Torsion bar install question

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440 Mike

440 Mike

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After a complete tear down I'm putting the front suspension back together. I was planning to install the torsion bars with only the lca's and strut rods in place loosely. No other suspension pieces (uca's, spindles, lower ball joints) are installed as of yet.

I've searched a bunch of threads and most say that the lca's should be hanging down as far as possible and hitting the K frame.

The strut rods are holding the lca's up a bit from the K. To align the T bar flats with the lca socket I had to pull the lca down a little by hand.

I'm wondering if I'm off by one flat with the strut rod holding the lca from hanging down far enough?
 
Hmmm, possibly. I didn't put the strut rods in until later. Though that was a bit of a pain — I can see why you are trying it this way. I would look at the sequence in the FSM procedure.
 
Factory service manual has all of the components in place but the upper bump stop is removed. Wish it had a sequence or order of assembly.
 
One consideration is the lever/finger on the control arm that the adjusting screw presses against.
Years back I bought a set of 1.15" torsion bars from Bergman Auto Craft. He had some surplus bars from XV Motorsports.
On Peter's advice, I aimed that lever/finger level with the ground and the torsion bars slipped right into place.
Now, this was probably because the 1.15s are so thick, they don't need as much preload with that adjuster to get to a desired ride height. Still, this was a good nugget of advice that served me well.
 
What torsion bars do you have?

Installing the bars a hex flat off, with torsion bars that have the factory hex offset, is nearly impossible. It really only comes into play if you have tubular LCA's, which don't hit the K frame so they can hang straight down and allow a different flat to be used (not good!) and with really large torsion bars that have little or no hex offset. The large bars will install with the LCA much closer to its final ride height position, because they don't move nearly as much with the weight of the car.

So, it's really unlikely you're a hex flat off just by pulling down the LCA's a little bit. The other question to look into is, is the LCA lower than it will be with the bump stops installed? If it isn't, that would mean your strut rods will bind the LCA within your range of suspension travel, which is not a good thing.
 
Torsion bars are original 892/893. Still have the blue paint daubs.

With no UCA's installed, just strut rod, LCA, and T bar the lower bump stop has about 1-3/4 inch gap below the frame pad. How does that sound to you?
 
A few weeks ago I unloaded the right tortion bar to check the condition of the lower ball joint etc.

All the suspension was in place. With the suspension hanging and unloaded I could have removed the tortion bar.

I suspect the small movement down was due to the strut rod bushings
 
I installed new strut rod bushings, but tightened them just enough to keep them seated in the K frame. The strut rod definitely prevents a loosened LCA from dropping down all the way.
 
440 Mike said:
Torsion bars are original 892/893. Still have the blue paint daubs.

With no UCA's installed, just strut rod, LCA, and T bar the lower bump stop has about 1-3/4 inch gap below the frame pad. How does that sound to you?
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That should be pretty close to the bottom of the range of travel with the bump stop in.

With those torsion bars there’s almost no chance they’re a hex flat off, it’s pretty hard to do that with a factory bar.

440 Mike said:
I installed new strut rod bushings, but tightened them just enough to keep them seated in the K frame. The strut rod definitely prevents a loosened LCA from dropping down all the way.
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Rubber strut rod bushings or poly?

Ideally the LCA’s would hang down freely past where the bump stop would be, but with factory strut rods and bushings the bushings have to compress to get that kind of range so if they’re brand new that makes sense.
 
72bluNblu said:
Rubber strut rod bushings or poly?
Click to expand...

I used rubber Moog strut rod bushings. Late style K frame with no sleeve type bushings.

I had to pull the LCA down about 3/4 inch (resulting in the 1-3/4" total bump stop clearance) to line up the T bar flats.

So if all sounds good, I'm going to finish assembling. Thanks for the help!
 
440 Mike said:
I used rubber Moog strut rod bushings. Late style K frame with no sleeve type bushings.

I had to pull the LCA down about 3/4 inch (resulting in the 1-3/4" total bump stop clearance) to line up the T bar flats.

So if all sounds good, I'm going to finish assembling. Thanks for the help!
Click to expand...

Yeah, should be fine. The bushing has to compress to allow that much travel so it all makes sense, the new bushings are probably a bit stiff since they haven’t been worked in.
 
One more thought: Should I torque down the K frame end of the strut rod bushing before I finish installing the T bar? Just thinking that compressing the bushing fully would help with getting the LCA pivot shaft and T bar into final position.
 
440 Mike said:
One more thought: Should I torque down the K frame end of the strut rod bushing before I finish installing the T bar? Just thinking that compressing the bushing fully would help with getting the LCA pivot shaft and T bar into final position.
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It shouldn’t matter much. I usually install the torsion bars into the LCA with everything disconnected.
 
440 Mike said:
Torsion bars are original 892/893. Still have the blue paint daubs.

With no UCA's installed, just strut rod, LCA, and T bar the lower bump stop has about 1-3/4 inch gap below the frame pad. How does that sound to you?
Click to expand...
You should be fine. Just don't tighten everything completely until you have the car on it's feet with a normal load in it. Otherwise, the bushings will be in a bind and may not last long.
 
So I just did my front end today all stock moog bushings but the 73+ disc set up. All went well but the pass side t bar when in 1/4 in. Past the clip groove, the driver side went in just enough to get the clip in and won’t go any further. Any thoughts??
 
If they're both in and clips installed, you should be fine. These cars were never built with exact precision. If the alignment is in specs, you're golden.
 
I recently bought a set of 892/893 bars.

The seller had several sets.

Of the bars were 1/8" shorter than the others.
 
Good to know I was going to take dr side apart to check everything.
Now I swapped everything to discs so can’t put it on the ground till I order new rims and tires. Now everything is snug not tight. Can you Jack the LCA to simulate being on the ground to torque everything? Everything is new all moog parts and bushings.
 
Tony Barracuda said:
Now everything is snug not tight. Can you Jack the LCA to simulate being on the ground to torque everything? Everything is new all moog parts and bushings
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I would hold off, do it right once or do it wrong twice.

If you are going to 5x4.5 pattern you might be able to barrow some wheels off another car?
 
Tony Barracuda said:
Good to know I was going to take dr side apart to check everything.
Now I swapped everything to discs so can’t put it on the ground till I order new rims and tires. Now everything is snug not tight. Can you Jack the LCA to simulate being on the ground to torque everything? Everything is new all moog parts and bushings.
Click to expand...

Yes. You don't even need to jack the LCA if you know the final ride height of the car already. There doesn't have to be weight on the suspension, the LCA just needs to be in the same position as it will be at ride height. So you can loosen the torsion bar adjusters and just lift the LCA to its ride height position.

The only reason it's done like that is for the rubber bushings, especially the LCA bushing. Because nothing in the LCA bushing assembly spins or rotates, the travel in the suspension is flex in the LCA bushing. The rubber won't flex far enough for the whole suspension travel, so, you tighten the LCA pivots at ride height so half the travel is flex up, and the other half is flex down. Doesn't have to be perfectly centered either, just close. The rubber bushings are not precision parts.
 
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