Updating my 89 fiberglass springs to 97 steel springs

[tinworm]

had some stuff break on my stock 200k fiberglass suspension, and figured I would start a thread with my solution to the problem via the method of throwing lots of money at it.

I have an 89 shorty, and the driver side leaf upper clamp broke recently-



I have been waiting to swap in a 97 diff assembly, which has some differences apparently, so I went on the interwebs and bought all the related components to the 97 rear suspension to bolt on my 89.

As soon as parts arrive tomorrow ill be trying to complete this swap at a breakneck pace since I (as usual) have work needs for this van, specifically on saturday. This afternoon id like to get the entire current rear suspension out though, so if anyone has any advice or tips, please let me know!

[doyoulikeithere]

so I went on the interwebs and bought all the related components to the 97 rear suspension to bolt on my 89.

Hi There.
Could you please give more details about exactly what you got?
As near as I can figure for the axle perches, your gonna need the u clamp that goes Under, and the bracket that goes over the axle, as well as a regular U-Bolt, for each side of the axle.
Then, you need steel springs.
So, You can buy special conversion steel springs that fit in the fiberglass front hanger clamshells, or, (hopefully) Did you get the style that bolts to the OEM steel spring mounts in later year vans?
The answer to that will determine if you need the different style OEM front spring hangers, or not.
You can re-use the original shackles with thick spacers, it works fine with a 1/4 spacer at each side.

[tinworm]

I went nuts on GM parts east website. There I bought stock spring upper and lower inner clamps for a 97 astro, front spring hangars, and just to complete the set, rear shackles. Ill post part numbers as soon as this package arrives

I then went a website called ATSsprings.com and got their replacement spring kit for a 97 astro van, which included hardware.
product info- product ID- BT1195CK
http://www.autoandtrucksprings.com/prod ... 030-0.html

I received the springs 2 days after, and hopefully the rest of the OEM stuff is here tomorrow

[doyoulikeithere]

A great list !
Might wanna get a new rubber brake line and maybe even some new emergency brake cables as well whilst your in there...
The ebrake cables are a bit known for seizing up, holding your brakes.

[tinworm]

A great list !
Might wanna get a new rubber brake line and maybe even some new emergency brake cables as well whilst your in there...
The ebrake cables are a bit known for seizing up, holding your brakes.

Im toying with getting rid of the entire cable parking brake system. Ive been researching drifting stuff ( I know), and im seriously considering a hydraulic handbrake located next to the shifter. The simplicity of the concept fascinates me. No cables, no adjusters, no nothing to rust and jam apart from brake line. Instead you just run your rear wheel brake line into a master cylinder on the hand brake lever, and run it back out to the rear brakes. I pull up the handle, the hand brake master activates the rear brakes just like the pedal. Definitely something im interested in pricing out and researching further, but for now, no parking brakes are being installed. Ill do that later, I have a set of wheel chocks for insurance at the moment.

Im trying to discover if these hydraulic setups are ratchetable for actual parking brake use, or if they are only for drifting, and spring back like a regular pedal. There is also the legality issue, and the safety issue.

Either way, right now im not putting in any parking brake stuff because all I have is super rusted and I want to figure out my parking brake arrangement as far as the handle first. I may do new cables instead

[tinworm]

so here are my parts finally arrived-

This is the stuff I got from GMpartseast.

consist of-

2ct 15732089 Front Hangars
2ct 15688335 Plate ASM
2ct 15707588 Shackle A
2ct 15722955 Plate

None are painted, and GMpartseast is not about to get any awards for packing these items since they were all thrown in a falling apart box with no padding, but quality seems decent. Going to fix the one bent piece, and paint everything up




Here are my springs-

Look like nice high quality units, excellent finish on them-



couple questions-

A- what is this tab for on the 97 diff assembly? I don't have this on my 89.
B- is there some sort of rubber gasket that goes between the brackets and the spring pack?
C- I can't believe I have to drop the fuel tank to get the DS hangar out! Do the bolts fit if I go in from the outside of the van when I put them back in with the new hangar?

[tinworm]

well so far im getting my ass kicked on this project. 4 hours in, all I have is the diff down, and one fiberglass spring out. All bolts rusted, all bolts seized in the bores of the bushings and requiring major work to extract.

Fortunately I just recently took down the fuel tank, so getting into that I know the bolts will come out when I start on the driver side spring.

One mistake I made is I neglected to buy 2 bolts for the front steel spring to hangar mount, so off to fastenal tomorrow to get those. Also I need to buy new bolts for the rear shackles, I just cannot get the fiberglass spring to shackle bolts out. Even with decent heat those suckers are rusted solid. Might try a 12 ton press next, but honestly it will be easier to buy new bolts instead.

some pic-

here are the diffs-

rusty one on the left is the 97-



Luckily I managed to disconnect the solid brake line at the wheel cylinders and pry back all the tabs, and after removing the shocks, I was able to zip tie the brake line up without bending it really-



difference in the spring seats on the axle housings-

steel spring-



fiberglass spring-



97 diff is a bit more angular than the 89-




front fiberglass hangar, what a pain this turned out to be to unbolt. unfortunately this has the easier access of them all



to answer my previous post question, yes there are rubber things that I need for the brackets, these appear to be glued or corroded to the fiberglass setup, I might cut them off to use on the steel spring

[doyoulikeithere]

good progress being made. Excellent !
Aside from how you did the brake lines (which i did the same) and undoing the ebrake cables...
One thing I would have suggested is not to bother at all undoing any bolts except the ones that hold the top of the shackle to the frame, and the ones that hold the top of the front hangers to the frame. Drop the whole axle and springs out together in a lump. Coming along though nicely ! Keep the pix flowing. Oh ya, the one thing about the ebrake cables is it adjusts your brakes when you use it and your brakes dont auto adjust at all without it.
Also, put a block under your gastank so it doesnt come right down, dont diconnect the tubes wires, support it on a block and just move it to the side a bit to get those bolts in and out. then put the tank back. I used a tree round AKA the chopping block.
BTW the tab is for mounting your bump stop like in your other pic...

[tinworm]

Good call! moving over the bump stop, need a second one. somewhere in the life of this van one was lost.

Update- new suspension in, and diff back up!

I discovered two things-

1- if you disconnect the front spring hangar first, its way easier to remove the spring. If you unbolt the rear shackle, the fiberglass spring has a tendency to pop up, and it puts force on the front bolts and makes it difficult to pull the bolts out. You have to unscrew them all the way out pretty much, its annoying.

2- The gas tank does not have to come down if you cut the heads off the bolts and drive them out on the rocker side of the hangar. You just need a sawsall and some new bolts.

So here is the fiberglass spring compared to the 3 leaf replacement-



passenger side 97 front hangar installed on 89 mount-



difference between lower U clamp piece between fiberglass and steel-



To remove the driver side hangar, I removed the nuts on one side, and drove the bolts out the expose the shanks like so-



I then lopped off the heads with a sawsall. Toasted two blades, but was fairly straight forward-



I then spun the nuts back on the the threaded ends, and using a pry bar, extracted the two bolts, and the hangar dropped out, hangar was horribly rusted-




Then reinstalling, I put new bolts in from the outside, there was enough clearance. I cannot believe that GM assembled these vans this way, just a thoughtless production mistake, especially if the bolts can come from the opposite direction



Doing this again, I should have bought the rubber gaskets that went with the 97, but I made the fiberglass ones work. They were really really really well glued to the fiberglass spring, requiring them to be carefully shaved off with a knife-




I also cut out the centers to compensate for the steel springs- Not pictured I trimmed the sides too for them to fit-



and its in!



Now I need to reconnect the brakes, and need to do some wire wheeling before I place the brake line next to this rusty axle tube. Would have been better to refinish it off the van, but I was pressed for time and space, and Ill do the refinishing at a later date

[doyoulikeithere]

Very Nice.
I gotta get me one of them Sawzalls !
So, Now you have 4.56 gearing ?

[tinworm]

Very Nice.
I gotta get me one of them Sawzalls !
So, Now you have 4.56 gearing ?

sawsall is the ultimate tool for violent non precise cutting. Also makes a handy weapon, you definitely need one!

yup, 4.56 time! can't wait to get a test drive under my belt on this, see if it has the gearing result im hoping for

[mdmead]

Great job! Interesting you were able to do the front mount without dropping the tank as I'd wondered if it was possible. This will be the way I do it now! You wonder why they were put in this way on the production line... I'm sure it was easier for them at the time, and I'd I also guess it was a bone tossed to dealers to boost profit. The harder they can make it to do certain things, the more a dealer stands to make in the service department!

[doyoulikeithere]

so you said you are gonna be haulin a full load this weekend ?
You gotta get some video of the beast in action eh?
[youtube]justputithere.lol[/youtube]

[tinworm]

so you said you are gonna be haulin a full load this weekend ?
You gotta get some video of the beast in action eh?
[youtube]justputithere.lol[/youtube]

did I do this right? short run around the block, sorry about my elderly handling, just held the camera, turned out to be nearly impossible to drive holding a camera like this.

end of video is a short hill the van couldn't really climb with the 3.23, now with the 4.56 is putters right up without issue, I could have upshifted if it were longer

[youtube]http://www.youtube.com/watch?v=9pOhjKl-uwI[/youtube]