Powerflex Bushings

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jonclancy
Posts: 942
Joined: Tue Nov 01, 2011 9:30 pm

Re: Powerflex Bushings

Post by jonclancy »

I have lots of bushes on my kitchen table. We do, in fact, have one full spare set of WSC (front) and our new rear bushes.

If you would like more details, please message me...

Thanks folks.

Jon
jonclancy
Posts: 942
Joined: Tue Nov 01, 2011 9:30 pm

Re: Powerflex Bushings

Post by jonclancy »

just a reminder that we do have one full set of bushes spare. That is a set of WSC fronts and our new rears.

16 bushes that will transform you into a driving God!*


Please message me through the forum ASAP.

Cheers

Jon










* Maybe...
jonclancy
Posts: 942
Joined: Tue Nov 01, 2011 9:30 pm

Re: Powerflex Bushings

Post by jonclancy »

Well, I have been having a go at this project! Removing the old metalastic bushes required the acquisition of a 12 ton hydraulic press. Using a 23mm bearing press, and a suitable socket, the metalastic bushes in one arm were removed. The first time the bush popped, I thought my socket had cracked! Once the bushes were most of the way out, I used another socket to press them into a hole through a bit of 4*2 wood.

Worked well. Despite over 6000 miles on them, but bushes didn’t look too bad. I hoped they would be shredded! :D

New bushes installed with PTFE silicone white grease using my bench vice and a couple of sockets. It was a bit fiddly to get the sleeve and the bush centred correctly.

As noted earlier in the thread, the chassis end shear arms can be bent out slightly to ease installation that end. Interestingly, but bots at that end wouldn’t just pull out. They needed to be screwed out. I suspect the holes are not perfectly aligned.

An unfitted bush with crush tube and thrust washers fits fine in the rear axle mountings. But, when the bush is pressed into the trailing arm, I suspect the slightly fatter width of the length-modified Powerflex 116 causes the poly bush to squeeze slighly. The bush will fit without the thrust washes, but not with. I am unsure at to whether I should use a strategically-placed nut and bolt inside the bracket to wind it out slightly to allow the bush to fit, or whether this will ruin the axle brackets. Advice welcome in this respect, please!

I was hoping to install the bushes now, and then, over the winter, to remove the trailing arms for a repaint. It’s a pain doing these one at a time, but removing all of the trailing arms causes the diff to move around, even with the shockers still attached. Removing the whole axle assemble over the Winter is on my slop chit, as I want to fit new, sealed bearings, and check to see if I need a speedy sleeve installing on one side. Bit of diff oil leaking into the drum.

What was meant to be a quick job has turned out to take much longer, and has thrown up a couple of problems to solve, but the first arm off sets the learning curve. Now I have identified which sockets bearing press to use, the process should be a lot simpler. I have new bolts from WF, and new washers and nylocs. BTW, order the bolts over the phone. The postage charges the system calclulates are excessive!! £6 vs £19!

Back to it later this morning. Yes, it is 0310. I am jet-lagged! :roll: :shock: :P
jonclancy
Posts: 942
Joined: Tue Nov 01, 2011 9:30 pm

Re: Powerflex Bushings

Post by jonclancy »

Hi All,

I have worked out what’s up here.

The bushes are indeed the correct size. In “free-air”. 38mm. Once the bushes are pressed into the trailing arm housing, they are squeezed a little. Remember that they are a slightly wider diameter than the metalastics. They are slightly fatter due to the fact we used the -99 poly to safe huge re-tooling costs. The effect of this squeeze is to lenghen the poly by around a mm. This makes one of the thrust washers catch the axle mount bracket. Yes, you could make it fit with just one thrust washer. I am going to try an alternative approach. Press the bush and crush tube flat to the trailing arm housing, then scalpel-trim the excess poly. Then replace the thrus washer either side, squeeze in the vice to recentre the crush tube. Simply place with ease into position and bolt up.

Will report back....
jonclancy
Posts: 942
Joined: Tue Nov 01, 2011 9:30 pm

Re: Powerflex Bushings

Post by jonclancy »

Update:

Penny has dropped! And it’s really a very simple fix...

The short answer is that the plastic thrust washers are too thick, given the width of the trailing arm tube. Around a mm excess. Solution is to get hold of some M16 repair washers. The 7/16 washers I have here are half the thickness of the plastic washers. With thinner thrust washers, the arm should fit the axle mounting without needing to prise it open. The shear plate on the chassis end is fine, and you could stick with the plastic washer if you wished.

I’ll pick up some washers from my local fastener supplier tomorrow morning, and report back. This should have been a relatively easy job. I go through this pain so you don’t have to! :D

(I still think that less Anglo-Saxon was deployed then comparing this job to Splat’s weekly shirt ironing pile! :D )
jonclancy
Posts: 942
Joined: Tue Nov 01, 2011 9:30 pm

Re: Powerflex Bushings

Post by jonclancy »

Form B or Form D washers are 2mm thick in M16 size. I will check the plastic thrust washers with my micrometer.

Also, the “squeeze” that elongates the bushes actually works in our favour here, as the bush increases length to around the length of the trailing arm tube. Another option might be to drill out some M12 washers to 16mm. They would sit on the face of the bush, not bind the trailing arm, and are 1.6mm thick in Form B.

https://www.fastenright.com/general-fix ... -c-d/wsr29

Edit: the plastic thrust washers are 2mm thick. Drat. Maybe widening the bracket by a couple of mm is the easiest option now...

Edit: will try to source some M16 shim washers tomorrow. I have found M16x22mmx0.5mm online. With a diameter of 30mm, like the plastic originals, they could be quite useful to provide thrust, but still keep the overall with of the washers and polybush less than the crust tube to stop the arm from binding...
jonclancy
Posts: 942
Joined: Tue Nov 01, 2011 9:30 pm

Re: Powerflex Bushings

Post by jonclancy »

Picked up some stainless washers from my local supplier. They are marginally slimmer than the plastic ones. Could be the solution. A belt sander, or drill to rotate on a flat plate could lap them a little thinner. I will try them later... Could ge the solution. :D
jonclancy
Posts: 942
Joined: Tue Nov 01, 2011 9:30 pm

Re: Powerflex Bushings

Post by jonclancy »

Another option I considered was to split the poly bush but taking a kerf out of the centre. Packed with silicome PTFE grease, it should, in theory, provide a small lubricant reservoir as well as fitting the trailing arm housing perfectly.

Still hunting for 1mm washers. If I could get the blanks, I would punch out my own...
jonclancy
Posts: 942
Joined: Tue Nov 01, 2011 9:30 pm

Re: Powerflex Bushings

Post by jonclancy »

I have a selection of Q-Max metal punches at home. I used these in the past for putting holes in cases for audio gear I had built. The qma16m punch uses an 8mm pilot. So... M8 x 30 penny washers are on the way. Theys are cheap, and slim at 1.6mm. I just couldn’t find 1mm washers in the correct size anywhere. Lapping to 1mm (or as required) should be easy enough. I will probably just set up my pillar drill with a stainless cutter. The punch would work well on mild steel washers, but I would rather use A2/304 stainless to keep them looking nicer for longer.

Will update after the weekend when I have all the gear in my mitts! :D
Westfield 129
Posts: 867
Joined: Sat Jun 04, 2011 4:20 am

Re: Powerflex Bushings

Post by Westfield 129 »

Don't notch the bushings inside. They will split.

Your washers should be the same diameter as the bushing so that the thrust washers center the bushing in the arm, and should not contact the arm itself. The best setup would be a stepped bushing but that would be a bit difficult to machine on material that thin.
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