Gearstick Hiss

[Tom Brearley]

Having not driven from June 2016 - Feb 2020, I find the hiss of the gearstick much more intrusive than I used to! When refitting it I installed the correct damper (which was missing) but that doesn't seem to have made any difference.

Today (during a lovely run over the Blackdown Hills - the B3170 down to Taunton is highly recommended), I removed the gear knob when it was safe to do so and the hiss was gone.

So can anyone recommend a 1973 style knob that stays quiet? The type is as shown in the photo.

Many thanks

[Vic Butler]

The gear knob would appear to be acting as an amplifier for the hiss. I don't know if PTF tape wrapped round the gearstick thread would help.

[Allan T]

'Great minds ...', Vic. I think it would.

Tom? Did it?

[JohnH]

All MGB gearboxes have this hiss, even when new. I suspect you need to change the nylon cup that snaps onto the ball at the bottom end of the stick.
Probably gone hard and split. Easily replaced from inside the car. Hope this helps
JohnH

[Peter Cresswell]

Hi Tom,
Lots of BMC gearboxes seem to do this. The answer on early Mini Coopers was to put a length of rubber hose over the gearlever and this seemed to damp out the vibrations. The Competitions department did this as a standard part of preparing the cars for rallies.
Since the hiss stopped when you removed the gear knob, you could try a lighter one such as the ball type from the Mk2 cars up to 1972.
I'm not sure what you mean by 'replacing the damper which was missing'. Can you elaborate a little?

[Tom Brearley]

Many thanks for the suggestions. Well, I have installed a piece of garden hose over the gear stick and applied PTFE tape to the gear knob threads. Unfortunately, there is little if any difference in the ambient level of white noise. I've sourced an OE gear knob but it weighs exactly the same as the reproduction ones and is no quieter.

I'm not minded to use the ball type gear knob as I prefer the feel of the bigger BL one in the hand.

John suggested I replace the plastic cup at the base of the stick. I actually did that just last year, so unfortunately it can be ruled out.

Peter, the thing I called a damper (no doubt that's the wrong word) is assembly 70 to 73 in the attached picture.

Maybe I'll just need to get used to the hiss -- but any other suggestions would be welcome.

[Peter Cresswell]

Hi Tom,
Check the mounting of the Gear Lever Retaining Plate (Part 58 in your picture above). This should be held in place by 3 shouldered bolts (Part 67) which allow an amount of movement in the plate. This movement is controlled by double Spring Washers (Thackery Washers) Part 68. If the bolts only have normal spring washers this might be the cause of the rattle. The bolts should be done up to sit on the shouldered part of the bolt.
Pete

[Tom Brearley]

Thanks Pete. Just to be clear, it's a hiss not a rattle. It definitely has Thackery washers but are you saying the bolts should not be snugged all the way down? If so, how much compression of the washers should there be?

[Peter Cresswell]

Hi Tom
The shoulder of the bolts should pass through the retaining plate and be tightened up. The remaing length of the shoulder then gives the right compression on the Thackery Washers.
Pete

[B Faiers]

Have you tried a different bush (No.69 on diagram). This I think was originally a nylon bush. Perhaps the after market part is not the same material and the usual 'if it looks right it is right' has been applied. This could transmit the buzzing instead of dampening it.