47-55.1 Tie rod questions

[MARTINSR]

I have only set up one frame clip before and I went with the basics that may help you here. You want it at ride height. Now, if the weight an AD and the weight of the car or truck that your suspension came from is way different this could be hard. If it is, the springs should be changed so they put the truck at the same ride height as when those parts were on the originally. But that isn't likely, soooooooo you will be guessing a bit.

But, if you remove the shocks and put a piece of all-thread in place of them and tighten up the all-thread shortening it bringing the truck down compressing the springs to a ride height similar to what the truck will have with all the weight on it you will see all the angles of the suspension that it will have once the truck is assembled.

This may provide you with the comfort knowing it will all work, or it will throw you a loop that you have some changing to do.

If the suspension came off something with similar weight as your AD you could simply measure the distance between the lower control arm and the crossmember and put it at that. But when those weights are off and you have different springs that is all pretty tough. But realistically as has been mentioned that lower control arm should be level, plain and simple. If that is how it will be, we don't know but that is where it SHOULD be.

Put some all-thread in there and pull it down. I did this before and it really helped set it up.

Brian

[mr48chev]

Those front springs just look a lot beefier than what we are used to seeing for S-10 springs. If they were supposed to be S-10 springs.

One of the threads I read on the net while hunting for answers on this mentioned that that builder had used 4 cylinder springs and had cut 1-1/2 coils off. I looked at so many Danforth crossmember threads across the net that exactly what was said in what thread is a jumble. I get wrapped up in one of these things and spend hours on end doing research to see if I can come up with an honest answer rather than an opinion.

The only across the board answer that I came up with is that it is very apparent that Scott started selling the crossmembers way before he did any real research and development and put at least 10K on a truck with one on it. Good ideas but his customers were his research department.

I was all set to buy one of Industrial Chassis's Dakota crossmembers when he stopped making them for a while because of some issues. The main issue being that he got a bit tired of building pieces to sell rather than building complete builds. They are selling a revised edition of that one and I still have all of the Dakota pieces sitting out here. That unit is right at a thousand bucks but Dakota front end parts are pretty cheap at the wrecking yards. Bolt pattern is a bit of an issue but with a caliper bracket he sells you can run 12 inch rotors on the front with either a 5 on 4-1/2 or 5 on 5-1/2 that matches the pattern of the F-150 nine inch I have for it saving having the axles and drums redrilled. I have the right rotors out in the shed to boot.

This still has my curiosity up and I am still doing some research. I've got the 92 Dakota rack (Dakotas come stock with a rack) and a couple of Pinto/ MII power racks and was going to measure tie rod pivot point to tie rod pivot point on those racks to see what they were.

[51 3600]

Curb weight of the 02 Blazer my suspension came from is listed as 4400 lbs. My 3600 when mods completed I'm guessing will be around 3150 lbs. Pretty much tells me the stock Blazer springs are too much for my truck. Right now without front clip, hood, radiator and AC on the truck I'm probably 300 lbs shy of total weight on the front of the truck.

I'm going to try this process as well as all-thread without springs and see what it tells me. As I try to visualize what will happen my brain gets all tangled up so I'll probably be back with more questions.

[51 3600]

Originally Posted by mr48chev

This still has my curiosity up and I am still doing some research. I've got the 92 Dakota rack (Dakotas come stock with a rack) and a couple of Pinto/ MII power racks and was going to measure tie rod pivot point to tie rod pivot point on those racks to see what they were.

I have googled my brains out the last couple of days digging for info. One of the hardest bits of info to find are those pivot point dimensions.

Thanks for all your hard efforts (others too). I'm sure it will be helpful to more than just me.

[mr48chev]

Body tube length of a MII rack is 19-1/2. The pivot points on the aftermarket universal crossmember I have out here are 22and 1/8 to 1/4 center to center.

I couldn't find either MII racks I have and have to figure out where I moved them to.
The Dakota rack I have measures right at 25 inches pivot point to pivot point as far as I can figure.

I still don't think the length of the actual rack is the issue on yours though. The tie rods appear to match the angle of the Control arms pretty well spot on. Spacing in/out from the crossmember to stay even with the ends of the steering arms might be an issue though. Some of the theories on that don't match my training at all. I may have to dig out a couple of my old auto mechanics text books and do some homework.

[51 3600]

Tried the all-thread trick to compress the springs. Using the largest all-thread, 1/2", I could get through the hole in the upper spring pocket, I didn't feel comfortable going far enough to bring the lower control arm up to level. Looked like I would have to compress that spring a long ways and it wasn't compressing very easily. Have a buddy coming over tomorrow to help me remove those springs then I will again use the all-thread to level the lower arm and see where the ride height sets.

To position the upper arms correctly on the mounting plate will require notching the frame. Not sure I want to do that. Last time I searched for tubular arms with a dogleg like stock, they were extremely expensive. Guess I'll try a second search before resorting to the notch. There is a possibility that once I level the lower arm the upper arm may not need to have the dogleg in it.

Also removed the butchered inner tie rods from the Camaro rack. Pivot centers on that rack are 26" apart. Lower control arm centers are 19.75" apart. I will check tomorrow but initially when tinkering with this rack I didn't think the front end could be aligned due to inner tie rods being too short. If that proves the case, I'll probably just by new tie rods for now. It will be awhile before this truck is drivable so I may live with what I have. MII may be better but unless I know it's definitely needed, I'll wait till later.

[51 3600]

Progress report for those interested. I'm optimistic. What do you think?

Took out springs, installed threaded rod and wrenched on it till lower arm was level. Forgot extra nut to keep suspension from dropping all the way down, that's why the jack. I'll correct that tomorrow. Rack horizontal with lower arm and inline with steering knuckle. Of course no change in lower arm to rack pivot point location.

Upper arm in more workable position but as you can see I definitely have to mount it behind the mounting plate to correct some of the extreme positive camber. With stock upper arms that means I would have to notch the frame. However, I placed the tubular arms I originally had used on top of the stock ones and it looks like I can now use those so no notching. Will try that tomorrow also.

What to do with springs? These 02 Blazer springs are 13.25" long and were compressed about 1" as the truck sat before I started this thread. Setting the ride height now has reduced the top to bottom height of the spring pocket (where the shock mounts) by 2.625". That dimension now is about 9.625" near as I can measure. Still have another 350 lbs +/- of weight yet to add to the front end of the truck.






Looking down rack runs in straight line


Tubular arm laying on top for comparison

[dsraven]

check the heidts site, tech articles, for something called "understanding independent front suspension". it may help you understand how things should look. secondly, check out a vehicle like the one your kit is supposed to mimick. see if the lower control arms are level with the ground with the weight of the vehicle sitting on the tires. the whole vehicle, complete. usually the lower control arm is level to the ground at ride height but your "mimick" truck mey be different. if it is supposed to be modelled after an s10 check the gmupfitters site, bodybuilder manuals, and choose your model. there is usually an engineering drawing of the front end and other stuff so you could see how the control arms should look. maybe some dimensions too if youre lucky

[leegreen]

I think your set a little lower than the factory blazer would have been, the lower arms would have angled down 2-4 inches over its length. That is referred to as Z height, the drop from A arm bushing centre to ball joint center. I don't know what the blazer spec would be.

The more important thing is to set the suspension to the ride height you want your truck to be at, then figure out how to adjust the suspension to suit.

I think you are on the right track with swapping to the tubular upper.

The springs look beefy in diameter and un-finished at the ends, normally the end of the coil lies a little closer to the coil beneath. Is it possible the doner truck had been jacked up to make it look like an offroader?

I think these are stock style replacement springs: https://www.moog-suspension-parts.com/moog-80994 they look like a softer spring than yours.

[dsraven]

just looked on the gmupfitter site. it seems the s/t truck info has been removed. I will look in my stuff and see if I still have a copy of that s10 IFS somewhere.

[dsraven]

do you know what year your blazer parts are supposed to be from? dunno if that makes a difference.

[dsraven]

I looked for a copy of the s10 front end stuf I had but I guess it is put a\y so well I can't find it. sorry man.

[dsraven]

http://67-72chevytrucks.com/vboard/s...d.php?t=670981

[51 3600]

I'm slow responding. Had to take a break from this for a day as my brain was getting fried. Trying different approaches helped me understand (a little) this suspension business. Learned something, solved some problems, created new questions, more searching.....Still a ways to go.

dsraven, thanks for the references. Haven't looked them up yet but I will.

Originally Posted by leegreen

I think these are stock style replacement springs: https://www.moog-suspension-parts.com/moog-80994 they look like a softer spring than yours.

Opened the Moog link and found at the bottom the dimensions of that replacement spring. Same as mine except I'm .38 inches shorter due to wear I'm sure. Very helpful, thanks.

You also brought up z-height. (Thanks a lot. Just when I thought I was understanding it all, ha.) Prodded me to search the web SOME MORE. And found this on GMfullsize.com.
"Z height is the distance between the center lower control arm pivot bolt, to the bottom part of the steering knuckle. On a level surface, measure the distance from the center of the control arm pivot bolt to the ground, then measure from the bottom side of the steering knuckle to the ground, subtract the measurements. This is your Z height, On a 02 Blazer the Z height is 4"7/8" inches. Does not matter if the Blazer has been raised 12 inches with a lift kit, The Z height always has to be adjusted for correct suspension operation. If you do not reset the Z/ride height back to factory specs after installing a lift kit, you risk damaging the cv joints, Control arm bushings, Torsion bar, ball joints, etc...."

02 Blazer, that's me. Can't get more appropriate although that site and others talks a lot about vehicles with torsion bars for adjusting z-height which I don't have. Again, very helpful.

This pic from 3 years ago when I first had the tubular arms attached. Problem.


Then I went with the stock arms to solve the problem as seen in previous posts. Now (below) with the all-thread and tubular arms, setup looks workable. If I incorporate a z-height. I'm not sure if the tubular will still work. Will experiment.

Oops. See next post.

Also with the tubular arms I now have some negative camber. Upper arms aren't adjustable so will have to look at the lower to see if they have camber kits. If not, gonna look to see if they are available. Was at an alignment shop today and tech showed be a GMC with no camber adjustment possible without replacement parts. Tires showed it too.

One more thing just to keep y'all interested. Rack pivot point to steering knuckle dimension is 1" longer on drivers side than passenger side. Probably not desirable huh? I can just barely remount the rack 1/2" to the driver's side and squeak enough space for the the pinion to clear the frame. I think. If I decide to change to MII or another shorter rack I'll deal with that later.

Then there's the spring decision, but I'll quit for now.

Thanks all, you're great teachers and so helpful.

[51 3600]

[dsraven]

last pic looks a lot better, less angle on the upper ball joint. some control arm manufacturers have the ball joint attachment part on an angle to the control arm for better ball joint angle I think.you would have to research that or simply modify the control arms you have.
so, the way it is set there, as the suspension goes up, the tire will lean out for a bit at the top until the control arm comes up past its center/level point then lean the tire in as the suspension goes up further. the lower control arm looks pretty level. if it is below the level point then it will also lean the tire out but at the bottom until the control arm hits it's level point, then the bortom of the tire will lean in as the suspension goes up. if you wanted to see how the angles will affect the tire leaning/rubbing the fender, you could do a cardboard mock up using the lengths and angles of the control arms as they will sit at ride height. that way you don't ruin a tire/fender/paint when you get it all together for the last time and go for the first road test. thats never a good time to find out. it is also a good idea to assemble the front end without springs and see if there is bump steer as the truck is jacked up or down with the tires sitting on the ground. do a toe in style check at several points as the truck is moved up and down. you can scratch a mark on the tire tread with a nail on a block as the tire is rotated, both sides, and use that as a reference to take dimensions from in front and behind the axle, so on the front of the tire and on the rear of the tire. they can be dangerous to drive if there is bump steer caused from improper IFS set up. also, check the tire diameter and wheel offset and compare the stock specs to what you plan to use as the final set up of your truck. if the offset or diameter changes too much from stock s10 specs then the steering is also affected. it is called scrub steer, king pin inclination or steering axis inclination. there is a bunch of info online regartding this and how it affects the steering effort and the vehicle wanting to follow every crack in the road.
on a MII cross member I was sold, that was packaged as the wrong year apparently, I had to modify it to fit the frame. I went with the lower control arm level and the upper control arm lower at the frame end by 4 deg. that way the tire was gonna always get further away from the fender as the tire went into the fender. when the suspension went down the tire had more clearance anyway so wasn't worried about that part. it was on air bags but not gonna be a "rockers on the road" style of air bagger, just a daily driver that was lowered and on air bags for the smoother ride.

https://tiresize.com/wheel-offset-calculator/

[dsraven]

it does seem like the rack pivot points for the tie rods is gonna be out of plane for the control arm pivots, which is gonna affect the steering when the truck goes over a bump.

[dsraven]

in the link I attached a few posts back the guy used a thunderbird rack. I think there are several different attachments available for them to lengthen the pivot point to match the set up in place. they are commonly used on the MII systems so lots of support.

I know it seems like a lot of frustrating researching etc to get things right but it will be worth it to get it right the first time.
keep up the good work and post lots of pics. we aren't trying to pick your work apart, just trying to set up for success the first go around. it is your truck so build it how YOU want, but, build it safe cause we are all driving on the same roads.

[dsraven]

https://www.wheel-size.com/calc/

https://low-offset.com/workshop/scrub-radius-explained/

[leegreen]

If you want to measure it all out, this online suspension tool looks pretty cool. I'm not sure it can model control arm pivots that are not parallel to the center line like the g body upper

http://vsusp.com/

[51 3600]

I played around awhile today moving the control arms up and down trying to get that z-height and seeing what would happen with the tubular upper control arm. The first pic below shows about how far I'm willing to go with that upper arm. In that location it looks to me like the ball joint would have a short life and the lower arm is not even headed toward the z-height that GMfullsize.com poster stated.

If I put the stock upper arm on (which I can't do unless I notch the frame) it would be about where I started out in this thread. The bottom 2 pics show the before and after ride height of my truck from where I started in this thread to where it sits now with the upper arm positioned as in the first pic. Lower arm is angled down just a few degrees past level. The truck frame is 3.5" lower measured just behind the lower control arm.

So to my thinking at this moment (disregarding the r&p and springs questions), I have 3 choices. 1) Notch the frame and put the stock upper arm back on. 2) Using the tubular arm set the lower arm level which will fix the upper at a better position. 3) Leave the threaded rod in and do nothing until I get the truck all together then revisit the whole subject. I keep making comparisons to the donor Blazer setup but I don't think that can be duplicated in this application so matching it or using those geometries ain't gonna happen. I just need to get it safely functioning within tolerable parameters. What say all of you?

In the late sixties, in the summers I worked with two friends of mine setting up and pouring concrete foundations for steel grain bins. We went to work each day in an 50s vintage pickup that was worn out to begin with. We loaded it down with steel forms a good 3' longer than the bed plus tools and equipment. Driving down the road you had to constantly turn the steering wheel at least 1/8 of a turn left and right to keep it going straight. We called it the "Hugger" cuz it didn't hug the road.

Point is, I can tolerate things that aren't perfect and I can live within the bounds of certain limitations. I don't think I'm creating a death truck but I also know it's not going to be track ready.

[dsraven]

oh, hey. don't give up man. you can beat this thing.
maybe pm the guy in the link I posted who has done the same cross member on his truck and see if he has the directions still or if he knows if it contained dimensional info.
worst case scenario modify a set of tubular upper arms so you get the correct geometry.
once the control arm geometry is right I would seriously look at the rack as I think it is out of geometry and will cause you some serious problems with driving. center it and see if the tie rod pivot points are gonna be inline with a line drawn between the upper and lower control arm pivot points. if not shorten or lengthen as needed or grab a rack from something else that will work.
will you be planning on dropping the suspension like a low rider? up-down- up down all time time? with coils springs I would tghink not. so, put the lower control arm where you want it, whether it is in the correct height or not-I wouldn't go any further up than level, then get the upper control arm bnuilt or modded or whatever
when the lower control arm imaginary line drawn between the pivot points and the ball joint is just below level it means the bottom of the tire will kick out slightly as the suspension travels up then it will kick in after that as the suspension continues to travel up
if the upper control arm imaginary line is parallel to that the tire will stay relatively straight up and down except that the upper control arm is shorter, which means the upper part of the tire is always gonna kick in as the suspension travels upward
this is what will keep the tires from rubbing fenders as the suspension travels up and you are turning, like over the bump into a parking lot.
if you assemble the truck and then do the front end it just means the front sheet metal may have to come off a few times to get things right. just tape stuff off so if it bangs together there will be minimal damage. sometimes a different project can be like a breath of fresh air because you make forward progress, then you come back to the hard project and go, duh, I just need to do this.