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English axle - knocking noise on cornering & acceleration?
dickie b - 10/9/15 at 08:38 AM

Dear all

I am trying to work out a strange knocking noise from my Fury's standard-spec English axle. On medium to hard acceleration a 'rotational' knocking noise is coming from (what sounds like) the rear hubs. Similarly on tighter bends the noise comes back but much louder and rather more worrying. In a straight line the noise is absent.

On inspection the propshaft / diff is completely clear of any obstruction. All handbrake cables and rods are securely fastened down. The wheelnuts / wheels / spacers / drums are all equally tight and secure with no contact with wheel weights or anything obvious.

With the drums off, the hub and shoes all appear normal with secure springs and with no 'play'. I can't see any witness marks to suggest that something is catching. This includes a lack of any contact between the drum rim and the hub backplate.

I am still generally running the car in (and the shoes are new) so is this just a symptom of a rebuilt axle that needs bedding in, or a badly adjusted handbrake / misaligned shoes that are somehow 'catching' ?

I have had the car drive around myself in circles in a carpark and the rear drums / hubs appear to be the main source of the noise. I hope it isn't a classic symptom of a knackered diff..


Sorry if this is all a bit vague but if anyone has had a similar experience and solved it ?

thanks in advance

Richard

jeffw - 10/9/15 at 08:56 AM

Does it only happen in one direction or both?

dickie b - 10/9/15 at 09:01 AM

Both- but more pronounced on one side (turning right)

r1_pete - 10/9/15 at 09:02 AM

Could be wheel or the inner diff bearings.

A simple 1st check for the diff - try turning the prop with the handbrake on, there should only be the slightest movement due to the need for a little backlash in the gears.

dickie b - 10/9/15 at 09:27 AM

Ok thanks - I have the car up on stands tonight and will give it a try.

The drive shaft bearings are both brand new units. In a straight line everything is lovely and quiet with no untoward noises.

My assumption (based on the knocking sound) was the brake shoes somehow catching on the rotating drum, causing them to 'clang' against the backplate; causing such an audible noise. An uninformed hunch though !

I will strip the whole assembly down and rebuild it (swapping shoes around from side to side just for the heck of it) and see if that solves it. A bit stumped here so help very welcome.

jeffw - 10/9/15 at 09:34 AM

Check the prop/diff flange isn't touching the tunnel panels on hard cornering...happened to me because the axle was miss-aligned.

coozer - 10/9/15 at 09:45 AM

Like Jeff said there. Hard cornering in my Striker had the diff flange touching the inside of the tunnel panel.

On inspection standing still it was miles away but I could see where it had been rubbing. Surprising how far across it moved in action!

The other thing to check is the wheel bearings are in good orders and tight bon the half shafts, they take a lot of punishment during cornering.

steve m - 10/9/15 at 10:23 AM

Ive also had the front flange of the prop touch the chassis, although there was a good 8-10 mm clearance

also brake shoes not bedded in have a slight snatch to them, could be that

steve

dickie b - 10/9/15 at 10:43 AM

Other than a quick glance I never looked too closely at the propshaft flange and the tranny tunnel sides.

Partly as there appears plenty of clearance between the two and never thought the whole assembly could move laterally to that much of a degree.

checking the bolts on the bracket that retains the half-shafts is also on the checklist

coozer - 10/9/15 at 11:22 AM

Yep, my flange looked about 2" clear each side and I was surprised to see how far it moved over in action!

beaver34 - 10/9/15 at 11:57 AM

not got a plate diff in there has it?

dickie b - 10/9/15 at 12:18 PM

Nope - nor a prop catcher

Standard 1993 fury chassis (a very early one plated with ship iron..)

jeffw - 10/9/15 at 12:59 PM

I would never have thought to follow Plate Diff with prop catcher....lol

How much does an English Axle move on a Panhard rod?

Answer....lots

dickie b - 10/9/15 at 01:32 PM

ha ! - sorry I got it in my head a diff plate ( the protective steel sumpguard thing)

sorry, no - its a standard boggo diff. Nothing fancy.


The video is an eye-opener !

JMW - 10/9/15 at 01:39 PM

quote:
Originally posted by jeffw

How much does an English Axle move on a Panhard rod?

Answer....lots



JeffW, is that about a good inch or so, judging against your wheel arch extension? i.e plus/minus half an inch from static? What bushes do you have at each end of the Panhard rod?

pre lit - 10/9/15 at 01:41 PM

check the bushes in the trailing arms you will be amazed how much an axle moves

jeffw - 10/9/15 at 05:59 PM

quote:
Originally posted by JMW
JeffW, is that about a good inch or so, judging against your wheel arch extension? i.e plus/minus half an inch from static? What bushes do you have at each end of the Panhard rod?


Something like that, certainly 15-20mm in each direction is the clearance I need in the arch. The car has adjustable Panhard with the standard Metalastic bushes that Fury/Sylva use. If you go to rose joints you would need to run a rear ARB to replace the effect the bushes has.

dickie b - 12/9/15 at 03:26 PM

Update : rear drums rebuilt, shoes readjusted and then some roadtesting with heavy braking to bed them in.. Problem now solved. Hurrah.

Thanks for all your help chaps - really grateful !