Torsion bar removal/installation

[apriliadriver]

Can any of our erudite posters give me any tips about removing torsion bars, adjusting them etc ?
Thanks,
Nick

[Scarpia]

yep, don't try it......

Seriously i did it a few years ago because the "out" end of the bar where it locates in the trailing arm was worn and had rotated in the splines .
I released the transverse spring (challenge in itself) (I'm now trying to recall if this was stricktly necessary or if I was doing another job at the same time?)and then aligned the two trailing arms by measuring relative to the wheel mounting flanges. This you do in principle by placing the trailing arm the on the correct splines to ensure the same ride height on the two sides.

Remove the bars by knocking them out from the other side. You need to release pinch bolts in the middle I seem to recall also.

My splines were worn. I tried reversing the torsion bar (i think ) but this didn't help .In the end I welded the trailing arm face to the protruding end of the splined shaft .This is the usual method of solving this problem but new shafts would be better of course.I actually cannot recall if the splines in the trailing arm were really the problem or those on the shaft itself , probably a combination. Until now the weld has held fine but one day I will try and effect a replacement.

If you need to know more (dimensions) I will check my notes and crawl under the car .What you think you did is not always the same as what you actually did after a few years of memory loss.....

[fay66]

Hi Nick,
Go to this link http://www.lancia.myzen.co.uk/forum/index.php?topic=1366.0
As there was quite a discussion in 2008 on Aprilia rear suspension.

Brian
8227

PS. Long time since our run around La Mandria

[apriliadriver]

Brian,
You are right about that  -  3 years since our adventurous run to Turin. Funnily enough, the sight I enjoyed most was our visit to the cinema museum at the Antoniella Mole in Turin. After that me and my co-driver walked up past the church holding The Shroud to a derelict railway museum about half-a-k past the huge open-air market.

I enjoyed the Centenary but do feel sad that we were never allowed to visit the Lancia factory collection of historic cars.
Nick

[fay66]

Brian,
You are right about that  -  3 years since our adventurous run to Turin. Funnily enough, the sight I enjoyed most was our visit to the cinema museum at the Antoniella Mole in Turin. After that me and my co-driver walked up past the church holding The Shroud to a derelict railway museum about half-a-k past the huge open-air market.

I enjoyed the Centenary but do feel sad that we were never allowed to visit the Lancia factory collection of historic cars.
Nick

We visited and had a look at the Shroud Replica on a previous visit, I knew the Train Museum was about, but not where.
It was a shame that we didn't visit the Lancia Collection, fortunately for me we were priviliged to visit the collection in 2004 with Dr Massala as our guide, magic.

Brian
8227

[apriliadriver]

Right, then, here's the advice I need.

I have a spare trailing arm in the workbench vice. The torsion bar is free at the inner (diff) end and the big circular collar is still installed at the outer end of the tube. I have removed the pinch bolt at the outer end and wedged a very large screwdriver in the split end. There is no sign of welding on the torsion bar itself. I have given the inner-end of the torsion bar several hefty whacks with a copper hammer and there is no sign of the bar moving.

Have I missed out some other vital step before I can remove the torsion bar from the trailing arm ?
Thanks, everyone,
Nick

[GG]

I enjoyed the Centenary but do feel sad that we were never allowed to visit the Lancia factory collection of historic cars.
Nick

Still OT, but sometimes its just luck. I had seen the collection c. 1980, and wasn't planning to go again, but this time it worked out well.  
Geoff

(mod. 12.18, better PDF. Still downsized for uploading. If a better one is desired, please email. Happy to send out.)

[apriliadriver]

Geoff,
Great article  -  thanks for posting.
Nick

[ColinMarr]

Nick,

It’s easy for me to say this, having not attempted to do the job for more than 40 years, but it should come out easily! I guess the splines have just sort of fused together over time – maybe a bit of heat could free it up.

My memory is that once all the clamps had been freed, the bar could be pulled out gripping it by a bolt screwed into the outer end of the torsion bar.

Good luck,

Colin

PS. Which was the article you were thanking Geoff for posting? Did I miss something?

[donw]

40 years ago the Club had an ex Lancia spring stretcher which made removing the rear suspension easy, it used to be kept by John Maltby but I dont know where it went or it still exists. Like Colin I have not had an Aprilia for many years now so my memory of doing the job is a bit vague.

Don

[ColinMarr]

My memory about this is not vague – it’s very precise. It’s just that 40 years of tightened-up elapsed time might have jammed up the splines in a way that might not have been true that long ago. Also, Nick is posting about torsion bars and not the leaf spring – the tool to straighten which is not really relevant, although it might be a good thing to have when it comes to putting it all back together. See earlier posts.

Nick, one further thought – if the torsion bar had been hammered into position (perish the thought) it might have belled-out a bit. Perhaps best to ensure you are easing it out, rather than in!

Colin

[apriliadriver]

Thanks, Colin and Don. I think you are right -  it is probably jammed in. I will apply heat next (just the day to do it as well !)

Colin, the article is a subscript attachment at the foot of Geoff's post and is a report of a 2008 photo-tour of the Lancia Museum collection. The script is tiny and easy to overlook. If you cannot retrieve it I will save the file and forward it to you.
Nick

[ben]

Hi Nick
         I doubt if heat will help unless you have a blacksmiths forge fire to sit the arm in!!! Try soaking with penetrating oil. I swear by Plus-gas.To get it moving I think it is worth striking it inwards using a drift about 2/3rds of the bar size (to keep the contact well away from the splines to avoid damage) then as soon as any movement occurs you will be able to tap it back through from the other end. The outer spline diameter is too large for the bar to pass inwards through the tube but there is clearance for some freeing -up movement as described.
        In case you should need it the Club spring compressor tool is currently with me.
PS
     Excessive wedging apart of the clamp section might be causing the splines to be gripped instead of releasing them.They are very precisely machined so any distortion will cause them to jam.

[apriliadriver]

At last, the torsion-bar has emerged from its snug fit in the trailing arm.

Thank you, Ben, for your suggestions  -  lots of PlusGas and you were right, the splines on one side were binding. I snugged up the pinch bolt and a mighty welt from a copper hammer did the trick. The splines are in good nick, happily.

Happy New Year, everyone.
Nick