8 replies to this topic

[colinu]

Folks,

As much as I love the whine of my straight cut drop gears, it would be nice if they were just a little bit quiter (especially as I have the prospect of a 600 mile drive next month!). I read an article ages ago where a guy had his drop gears "topped"... a few thou taken off the ends of the teeth which made them a lot quieter. Has anyone here had that done? Does it reduce noise much? Any idea how many thou should be removed?


Cheers,
Colin.

[Ethel]

I've not heard of it being done to transfer gears.

It was a fix for noisy gearboxes: if the peak of one gear "bottoms out" in the trough between the peaks on the other gear it will try and push the 2 gears apart.

You'd need to grind them, gears are hard.

[Paul Wiginton]

The drop gears dont bottom out so it wouldnt help

Paul

[Cooperman]

Straight cut drop gears are really only meant for competition cars as they are just so noisy. I won't drive mine far on the road unless I have to and then I wear earplugs. I try to take it to events on my trailer. It wasn't quite so bad when it was just a SC gearbox, but after stripping the teeth on the transfer gear on a rally I decided to change to SC drops as well. It's a horrendous noise.

[Paul Wiginton]

It's a horrendous noise.

But I love it, especially with my semi SC CWP

Paul

[Ethel]

Every time this comes up I have to ask why no one has made a taper roller idler gear for helical gears

If anyone is man enough to machine the centre out of an idler I'd even volunteer to be the guinea pig.

[colinu]

Folks,

Thanks for the replies. Looks like I can get a set of standard/helical drop gears from a mate... and as he said "If the drop gear teeth are bottoming out then noise is going to be the least of your probems - horrendous wear and spectacular failure!".

Cheers,
Colin.

P.S.
I'll keep the s/c drops tucked away... "just in case"

[mini13]

they arnt that noisy,

i have no carpet or soundproofing in my car, my mrs slept quite happily on the way back from the l2b on the motorway.

[Cooperman]

I have carpets, but no soundproofing. I have SC box and drops, a 3.9 final drive, 10" wheels, twin 1.5 H4's and a twin box RC40 exhaust system. Since I suffer from tinitus, I do wear earplugs whenever possible when driving it. It's a seriously quick and successful Historic rally Car, but the noise inside is horrendous except when wearing helmets or using ear plugs.