Anti-roll bar Bristol 410

[DODD]

Hello,

Can anyone offer some advice please before I start to strip down the front end of my 410.
The problem I have is to the anti-roll bar fixings. The area in question is at each end of the straight section of the roll bar, this is where the rubber bearing and bearing clamp are (indirectly) attached to the chassis. There is a small box section of steel welded between two pieces of tubular steel to which the bearing clamp is attached. The steel to the box section has corroded on both side of the car to the point it needs replacing. I don’t think this part is available off the shelf, so I intend removing the offending parts together with the associated brackets etc and have new ones made. I intend to do one side at a time.
Do any members have a detailed drawing of the part in question of even old ones which I could use as a template before striping the front of my car down. Any advice or help will be very much appreciated.
Regards
Brian

[Zorglub]

Not sure that helps a lot, but here are pictures of a very rusty 410 roll bar

[DODD]

Thanks for the photos, unfortunately the photos don’t help me. Ideally, I would like photos or a detailed drawing of the actual part or even an existing bracket that has been removed from a 410 which I could use as a template. The obvious risk of using an old bracket as a template is that it may be distorted if the car it came from had been involved in a front end shunt.
I will probably start the removal of my existing brackets sometime in November once they start spreading salt on our roads.
I will post a few photos of the offending part once it’s removed and hopefully the new replacement.

[DODD]

Zorglub,

Thanks once again for the photos you sent, if it’s not too much trouble are you able to take another photo from ground level looking up to the underside of the anti-roll bar bracket, please? This would certainly help when I reconstruct the framework.

Now that I have removed the radiator and cover plates etc. I have a very clear view of the problem.

My 410 has previously had the mounting brackets for the anti-roll bar replaced. Who ever did those works appears to have cut out the existing brackets back to good metal on the adjoining tube framework and welded in the new brackets in a “near enough” position. This position resulted in one of the fixing bolts on each side of the car being almost inaccessible. The only area of the tube framing and anti-roll bar brackets that has corroded is the actual bracket, all other adjacent steelwork is sound. The problem as to the cause of the corrosion is two fold. Firstly because the repairs were done in-situ any paint that had been applied to the bracket will have burnt off and the repainting would have not been adequate. Secondly, the brackets as installed (this may apply to other Bristols and should be checked) form a “cup” without any drain holds which will hold water and allow the brackets to corrode from the inside, as mine has done.

I have attached a few sad photos of the affected area, it can be clearly seen the areas in question and the misalignment of the tubes.

I will post a few more photos once everything is removed.

[Zorglub]

Dear Brian

I ended up using a 411 anti roll bar rather than the set-up for the 410 - mostly because BCL could not supply me with anything else at the time. You need to do a few modifications for the 411 bar to fit: mostly drilling four holes into the chassis and inserting steel rivet nuts. I originally used aluminum in 5mm, and then moved to steel inserts in 6mm. I am attaching a few pictures to illustrate this. Hope that helps

[Zorglub]

You can see circled in red the attachment points

[DODD]

Dear Zorglub,

Yes, it certainly does help, I am assuming that you have fitted the roll bar on the rear section of the lower wishbone, is that correct?
If you have fitted it to the rear of the lower wishbone, was there sufficient clearance between the engine sump and the exhaust downpipes? Were you able to reuse the existing lower wishbones?

I hadn’t thought it possible to upgrade to a later model, I will be making a few phone calls in the morning for parts availability and costs.

It’s also my intention to replace the rubber bushes on both the upper and lower wishbones during these works, working on the principle that they haven’t been done for very many years and it’s probably easier while the car is partially stripped down in this area anyway.

[DODD]

Sorry, I posted a reply before seeing your second posting which answered most of my queries.

[DODD]

Bristol 410 Anti-roll bar update

I thought I would provide an update of the works to the front suspension on my 410. As noted sometime ago, I had corrosion in the brackets supporting the ant-roll bar. Initially, I was intending just to replace the brackets and renew the rubber bushes. The existing brackets on my car showed signs of previous patch repairs, I wanted to renew them completely but was unable to obtain replacement sections or even an existing section I could use as a template prior to dismantling my car.
Zorglub made the suggestion that I could upgrade the position of the ant-roll bar to that on a 411. This made a lot of sense to me for a number of reasons.

As with all of these jobs on old cars you will make decisions to replace other parts in the process and this is precisely what I did in the hope of not revisiting any issues in the vicinity of the front suspension whilst in my ownership.
The works involved the complete strip down of the front suspension and replaced, renewed and upgrading the following:-
Coil road springs, rubber donut and large steel retaining “washers”
New coil spring pans were used as part of the upgrade to the 411
Replacement anti-roll bar and bushes etc. also from a 411
Suspension struts were sent away for checking and servicing
Upper and lower ball joints renewed
Brake calipers sent away for refurbishing, new pads, flexible brake hoses and copper brake pipes.
New outer track rods and ends
Replaced all the wishbone bushes.
Replaced all nuts, bolts and washers with new; washers were a rarity on my front suspension for some unknown reason.
The small brackets which attached the bottom of the suspension struts to the coil spring pans were cracked (a common fault I believe), replacement brackets were expensive for what they were, so new ones with a much improved design were made for a less than £10.

Doing these works, the following changes and hopefully improvements were made:-
I replaced the 4 LH outer track rod ends and track rods to the more conventional 2 LH and 2 RH outer track rod ends and track rods; this simplifies the tracking into a very small and quick job.
As mentioned above the lower strut brackets were upgraded to an improved design.
The 1/4” bsf nuts, bolts and washers to the inner brackets of the upper wishbone were replaced with 5/16” bsf bolts.
The area of the original anti-roll bar brackets was taken off and the corroded areas cut out and new section of steel plate were inserted to provide additional rigidity, as these brackets support the front bumper.

Everything in the area I was working in was taken back back to a sound surface and treated with 2 coat of primer and two top coats of black paint, plus prepare and touch up the under seal in the same areas.

The central track rod ends, wheel bearings and oil seals all appeared to be ok, so these were left untouched.

In addition to the above I had the rear brake calipers refurbished, new brake pads, one new copper brake pipe and two new disc brake shields (these were made in my workshop for a material cost of £2).

To summarise the works, having completed approximately 500miles in the last couple of weeks my car is driving very well and the handling excellent. I also had the car MOT’d with a pass and no advisories plus a few complementary comments by the examiner.

Special thanks to Zorglub for pointing me in the direction of the anti-roll bar upgrade and also to SLJ who helped me out of a few very sticky corners with their expertise.