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replacing the metal bushes in a mk. how much of a PITA?

Posted: Thu Nov 02, 2006 9:01 am
by pongo
Ive never had to replace metal bushes before, but after driving home from tinys at no more than 50 k/hr i found these the prob.

SO basically just after any tips,etc to help me do it.
No amount of grease is going to help with this one. ;)
Cheers

Posted: Thu Nov 02, 2006 9:52 am
by pongo
Pedders only want to charge me $398 fitted, but they come with the bushes for the leafs.

Peps only want $25 each for the bushes.

Just need some help to sort out getting these puppies out.

Posted: Thu Nov 02, 2006 3:45 pm
by David_S
If the bushes have not been replaced for a while they can be a pain to get out especially the upper ones. The problem is that even if they have been greased regularly at the nipples (on the end of the pins) the grease takes the easiest path out from the hole in the centre of the pin and thus only lubricates one half of the bush.

The only way I have found to lubricate them properly is to periodically remove the pins completely and coat them with grease. If you don't do this the the pins wear as well as the bushes and they are not cheap to replace. For a quick grease without removing the pins you should lift the body of the truck with a hi-lift jack so there is no load on the springs apart from self weight and there is more chance of the grease going in both directions. The upper pins/bushes don't wear as much as the lower (spring eye) ones because they are not subject to the same twisting action as the lower ones.

To remove the bushes I would recommend that you fabricate a decent heavy drift from 3/4" rod (19mm) i.e just under the outer bush dia and have it turned down at one end to 15.5mm (i.e just under the 16mm bush ID) for a distance of at least 50mm. You need this length to ensure it seats properly. My drift is about 30cm long overall to give it a bit of mass.

Then insert the drift and belt it hard with a 4lb hammer! If it does not want to come easily you may have to use a bit of heat to free things up. Once out, keep them lubricated and keep the drift for next time.

I tend to use steel bushes in the top but have replaced the lower ones with 5/8" phosphor bronze bushes reamed out to 16mm. They are a bit cheaper than the steel ones but more importantly they wear and not the pins.

And when you replace the hangers make sure they are parallel to each other. I measure mine carefully at top and bottom with calipers and adjust with washers/shims as necessary. And when you torque the castellated nuts (53-72 ft-lbs) remember to back them off a quarter turn before inserting the split pins or your suspension will be rock solid!!

A final tip. While you have the front of the spring hanging loose slip a length of old motorcycle inner tube over the spring and after you have connected and lubricated everything pull it up over the whole shackle assembly. I have found these socks remarkably effective at keeping the assembly clean and the grease in even with frequent river crossings.

Sorry for the length of reply but hope it's of some help.

David

Posted: Fri Nov 03, 2006 12:01 pm
by Tiny
I would second the brass ones, maintaining the steel shims or they will knock, you are best to replace the pins as well, feel free to do it atr the shop if a large concrete area will be easier, you can cook me fish and chips afterwards lol :finger:

Posted: Wed Nov 08, 2006 10:00 pm
by Johan Safari
Thinking about installing sealled 37mm (16mm inner dia) bearings in the hangers. Keep the bush and the pin at 16mm and leave the bearings to do the work. Would need new machined hangers and some spacers. My only worry is if the 37mm bearings would last? :roll: