davidm Posted October 7, 2019 Report Share Posted October 7, 2019 Hi All, After many years bumping along on dubious road surfaces, I now have the small issue of a cracked near side trailing arm. Hopefully repairable. Has anyone in the UK any experience of successfully welding these 40+ year old aluminium castings and if so who did the work? Any tips and recommendations gratefully received. Many Thanks. Mark. Quote Link to post Share on other sites
RogerH Posted October 7, 2019 Report Share Posted October 7, 2019 (edited) Hi Mark they can be weld repaired. Most decent garages would probably be able to do it. Any home DIY'er with a mig welder may also be able to do it. When you get it done consider welding fillets immediately above it to support that rear cup Roger Edited October 7, 2019 by RogerH Quote Link to post Share on other sites
Z320 Posted October 7, 2019 Report Share Posted October 7, 2019 Hi, I've been told this happens when the shock absorbers are too long, or the bracket for the telescopic shock absorbers is too low. I would check this, also on the left side trailing arm. Ciao, Marco Quote Link to post Share on other sites
BlueTR3A-5EKT Posted October 7, 2019 Report Share Posted October 7, 2019 3 minutes ago, Z320 said: Hi, I've been told this happens when the shock absorbers are too long, or the bracket for the telescopic shock absorbers is too low. I would check this, also on the left side trailing arm. Ciao, Marco +1 Quote Link to post Share on other sites
Ian Vincent Posted October 7, 2019 Report Share Posted October 7, 2019 If you are going to weld it up yourself, make sure you prep the area first by grinding out a decent groove along the line of the crack so that you can get full penetration. Rgds Ian Quote Link to post Share on other sites
davidm Posted October 7, 2019 Author Report Share Posted October 7, 2019 Hi Roger, Thanks for the tip, beyond my means for welding and nervous to leave such a vital part to a local garage, but will approach some of the TR support trades. Marco, Thanks for the info. As far as I can see LHS ok, will check relevant lengths/position of components but I suspect, as seen in photo, a small casting defect (indent) near crack hasn’t help the situation. Mark. Quote Link to post Share on other sites
Z320 Posted October 7, 2019 Report Share Posted October 7, 2019 Hi Marc, are you trailing arms powder coated? They look like this. Ciao, Marco Quote Link to post Share on other sites
Waldi Posted October 7, 2019 Report Share Posted October 7, 2019 Marc, I would source it out to someone who is familiar with Al repairwelding. Correct polarity, shielding gas, weld filler and weld preparation are important. Waldi Quote Link to post Share on other sites
ChrisR-4A Posted October 7, 2019 Report Share Posted October 7, 2019 1 hour ago, BlueTR3A-5EKT said: +1 Just to expand the above,. the shock absorber should have sufficient movement so when the swinging arm goes up it hits the bump stop before the shock bottoms out. If bought with a conversion kit the shocks should be ok but if replaced later may not be.there should be minimal stress on the part of the arm where the shock is, the spring pan should take most of the load. Chris Quote Link to post Share on other sites
davidm Posted October 7, 2019 Author Report Share Posted October 7, 2019 As always great information and help, Thanks everyone. Spax conversion part of a kit supplied by Clive Manvers, 14 years and 50,000 miles ago ! BUT, bump stops missing and I suspect the main culprit from this problem now, thanks Chris. Waldi, agreed and I was slightly hoping someone has gone before me and could recommend someone! Marco - yes powder coated. Mark. Quote Link to post Share on other sites
Z320 Posted October 7, 2019 Report Share Posted October 7, 2019 (edited) The powder can cover damages so you possibly can not see them. My joice was to let them as they left the factory. And the powder is very badly to remove before welding. Since I had to weld something powder coated for a friend I'm give nothing away to powder coat anymore. Edited October 7, 2019 by Z320 Quote Link to post Share on other sites
Andy Moltu Posted October 8, 2019 Report Share Posted October 8, 2019 I would advise not to sand or shot blast them before welding as the residue makes welding more difficult. (Grind or vapour clean) Mig welding aluminium can be very tricky - TIG in the hands of a skilled welder is probably a better option and will give a satisfactory repair. Replace your bump stops and check (by jacking up with the spring removed) that the bump stop makes contact with the trailing arm before the shocker gets to full compression. Quote Link to post Share on other sites
Dave McDonald Posted October 8, 2019 Report Share Posted October 8, 2019 On 10/7/2019 at 11:32 AM, Z320 said: Hi, I've been told this happens when the shock absorbers are too long, Ciao, Marco I've had a rear cup break off completely for exactly that reason, approx. 21 years ago. Had it TIG welded by a specialist aluminium welder, changed the telescopic shock absorbers to shorter ones, and it's still giving no problems all those years later. Sorry, I know a good contact who could do it my area, North Nottinghamshire, but I'm sure you'll find someone closer to you. How about a search for a suitable welder on the Sywell Airfield complex which I understand has a number of Classic car and aircraft restoration companies. Not too far from you and there may be someone there. Good luck. Dave McD Quote Link to post Share on other sites
ianc Posted October 9, 2019 Report Share Posted October 9, 2019 As Mark is in Leighton Buzzard, he could have a look at Bicester because there are many classic car restorers based there now at the old airfield. Ian Cornish Quote Link to post Share on other sites
Dave McDonald Posted October 9, 2019 Report Share Posted October 9, 2019 Ah, my mistake on locations - Bicester is where I meant. Sorry for any confusion. Dave McD Quote Link to post Share on other sites
foster461 Posted October 9, 2019 Report Share Posted October 9, 2019 What does that Manvers shock mount look like ?. Some of these conversions have other issues but perhaps yours is a better design. Stan Quote Link to post Share on other sites
davidm Posted October 9, 2019 Author Report Share Posted October 9, 2019 Thanks everyone for all this good sound advice. Hi Andy, yes TIG was on my mind and testing absolutely on my list. Will need to find a way to extricate the sheared bump stop studs, (All that’s left) Easiout or Drill & Tap but will probably combine with the welding exercise, if I can. Hi Dave McD, will try Bicester 1st but North Nottingham not a problem as often travelling up to Sheffield. If you don’t mind letting me have your contact that might be useful. (Previous good results not to be underestimated!) Hi Ian, yes Bicester just round the corner. 1st stop. Hi Stan, not Clive’s original but I suspect purchased from one of the reputable suppliers. Photo attached so any observations much appreciated, but I suspect age, many enthusiastic European miles, atrocious UK roads and missing bump stops are the issues. Quote Link to post Share on other sites
foster461 Posted October 9, 2019 Report Share Posted October 9, 2019 If that bracket is just bolted to the original lever shock mount it is vulnerable to ripping the side out of the crossmember and breaking the welds that secure the crossmember to the chassis. Lots of examples of this failure on the internet including mine. Stan Quote Link to post Share on other sites
RogerH Posted October 9, 2019 Report Share Posted October 9, 2019 I have something similar but fabricated from square tubing. It is a three point attachment - utilising the down bump stop as its third pick-up. Roger Quote Link to post Share on other sites
harrytr5 Posted October 9, 2019 Report Share Posted October 9, 2019 There is a company I have used for many, many years and they have moved to Leighton Buzzard, so on your door step. It is a father and son engineering shop although the father (Brian) has probably retired. The son is into Lambretta's and likes classic cars. He is your man. Challenge Engineering. I have looked for them with out luck and when you get in contact please drop me an email. Regards Harry TR5 Nutter Quote Link to post Share on other sites
Andy Moltu Posted October 9, 2019 Report Share Posted October 9, 2019 3 hours ago, RogerH said: I have something similar but fabricated from square tubing. It is a three point attachment - utilising the down bump stop as its third pick-up. Roger Some have an additional mount that goes through the wheel arch which also helps to hold the body more rigidly to the chassis. Quote Link to post Share on other sites
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