Bit of a warning

[dbazdavies]

Just to point out that to all the guys with spacers between the rear spring and the rear axle that you check the condition of the spacer - noticed that mine looked like they were covered in fluff but it is actually the spacer that is turning to powder !!! So check yours !!!

[stevejgreen]

Re: Bit of a warning

I listed all of the Superflex suspension components here or there
Are you talking about the Saddle Pads?
If so, the chances are that when you try to undo the UBolts, one will shear, so have a look here or there

[dbazdavies]

Re: Bit of a warning

No the thick alloy spacer block !!

[stevejgreen]

Re: Bit of a warning

The tapered alloy spacer was of Marlin supply. The 'fluff' you describe must be aluminium oxide. Steel and aluminium are not best of friends.
Further analysis is necessary.

[dbazdavies]

Re: Bit of a warning

I am talking about the 2 inch thick spacer which so far has gone to powder up to the axle U clamps front and rear !!..

[HairyDave]

Re: Bit of a warning

As a Land-Rover owner dissimilar metal corrosion is not unknown, but I wonder if there may be some stray electrical currents causing severe corrosion or maybe loads of road salt. My '91 hardly used ally blocks are a little white but nothing more.

[greyV8pete]

Re: Bit of a warning

Just to point out that to all the guys with spacers between the rear spring and the rear axle that you check the condition of the spacer - noticed that mine looked like they were covered in fluff but it is actually the spacer that is turning to powder !!! So check yours !!!

The only time I have seen aluminium produce "fluff" and turn to powder is if it is contaminated with mercury, which eats it away big time; Which is why the old type mercury filled thermometers are a no no in aircraft . Peter.

[Alan c]

Re: Bit of a warning

Its how far apart the metals are in the nobility table (electrical difference) worse is you have big volume of high nobility and small lesser noble . That's why you have zinc sacrificial anodes on ships. Or the reverse copper nails in steel sheet.

The big steel axle with small aluminium block - not good - table below

[stevejgreen]

Re: Bit of a warning

What I don't have are dimensions of the block, never thought to measure it when I had one in my hand.
There is a short tube around 1" diameter that locates it on the axle pad. Much larger than the similar pin found on spacers for Ford axles, that are not tapered.

[stevejgreen]

Re: Bit of a warning

On a hunt through my pictures I found these from when I installed my Dolomite Sprint axle. This required welding a new pair of leaf spring pads from a Ford to the Sprint axle.

This first pic is the Marlin lowering block alongside the Ford axle spring pad. they are fundamentally the same size but you can see clearly the 1" locating boss on the Marlin part and the much smaller pin diameter that the Ford uses.

Wedge Block 1.jpg

This pic shows the original angle of the block.

Wedge Block 2.jpg

These pics were from a car that had been on the road for about 20 years. They had been Hammerite painted, maybe that preserved them.

On a discussion point: Can anyone explain why the tapered block. On my Roadster for the vast majority of the time when being driven, my propshaft is horizontal but constantly on the move with the axle mostly towards the top end of its travel. So what does the taper achieve?

[dogoncrazy]

Re: Bit of a warning

Back in my RAF days we used a Pigmented jointing compound between panels [we called it parrot sh--] to prevent corrosion. presumably a hylomar or similar jointing compound would help.
My SWB roadster had the tapered blocks which I understand where required to align the drivetrain, not sure if they were required on the LWB version?

[dbazdavies]

Re: Bit of a warning

" On a discussion point: Can anyone explain why the tapered block. On my Roadster for the vast majority of the time when being driven, my propshaft is horizontal but constantly on the move with the axle mostly towards the top end of its travel. So what does the taper achieve? "

the tapered wedge was a BL modification to stop the rear axle being noisy due to excessive load being applied to the diff pinion nose bearing.. If I remember correctly we were given 30 mins to fit the wedges and spent nothing for a week but fitting them - in the end we got it down to under 10 mins with the help of air guns and an apprentice working the ramp !!!

[stevejgreen]

Re: Bit of a warning

" On a discussion point: Can anyone explain why the tapered block. On my Roadster for the vast majority of the time when being driven, my propshaft is horizontal but constantly on the move with the axle mostly towards the top end of its travel. So what does the taper achieve? "

the tapered wedge was a BL modification to stop the rear axle being noisy due to excessive load being applied to the diff pinion nose bearing.. If I remember correctly we were given 30 mins to fit the wedges and spent nothing for a week but fitting them - in the end we got it down to under 10 mins with the help of air guns and an apprentice working the ramp !!!

Do you have a date on that please?
Parts books suggest it must be post 1977.
Up until that date the Marina axles had horizontal (to the pinion axis) leaf spring pads. But later axles were apparently built with the leaf spring pads angled at 3 Deg, but I can find no definitive info?

[dbazdavies]

Re: Bit of a warning

would be post 1976 Steve and up too 1979 when I left to work on Jaguars !! It was all due to axle noise... Does the club not have a list of BL issued call backs/modifications..???

[dcunn]

Re: Bit of a warning

Not that I know of