Coupe Rear Tie Rod bushes

[Error404]

The machine shop suggested 316 over 304, but TBH theres not a lot in it once tooling is accounted for.

The chamfer is drawn on to match the chamfer on the rod end but radius would do it if thats easier / cheaper

One thing i'm not 100% sure of is the tolerances, especially for the interferance fit into the rod end - if the bush was 0.1mm oversize to the rod end bore, would that work?

[S2central.net]

Sorry - what is on offer here again... Losing the plot...

Is it uprated bushes for the factory rear tie rod or a new tie-rod complete with uprated bush ?

[Error404]

Poly bushes for the factory rear tie rod Paul

[4WheelDrifter]

I'm interested, but would it not be better to make a single piece bush, rather than 2 piece?

I'm thinking tighter would be better too, as I guess the original bush doesn't rotate much.
That's what I've noticed on the Superflex vs Powerlfex wishbone bushes, as much as I hate to go over that again.
The Superflex ones are much tighter, and seem to act much more like a stock bush and don't squeak. I have to put most of my weight on them to make them rotate.
The Powerflex on the other hand allow the wishbone to fall under it's weight. And they squeak like mad.

HTH

[Error404]

I was advised a cotton reel bush would be do-able, but not in 90-95 Shore as it would not like being pressed into the rod end - you could do that with a much softer grade of poly, but that kinda negates the benefits poly can offer in terms of rigidity.

The bush needs to rotate around the sleeve, thats how the joint movement is acheived. In the stock bush the rubber flexes providing the necessary movement. I think you're right though, it needs to be as tight as possible, i had thought a slight interferance fit would be ideal, but i'm not wise enough in engineering terms to suggest the level of interferance between the sleeve and bush.

AFAIK Supeflex use a different design and much softer grade of poly so possibly not a totally fair comparison to Powerflex?

[4WheelDrifter]

That's the point I was trying to make. I wondered if the stock movement of the bush would be better. I know the 'cotton reel' are hard to press in. Have you ever done a front wishbone bush on a Golf/A3/TT/WHY...?
It could be a bit of trial and error to get them to work right. How many times have Powerflex changed the design of their wishbone bushes? For example.

[Error404]

very true, but unfortunately trial and error cost a lot in tooling costs - if i had a lathe it'd be a different story

My (potnetially flawed) theory is that ideally you only want movement in one axis on the rear tie rods - up and down. Any movement in other axes is undesireable - does it matter how stiff the movement is in that axis? I would argue not.
AFAIK powerflex have changed the deisgn becasue people complained about sqeaking, which is why they introduced the knurling, to reduce the contact area between sleeve and bush and retain grease

[S2central.net]

I see no problem with bushes (like power flex) which rotate nicely in the intended direction of movement, but strongly resist movement in the undesireable direction... The bush isn't supposed to add any damping to up and down movement of wishbone for example - it is to reduce its longitudinal movements - right ?

[4WheelDrifter]

I seem to remember the rear tie rods being quite hard to move up and down when they are bolted up at the subframe end. But It could just be my extra layer of paint.
I have limited access to a lathe. Although I have a list of jobs already on the waiting list. I think it could be worth experimenting a bit before you commit to a large order.

[ciaranthemurph]

I'm in.

Madwolf_uk
Acidburn
Andy_casey?
S2central
Spink?
Anton
Goodall
Terrybullwon
k.alle
mikeraz1
s2driveruk
Graham
Greg_S
Kieron20v
Pirvu Eugen
Jas11n
ciaranthemurph

[stiglet]

Madwolf_uk
Acidburn
Andy_casey?
S2central
Spink?
Anton
Goodall
Terrybullwon
k.alle
mikeraz1
s2driveruk
Graham
Greg_S
Kieron20v
Pirvu Eugen
Jas11n
ciaranthemurph
stiglet

[Graham]

The 2 piece design will do fine, it is captive in the frame it sits in, and is easier to fit. From a machining point of view it is easier to machine a chamfer unless you already own a full set of incramented raduis cutting tools.
The rods basic job is to control and stop any forwards/backwards motion of the wishbones, but be free to move up and down with the suspension.

[Graham]

Oh and where do i send the cash to

[s2belgium]

I'm in

Madwolf_uk
Acidburn
Andy_casey?
S2central
Spink?
Anton
Goodall
Terrybullwon
k.alle
mikeraz1
s2driveruk
Graham
Greg_S
Kieron20v
Pirvu Eugen
Jas11n
ciaranthemurph
stiglet
S2belgium

[Error404]

This is on hold for the moment as I can't spare the cash to get them made and get a prototype done to test fitment etc.