LeGrand Mk 21 FF front suspension failure.

[Keith Robinson]

Racing at the weekend and the 'wheels came off' well only one actually!
I don't know how to post a photo but the break was fairly simple.
Where the top link is attached to the top of the knuckle the ball joint sits in a 'cup' that is brazed to the link.
That part fatigued and broke off at the brazed joint! Interestingly the braided brake line 'tethered' the wheel assembly and kept it with the car (the bottom ball joint had sheered off due to the failure of the top link)!
Luckily it happened in a slow corner and I didn't hit anything or anyone!
So where to go for information on parts and information for this car. I've raced it for two years and I like the car, never had
any prior problems?
I've been on this site for over 20 years and this is the first time I managed to post a photo :-)

[Earley Motorsports]

Take the broken pieces off carefully and have new ones made. Not a big job. Similar to many formula fords.

[Keith Robinson]

Take the broken pieces off carefully and have new ones made. Not a big job. Similar to many formula fords.

Thanks for the reply.
Can you recommend anyone in the North West that will 'make a new one'?

[10rmotor]

Can the machined and threaded bearing cups be bought? Making a jig for that wouldn't be too difficult. I've made similar parts for my cars' front lower control arm. I'd braze the broken one together first, then make a jig, then make the little sheet metal parts and off you go!

[Roland V. Johnson]

Call Ethan Shippert at Sonoma.

[DanW]

Call Ethan Shippert at Sonoma.

+1 for Ethan's work, but Mike Edick in Gig Harbor probably has the fixture to make them.
mteracing36@gmail.com

[teamwisconsin]

Call Ethan Shippert at Sonoma.

Thanks Roland, but I too agree with Dan on this one. Send it to Michael Edick. Not only does he likely have fixtures for it, but his work is stellar and his pricing is more than fair.

Keith- I would use this failure as a solid indication that you need a full car set of suspension. I have seen more suspension failures over the past 5 years than I saw in the previous 20. All this stuff is just flat getting old. Years of internal corrosion, embrittlement from plating, a zillion cycles of stress, kerb strikes, off track excursions, overzealous applications of ratchet strapping in improper locations, etc etc. Just make it all new. It will likely cost you somewhere between $1500-$3000 depending on the complexity of the suspension. But like the old adage says “an ounce of prevention is worth a pound of cure.” The peace of mind of new wishbones and radius rods far outweighs the risk of tens of thousands of dollars of racecar parts, and/or your own physical well being. Those old girls have served their purpose. Time to put them out to pasture.

[Marty Nygard]

This is probably obvious but when you reassemble the suspension be sure to replace the already stressed brake line.
Also, it may be prudent to replace the same suspension piece on the other side of the chassis.
M

[DanW]

If I could add a little nugget to Ethan's post about replacing the entire set of suspension parts, Mike Edick worked for Red LeGrand for about 6 months before going to Cal Poly for his mechanical engineering degree.

Mike said that Red was an admirer of Colin Chapman's "Simplify and Add Lightness" philosophy on his designs. I replaced all my suspension parts on my Crossle 25F because of age/fatigue concerns.

[mont7]

Keith- I would use this failure as a solid indication that you need a full car set of suspension. I have seen more suspension failures over the past 5 years than I saw in the previous 20. .....

I had the lower left wishbone on my 1972 Mallock collapse last year at Gingerman on the straight between 6 and 7. I opted to replace both sides, and will likely replace the uppers over this coming winter.

Maybe take the good one off and send it to the fabricator and ask him to make two, one for each side.

[Keith Robinson]

If I could add a little nugget to Ethan's post about replacing the entire set of suspension parts, Mike Edick worked for Red LeGrand for about 6 months before going to Cal Poly for his mechanical engineering degree.

Mike said that Red was an admirer of Colin Chapman's "Simplify and Add Lightness" philosophy on his designs. I replaced all my suspension parts on my Crossle 25F because of age/fatigue concerns.

As expected lots of good information from 'ApexSpeed' members, thank you all!

Researching LeGrand front suspension I've found there are two versions made over the years.
One is a cup brazed onto the top link with the ball joint inside it and the other is a threaded link with a large Heim joint on it.
The brazed cup is 'Lotus style' lighter but I'm not keen on the butt joint brazing (which is what fatigue/deteriorated on my car).
The Heim joint version is heavier but looks stronger!

I've received several recommendations/suggestions where to go for help; Mike Edick in Gig Harbor is closest so I'll try him first!

Yes I do recognize that 50 year old Formula Fords are getting a little fragile! I also own an RF75 Van Diemen which appears to be built
a lot stronger than most (but it was not one of Mr Firman's quickest cars!).

Thanks again for all the input, much appreciated :-)

[scott fairchild]

another consideration for timing out is the welded axles common in the first generation of FF

[Keith Robinson]

Lots of helpful information from Micheal Edick and others, thank you all.
I've concluded the Heim joint top links are the way to go for an upgrade which will be fairly simple and make camber adjustment easier!
The bottom ball joint is more of a problem, the ball joint sheared off and I'm looking at a tricky repair trying to drill out the threaded piece. Replacing the knuckle would be best if I can find one, all suggestions would be appreciated.