rather miserable day to work and I will never again will I do that, it's pretty terrible and the chemistry has to be just right... Like it was here.

Report

Overall this is the most amount of work I've done on any vehicle in such a short time. When the brakes are bled, she should be OK to roll, slowly and carefully. Still, there is a laundry list of fixes due to constraints...
- Straight Alu-blocks in the spring packs, makes for incorrect caster. Hopefully she's not too bad too drive.
- No parking brake
- Grade 5 bolt instead of 8's for the rear-leaf anchors.

Those can all be taken care of one at a time though, and since everything is fresh it should take a lot less time.

To be honest at this point of time the van has a much more "Grrr, nasty" look to it instead of the VW like "Old school, somewhat cute" look to them.

I think it's more balanced this way. =D

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tristessa
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Re: Viva La GMC!

Post by tristessa » Thu May 14, 2015 11:31 am

Looking good!
Remember, only YOU can prevent narcissism!

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Xelmon
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Location: LA or Portland, OR
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Re: Viva La GMC!

Post by Xelmon » Thu May 14, 2015 5:54 pm

Thank ya, took long enough to get it together.

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Amskeptic
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Re: Viva La GMC!

Post by Amskeptic » Tue May 26, 2015 12:11 pm

Xelmon wrote:Thank ya, took long enough to get it together.
I can imagine the course of that surgery, the need to think on your feet. Although the suspension looks easy and simple, I can see the areas where things can go wrong. Tracking errors, wheel base errors, caster . . .

I cudda done both VW axles in less time, fully independent transverse torsion bars and all, with perfect tracking and caster, because there is no room for adjustment.
Colin
(good job, are you happy with how it drives?)
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Xelmon
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Re: Viva La GMC!

Post by Xelmon » Thu May 28, 2015 11:07 am

Wheel base is more or less set in stone, as the rear fit in perfectly and the front... Well I had to slide the front axle to clear the wheel-arches in the front, so it's a very close fit.
The caster on the other hand is the real killer here. Difference of 4-5 degrees improved the van from "Oh god, I can't drive this" to "Eh, gotta be on my toes". Highway speeds are still out of question.

At this point of time I'm certain that I'll have to have another set of springs made up as the current springs just do not have the strength. The up-side is that that swap would be very easy.
I have some other stuff to do too, like replace the cooling fan. I'm pretty sure though that I'm not happy with where the shift-points are at now.

(In short, Not what I expected, will have to fine-tune things further.)

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Xelmon
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Re: Viva La GMC!

Post by Xelmon » Sat Aug 08, 2015 3:14 pm

It has been many months, and I think it's about time for a full update on the state of the... Whelp, union. XD

As said the immediate caster correction had to happen, which took the form of machining some Al blocks.

Took 3/4" forged aluminium and milled it to have at least some kind of caster.
A few hours passed watching this as I wanted low tool stress.

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The end result. This thickness I was still comfortable with as it really can't really flip out, and also it probably wouldn't crush.

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All is better, the van is even more or less drivable now!
Well, somewhat. Oh well, it'll work for a while...


Or so I thought, as I have said a new leaf packs were a happening thing. A week later when I wanted to go in the shop I planned to stop on the way by my fav thai place on the way to work for breakfast. When I made a turn over a bump I just heard a "BBBRRRMM"

I stopped for a sec and thought: " :silent: ... So that's what that sounds like."

Inspected at the thai place... Yep, the axle slipped back, like I figured it would. You see guys, the spacers that I made had no center pins, so under heavy breaking the axle was slipping off the leaf pack.
Yeah, that is not kosher.

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So in I went to redo the position of the axles. Everything pointed to new leaf packs, it just simply was.
Also, note that since that time I've had to re-torque the bolts 2 times due to motion and slipping. About 2 weeks ago in mid-July I did some stuff on the van, I finally measured out the leafs and that time I didn't have to re-torque.

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A bit later I had to readdress another issue. Oil leaks...
I had to do a lot of gluing, and I am not proud of it.

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Everything was fine until I got here... Notice something missing?

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Yeah, somehow the right-side bolt got loose. Great.

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At the end of the day though, she does have a nice belly.

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And finally I started work on redoing my kingpins on my spare axle.

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For the most part it was easy to take apart, until the kingpin itself.
Why won't it come apart? I even used that bolt thing below to try to hammer it out, wouldn't budge.

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Dad later pointed out that there must be some bolt to hold it in place. I actually figured the same exact thing, however didn't see a bolt!
So dad told me to take a wire brush and go to town in that area.
Lo' and behold, pin in place.

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So what am I doing now?

* I did a rough measure of the wiring harness, haven't figured out the individual gauge lengths. I am thinking of doing it all PTFE/Tefzel, however I don't know how much more it would run. Alternatively I buy a harness kit and call it a day.

* Finishing axle disassembly. Also gotta find a source for brass/bronze bushings, not comfortable with using polyurethane that specced in the manual.

* Got the call back from the leaf shop! Quoted 1 month build time.

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Xelmon
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Re: Viva La GMC!

Post by Xelmon » Thu Oct 22, 2015 9:57 am

And that last post of "quoted 1 month" was definitely an understatement for the leafs!

A week ago I finally went down to the shop to pick up my leaf springs. As said before, these are custom springs so I was anxious to install them and see how far off I was.

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Mmm, so nice looking, they even have pre-load disks on them!
It is a 6 leaf setup with safety wraps. There is just something about having that piece of mind of not having the spring break underneath you completely.

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Anyways, enough fawning, to work!

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First order of business was an approximate inspection to see how close / far I was with the measurement...
It's looking decent enough! Hopefully it'll be just as good once it goes in the van.

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First order of business was shortening the center bolt so that the... Top piece can go over it. No bigs.

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Next was to fit the bushing into the end of the leaf and... Cutting things... To size.

Oh hell... I got the wrong inner shaft size. My odd-ball suspension bolts are 9/16" diameter, and I had asked for 1/2" sleeves.
What's worse is that I couldn't just shove the bolt in there and have it ride on the urethane bushing, it would kill it. I also couldn't reuse the old bushing as apparently I have eaten through it. I do not understand how it got that bad is less than a year, but it did.

At this point I'm going to replace all of my bushing with sleeved urethane bushings. I'll go back to rubber if they are too harsh.

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Queue resources at work, I looked the metal pile and found a pipe that was 5/8" inside diameter. Eeehhhh, it's not perfect, but I can't leave the van here either, so It sufficed. I had to press in the sleeve, so I will have to press it out once I get to that stage... Eventually.

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Once I got the shaft length to where I wanted it, I cut down the bushings. Tough little buggers.

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And now for installation!!
Once I rotated in the spring and put it in the shackle end I developed this nagging feeling that the leafs are really tall compared to the previous springs. I had to use the jack to push the spring up a bit to fit the caster wedge in.

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And now that everything is secure, let's drop this van!
...
Oh man, uh... That is really tall. Like, waaaay taller than it's supposed to be.
A quick measure revealed that the roof seam the van as of installation was more or less level, 73.5"/74" front to rear. That's OK for now as the van has to roll. Long-term and especially if I put load into it, the rear will sink down a bit making for a rather unpleasant angle on the van, making for an "Eh" visual feel.

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On the plus side the van rides... Modern. It has predictable rebound, and the 6 leaf / urethane combo makes it so that the ride is firm yet not harsh.

So to get the van "perfect" I have a few choices.
1, Take the spring back and have it slightly de-arched. Like an inch or so.
2, Get slightly longer shackles for the rear.

As of now I am still torn which one I'm going to do. Also, because of the tire's size, I will start having to add scrape surfaces/pipes to ensure that the tread isn't catching on sharp edge.

Will work on stuff in a week or so, just in time for Halloween.

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Xelmon
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Re: Viva La GMC!

Post by Xelmon » Fri Mar 18, 2016 2:58 pm

Holy... I haven't update this in foooor-eeeveeeerrr...

I'll do a compendium of more recent work sometime this weekend. =)

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