Slipping solid steering rack mount

[jamesdennison]

Spitfire 6

 

Car passed MOT today without advisories so all good, but on the way home I turned the wheel and the car carried straight on ... scary stuff.

 

Pulled over and called the MOT garage who came out to have a look (thinking they'd done something).

 

Turns out he rack was slipping left and right through the solid aluminium rack clamps I fitted a few years ago causing huge amounts of play.  I reckon this must have been caused by the tester turning the wheel lock to lock.  Far rather this happened in these circumstances than on a run.

 

When we took the mount off off it was clear than the clamp was only touching the rack in a few places rather than the full surface.  Garage recommended returning to the original spec with a bush.

 

I can't find the original mount so looking at spending cash on getting the car back to standard which will be a shame as the solid mount definitely gives more feel.

 

Other option is running some thin silicon or rubber tape between the solid mount and the rack so its not metal on metal and less likely to slip.... which is what I think I'll try.

 

Has anyone else had this issue?  Can't remember where I got the mount from, possibly club shop or David Manners.

 

James

[John Bonnett]

James I would never use these clamps. I know many do but they only rely on friction and as you've found out they can let you down with terrifying results. Take my advice and throw them away and fit standard clamps with Polybushes. The rack cannot move sideways with the standard clamps fitted. 

[Ben Caswell]

James

If your set on using the solid clamps try dressing the mating faces of the alloy blocks off so they don't butt together before clamping the rack tube. Also mount the clamps as far outboard as the chassis plate allows  then they should be tight against the plates on the rack.  

[Clive]

I have seen some solid mounts where the lower half is wide enough to engage against the rack "washers" (or whatever the term is) but cannot for the life of me remember where.

I have a ali set of mounts bout over 20 years ago that have never been an issue, and they were used on some cars from the factory. So should be OK.

However, on my current car, I needed to raise the rack as I have lowered front springs. I used 8mm steel plate and made up squares so they have the holes drilled for teh u clamp and the edge of teh steel butts up against the rack, belt and braces. It may be possible to make a spacer up that adds little/no extra height to the rack mount? even a small block of ally/steel as a tight fit and glued in place? (tiger seal/gorilla glue etc)

Or is it possible to redrill the chassis plate area to get them fitting "flush"

[Pete Lewis]

And an old nut shell to go with solid mounts is they dont retain thebrough road anti rattle plug which is held in by the rubber or poly but not the short ally clamp so it drops out of the passenger side of the rack tube

soloution is to add a hose clip to clamp the little button in place and keeps road dirt outf

 

but many are now missing ive seen the full width ones Clive mentions but no idea where they originate from but the short ones defy logic relying on grip on a film of paint

 

 

pete

[John Bonnett]

but the short ones defy logic relying on grip on a film of paint 

 

My thoughts entirely Pete and I can see absolutely no reason not to use the standard mounts. The thought of the rack moving rather than the wheels is too awful to contemplate.

[Clive]

It may be moss who supply them?

 

But honestly, my solid, narrow mounts have not given any bother in what must be over 50K now.....but they were made when there seemed to be a bit more quality about.

[JohnD]

If its moving then it ain't clamping.

And if it ain't clamping then the faces of the two parts are too high, so that when the U-bolts are tight, the pressure is on the faces, not the rack tube.

As the faces are NOT supposed to meet, it's not a precision job, and you can remove some metal from the faces with a hacksaw.

Neaten it up with a file, make sure that the two parts meet more or less level, and refit.

 

Clamped in rubber/polybush/silicone, the rack WILL move about, a bit.

In metal it will not.

 

JOhn

PS If you are worried about clamping on a "film of paint",  a strip of sandpaper is your friend,  but grease it on fitting (Yes, grease it - we're talking interference fit here.)

[jamesdennison]

If its moving then it ain't clamping.

And if it ain't clamping then the faces of the two parts are too high, so that when the U-bolts are tight, the pressure is on the faces, not the rack tube.

As the faces are NOT supposed to meet, it's not a precision job, and you can remove some metal from the faces with a hacksaw.

Neaten it up with a file, make sure that the two parts meet more or less level, and refit.

 

Clamped in rubber/polybush/silicone, the rack WILL move about, a bit.

In metal it will not.

 

JOhn

PS If you are worried about clamping on a "film of paint",  a strip of sandpaper is your friend,  but grease it on fitting (Yes, grease it - we're talking interference fit here.)

 

That makes sense Jon, the chap at the garage measured the diameter of the rack (24) and the internal diameter of the mounts (22) so the faces shouldn't meet ... but clearly they are.  He also used a punch to roughen up the inside of the clamp to give something to bite.  I'll have a good look over the weekend.  Rack isn't painted, though grease does seem counter intuitive to stop something moving!

 

If I had the old mounts to hand I'd probably fit them, but the solid rack does make a big difference to feel of the car.  That said, I will ditch them if I can't get to a position where I feel safe.

 

Cheers

 

James

[Steve C]

I have the solid mounts on my car and they have given no trouble, and I am on my second rack. The clamps were supplied by John Kipping, and are fairly wide ally blocks. I much prefer the very direct feel they give the steering. These from Canley's look very similar:

 

http://www.canleyclassics.com/suspension-steering-and-brakes/alloy-steering-rack-mount-kit

 

As John D says, it sounds like they are a bit oversize and not clamping correctly.

 

Regards

 

Steve

[jamesdennison]

I have the solid mounts on my car and they have given no trouble, and I am on my second rack. The clamps were supplied by John Kipping, and are fairly wide ally blocks. I much prefer the very direct feel they give the steering. These from Canley's look very similar:

 

http://www.canleyclassics.com/suspension-steering-and-brakes/alloy-steering-rack-mount-kit

 

As John D says, it sounds like they are a bit oversize and not clamping correctly.

 

Regards

 

Steve

Yes - that's what they look like.

Will have a good look over the weekend.

[Clive]

Found the wide type, it was Moss! (my memory can't be as bad as I thought!!!)

http://www.moss-europe.co.uk/uprated-steering-rack-mounts.html

[dogsbody47uk]

A bit late coming in to this  topic. I fitted clamps. Tried to move steering when still, rack moved. Threw them away, fitted polybushes.