Penton Owners Group

General Discussion => Penton Talk => Topic started by: tmc3c on November 27, 2007, 07:59:55 PM

Title: Swing Arm opinion needed
Post by: tmc3c on November 27, 2007, 07:59:55 PM
I have a 76 250 gs and I am in the process of rebuilding the swing arm. It has 2 small plugs in the top of the swing arm as to lubricate the needle bearings with transmission fluid.Has anybody ever put grease fittings in these plugs and used grease instead? I am afraid that when putting grease in I would blow the o-rings out.Any Ideas?



Thomas Carmichael


1970 125 Six Day
1976 250 Hare Scrambler
Title: Swing Arm opinion needed
Post by: Steve Minor on November 27, 2007, 08:40:42 PM
My 77 400 GS6 has them and my manual says take to out both plugs and top off with automatic transmission fluid....replace plugs.

It explains that having both plugs out while filling allows trapped air to escape.....

Steve Minor
Wilmington, NC
Title: Swing Arm opinion needed
Post by: Chakka on November 27, 2007, 09:38:11 PM
Thomas,

I have used grease fittings on 3 of my swing arms so far. McMaster Carr  has metric fittings. I haven't had any problem with the o-rings but due to the tight fit of all the components ATF might be a better option.

Chris
Title: Swing Arm opinion needed
Post by: tmc3c on November 28, 2007, 09:23:11 AM
Thanks Guys!!!



Thomas Carmichael


1970 125 Six Day
1976 250 Hare Scrambler
Title: Swing Arm opinion needed
Post by: Big Mac on November 28, 2007, 03:00:58 PM
The bane of the needle bearing setup is that it doesn't take much to cause the needles to decide to stop rolling and then just slide on the inner tube. The bearing then becomes like a bushing, and the stuck needles wear divots into the inner tube, permanently damaging the smooth surface. They'll stop rolling due to no lube, of course, but I've pulled out tubes where someone had installed with a heavy dose of grease and the grease dried up some over time, causing the same needle lockup problem.

There's very little room for grease to get in around the cage and needles. My opinion is that a medium weight oil is better and creates less chance of ruining the needle bearing action. Might be why the manual called for oil too.

Jon McLean
Lake Grove, OR
Title: Swing Arm opinion needed
Post by: tmc3c on November 28, 2007, 06:44:13 PM
Thanks Jon! I belive you are right,Now if I could just find the adjustment nuts and bearing sleeve I would be in business!!



Thomas Carmichael


1970 125 Six Day
1976 250 Hare Scrambler
Title: Swing Arm opinion needed
Post by: Chakka on November 28, 2007, 07:13:53 PM
I wonder if a better system all together would be a soft bushing like the Sachs engined bikes had. Jon is right on the money, I have yet to take apart a swing arm with needle bearings that didn't have completely destroyed needles and inner cages. Not to mention it's a bear of a project to extract the old bearings

Chris
Title: Swing Arm opinion needed
Post by: tmc3c on November 28, 2007, 08:57:55 PM
Chris, You said it!!It is a bear and it had a fight with a 50 ton press at work!!:DThus the bad caps.I don't belive these bearings have seen light since the factory! But when I get this over with it will be a yearly deal.



Thomas Carmichael


1970 125 Six Day
1976 250 Hare Scrambler
Title: Swing Arm opinion needed
Post by: rob w on December 13, 2007, 09:25:31 AM
Thomas, If you're still needing these parts, I can help. Bob
Title: Swing Arm opinion needed
Post by: john durrill on December 13, 2007, 12:16:47 PM
Thomas , rob , Jon,
 If one of you can send a inner sleeve ( bad one ) with one of the nuts ( they are a little special ) to David Haines in SA he said he would see if they could  get someone to re-pop'ed them. He was the one that was able to get the 100/125 (Isolastic SP?) bushes made up for our CMF Pentons swing arms.
 Can someone supply a damaged sleeve and at least 1 nut to give this a try?
 hope this will help
 John D.
Title: Swing Arm opinion needed
Post by: tmc3c on December 15, 2007, 01:06:47 PM
John,The old parts I had after the rebuild were trashed.Sorry.

Rob, I was able to find them from another brother here in POG but Thank You anyway.

Thomas Carmichael


1970 125 Six Day
1976 250 Hare Scrambler