Diff, Steering and front axle 408

[408Berlin]

Hello, I own my 408 since 2007 - Chassis number 7035. Now I have to do some work on the diff, the steering box and the front axle. Does anyone have any experience working on these parts on a 408? Do you have some more information about getting parts, some advice how to repair? Is Bristol Cars the only source for parts?

Thanks a lot, best regards Hans

[David Olivant]

Good afternoon Hans
, I to have a 408, Good simple information on the diff is available as a
downloadable manual on the Sunbeam Tiger website, it uses a similar
Salisbury unit There is a UK company who service and supply parts, a Google
search will find them. You may have one locally
The steering box components are, to my knowledge only available from Bristol
cars [Brian Marelli]
The axle itself suffers from corrosion round the 'top hat' turrets for the
front shock absorbers. shocks are available again through Bristol cars and
Koni in Holland. The bottom plate of the axle also corrodes from the inside
out. If removing the axle Tie the front chassis legs in position with
screwed rod and plates to stop spread! Take detailed information on the
bolts holding the axle on as some are different to clear the steering tie
rods>
I found it easier to remove the front axle, rebuild it completely then
replace.
Hope this helps and good luck
David

[geo]

Originally Posted by 408Berlin

Now I have to do some work on the diff, the steering box and the front axle. . . . Do you have some more information about getting parts, some advice how to repair? Is Bristol Cars the only source for parts?

When I worked on these some years ago on my MK.I 408, the rear axle is no problem as the Salisbury unit is similar to a number of other applications and there are specialists in various parts of the country who can source any parts you might require.

There used to be some intelligence in the BOC (based upon one of the Bristol books) that the steering box or its innards was shared with that of a P5 or P6 contemporaneous Rover, I spent ages comparing the bits I required and can confirm that it might be tantalizingly close to one of these, but none of the parts are interchangeable. I cannot now recall the manufacturer, but other than supplying information, they were not able to assist with the supply of spare parts. Bristol used to supply the 409 (unassisted) steering box as a replacement and this is what I fitted.

Other than new steering ball joints and rebuilt callipers, none of the front axle assembly required any attention during my ownership so never investigated substitute parts.

George

[MYTA21]

Adjustable shockers are available from SPAX in the UK - just be wary of
carriage charges if elsewhere. The Koni disributor recognised the part nos
but said they were obsolete, but a local ( Australian) dealer
reconditioned them.
As a " home mechanic" I found the front end relatively easy to work on, but
you need a good strong length of threaded rod to take the load of the front
springs!
There are lots of postings about the front end work- invaluable!

Mike O

[Nick Challacombe]

I can confirm that the 409 steering box will fit as my 407 was fitted with
one by
Bristol Cars quite early in its life. Always try Brian Marelli at Bristol
Cars first but
if he does not have the parts then try Martin Barns at ACCS 44(0)2072789786.
For second hand bitsBrian May on 44(0)1214303767 is very useful.
I concur with all that is said about the Salisbury Diff, parts and recon
diffs
are easily obtainable.
Happy Bristoling and good luck with the repairs.
Nick

[lansdownplace]

BCL fitted new Spax to the front of my 411 and tightened them right
up almost to max hardness with a mid/soft setting on the rear. It
transformed the handling, you can throw it around quite a lot. You
may have read in the old books that they used to test every
shockabsorber before it was fitted, rejecting loads. I was
astonished to find that they still do this, and using the same
machine which is attached to a tiny 4cly car engine. It produces a
card with a graph on it. They still reject a surprising number of
parts.

Paul

[408Berlin]

Dear all, thanks a lot your answers which are helping a lot - guess I have some work to do. Hans

[Kevin H]

Was the 408 steering box a 'Marles' ?

Brakes were Dunlop, probably very similar, if not identical to Jag E-Type and Aston DB4.

I wonder if you could convert to the larger Girling brakes.

[Nick Challacombe]

According to mt MOT man , a set of Dunlop Discs set up well are far better
than Girling.
My car on his MOT meter pulls up a far greater force than many moderd cars
he tests.
They are indentical to an early E type upon which they did not work as well.
Maybe something to do with the Lockheed master cylider and the large servo.
The 407 and 408 were indeed Marles, hense I think the factory change on mine
to a 409 box.

Nick.

[408Berlin]

If Bristol used Marles steering boxes they should be also built into other car of that period? Do you have an estimate about prices for good steering boxes - maybe as P/X for 407 - to 409 models? Concerning brakes - my 408 is converted to Girling - very good results.

[Kevin H]

Originally Posted by Nick Challacombe

According to mt MOT man , a set of Dunlop Discs set up well are far better than Girling.

I guess that's why Bristol changed to Girling brakes on the 409!

And Aston changed from Girling to Dunlop for the DB4 then back to Girling for the DB5 and DB6 and V8.

I had a DB4 with the exact same Dunlop brakes. They were adequate so long as you didn't have to use them often. When I did the 4 day Adelaide Classic rally in my DB4 I found they started to fade quite badly once they got hot.

The fact is, the Dunlop brakes were two piston calipers with a very small friction pad surface area. Whereas the Girling brakes brakes had three piston calipers and at least double the pad surface area. The Girlings were far superior brakes, which is why they were also used by Aston Martin, Jensen, Iso, Ferrari, Maserati and TVR.

[seanmcs]

We've had this conversation before. I think that Nick makes an
excellent point: setting up any brakes is a big part of it. I found
that on the 406 the Dunlop discs were just splendid. With the
booster, capable to lock up the wheels with one aboard. Even the
drums on my early 405, with Alfins, are pretty good, and Sebastian
has just added a booster, so should be even better now. I suspect
the Dunlops on the 406 Zagato will do more than you ask. We'll know
in earlt=y 2010, hopefully.

Best. Sean

ps: Interesting that 40% of the Bristol Zagato 406 models are on the
market now. Never before

[Nick Challacombe]

Try ACCS or Brian May. details as before.
BCS not likely to have second hand ones, I think they found the Marles box
unsatisfactory which is why they
retro fitted 409 boxes to the 407 and 408 when in for service etc.

[Kevin H]

Originally Posted by Nick Challacombe

...I think they found the Marles box
unsatisfactory which is why they retro fitted 409 boxes to the 407 and 408

The steering box on the 409 was also Marles box.

Originally Posted by seanmcs

We've had this conversation before. I think that Nick makes an excellent point: setting up any brakes is a big part of it.

I don't quite understand what "setting up" means, although that was not the point that I was arguing anyway.

My issue was with Nick's statement saying "a set of Dunlop Discs set up well are far better than Girling"

I don't believe that is true.