Suspension bush + Crush tube issues

[Tatey]

I started putting the suspension bushes and crush tubes into my wishbones today, however I have ran into the issue of the bushes being an unbelievably tight interference fit into my bush tubes. They require a lot of force on my vice to get them to go in, however if they go in anything other than perfectly square then they deform and are pretty much ruined. I've already damaged one so far.

I've then discovered the issue of the crush tubes being a very tight fit again in the bush tubes, so tight that it is impossible to rotate the crush tubes by hand, even when they are only 1/4 of the way through.

Am i doing something wrong? I've checked the dims of the bush tubes and they seem ok. However i haven't checked the dims of the bushes or the crush tubes.

Wishbones, bushes and crush tubes were bought from SSC, so they should all be to spec.

[mark]

have you painted or powdercoated your wishbones?

mine were the same due to my powdercoat, i fettled the inside of the bush tubes until i was happy with the fit which also required me to remove the seam inside the bushtube until it was flush

dont over do it though! they need to be a snug fit.

[Enoch]

I found when I put mine together that I had to use a smear of copper grease. They will be quite tight but should go in ok as long as you keep them square. Someone told me that when the wishbones are in place they should be fairly easy to move up and down by hand but should have enough friction to stay where they are put. That's how mine are so I hope it's right.
Best,
Enoch

[Tatey]

They have been very lightly spray painted, but not on the inside of the bush tube, so i dont think that will cause the issue. I will fettle a bush tube later on, including removing the weld seam to see if i can get them to fit properly.

Should the bushes just push in by hand?

[Bonzo]

Hi simon

As it happens I have just fitted all of mine.

May I ask if your wishbones have been painted ?
one thing I noticed on mine, it did not take much of a layer of paint to make the bushes too tight .... Had to sand most of the inner sufraces right back.

They will snag & become damaged if not inserted exactly square, my own bushes needed only the lightest tap with a small plastic mallet.

Personally I would avoid the use of lubricant to the bushes but some silicone grease would be usefull when fitting the crush tubes.
These crush tubes will be too tight to turn by hand as they are meant to be a tight fit.

Once the wishbone is fitted, provided you can lift the wishbone up & down without too much resistance they should be fine once bedded in.

[David_17]

I used copper grease and a vice for mine.

Make sure there's no surface rust, weld splatter, paint etc inside the bushes first :)

[spud69]

They are supposed to be a tight fit Tatey, the bush tube is 33.7 x 2.6mm ERW with the weld left on the inside. They should be left tight so that the bones do not rotate on the bushes but on the crush tubes instead - the weld helps to hold them in place.

If you use some 120grit paper and taper the leading edge of the bushes then push them in with the vice, making sure to keep them square. Push in 1 side at a time. Put some copper slip or silicone grease on the crush tubes, then push these in with the vice. Once you've pushed them all the way through with the vice, clamp it up tight and you will be able to rotate the bone on the crush tube. Do this with all and you will be fine.

You want them tight so that there is no play in the bushes, leading to poor feedback / handling and wear. Once all the bones are fitted the leverage on the bushes will move them nice and freely.

All the Best.....AndyH

[mark]

Thinking back mine were that tight that when assembled and on the car you could push the car down on a soft damper setting and it wouldnt come back up! and it wasnt a clearance issue it was just that the tubes were so tight in the bushes, so they do sometimes need a fettle and they can be too tight.

As spud says though, you want them tight enough to have no play so it handles the way it should, which is like s#*t to a blanket!

[Talonmotorsport]

The bush tubes should be machined to 28.5mm ID either by using a boring bar or using a core drill. If the seam is still in the bush tube then they are likely to be 1-1.5 too small in which case it will be a very tight fit. If the crush tubes are inserted in the poly bushes and they push in to the bush tubes by hand together they are scrap. If you can't get the poly bushes in the bush tubes I'd send them back to SSC and have them fit the bushes.

[flyerncle]

I have just put all of the front and rear suspension together including bushes and tubes and apart from removing the sharp edge where the bush was cut I had no problems and they were supplied by Saturn,all millimeter perfect and yes they are a tight fit but work a treat.

It does pay dividends to put a tiny chamfer on the arm/tube and bush.

[spud69]

The thread below sums up previous discussions that have arose regarding bush tubes and fitting of the poly bushes:

http://www.haynes.co.uk/forums/showthread.php?t=2901&highlight=poly+weld

Any search on poly bushes on the forum will show this to have come up many times in the past and before the forum melt down there was a large discussion where the consensus was to leave the welds in place to help keep the poly bushes fixed in place.

The bushes must be held in tight so that, as the crush tubes are clamped in the brackets, the bones and poly bushes can still rotate on the crush tubes but are solid enough so that any minor vibration is dampened by the poly bushes and not transmitted through the steering and chassis, the difference with rose joints is that they don't and give a much harsher ride and handling. However, not lose enough so that they do not move within each other and cause wear, but also still transfer feel and feedback through the steering. The poly bushes can be awkward to insert but can be done with the right technique without a problem. When you buy poly bush upgrade kits for production cars they can be very difficult to insert. As a manufacture and regular driver of various Haynes cars i do speak from some experience. Infact we have just fitted a full set to a car today and they are nice and firm but the bones also rotate very smoothly on the tubes, as Mark said you should be able to move a single wishbone and it will stay where it is with no load on. They may even squeak for a bit until they are worn in.

Admittedly, we have only recently started chamfering the inside edge of the bush tube (to ease inserting the poly bushes) in the lathe so if anybody is having any trouble or worries about fitting the bushes, including yourself Tatey, please return them and we will fit them and return them free of charge no problem.

Added pictures of bones and bushes in situ with nice firm but free movement, bones stay in place under their own weight and move freely.



Regards.....Andrew