jpbritten42

I think Ian may well be referring to a potential cause, particularly on metric chassis like mine. I spoke with Phil at R&R this afternoon and i'm inclined to agree with him that the metric chassis is the consistent factor in this issue although how I would resolve it if metal washers are necessary for alignment / mounting is beyond me. I'll have a look underneath my car at the metalastic bushes in the chassis tonight. As for sound deadening, it would appear so far that I'm the only person whose considering this. Which doesn't bode well... Very grateful for all the input so far though, I'll do some more research and then experiment.. (with sound deadening!) Paul

I must be honest and acknowledge that my assumption is that the crown wheel & pinion is the route cause of the whine but it could well be other factors like shims or alignment. I'm fairly confident that the diff is aligned correctly though but maybe the shims necessary to align it are a factor. I think the reason for me exploring other solutions is that people have chased the cause of the whining noise and given up. Changing to a different brand of diff oil may be a temporary solution but as it's only done a few hundred miles since the replacement R&R diff was filled and fitted by a well-respected Caterham specialist I'm not inclined to change it. For what it's worth it's just the whine at a constant speed I'm looking to address in some way, I don't actually mind the clonks at low speed and backlash when decelerating. If I can just reduce the whine my car would be perfect (for me!).

Thanks for the feedback DJ. Your experience follows along the same lines as mine. Intercom headsets do appeal, may try that after the sound deadening idea

Sorry SMT25, was typing when you posted your last response! I don't think complaining will make much difference, they'll want to have it back to check it (which I understand) but that means another £400 for someone to take it out and put it back in again (properly), and they'll probably find nothing wrong. It's got to the point where I'm considering other options, all be it ones that might not have been tried before...!

Not sure what oil, but it was newly built diff was recently fitted by a well respected Caterham specialist who I'm fairly confident put the appropriate oil in. Will ask them what oil they put in though. I have used ear plugs which do help, but I was wondering wether anyone had tried some of the lightweight sound deadening material that you can get these days.

They're the ones who built the diff....!

Evening all This may be an old topic but I'm trying to come of with a way of reducing the volume of the diff whine at cruising speeds of 50-60mph. I appreciate the old 'TATHS' responses when it comes to the last Ford diffs so I wondered if anyone had tried tackling the issue by fitting sound deadening to the boot area and / or the panel that sits behind the seats. Has anyone tried it and if so what material / product did you use for the material..? Any advice or feedback would be greatly appreciated!

Provisionally sold to Mankee pending collection & payment

New price

Complete assembly (casing and diff) Standard Ford open differential 3.92 ratio Originally fitted to a 2008 Sigma engined Roadsport from new which had covered 12,000 miles. No damage or mechanical faults, casing is in excellent condition. Exhibited the usual noise / whine for diffs of this era but by no means the worst! Suitable for immediate use, upgrade to LSD spec, or as a spare assembly. Diff located in Milton Keynes, could also bring to the Silverstone Classic next weekend if required. Pictures available, not sure how to upload them on here so pm me and I'll email you a selection. SOLD