FE-FC Holden Discussion Forum

Technical Board => General Technical => Topic started by: No Soup For You on May 10, 2018, 11:32:17 AM



Title: Gearbox has a bad whining sound in first gear
Post by: No Soup For You on May 10, 2018, 11:32:17 AM
Hi all,

I have question regarding my FC grey gearbox. Many years ago I had someone "recondition" the gearbox and since then it has a bad whining in 1st gear. THere's no vibration, just the sound that increases in pitch and volume as the speed increases. Other gears are fine. I haven't driven the car in a long time as it's been in storage but I remember the sound, it wasn't good :(

I'm going to pull it out and get it fixed but I thought I'd ask the question here just to see if anyone knows what the problem might be.

Appreciate any advise,

Thanks
Dave


Title: Re: Gearbox has a bad whining sound in first gear
Post by: Harv on May 10, 2018, 02:42:53 PM
A whining noise that increases with speed normally means your partner doesn't like the way you drive  ;D

It can be bearing noise, with first gear loading up a particular crook bearing in a way it dosen't like. Usually though bearing noise keeps going in all the gears, not just first. The shafts all keep spinning, just not necessarily under the same load.

The unique part of first gear is the first and reverse sliding gear meshing with the countershaft gear. You could have a buggered surface (from rust) or chipped tooth (from handling) on one of those.

If you get the thing in pieces and find a buggered gear, give me a yell and I'll check the spare parts department.

More info here:

http://forum.fefcholden.club/index.php?topic=22894.0

Cheers,
Harv


Title: Re: Gearbox has a bad whining sound in first gear
Post by: No Soup For You on May 10, 2018, 02:49:43 PM
Cheers Harv,

I'll let you know how I go  :)


Title: Re: Gearbox has a bad whining sound in first gear
Post by: ardiesse on May 10, 2018, 07:28:10 PM
Dave,

I'll add to what Harv just said -

Check your gearbox oil level.  They don't like running without oil, and make noises like you describe if they run dry.

I'm assuming second gear is sweet and musical?

If second is quiet, and first is noisy, the problem will be the condition of the gear teeth on the cluster gear and/or the first-reverse sliding gear where the two gears mesh.  They'll be pitted, or look like a groove has been ground along the face of the gear teeth.

Or, the internal bearing surfaces of the cluster gear will be pitted, where the needle rollers run.

These probelms don't appear overnight (except for lubrication failure), so I wonder, being a cynical bastard, if your "reconditioner" didn't take your good cluster gear and replace it with a dodgy one.

Rob


Title: Re: Gearbox has a bad whining sound in first gear
Post by: No Soup For You on May 10, 2018, 07:48:33 PM
Thanks Rob,

Yeah, the gearbox was working quite nice beforehand. It was so long ago, I can't remember why I even thought it needed a recon. Anyway, yeah I think you're right about the dodgy parts.

I'll check the oil first up but I'm guessing it's gonna need some tlc. Thanks for the help


Title: Re: Gearbox has a bad whining sound in first gear
Post by: Trevor_B on May 11, 2018, 03:56:42 PM
Dave,
When/if you replace the oil in the gearbox I recommend you use Penrite T90 which is a single grade non modified oil best suited to the grey box and the closest I could find to the original SAE30 straight mineral oil.

If you use multigrade oils or friction modified oils it can impact the way the syncro's work due to the change in friction between the syncro ring and it's mating brass surface. You can end up difficulties in changing gears.....

Cheers,
Trevor_B


Title: Re: Gearbox has a bad whining sound in first gear
Post by: No Soup For You on May 11, 2018, 04:12:09 PM
Thanks Trevor, I didn't think oil could have that much of an impact, appreciate the heads up.  :)