Quaife quick rack "knocking"

[309jazzpanda 41]

Evening all, hope all is well.

During lockdown I did a bit of long overdue work on the 309 (many might remember my 3.1 thread from back then) and part of this was fitting a quaife quick rack in my non PAS steering rack. 

Got it all built up and back in the car but due to being let down by 2 welders it's only now back on the road.

Anyway. I've got a but of an issue which after searching through here I can't see others having, when braking or rough terrain I'm getting a knock from the N/S of the rack, after stripping and doing some diag I've found the main rack shaft has movement within the phosphor bronze bush, confirmed today by fitting a new original plastic bush back in, noise has gone and play is no longer there.

I want to use the uprated phos/bronze bush as I've seen the plastic ones can collapse under hard use and this being a targa/road rally car it would be nice to not worry. 

 

Has anyone come across this before?. Only things I've seen are the issues people had with column bearings but never seen any issues with knocking before. 

 

When rebuilding I've got the two shims either side of the phos/bronze bush but left the rubber inserts in the original plastic bushing. I don't think this should have caused an issue as the play feels between the shaft and inner face of the phos/bronze bush itself. 

Any thoughts?.

[Ozymandis 97]

Its a common knock, power rack bodies have a bronze bush and it always starts to knock after a while, I made a bespoke bush , and that also knocked after a while. Dont worry about it, Its a fobile of these old sheds.

 

The worst thing like this is base model Girling front calipers, the clack and bang as Your setting off, stopping or reversing direction feels like the TCA bushes are knocking, thankfully every other base setup I have has Bendix, far less susceptible to it.

[Anthony 1,003]

As above - while I've no experience of the Quaife rack, the standard PAS rack has a metal bush that wears and will eventually have sufficient play to be flagged on an MOT.  I'm not sure if there's anything available now, but certainly there didn't appear to be replacements available when I looked a few years back.  Would be easy enough to have one made though, but would be disappointing if that didn't last as Jay experienced above, particularly on a new and presumably unworn/blemished rack.

 

2 hours ago, Ozymandis said:

thankfully every other base setup I have has Bendix, far less susceptible to it.

 

That's odd, as the 1.6 GTi/TD Bendix setup - which I thought was identical to base models other than the wider pad carrier - is terrible for knocking and odd pad wear.

 

No experience with the base model Girling stuff (only the 1.9 GTi Girling calipers, a quite different design but one that works and lasts very well IMO) so I can only conclude that it must be pretty dire if the Bendix stuff is an improvement!

[309jazzpanda 41]

Thanks for the replies lads, I've got some niggles to go through with it but I'll pop the bronze bush back in.

Just glad it isn't only myself getting this issue. 

[Ozymandis 97]

Yes Anthony, the Bendix knockiness was why I tried a pair of the base Girlings, they are nothing like the 1.9 Girling, and are much worse than the Bendix.

 

The slider pins are much smaller and they have  a lot less surface area of alloy and wear very quickly leading to BANG`s, KNOCK`s , they squeal like a stuck pig  ,until You  fit the third iteration of the anti-squeal shims, which tilts the piston over in the bore, to apply force to just the leading or trailing edge of the friction material, I forget which.

 

The Bendix are a delight in comparison.

[Tom Fenton 1,542]

I’ve thought about a number of times boring some Bendix alloy bodies out to accept a glacier bush on the slider bores to cure the knock. Like many of my bright ideas I’ve never actually got around to it.