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Is it possible to get polyurethane shackle bushings?

4K views 21 replies 6 participants last post by  MI_Ghost 
#1 ·
I am looking for polyurethane replacement bushings for the stock shackles on my van. The shackle to frame connection to be specific.

I removed the shackles, got the rubber out, bonked out the metal cups the rubber was in, and cleaned them up.

I took a lot of measurements with my calipers of the shackles and stock sleeves (there were two per shackle because there was a bushing pressed into each side of the shackle). I also have Prothane 19-608 for reference, as I had thought they would fit. It is not so. They are too small of an OD and definitely too short

Pictures are attached, but here are the important measurements -
- ID of shackle ~ 1.61"
- Length of shackle ~ 3.93"
- Width of shoulder needed - 0.25"
- OD of stock sleeves - 0.82"
- ID of stock sleeves - 0.62"
- Length of stock sleeves - 2.23" (x2 per shackle)

I have emailed many companies that produce or sell poly bushings this past week and have not gotten any helpful responses.

Does anyone know of a bushing that will work for our stock shackles?

It seems like I have a couple options -
- buy multiple sets, then shave them down so the OD fits inside the shackle, and cut the hat off another to fill the gap in the middle. Then get/make a sleeve that is long enough.
- install new metal cups like there were before, and put bushings in that will fit - still will probably have an issue with gap in the middle and sleeve length
- other???

The few other threads on this forum and the other where people are looking for bushings all seem to assume the cups are being left in, or it is for non-stock shackles. So, unhelpful.

I had no idea replacing these bushings was going to be such a pain. I am considering going back to rubber just to get it done - but I really want poly for ease of install and replacement more than anything.

Anyone have any ideas for me on where to get these? Thank you!
 

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#2 ·
Still wondering if anyone has info about this?

At the moment, it is looking like I will do this unless I hear otherwise:

- Buy 2x 4-7/16" long, 3/4" od, 0.56" id, .095" wall thickness stainless tubing from here - https://www.speedymetals.com/pc-3430-82 ... -tube.aspx
- Buy 6x these poly bushings, 43mm od, 3/4id, 0.25" shoulder thickness. I'll cut the hat off two of them and use them in the middle. https://www.offroaddesign.com/catalog/p ... egory/415/

I might have to sand down the od of the bushings just a bit to get them to fit, as 43mm is like 1.69".

Not ideal, but this is the best option I've found so far.
 
#3 ·
#4 ·
Got to your LAP and have them cross reference the part numbers for your van to any other GM vehicle. You will find many of the suspension components like bushings are widely used across the van and truck lines. Knowing what else will work can open up the sources for finding what you need. :)
Mark
 
#5 ·
What about the possibility of swapping the s10/blazer shackles?
Anybody got specs for those?

Stock Shackle Bushing specs
ACDelco Pro 45G15393
Outside Diameter: 42.7 MM
Thickness: 28.45 MM
Height: 76.2 MM
Inside Diameter: 0.560 IN
Interchange Part Number: 274-6977, 35400, 576-3393, 576-3393B, 88913006
 
#6 ·
dcsleeper said:
measure your center to center distance of your stock shackles and tell me.
What do you mean by this?

astroracer said:
Got to your LAP and have them cross reference the part numbers for your van to any other GM vehicle. You will find many of the suspension components like bushings are widely used across the van and truck lines. Knowing what else will work can open up the sources for finding what you need. :)
Mark
Good point, I should go ask Autozone

MI_Ghost said:
What about the possibility of swapping the s10/blazer shackles?
Anybody got specs for those?

Stock Shackle Bushing specs
ACDelco Pro 45G15393
Outside Diameter: 42.7 MM
I believe the upper part of the shackles on other vehicles is too narrow compared to ours, not sure though.
However, if 42.7mm is really the od of stock replacement shackle bushings, then the 43mm od for the poly bushings I found is darn close. That's nice.
 
#11 ·
SportsBoy said:
Still wondering if anyone has info about this?

At the moment, it is looking like I will do this unless I hear otherwise:

- Buy 2x 4-7/16" long, 3/4" od, 0.56" id, .095" wall thickness stainless tubing from here - https://www.speedymetals.com/pc-3430-82 ... -tube.aspx
- Buy 6x these poly bushings, 43mm od, 3/4id, 0.25" shoulder thickness. I'll cut the hat off two of them and use them in the middle. https://www.offroaddesign.com/catalog/p ... egory/415/

I might have to sand down the od of the bushings just a bit to get them to fit, as 43mm is like 1.69".

Not ideal, but this is the best option I've found so far.
Ok, as an update, I did end up donig this.

One note - the shackle bolts are m14 (14mm) - which is slightly smaller than 9/16". 9/16" bolts won't fit in these stainless sleeves.

Got the tubes in the mail and filed the ends to clean them up. Got the bushings in the mail too.
2021-02-06 17.04.16.jpg

2021-02-06 17.40.47.jpg

2021-02-06 17.54.33.jpg

2021-02-06 17.04.34.jpg

2021-02-06 20.35.10.jpg

2021-02-06 20.35.15.jpg

2021-02-06 20.35.25.jpg

No pic of it installed yet - though it is in with the leaf spring attached.

It was a snug , but good fit - I think a 4-3/8" sleeve would have worked as well and tightened up just fine. 4-7/16 was definitely just a hair less than the space.
 
#12 ·
MI_Ghost said:
Stock Shackle Bushing specs
ACDelco Pro 45G15393
Outside Diameter: 42.7 MM
Thickness: 28.45 MM
Height: 76.2 MM
Inside Diameter: 0.560 IN
Interchange Part Number: 274-6977, 35400, 576-3393, 576-3393B, 88913006
Did some back tracking on the interchange for this and got broadsided by the :chevy: C1500.
88-98 Chevy C1500 RWD also use this bushing.

The good news/bad news is that the poly version is available in the Prothane 7-1055 kit, but the leaf spring bushings are the RB172 bushings. The Astro/Safari leaf springs use the RB255 leaf spring bushings.
The only other issue I see is the 3 inch length will need a longer inner sleeve for the bolt and leave a 1 inch gap in the middle of the shackle. :shrug:

But all is not lost. :shrug:

Everyones favorite S-10 leaf spring does use the RB172 bushing.
The 7-1055 kit will work for the S-10 spring swap.
 
#14 ·
Be careful how you look at pictures. Those big bushings on the right are for the leaf spring.
The shackle bushings are the left side. Note the difference in the flange area.

I am also wondering about this as they only provide the 3" sleeve.
I keep running into conflicts between spring and bushing specs. :confused:
 
#15 ·
MI_Ghost said:
Be careful how you look at pictures. Those big bushings on the right are for the leaf spring.
The shackle bushings are the left side. Note the difference in the flange area.
Exactly, on our vans the leaf spring bushings have a smaller diameter than the shackle bushings, so if the biggest bushings there are for the springs, then that kit won't fit.

As I mentioned, I did take a pic of the shackle installed - the first 50 miles went well!

2021-02-14 12.10.23.jpg
 
#16 ·
SportsBoy said:
MI_Ghost said:
Be careful how you look at pictures. Those big bushings on the right are for the leaf spring.
The shackle bushings are the left side. Note the difference in the flange area.
Exactly, on our vans the leaf spring bushings have a smaller diameter than the shackle bushings, so if the biggest bushings there are for the springs, then that kit won't fit.
Correct. As noted in my post.
Only the shackle bushings in that kit will work for our vans.
I am still looking to see if the shackle bushings can be found ouside of a full kit.
 
#18 ·
MI_Ghost said:
SportsBoy said:
MI_Ghost said:
Be careful how you look at pictures. Those big bushings on the right are for the leaf spring.
The shackle bushings are the left side. Note the difference in the flange area.
Exactly, on our vans the leaf spring bushings have a smaller diameter than the shackle bushings, so if the biggest bushings there are for the springs, then that kit won't fit.
Correct. As noted in my post.
Only the shackle bushings in that kit will work for our vans.
I am still looking to see if the shackle bushings can be found ouside of a full kit.
Ok, I'm confused - we've got to be miscommunicating here somehow.
The leaf spring eyelets, at least on the 22-687hd's I just swapped are 1.5" diameter.
The stock van shackle are ~1.63" diameter bare with no sleeve.
If the largest bushing in that kit is for the springs, it would have a 1.5" diameter.
Meaning it would be too small for the shackle.
Am I still misunderstanding what you're getting at?
 
#20 ·
SportsBoy said:
MI_Ghost said:
Correct. As noted in my post.
Only the shackle bushings in that kit will work for our vans.
I am still looking to see if the shackle bushings can be found ouside of a full kit.
Ok, I'm confused - we've got to be miscommunicating here somehow.
The leaf spring eyelets, at least on the 22-687hd's I just swapped are 1.5" diameter.
The stock van shackle are ~1.63" diameter bare with no sleeve.
If the largest bushing in that kit is for the springs, it would have a 1.5" diameter.
Meaning it would be too small for the shackle.
Am I still misunderstanding what you're getting at?
The kit is for the 22-1221 springs for the C1500/Siverado. Which has a bigger front spring eye.
The 4 big bushings are the 2.0" RB250 bushing for the front spring eye.
The 4 middle bushings are the 1 11/16" RB172 bushing for the rear spring eye.
The 4 small bushings on the left are the shackle bushings. Note the smaller Flange/lip.
 
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