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Index > Suspension > Thread: Greasable shackles and spring pins?
Thread: Greasable shackles and spring pins?
Brad


Rotorhead
Posts: 1672
posted February 20, 2007 12:29 PM

Greasable shackles and spring pins?

Anyone know of greasable shackles and spring pins for our application? So we can grease the leaf spring bushings.

Bushing I.D. is 17mm, can't find any greasable bolts in that size...... Might have to buy some bolts and have them gun drilled and a zerk threaded in. Spring pin is another story.

I had the upper bushing, passenger side, sieze up. Would not swing at all. 3.5 year old bushing that got lithium greased when installed. Will not come off the shackle now either. Required mallet + 2x4 + a sore sholder to get the shackel out of the leaf.

The drivers side upper bushing would swing but it took a lotta effort to remove it from the shackle.
____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge

       
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repu510


Hauling
Posts: 141
posted March 23, 2007 09:08 PM

greaseable shackles

I've wondered about that too. I just replaced the leaf bushings on my REPU this past week and wondered how they stay lubed. I greased them when reinstalling them, so they should be ok for now. Also replaced the rear shocks and it almost feels like a new truck! I'll be tackling the front lower ball joints and brakes this weekend.

       
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Brad


Rotorhead
Posts: 1672
posted February 11, 2008 02:16 PM



I've been researching this. The official word is Rubber in a rubber bushing does not need greasing. Because the bushing is soft and TWISTS during suspension movement. The problem is, the bolt that goes thru a shackle and spring pin bushing can go dry, rust, and seize onto the inner sleave of said bushing. Then the whole thing BINDS UP and you've increased the install rate of the spring. The shackle bushing will groan and moan and once the bush reaches max twist it will then bind, and snap - unwind real quick.

As you can imagine, handles terrible. I've spent upwards of an hour hammering a shackle out.

Now, onto your question. The REPU uses a very odd sized 16.97mm OD shackle pin. Let's call that 17mm. Well, on paper there is no such thing as a 17mm bolt. Just not made and my local bolt man at the hardware said so.

I cannot find ANY 17mm bolts ANYWHERE and the closest standard size is 11/16 which is an odd bird and 18 thousandths larger than a 17mm.

So offhand I don't see an easy solution to this and here I am with a bag of poly leaf bushings ready to go. Poly MUST be lubed since poly does not twist. The shackle bolt, and front spring eye bolt must be able to twist inside the poly bushing.

What I really want to do is have some greaseable spring pins and shackles made but w/o the right sized bolt that is not good. Other option is to have the inner sleeve in these poly bushings remade with a standard sized I.D.


       
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sparky


Redlining
Posts: 299
posted February 11, 2008 07:01 PM

Brad... Here is a possibility. May be a dumb one...but what the heck. Could you drill and tap a hole on the metal sleeves the bushings are pressed into. Install a modified Zurc fitting that extends through to the ID of the poly bushing. The zurc will keep the OD of the bushing from spinning and grease can be delivered down to the shackle pin.
What do you think???

       
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Brad


Rotorhead
Posts: 1672
posted February 13, 2008 03:51 PM

quote:
Brad... Here is a possibility. May be a dumb one...but what the heck. Could you drill and tap a hole on the metal sleeves the bushings are pressed into. Install a modified Zurc fitting that extends through to the ID of the poly bushing. The zurc will keep the OD of the bushing from spinning and grease can be delivered down to the shackle pin.
What do you think???


I've seen aluminum outer shell leaf bushings with a delrin inner shell that do this. Zerk is in the aluminum outer shell, on the very edge where the bushing OD is much thicker. I'm concernet the urethane will shear or crumble if drilled thru axially. Plus urethane will compress and crush slightly at the outer edges during installation.

These urethane bushings I have, have an inner sleeve the bolt goes thru but no outer sleeve. The spring eye itself or the frame mounted tube for rear frame bushing are the outer sleeves effectively. I can't drill into the spring eyes.


____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge

       
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sparky


Redlining
Posts: 299
posted February 13, 2008 07:02 PM

Instead of drilling...How about melting the urathane with a heated drill bit of proper diameter. Then you could drill out the inner metal tube the bushing is bonded to. I don't think drilling a 3/16" hole on the spring eye will damage it. Anyway....Just an idea.
If I had the same issue with finding a way to grease the shackles I'd probably drill a 1/16" diameter hole from the threaded side of the shackle 2" into pin/bolt. Drill another hole through the pin/bolt to get the grease to the inner tube of the poly bushing. Let me know how you end figuring it out.

       
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Brad


Rotorhead
Posts: 1672
posted February 13, 2008 10:39 PM
Edited By: Brad on 13 Feb 2008 22:48



Thing is, the metal tube is supposed to twist and rotate. Blue urethane bushing stays put.

       
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bwaits


Hauling
Posts: 119
posted February 14, 2008 05:36 AM

Brad, is the ID of the metal sleeve or the ID of the urethane bush 17mm?

Can you ream out the metal sleeve for 18MM or will the wall get to thin?

You may also be able to take a bit out of the urethane bushes and then have a metal sleeve made larger OD and 18mm ID. Urethane cane be turned with a sharp pointed lathe tool. You can also put the bushings in the freezer to "harden" the bush enough to turn.

-billy
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Brad


Rotorhead
Posts: 1672
posted February 14, 2008 03:05 PM
Edited By: Brad on 14 Feb 2008 15:34

Sleeve ID 17.01mm
Sleeve OD 22.16mm

Bushing ID 22.06mm
Bushing OD 32.20mm

Once sleeve is inserted into bushing then Bushing OD 32.36mm.

Sleeve ID has a very thin spiral surface, like a coarse wire wheel was buzzed thru it. To hold grease. Bushing ID is completely smooth.


       
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bwaits


Hauling
Posts: 119
posted February 15, 2008 07:13 AM

If you reamed out the ID of the sleeve you would take it from .101 wall thickness to .081 wall thickness.

Since the forces will be pushing into urethane bushings I do not see the sleeve failing from .081 wall thickness.

Maybe have them reamed out and then ask the machinist to put in a boring tool. Set the machine for a course thread pitch and "internally thread" it .020 or so deep. This will give you the lube grooves after the ream.

-billy


       
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