Lomax 223 rear wheel problems.

[cmwbob]

Ha ha AlanM,
i did realise it was not a criticism and my response did come with a very large tongue wedged into my cheek.

Rocketman
Yes, as you anticipate both cut portion stubs of the orginal arm should penetrate into the extension tube, and not be just butt welded.

[AlanM]

Hello Bob

Thanks for the reply.

Hello Rocketman

Just a thought. ''It would be much easier to obtain a standard replacement arm and have it modified from scratch rather than to repair a damaged item.''

Alan

[Rocketman1955]

Further to my post 10-April-22, my replacement arm (without any reinforcing) has done about 1000 without deformation at the weld behind the backplate.
However, to try and reduce the risk of deformation I have fitted 3 webs spaced around the backplate. (avoiding brake adjusters and brake line) The 5mm thick webs are welded to the extension piece and then over the weld and onto the short stub behind the backplate.
For good measure the welds then run up the backplate, but I doubt that will contribute much extra strength. ( The original arm that failed had a similar single vertical web underneath and only failed in tracking, but was ok in camber )

Meanwhile I have measured the load on each wheel.
With 2 adults the load on the rear wheel was too close to the accepted unreinforced load, so I have added top and bottom webs to the arm to increase capacity.
Hopefully the arm should be bullet proof now, but then potholes are getting worse…….!

[SafetyPete]

Hi all

My new 'project' 223 has this same issue, but the arm is corroded - is there a detailed specification or design drawing for the required modifications as I think my most likely course is to obtain a standard 2cv arm and have it modified.

Unless someone has an unused/unwanted arm?

Thanks

Pete

[Rocketman1955]

The only details I have seen is for reinforcing the arm/extension from this thread, in a post post dated April 2022 advising what size webs to add.
As previously mentioned & observed in this thread, the main reported issue appears to be at the weld close behind the backplate, not the arm.
My fix to add 3 off 5mm triangular webs bridging the weld appears to be good so far, despite hitting some exciting potholes while carrying a passenger.

There is only a very short stub on the backplate to weld onto the extension.
For the webs to be effective they must be a close fit across the weld and onto the extension piece and the stub with similarly accurate welding on both sides.

If you are starting from scratch maybe there is a better way to engineer the extension required to centralise the wheel in the chassis?
You could add more webs like mine, but beware of access required to fit the brake line, adjust the rear brake, the slave cylinder fixings and bleed point.

[rocketronbish]

Message for KARL MULCAHY ... Hi Karl.. I am trying to help a local member replace a bent rear arm and have been try to locate the jig or someone with a jig who can help ...but without success !! You say that you have spoken to "The Lomax man" and would be very grateful if you could let me know who and a contact , if possible . Bpb B has sent me a picture of a rough jig but as far as I can establish the original jig now resides in Spain ?
If you could point us in the right direction it would be appreciated by us both. Regards Ron Bishop 01225 ( Bath ) 335777

[rocketronbish]

Hi Safety Pete .... good luck in trying to locate an already modified arm ..../despite my best efforts i've had no luck in trying to find one /or someone who can do the necessary for a local Club member..
You say get another arm but......unfortunately you will need BOTH arms to do a proper job . Mine was done more than 30 years ago and luckily it has proved the test of time .
I have a drawing ( hopefully attached ) which I have produced after crawling under my car and taking measurements .... whilst I do not suggest this is every ones solution it might be of some help . You are welcome to call me anytime .....Ron Bishop 01225 335777 .
Sorry Pete ...tried ... but told File too large to send !! Do you have an Email Address ?

[rocketronbish]

Hi Safety Pete .... my grandson came in this afternoon and has reduced the size so , hopefully , can now attach my drawing.
Happy to chat if needed Ron Bishop 01225335777

IMG_0305.JPG (527.56 KiB) Viewed 30394 times

[Karl Mulcahy]

It was the current owner of the Lomax project. I supplied him with a NOS van arm. Job was well done other than he welded the brake backing plate on upside down. Wasn’t a problem though.