Spitfire 78 spit: rear suspension woes

[Russell Moore]

Recently had issues with my rear suspension (on my car!). Took it in somewhere where they stripped the lugs on one side (torqued to TR8 specs, doh!), then stripped the hub getting the lugs out. After they replaced the hub, I backed down over a curb and from that point have been having all kinds of problems. The driver's side sags so much it ripped the edge off of the tire. I replaced the spring with an uprated one from BPNorthwest (had an extra leaf). Backed out, and cut the edge off of the tire I just replaced (ugh!) as it sagged back into place. Found on the teglerizer site a refernce to needing to torque after lowering the car ( https://www.teglerizer.com/triumphstuff/new_trunnions_and_jacking_hints.htm ). Would not doing this cause the issue I am having? I noticed that the wheel seems to have excessive cambre (bottom further out)on the driver's side only : "/ |". I jacked up the car and it was ok to drive back into the garage - seems like it slips out of alignment (!!?) when I back up. Any ideas? Nothing underneath looks damaged. I guess next thing to do is loosen everything up, lower the car, and torque it back down, but one more full evening working on this problem without benefit may make me insane. Thanks!

 

[Bob Claffie]

If I remember from my years of mechanicing on Mk2's and Mk3's the tilt of the rear tires is directly dependent on the arch of the spring. (I never had any issues with the '76 I owned, rear ends might be different). Sorry I can't be any more specific. Bob

 

[Larry Kronemeyer]

Russell:
Check the fulcrum bolts they are the pivot points for the hub bearing, sometimes the break(rust) and really play havok with alignment. Always torque suspension bolts with full weight of vehicle on ground.
Also, check shocks, they can make trouble too, had some break at mounts.
Larry

 

[MDCanaday]

The best fix for a spit rear end sagging is to get 63 vet rear shocks, then install generic coilover springs on them. Preload the springs to 125 lbs or so(like the front ones)and you have like magic, no more problems.
Why vet shocks you ask?? the stock shocks are too weak to take the clamps for the springs, they just crush up and fail.
MD(mad dog)

 

[Dave Thielke]

Russel,
I recently replaced the rear spring on my 75 Spit.
While researching what to do, I ran across some notes and info about using air adjustable shocks that fit corvettes. I think it was at Triumph spitfire and TR6 magazine. Apparantly several people had info on what parts and where to get them.
I wound up with a new spring as the drivers side had been shimmed up with rubber pads sometime before I got the car.
Maybe this will help.
Dave T

 

[Russell Moore]

Thanks guys. I had actually thought of that as well as I have read it on other sites. While it sounded pretty cool, I had just installed konis. I kinda wondered whether the shocks should really be taking the load of the car. Another complications is that I have upsized my wheels (bought custom 15x6 with .5 offset from diamond racing wheels) , which now extend out to the wheelwell. The normal wheels would not have a problem, but now I only have about one inch clearance.

As an update since the original post, tightening down the bolts after the load is on the wheels did help a bit. It is now drivable, but not as high as I would like (still rubs when going over speed bumps). I was wondering if anyone has looked at replacing the vertical links, making them a little longer. They look like they would be pretty easy to have made - just a triangular peice of (heavy guage) steel with 3 holes in it.

 

[Russell Moore]

I have uploaded a pic of the wheels for those of you interested.
https://www.britishcarforum.com/PHPhotoalbum/displayimage.php?pid=554

This is a pic of the front wheel.

 

[Z28Quetzal]

Just a suggestion:

you seem to have had quite some work done, especially with heavy torque settings. I owned a 78 Spitfire, and while I was doing work on the rear suspension, I noticed the brake drums were cracked.

You might want to inspect your brake drums, mainly the one where the lugs were stripped and make sure it is not cracked. If that thing comes apart at speed you could really have some problems.

Also something to think about: when you replaced your wheels, did you replace the studs too? The 'original' ones are extremely small and if you are running 15" wheels, that is putting more load on the hubs. You might want to check into this. I had a set of Panasports on my Spitfire and the fellow I bought them from was a vintage racer with HSR. He was the one that originally suggested to upgrade to beefier lugs.

Regards,
joe

 

[Bugeye58]

Jeez, 15x6's on a Spit? Kind of overkill, ain't it?
With that much rubber on the ground, you are inducing loads on the suspension that it was never designed to accept. By all means, change over to 7/16" studs. The ones I used are for a Chevy S-10 pickup, as they have the small head on them and will fit the hubs easier.
Bugeye58

 

[spit6 guy]

Hello MD
can you tell us mroe about your coilover setup
like will it fit with a rotoflex rear and where
can you get the parts ?

Thanks Spit6 Guy
Kurt

 

[Twinkie]

Another common fix is to install another main leaf from another spring. This firms it up noticeably and postpones the inevitable sag.
OTH, racers will induce sag in the rear spring because the excessive rear camber helps with traction.
I think 15X6 tires will give you no end of trouble.
I would think the suspension would tear up on high cornering g's without some major beefing, and I can't see how you'll get 15's to fit in the well.
Good luck and keep us posted...