Jump to content
Click here if you are having website access problems ×

rattling good gearbox


Nigel Riches

Recommended Posts

Dear fellow 7ers, my B.G.H gearbox (sierra type9) modified ratios and internal gubbins, changes sweet, screams like a banshee chainsaw, and has a great set cogs, but when the motors idling and the cars stationary what a bloody racket, sounds like someones emptied a bucket of bolts into a cement mixer drum, any ideas, or thoughts gratefully recieved, (possibly a worn out main shaft needle roller, or input shaft front bearing perhaps) all the best Nigel.
Link to comment
Share on other sites

Nigel.

If you revert back to your old gear linkage, you won't hear it over this rattle!!!

 

Seriously though, the first motion shaft on type 9's rattle from new and seems to get worse with heat ie. after a hard thrash. Does the sound go away when you depress the clutch pedal? If so, its that FMS prob. for sure. Not a lot can be done though a call to Phil Stewart at 'Road & Race Transmissions' may elicit some info.(07736 333882)

 

PS. Phil used to work for Brian G Hill. (Brian was also Phil's teacher at school!)

Link to comment
Share on other sites

I have had an SC box from Brian that was a little noisy as you describe

and now a Semi heli one from SPC with the same noise... Nigel Mills who also

has a an SPC semi has the same.

The noise goes away on clutch depression.

Our noise is not so bad as to be annoying in any way though.

 

I assume it is what you get with CR bits... Am I wrong?

Link to comment
Share on other sites

I purchased my box from Steve Perks..5 sp pro box with straight cut gears and 2.04 first.

Box has proved bullet proof, and everything Steve said it would be.

It does however sound rattley and horrible on tickover, with noise stopping when clutch is depressed.

Must just be one of those things, small price to pay for such a good piece of kit.

 

Kenny HPC

 

 

Link to comment
Share on other sites

Thanks for all the replies, glad to know mines not the only noisy modified 'box, be it B.G.H. or S.P.C. and Blatman, I lived in Reading until '96, but now am residing in New Zealand, so probably wont be able to take up your offer of an earfull of gearbox noises, thanks anyway.

 

best regards, enjoy the British summer, Nigel.

Link to comment
Share on other sites

New Zealand ehquestion.gif Nice.........

There is a repository of sounds on the Se7ens net site somewhere, but I don't have the URL to hand. If some-one posts it, then good, otherwise I'll have a trawl through my browser and see if I can find it. There are one or two gearbox sound files, if memory serves, so it may help to have a listen.

Link to comment
Share on other sites

Nigel,

 

Not sure what sort of technical help is availbale to you in NZ... if you are in Auckland I know an excellent engineer. He (re)built the Lotus 61 I bought from him last year and is on to a new project, his work is of an exemplary standard (he runs an engineering outfit) and if he can't help, I am sure he will know a man who can... e.mail me off line if you want his details.

 

regards

 

Tricks

 

Y57 CDS "Mutley"

 

 

 

 

Link to comment
Share on other sites

When a vehicle manufacturer builds a car they usually check for resonances so that they don't coincide with any of the engines natural frequencies. So most thi8ngs on a car, if they vibrate at all must do so at high frequencies. Unfortunately there is clearly somethiing within a 7 drivetrain that does vibrate at low frequency and this is excited by the engine at tickover. I'll bet that f you increase engine rpm it goes away as the engine is now vibrating at a different frequency. However, if you do this you can't hear the rattle over the engine noise. Bummer. Another option would be to discover what rattles and make it heavier so it didn't vibrate at the same frequency. You may be able to tun the noise out a bit by adjsting your tickover slightly if it's really that bad.

 

Nigel Mills - xflow nay Zetec

Link to comment
Share on other sites

Blatman, I,ve found the sound files hear (sic) and had a listen,

sure there are some screamers, like mine but my main concern was with the noise at idle, may be indicating something not to happy on the inside, but, hey, no worries, when it all goes bang probably find out which bit was the weak link,

Regards Nigel.

P.S. We need to run real sticky tyres on the other side, in case Mr. Newtons gravity packs a sad.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...