Adjustable strut rod adjustments

[dusterbd13]

ok, so were haning the front sheetmetal now, and getting ready for the test drive. noticed while hanging the metal that the front tires are located differently in the fender openings. ok.. so that wasnt like that before. matter of fact, the drivers side front tire HIT the front edge of the wheel lip while turning. definately wasnt like that before. so i got to looking, and noticed that the amount of threads sticking out of the front nut on the strut rods was different by like 3/8 on an inch. more on the drivers side. meaning that i didnt adjust them right when i put the front end together. so to finish on the sheetmetal for the evening, i loosened the nuts, allowing the LCA to move back to center. it worked for tonight.
to make a long story short, how do i adjust these things properly? and in what order do i do things like set the ride height, toe, and strut rods?
please, help me out. and heres a picture of the design i have.




oops. forgot to mention the car: 70 plymouth duster. i know its a mopar, but still...

michael

[68nate]

1. Ride height
2. Caster (strut rod)
3. Camber (upper control arm bolt eccentric washer?)
4. Toe

Final adjustment should be on an alignment machine, but as a starting point after the ride height is set I would center the wheel in the wheelhouse or use wheelbase measurements (caster) - Then with the suspension loaded use a level on the wheel vertically (camber) - Center the steering wheel- Then toe it in 1/8" ( tape measure from front of left tire to front of right tire, then rear of left tire to rear of right tire-should be 1/8" shorter on front). Then to the alignment shop.

[dusterbd13]

thanks.
any suggestions on the strut rods so i can go test out the clutch and tranny today?
Michael

[High Plains Mopars]

Well, for a starting point you should have set them to be as close to the original strut length as possible. Then adjust them for additional caster. Lacking that, I'd suggest adjusting the offending strut to match the un-offenesive strut.

Your upper control arms can also throw the whole mess off enough to create tire interference as well. you might need to get a base alignmnet just to get everything in place before the fenders go back on.

I'm suprised you stayed with the stock upper control arms. Honestly, you can get more caster out of a set of aftermarket tubular arms than you can with adjustable strut rods.

[dusterbd13]

yeah, thats pretty much what i did over the weekend. clears now, but barely.
as far as the strut rods versus the uca's, i did so for two reasons:
1. my origonal strut rods were bent
2. i dont like the design uf the currently availible uppers. they just dont look all that strong to me.

the rest of the suspension is set up with a budget approach. poly bushings, big block t-bars, boxed LCA'a with rubber bushings, KYB shocks, 73 up disc spindles and steering linkage, Diplomat steering box and pump, 340 HD rear leaves, and addco sway bars at both ends. my goal was a budget approach to handling and comfort. havent driven it yet, but im hoping (based on a similar suspension in a friends a-body) that it will ride good and handle pretty good. i know already that there is absolutely no feel with the power steering. so ill need to eventually go with a FFI stage 3 box.

thanks for all the help. ill postpictures of the project when my wife brings the digital back from work.

Michael

[High Plains Mopars]

I haven't personally tested them all, but almost any tubular arm is going to be stronger than the stock arms, especially those built with straight tubing. The weak point in the stock arms is right around the ball joint hole. I'v eseen them crack there.

Adjustable struts are nice for any reason, even if they just provide a little extra caster.

KYB shocks aren't the greatest choice either, but you start with what you have and work from there. Since you are running stock sized t-bars and leafs, even some high pressure, over the counter gas shocks like Gabriel or Monroe will work out nicer than the KYBs. You will find the KYB ride is rather hard and abrupt. Look for threads on KYBs elsewhere in the forum for more opinions. Non-adjustable Konis are real good, adjustable QA1s even better if you want to get into tuning. These are especially nice if you plan on upgrading torsion bars further, which I'd recomemend if you are going to get into some serious handling.

[GMachineDartGT]

When installing an adj strut rod, you always want to check that you are not binding the lower arm bushings. Chances are you are binding the drivers side as you mention the wheel is too close to the sheetmetal.

When using urethane lower arm bushings, and urethane strut rod bushings, the factory strut rod length goes out the window.

Once you are able to feel the load on the lower arms by shortening the strut rod, back them off slightly to not bind the bushings.

Take a cross measurement from the lower ball joint grease fitting to a measuring point on the frame. This will verify the squareness of the lower arms to the chassis.

You can also take measurements to the leaf spring locating pins too, in order to verify the squareness of all 4 wheels.

Lastly, you can measure the leaf spring locating pins to the frame as well. This way there are no surprises when you hit the alignment rack.

[dusterbd13]

the t-bars im running are .90's. little bigger than stock. picked them up cheap, so im using them for a baseline. if i need to, ill go with the solo style t-bars. as far as the shocks, again, they were a budget minded purchase. better than the monroe/gabriels ive had on the car in the past.
i also figured with a fiberglass hood, aluminum heads/intake/waterpump/radiator, relocated battery, etc, i was dropping enough weight off the front to help the effectiveness of the front t-bars immensley. the 340 springs in the vack were what i had purchased the first time i restored the car. only a few thousand miles on them, so they were retained.

i adjusted the strut rods by setting the ride height after loosening the front nut. tightened the rear nut up until it was a little bit of a struggle to get another turn, then torqued the front nut. probably put them in a little bit of a bind, but it should be OK to get it over to the alignment shop this week, right?
also, will your average alignment shop know what to do with these things, or will i need to trailer the car to a race dedicated shop?
lastly, what should i do for alignment specs? i was thinking .75 negative camber, zero toe, and about 4-6 degrees caster. sound right? anything i can do with alignment specs to get some more road feel from the steering box until such time as i can afford one of the firm feel boxes?

thanks for all the help. i thought that i would be the only mopar guy. dlad to see i was wrong.

Michael

[GMachineDartGT]

I would assume that the alignment shop like almost all others are complete morons. Most regular techs these days have no idea what to do with a t bar front end. I don't agree with your methods of its good enough...

Take the measurements like I suggested and set the strut rods properly and square up all four wheels like I outlined. If you don't do this, you are assured a poor experience.

Neg .75 is a good place to start. 4-6 caster is not likely, 2-3 if you are real luckly. Tubular control arms, offset bushings and tall spindles are needed to get into the 5-8 world, like normal cars.

I agree with the others, the KYBs are a poor choice at best. The .92 t bars are a decent choice, but a little on the soft side.

[dusterbd13]

i would assume that thsi would be done at the alignment shop, but i know i should stop assuming these days (ask me about my assumptions with the power steering system). ill do that before sending it off to the shop. where would you recommend on the front fame sections? K frame bolts?
michael

[GMachineDartGT]

You are dreaming if you think the alignment shop would do this...

Get yourself the factory chassis manual, it will give you the proper points on the frame to use. Usually its from the front frame rails near the t bar crossmember.