MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - Steering wheel knock

There is a knock from behind the steering wheel when I drive over a bump. The wheel feels tight if I move it up and down so the column bush appears to be OK. I have tried pulling on the rack tie rod and that seems fine. King pins and suspension bushes are in good condition. I have a Front Line telescopic conversion. My suspicions are with the rack but does anyone have experience or advice?

Jan T
J Targosz

I'd say the most overlooked item on a midget is the bolt through the pinch clamp connecting the steering column to the rack---If you grab hold of the steering wheel and give it a good push towards the dash and pull it back towards you, there should be zero movement,
I've even struck these during scrutineering that when I've pulled on the wheel the column has come off the rack----not ideal---This is usually because someone has used a fully threaded bolt instead of a bolt with a solid shank--when you pull on the wheel with a fully threaded bolt in there, the threads can slide up the splines on the rack pinion-very very dangerous
willy
William Revit

I was recently talking to a fellow Sprite owner at a show, and they asked me why their horn kept sounding when they went round corners. I said have you got any play or end float in your steering column? They said oh no it's absolutely fine. But they assumed that a bit of steering wheel play was normal on old cars. We quickly demonstrated that the wheel could be turned a few millimetres before the rack moved, and the column had end float. On my first Sprite in 1971 I had the same problem, the splines were dangerously worn. A new column cured that.
Les Rose

Some years ago there was some sort of attempt to compile a list of safety items that should be inspected for on these cars, on a regular basis. Sort of a check list to add to a 3000 mile service. This column pinch bolt was top of the list, and is something I check regularly, if not every time I get in the car.

Off the top of my head 2 others were cracks around the base of the inner front suspension brackets, and cracks along the lower edge of the front wishbones, near to the outer fulcrum bolt. But there were many others!
GuyW

Don't rule out the FL conversion for the knock. Which version have you got? Tgey both wear and knock.
anamnesis

The column pinch bolt should be a 10.9 one with a solid shank as far as I remember. 8.8 is not enough. Torque 9-11 lbf/ft.
Lining up the column is also important. Turning the steering wheel with the wheels of the ground should feel even and light.

Flip
Flip Brühl

Very long shot (if all else has been tried) but which side has the steering rack shim been fitted? It should be on the passenger side.
Jeremy MkIII

>>>The column pinch bolt should be a 10.9 one with a solid shank as far as I remember. 8.8 is not enough<<<

Is the pinch bolt metric then?
Perhaps it is - I don't know. No reason why it shouldn't be I suppose, but I'd be a little surprised.
8.8 and 10.9 are tensile strength references for metric fasteners, basically (but not exactly) equivalent to grade 5 and grade 8 respectively on SAE bolts.
Otherwise Flip is right, either way it should be a high tensile strength fastener and a plain (blind) shank bolt, not a full threaded screw.

(I just checked and Willie described very graphically why this is so in the second post of the thread).
Greybeard

"...which side has the steering rack shim been fitted? It should be on the passenger side."

That depends on the age of the car and which rack is fitted. If it has the later, Triumph-derived rack, the shim goes on the driver's side.
Dave O'Neill 2

Greybeard
Noticed the metric bolt head ratings as well and thought I'd just add to your comment
I don't know why , but economy I guess, the high tensile bolts they're selling at my local hardware store all carry the metric hardness rating , both metric and imperial threads- I'm guessing from India.
But if I go into town to the proper bolt shop the imperial bolts have the traditional hardness markings on them and to be honest, just visually they're a better finished off bolt.
Cheers
willy
William Revit

Willie, I didn't know that. I don't recall seeing SAE bolts with numerical grading here. I'll keep an eye out for them.
I've noticed Indian made stuff being a bit eccentric before now, having bought hardware in India when I worked there.
Conventionally, for example, you would expect metric nylocks to have blue nylon rings and SAE nylocks to be white. Not in India - they seem to be mostly pink for some reason.
By the way, any idea what the green dot on the end of a length of metric studbar means?
Greybeard

Dave,

I've the earlier rack but Moss's parts diagram clearly states the later rack '72-'79, the shim mounts on the passenger side?


Jeremy MkIII

Jeremy
I believe Dave is correct.
The Leyland workshop manual for the 1275 later rack type, notes in Section J12 - packing on pinion side mounting bracket.
I guess it sort of sets the steering wheel angle towards the drivers door side of the car.

R.
richard b

I'm not doubting Dave's knowledge Richard, but Moss are advising people to mount the shim on the passenger side as the above snapshot shows.
Jeremy MkIII

The reason for the steering rack shim is that the rack was designed to match the wider cabin, with the steering wheel rather further out from the centre line of the car. Using that same rack, it has to be shimmed to turn the steering column fractionally inwards, so that the steering wheel fits the narrower Spridget cockpit.
GuyW

I have a vague notion, I may have one on both sides of my '66 Sprite. I'll have to check.
anamnesis

I have a feeling that Moss have just done a 'copy & paste' for each type of rack, without actually doing any research.
Dave O'Neill 2

I have noticed with my heritage shell that there is very little clearance at one side, around the hole in the fire wall that the column passes through. This could be the source of the knock and a shim would move the direction of the column and perhaps give more clearance.

Jan T
J Targosz

This thread was discussed between 06/10/2023 and 12/10/2023

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.