ride height questions after front end rebuild 1973 dart

[Newbomb Turk]

At what ride height?

Sure, in theory if two cars are at the same ride height and have similar front end weights they should have similar adjustments, if the torsion bars are new.

Realistically, if we're talking about used, original torsion bars that are now 50+ years old the condition and mileage on the bars will have a significant effect on the adjustment, even with everything else being equal.

I’d have to drop the engine in it and measure it. I have forgotten where I had it.

The engine is close to going back together and then it goes on the dyno for a while. I hope to have it off the dyno by thanksgiving but sometimes other things get in the way.

 

[Dave999]

how i did it
with the upper arm cam bolts undone
and the lower arm mounting studs undone and swiveling in their sockets knock em out abiit with a wooden mallet so they swivel
undo the nuts on the strut rods to the last 5 threads front of K
jack front up high.
have lower control arms disconnected at the ball-joints
droop them down as far as they will go a long way when not connected to the stub axle and the strut rods free to flop
undo the adjuster bolt leaving very little sticking out top side of the adjuster
slap the Hex socket lever over onto the adjuster
fit torsion bars.

do up the adjuster until you feel resistance

use a small jack to jack up each lower arm in turn and fit the lower ball joints back in
do them up and put in the split pin

get back under and wind each adjuster in nearly all the way

put the car on its wheels again and bounce it
bring the car down to desired height in stages bouncing between each
check its the same height both sides. method in the workshop manual or come up with your own

bounce it and leave it

next day do up the lower arm studs making sure they are pulled tight into their sockets
do up the strut rods

do your alignment

not saying its right
but i didn't have any problems with my 50 year old 273/318 thickness bars. which i presume are quite saggy.
whereas i have seen someone do the exact reverse of this...... and ask a similar question to this on my club message board

They in error jacked the lower arms up to fit the bars , got the torsion bar in some how, it was a struggle, and wonder why their suspension seemed like it was not working at all
torsion bars - Mopar Muscle Association UK

anything is possible with the right level of determination

Dave

 

[Daves69]

The first picture is passenger side , second is the drivers side . note how the drivers side blade is alot further from the frame .

I take it you have confirmed the trans crossmember T-bar sockets are sound and one hasn't spun.

 

[72bluNblu]

how i did it
with the upper arm cam bolts undone
and the lower arm mounting studs undone and swiveling in their sockets knock em out abiit with a wooden mallet so they swivel
undo the nuts on the strut rods to the last 5 threads front of K
jack front up high.
have lower control arms disconnected at the ball-joints
droop them down as far as they will go a long way when not connected to the stub axle and the strut rods free to flop
undo the adjuster bolt leaving very little sticking out top side of the adjuster
slap the Hex socket lever over onto the adjuster
fit torsion bars.

do up the adjuster until you feel resistance

use a small jack to jack up each lower arm in turn and fit the lower ball joints back in
do them up and put in the split pin

get back under and wind each adjuster in nearly all the way

put the car on its wheels again and bounce it
bring the car down to desired height in stages bouncing between each
check its the same height both sides. method in the workshop manual or come up with your own

bounce it and leave it

next day do up the lower arm studs making sure they are pulled tight into their sockets
do up the strut rods

do your alignment

not saying its right
but i didn't have any problems with my 50 year old 273/318 thickness bars. which i presume are quite saggy.
whereas i have seen someone do the exact reverse of this...... and ask a similar question to this on my club message board

They in error jacked the lower arms up to fit the bars , got the torsion bar in some how, it was a struggle, and wonder why their suspension seemed like it was not working at all
torsion bars - Mopar Muscle Association UK

anything is possible with the right level of determination

Dave

So, you followed the important parts of the FSM, and did a bunch of extra stuff you didn't need to.

Here's the FSM procedure. Notice, it calls for removing one thing, and one thing only- the upper bump stop. Everything else can remain in place- upper control arm, ball joints, hell even the shock. With just the upper bump stop removed the control arm and spindle assembly will hang down almost all the way to where the LCA will contact the K frame on most cars, typically more than enough to install the torsion bar.

If you're rebuilding the suspension the upper control arm bolts and LCA pivot nut wouldn't be torqued yet, but they don't need to be loose if you haven't just rebuilt the suspension and haven't had the car on its wheels yet.

And yeah, it is possible, but not easy, to mis-clock the torsion bars with factory parts. But you really need to make an effort to do it, to the point that if you just realized what you were doing seemed really hard and just stopped doing that you'd end up doing it the right way. With used bars the amount of sag depends on a whole ton of things, with the history of the car being a huge part. Certainly some 50 year old bars are probably fine while others are completely worn out. You know they're totally worn out when you run out of adjustment on the torsion bars adjusters before you get to ride height, simple as that.

 

[Dave999]

So, you followed the important parts of the FSM, and did a bunch of extra stuff you didn't need to.

Yeah i guess so, I was assembling it after all new bushes in an order that i felt would work
I just got on with it and did what i thought was best
I've got reasonable spacial awareness and and the ability to picture how things work in my head. Took me a long time to realise that not everyone has that... some people cant picture anything let alone picture it moving and interacting

and as i said my not be right but worked.... I avoided a pitfall that some don't
jouncing the car a lot was probably not necessary but it was all new i was trying to settle it and squirm the tyres across the rough laid concrete floor


Went got the service manual out to cover off ride height measurements, realised I didn't have the right tool but used what was discussed as a basis for sensible measurement to ensure consistency side to side.

Obviously the alignment stuff is not that useful for anything other than method..

dave

 

[moparjon]

so kinda a late update cuz things have snowballed of course . I backed the torsion bars out again and started over . they were clocked right . there is no way they are going to make it to the next flat . same result . the torsion bars are definitely worn out . but i did get it to height and am gonna leave that for now . thanks everyone !

 

[72bluNblu]

so kinda a late update cuz things have snowballed of course . I backed the torsion bars out again and started over . they were clocked right . there is no way they are going to make it to the next flat . same result . the torsion bars are definitely worn out . but i did get it to height and am gonna leave that for now . thanks everyone !

No problem!

And consider that the bars will continue to sag. So, you're going to continue to lose ride height. The only solution to that is to have the bars rebuilt, which involves heat treating them and correcting for hex offset. Firm Feel still does that, last I checked anyway.

That service though costs almost as much as a new set of torsion bars, so, you'd be better off going to something larger. 1" or better in my book, although opinions vary of course.