How to hand fit poly bushings?
02-09-2014, 06:58 PM
#1
Race Director
Thread Starter
How to hand fit poly bushings?
I am going to regrease mine when the new shocks go in next week. I know some are tighter than they need to be. Is there a way to (with hand tools) loosen them up a bit, either the poly or the control arm "hole"?
Thanks, don't guess unless it's really a good one. If you have done it, advise me how.
Thanks, don't guess unless it's really a good one. If you have done it, advise me how.
02-09-2014, 09:38 PM
#2
Le Mans Master
either the poly or the control arm "hole"?
Are you wanting the bushing to be loose in the arm?
That's not how poly bushings rotate. The pin rotates inside the bushing.
02-09-2014, 11:13 PM
#3
Race Director
Thread Starter
I could be all wet, that's why I'm asking you guys for suggestions.
02-10-2014, 08:38 AM
#4
Safety Car
Member Since: Nov 2000
Location: Shenandoah Valley Virginia
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Just how tight are the cross pins running through your bushings?? When I installed mine, they were "tight" but could be rotated with a pair of pliers. I used the Pfadt bushings. The sticky white grease they send with the bushings makes everything rotate very smoothly. When the A arm is freshly greased, you can install and it will easily move up and down. I regrease the pins at the end of every season.
If you need to clearance, I would not alter the inside bore of the bushing. I would remove the bushing and grind a bit from the bore of the A arm till desired clearance is achieved. I had to grind one bore on my original install. Used a Dremel tool with a sanding drum to slightly enlarge the bore till everything fit correctly. It did not take much removal to make everything work properly.
If you need to clearance, I would not alter the inside bore of the bushing. I would remove the bushing and grind a bit from the bore of the A arm till desired clearance is achieved. I had to grind one bore on my original install. Used a Dremel tool with a sanding drum to slightly enlarge the bore till everything fit correctly. It did not take much removal to make everything work properly.
Last edited by CHJ In Virginia; 02-10-2014 at 08:41 AM.
02-10-2014, 12:11 PM
#5
Race Director
Thread Starter
Just how tight are the cross pins running through your bushings?? When I installed mine, they were "tight" but could be rotated with a pair of pliers. I used the Pfadt bushings. The sticky white grease they send with the bushings makes everything rotate very smoothly. When the A arm is freshly greased, you can install and it will easily move up and down. I regrease the pins at the end of every season.
If you need to clearance, I would not alter the inside bore of the bushing. I would remove the bushing and grind a bit from the bore of the A arm till desired clearance is achieved. I had to grind one bore on my original install. Used a Dremel tool with a sanding drum to slightly enlarge the bore till everything fit correctly. It did not take much removal to make everything work properly.
If you need to clearance, I would not alter the inside bore of the bushing. I would remove the bushing and grind a bit from the bore of the A arm till desired clearance is achieved. I had to grind one bore on my original install. Used a Dremel tool with a sanding drum to slightly enlarge the bore till everything fit correctly. It did not take much removal to make everything work properly.
02-10-2014, 09:10 PM
#6
Race Director
Thread Starter
I spoke with Pfadt, great company, will really take time with you.
There "may" be some compression of the hole that the pin rotates on if you have to force the bushing in a lot. I did.
The suggestion is to hand fit them by sanding out both the CA hole and the OD of the bushing.
If you do anything to the ID of the bushing you will take the risk of removing the micro channels that hold the grease.
It's a long process, so I will try a couple as I have time.
It make sense to me.
This is how delrin is hand fit & sphericals also as far as I know.
I'll do a video.
He also said if they seem to be binding by putting hand pressure on them (to test) they are probably fine when the whole weight of the car is moving the parts.
Also the sticky grease is meant to stay put so it is not as slippery as other greases. Could offer some resistance.
There "may" be some compression of the hole that the pin rotates on if you have to force the bushing in a lot. I did.
The suggestion is to hand fit them by sanding out both the CA hole and the OD of the bushing.
If you do anything to the ID of the bushing you will take the risk of removing the micro channels that hold the grease.
It's a long process, so I will try a couple as I have time.
It make sense to me.
This is how delrin is hand fit & sphericals also as far as I know.
I'll do a video.
He also said if they seem to be binding by putting hand pressure on them (to test) they are probably fine when the whole weight of the car is moving the parts.
Also the sticky grease is meant to stay put so it is not as slippery as other greases. Could offer some resistance.
02-11-2014, 10:38 AM
#9
Instructor
Member Since: Mar 2013
Location: Peoria Arizona
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As everyone already echo'd above, lots of lube. A rubber mallet will also help if you get a bushing or pin that is stubborn. Use it to "gently" persuade the units in place without cutting or damaging the poly.
02-12-2014, 02:01 PM
#14
And you can pick up inexpensive hones to fit on a drill to open up the control arm. Example below:
02-12-2014, 06:47 PM
#15
Race Director
Thread Starter
And you can pick up inexpensive hones to fit on a drill to open up the control arm. Example below:
Powerbuilt 648401 Brake Cylinder Hone 3 Arm 3/4-to-2.25-Inch - Amazon.com
Powerbuilt 648401 Brake Cylinder Hone 3 Arm 3/4-to-2.25-Inch - Amazon.com
02-13-2014, 09:38 AM
#16
Instructor
When I did mine I cut the ones in half that were not already 2 pieces and removed material from the center so that the two halves were barely touching inside the arm. That helped more than you'd think when it came to the fit. The pins are still tight, I use a clamp and some sockets to get them out when I re-grease them. On the car they feel firm bit I can move them by hand without binding.
02-13-2014, 12:29 PM
#17
Race Director
Thread Starter
When I did mine I cut the ones in half that were not already 2 pieces and removed material from the center so that the two halves were barely touching inside the arm. That helped more than you'd think when it came to the fit. The pins are still tight, I use a clamp and some sockets to get them out when I re-grease them. On the car they feel firm bit I can move them by hand without binding.
I got my masters at WPI
02-13-2014, 12:43 PM
#18
I just finished my poly bushing installation and I'm not sure what to think of it.. I used Prothane bushings and I had a hydraulic press together with many tools to play with.
I made zerk fittings to all arm holes. I drilled 8 small (1/8") holes in the center of the bushing radial direction. I connected those holes with a 1/16" groove around the outer diameter so that the grease will have passage to the pin.
I used the hydraulic press to fit those bushings to arms. That was done dry, without any lubricant. It wasn't easy but I made it eventually.
I greased pins and pin holes with Prothane sticky grease and they got in by hand.
When I installed those arms to my car, they were making such a noise from both sides of the bushings leaning towards frame (especially in the rear upper a-arm) that I decided to grease them before tightening the bolts. At this point it got messy: On 1/2 of the bushings grease came out from the outer diameter of the poly bushing instead of the pin surface. It seems the Prothane grease is blocking the passage to the center so efficiently that the thinner grease I used (Marine grease) finds easier way out elsewhere.
Should I be worried about this? It might happen that the bushing will rotate in the a-arm hole instead of the pin surface now that the outer diameter is partially greased.
I made zerk fittings to all arm holes. I drilled 8 small (1/8") holes in the center of the bushing radial direction. I connected those holes with a 1/16" groove around the outer diameter so that the grease will have passage to the pin.
I used the hydraulic press to fit those bushings to arms. That was done dry, without any lubricant. It wasn't easy but I made it eventually.
I greased pins and pin holes with Prothane sticky grease and they got in by hand.
When I installed those arms to my car, they were making such a noise from both sides of the bushings leaning towards frame (especially in the rear upper a-arm) that I decided to grease them before tightening the bolts. At this point it got messy: On 1/2 of the bushings grease came out from the outer diameter of the poly bushing instead of the pin surface. It seems the Prothane grease is blocking the passage to the center so efficiently that the thinner grease I used (Marine grease) finds easier way out elsewhere.
Should I be worried about this? It might happen that the bushing will rotate in the a-arm hole instead of the pin surface now that the outer diameter is partially greased.