Torsion bars, strut bars etc

Rebel · Post by **Rebel** » Sat Jul 18, 15 2:55 am

There was for a short time, a glimmer of hope that my Charger would be at the Nats next week, but then, while tightening the LCA pivot shaft nut to 130 ft lb's ( as stated in the FSM ), it sheared off.
I'm using the Hotchkis, greaseable pivot shafts ( same as Morgan, pictured in previous post to this ).
I know my torque wrench is correctly calibrated and I've checked the specs in the FSM twice in case I misread them. Can only assume that the Hotchkis pivot shafts need a lower torque setting than original Mopar ones do. If I order another one today, it won't be here until the end of next week at the earliest, so, I'll have to do the Nats in my Fox Body

Anyone know the torque setting for the Hotchkis pivot shafts?

Rebel · Post by **Rebel** » Sat Jul 18, 15 3:04 am

Also, does the spindle look ok in the pic below?
I'm convinced that the bottom of it is leaning back ( towards rear of the car ), it also looks like the sway bar links will be on an angle as well, I'm almost sure that they should be vertically straight.
I'm thinking that the LCA isn't sitting far enough forward where it bolts to the lower ball joint.

Rebel · Post by **Rebel** » Sat Jul 18, 15 1:57 pm

Just spoke to a guy at Summit Racing via live chat, explained that the pivot shaft had sheared off when torqueing up to FSM specs, sent him a pic of the sheared off shaft and he is sending me a replacement pair free of charge.
also received the order confirmation via email.
Great customer service

ScottyDave · Post by **ScottyDave** » Sat Jul 18, 15 2:00 pm

That's great, sounds like top service

Bozwell · Post by **Bozwell** » Sat Jul 18, 15 2:30 pm

Rebel wrote:Also, does the spindle look ok in the pic below?
.

nope. looks totally wrong. I know it isn't at ride height but the lower ball joint shouldn't be that far back behind the top. that looks about 5 degrees negative caster. with power steering you need about 5 degrees positive at ride height.

as the suspension rises the top ball joint will move back but the bottom will also due to the arc of the tie rod until it is parallel. from then on the caster will go more towards negative as the suspension is compressed more.

the top arm is angled for antidive but this means when you accelerate you lose caster.

also with cars jacked up at the rear the caster is even worse. must drive horrible with a set up like that.

I would say on droop there needs to be zero caster (top ball joint directly above the bottom then as the suspension compresses the caster should go to a decent amount. I do basic set ups on race cars so have done a fair bit on set ups.

Rebel · Post by **Rebel** » Sat Jul 18, 15 3:14 pm

Thanks Boz, I'm not driving it like that, just busy putting it back together. The strut rod isn't tightened up yet, so it should pull forward a little. I'm more concerned that the new LCA bushes are causing the LCA to sit further back than it should. I was thinking that the spindle should be inline vertically, making both ball joints line up with each other.

Blue · Post by **Blue** » Sat Jul 18, 15 6:10 pm

At ride height the top ball joint should sit back a touch further than the lower, so the spindle leans back a bit, that gives you caster, picture the forks on a motorbike for an exaggerated image. I think those LCA studs must have a lower torque setting as they are hollow rather than solid like the originals.

Rebel · Post by **Rebel** » Sun Jul 19, 15 12:20 am

Thanks Blue,
I've emailed Hotchkis to get their advice on torque settings for their pivot shafts.
Had a look at everything earlier and found the below that might be causing the issue.
I'm assuming that the pivot shaft should go all the way in to the LCA, as can be seen in the pic, there's a gap between the end of the pivot shaft and the recess for it in the LCA. ( this is after trimming the bushes by the same amount as Morgan had to with his )
In the second pic, the black part with the arrow pointing to it is part of the poly bush, this coincidentally looks to be the same size as the gap left in the LCA recess. So the pivot shaft needs pushing in by that amount?
Looking at a set of original rubber bushes, they seem to sit flush with the LCA, so I'm now thinking that if the arrowed bit of bush wasn't there, the shaft would be in the LCA all the way. Meaning that the LCA would sit closer to the K frame, therefore eliminating the problem of the lower ball joint being to far back?

Rebel · Post by **Rebel** » Sun Jul 19, 15 12:27 am

This is how the LCA's looked after installing the new pivot shafts, it doesn't look as though I've done anything wrong, ( don't think you can when just installing bushes and shafts into the LCA ).
Starting to second guess myself now

Rebel · Post by **Rebel** » Tue Jul 21, 15 12:17 am

Just done some checking on the size of strut rod bushes, the poly ones that I have are thicker than the original rubber ones and not as squishable.
If the LCA bushes are trimmed to sit flush and the strut rod bushes are the thinner rubber ones, then when torqued up, everything should line up, yes?

Dave999 · Post by **Dave999** » Tue Jul 21, 15 8:57 am

yes

you don't want the lower control arm pushed back by too fat strut rod bushes because you won't be able to get any positive castor.

no positive castor will i.e negative castor will make the steering wheel pull to one side or the other and not want to stay in the middle

Rebel · Post by **Rebel** » Tue Jul 21, 15 10:51 am

Thanks Dave,
Have also just realised, aswell as being thicker, the poly strut rod bushes have a metal sleeve that they slide over on the torsion bar. It obviously isn't going to squash when torqued up, the original rubber ones just connect with each other ( male and female design ), now thinking that if the metal sleeve is removed from the poly strut bushes, they might have the ability to squash enough for everything to line up. Thinking about it as I type, the metal sleeve might be there to stop the strut rod eating the poly, so, it could be a better idea to do some measuring and just trim the metal sleeve a little to allow more squishability in the bushes.
I'll do some measuring and double checking later

Rebel · Post by **Rebel** » Thu Aug 06, 15 10:18 pm

Still having trouble with getting everything to line up. It looks as though the strut rod is stopping the control from sitting in the right place.
Without the strut rod everything seems to fit and line up, with the strut rod in place the pivot shaft pin won't go all the way home.
Am I overthinking it and really just need to put everything together and tighten it all up?
Will the strut rod pull the LCA forward as its torqued up?
Do the metal sleeves that fit over the end of the strut rod and inside the bushes need to be used ?
Anybody got any pictures of the front end set up without a drum or disc being in the way, so I can see what it should look like?

Pete · Post by **Pete** » Thu Aug 06, 15 10:49 pm

I have always bolted up the LCA pivot (but not torqued it up) and then done similar with the strut rod - but you sort of have to assemble them all at the same time.

I always let the car settle and adjust to correct ride height (in stages with the weight OFF the front end to reduce load on the adjusters) and often roll the car backwards and forwards to take out any bind before I torque everything up...the same approach with rubber of poly bushes........

Rebel · Post by **Rebel** » Thu Aug 06, 15 11:08 pm

Thanks Pete, I haven't got that far yet.
The LCA is in and the strut rod is in, shock absorber is bolted up and torsion bar is in, the problem is that when the bottom balljoint is attached to the spindle, I have negative castor. It's almost as though the strut rod is too long