View Single Post
  #119  
Old 14th March 2023, 17:42
MartinClan's Avatar
MartinClan MartinClan is online now
Senior Member
Enthusiast
 
Join Date: Sep 2004
Posts: 1,893
MartinClan is on a distinguished road
Default Trunions....

After several months of DIY I finally have some time to spend on the Marlin. I really should be completing the resto of the chassis but I fancied something a bit more interesting so decided to trial fit the front suspension. The Marina uses an odd setup for the front suspension using torsion bars and trunions, based on that used by the Morris Minor but, unfortunately, having no common parts. Parts are as rare as hens teeth....

The standard problem with the upright is lack of maintenance causes the lower thread on the upright to deteriorate. Ultimately the trunion can part company with the upright. Mine were no exception.

upright rusted thread 2 by Robin Martin, on Flickr

I was able to track down, thanks to the Marina Owners Club, some new old stock of "Walford Trunions" which were a period fix for the problem. Basically a new threaded sleeve is screwed on to the old damaged thread and a new oversize trunion fits to that.

original and walford trunion by Robin Martin, on Flickr

You are supposed to fit the new threaded sleeve using the supplied threadlock but that was a bit suspect being 30+ years old so instead I bonded it using an industrial Araldite. Jobs a good-un. I should say that it is also tightened up to 100 Lb/ft as well!

inner component of walford trunion by Robin Martin, on Flickr

walford trunion fitted by Robin Martin, on Flickr

Finally I fitted all the bits up to the car. The Marina uses a lever arm damber but on the Marlin this is replaced by a Mini upper suspension arm and a conventional damper (not fitted yet)

front suspension trial fit by Robin Martin, on Flickr

The critical point is that the torsion bar should pass through a hole, on the chassis where it is finally fixed, without any lateral or vertical tension. This is also the rubbish part about Marina front suspension as it makes it pretty much impossible to play with the castor or camber. Anyway after a bit of fettling it's a great fit.

torsion bar position by Robin Martin, on Flickr

Now that I am happy it fits, and I am not missing any major bits, I can take it all off again and complete the cleaning up of the chassis!

Cheers, Robin
Reply With Quote