I'm retired United pilot
Printable View
I'm retired United pilot
At the risk of controversies I've caused here in the past I’ll put my two cents worth in.
As Jerry has stated, the tie rod ends may not be designed for the loads applied by your application. While you may be planning on a low horse power to weight ratio and skinny tires (no traction), a future owner may not. Always error on the side of caution, expect the unexpected, stay with commonly known practices when it involves safety. Safety with your vehicle build will not only include you, but future owners, and a safety issue could also effect innocent bystanders. While I’m a huge advocate of working on, building and driving our classic cars and having fun, I’m also a huge advocate of doing it safely. PLEASE do not cut costs or corners on safety.
If you or others have concerns about critical product application, weld strength or other items on your car, don't speculate, check with the manufacturer and ask for their design sheets. If it’s a weld you have performed that has concerns, get it tested or go back to welding school until you're sure. It’s easy and the piece of mind alone is worth it (not to mention the life it may save). Remember, we only get one life, please plan accordingly. Be safe and live long.
OK, I’m done…
I'll throw in my 2 cents. While I would choose a heim joint just because they are common and easier for me, the tie rod end is going to be as safe as it gets. If a light load of a four link suspension is enough to shear a tie rod taper off, I think were all in trouble with using them on our steering. In the AG industry I've seen tie rod ends used in every angle holding many times the weight the rear end is ever going to see and they last for years and years. At the end they start getting a little loose just like any other joint will do with continued use. That's just what I see.
Tie rods were designed for steering loads not vehicle acceration and stopping loads ----anybody that thinks you have as much force thru your steering wheel as compared to any v8 engine torque/hp ------------
And-----in this install the weak/failute prone arae is where the end of the tie rod threads in the tube are-------
Is there a difference in the threads of a tie rod end and a heim joint end ? If I remember right the ones I used were 5/8 fine thread where maybe a tie rod end is 1/2 fine. Maybe Driver will chime in with more details.
Seth-Its not about the differance in the threads-------its about where the threds are screwed into the tube--------the failure will occur at the end of the threaded shank of the tie rod end in the tube-you are going from a solid amount of material to a thin tube that is weakened by the internal threads and that will create a weaker spot where the external forces on the link will cause the failure--------
The tapered shank in a correctly tapered receiving hole will actually fit up better than just a bolt in single shear mount--
Correct me if I'm wrong, but weren't heim joints originally designed for aircraft? I know a butt load were used on DC-8,9 and 10's.
I believe they were -might have been military but aircraft had them on every moving part------
Tie rod ends were developed for tie rods--------steering--------
Not suspension components carry weight, transferring vehicle acceleration/ deceleration------
Oh really? There's no high force load on a drag link or tie rod and tube at a knuckle? I beg to differ. I like how you're calling the tie rod stud insufficient but then blame his mount that will fail first. I don't really like the mounts either. Imo if the tapered portion was thicker it would make me feel better instead of the 2 piece mount he has. This is not the way I'd do it either, but I don't see it being a death ride because of it. Like Seth said, I've seen tie rods used in all kinds of weird places on ag equipment, even some old gse. For instance, a tie rod attached to a pulley transferring to a rod to operate another component. No torque or force there? Not to mention those ball stud ends are forged then heat treated in most cases.
I can appreciate the caution noted but maybe instead of saying I hope you're not on the same road as my family, offer a solution to why that's a bad idea. Hey, maybe this _____ is a better way. Rant over
So you are more concerned with the threaded sleeve splitting apart, compared to the potential failure of the 'rod end'. Interesting. I would then point out that the stress load on the threads decreases in direct proportion to the length of shaft inserted. IE: the deeper it's screwed in, the safer it becomes.
Remember also: work is calculated on the cosine, which for this application will always be one, so long as the rear end is centered.
Ryan you have misread what I probably haven't written too well---If this site would ever get where I could post pictures as I want, I could better illustrate the points that I think are failure bound------Its not the stud, tapered or not-its the threaded part of the tube at the very end of the tie rod end-in this case-6 to 8 inches from the end-
And I've worked on lots of ag and industrial equipment over the years and seen lots of thse shaker things-------the torque and force used there is no where near what you'll see on a v8 driven vehicle transmitting 400 hp or hundreds of lbs of thrust (engine multiplied by gear ratio) into the rods that connect the rear end to the frame-add in chough holes, bumps, slamming speed shift gear changes, full throttle downshifts---------
I emailed TRW about it, they told me that the design sheet/engineering data is not available.
I am using these tie rods and swedge tubes with 100% thread engagement. The threads on the tie rod is about 3 inches long, and the threads inside the tube is 1 3/4 inches long.
Seth, the tie rod shank has 5/8" fine threads. The castle nut on the stud has 1/2" threads.
Ryan, Thanks for sticking up for me! :) I'm not sure if I explained well enough how I made the mounts. I cut the mounts out of 1/4" angle iron. I then drilled a hole in them, and then welded a nut to the backside. I then cut the taper into both the angle iron and the nut. The thickness of the tapered part is about the same thickness as on a stock steering spindle arm. These pictures aren't really the best, but I'm not at home right now to take new ones.
Jerry, are you saying that the extra length of the tie rod vs. the length of a heim joint is going to cause the swedge tube to fail?
I'm trying to understand what difference that would make. Also, I know that posting pictures on this site is a bit convoluted. I could try talking you through it if you like.
Attachment 68779Attachment 68780Attachment 68781
I'll ride with you, I'm not going to stir the pot if I can help it but I still don't understand how the threads of a heim joint are any different than the threads of a ball joint. I have $0.04 in this conversation now. LOL
I just checked back in after the latest server crash and decided to look in on this build. I'm no engineer, but I think I have a pretty good "seat of the pants" feel for putting a rod together. Lord knows I've looked at enough of them through the years.
First thing I see in the rear is that there is no control to prevent chassis lateral movement. I would hard-mount one end of the spring like some of the fellows do on front springs to prevent the same thing. You could also do it with a Panhard bar, but as I've said before, someone should have pinched Rene Panhard's head off as soon as he popped out of the chute. A Panhard bar is, without question, the most horrible automotive design ever conceived.
Second thing I see is that there will be a fight going on between the spring mount and the control arms. Something is going to break unless you allow the spring mount to free-float. Rather than doing that, I would ditch the 4-bar arrangement and go with a modified ladder bar design, something like this......
http://st.hotrod.com/uploads/sites/2...nd%7C596%3A372
This more closely emulates the design that Henry started with while using a single spring, although his design pivoted in the middle on a ball/cup arrangement front and rear.
You will be able to see this malfunction by making up some heavy construction paper components swiveling on stick pins (paper dolls, as suggested by Carroll Smith (suspension engineer extraordinaire) and running the rear suspension through its cycles to eyeball differential angles. Right now, before you do anything else, purchase a flat bathroom door from someone in town and build a wooden or metal support for it, making yourself an impromptu cheapo drafting table so you can see some of these things work before you commit them to steel. If you would like to add to your library and learn from the very best, purchase Tune To Win, by Carroll Smith. He ran the team for Ford Motor Co. that went to LeMans and whipped Ferrari with the Ford GT40. Paper dolls are found toward the end of the book.
Although a highly irregular idea, using tie rod ends as a suspension component does not scare me at all. I can see Jerry's point, but in my mind all the force will be directly inline, with no bending at all and so it looks like it will work to me, although I dislike the harsh drive that results from metal to metal connections. I would be in favor of using a Johnny Joint or equivalent as a rod end.
https://www.youtube.com/watch?v=8dE_tFFvjfU
The paper dolls will be very helpful when you return to the front end to re-design those components. As noted by Jim Robinson, you will not like the results of what you have designed so far.
If I were to be involved in the front end, I might try fabbing up a rack and pinion system from a junkyard R&P. Here is a writeup of a commercially-available unit and how it works on a straight axle.
https://www.ford-trucks.com/forums/9...le-report.html
I would also design new steering arms that would provide 100% Ackermann. Come to think of it, I would probably design a whole new front end around a shorter tubular axle using disc brakes. Keeping within a budget is fine, but in my opinion, one must make allowances where driveability, performance and safety are involved.
If, in the end, the car does not ride and drive very, very nicely, then the entire exercise was a waste of time, money and energy.
.
So, is this the swedged tubes you used? http://www.allstarperformance.com/sp...s/pdf/1711.pdf
And since you used 5/8 threaded ones, they are short?
Seth---------you are mis reading the issue ---------its not about the threads of a heim joint against the threads of a tie rod end----------its about the threaded tube they are screwed into-------the weak/failure prone location is the next empty thread in the tube-basicly you go from a solid combo to a tube that has threads cut to a bigger(5/8 in this case) hole id and at the point/length its at in these pics will fracture/break much more easily than if it was close to the end.
Add as a referance of the load levels on steering components compared to chassis/drive line stuff--------do any of you actually think that you can twist the steering wheel equal/greater than the engine can twist the rear end??? and it gets multiplied by the rear end ratio plus any shock loading/impacts from rough terain, gear shifts, brake application------------
Jerry,
Yes those are the swedged tubes I used. I used those exact same tubes (3/4" size) as trailing arms during my 15 years of stock car racing. Those cars had nearly double the weight and triple the horsepower of my T-Bucket. I never broke a single trailing arm. I've seen many, many others doing the same.
Tech Inspector,
I am no suspension expert, but I have spent about three decades studying suspension design relating to oval track racing. I'm aware that this car does not have a highly advanced suspension design. It's a hot rod my man! If I were trying to build something that could qualify for the Indy 500........I would not be building a T-Bucket! :) I do plan on addressing the Ackerman, as Jim suggested.
Attachment 68782:confused:
Jerry, please clear some space for PM. Trying to send you a message.
.
Driver50X, You have been the biggest waste of my time in a long time. Thank you for yanking me back into reality. :whacked:
.
The 1 inch tubes are .095 wall with 3/4 threads while 7/8 tubes are .083 with 5/8 thread-----and heims with 3/4 thread mounted in double sheat are lots different than TIE ROD joints with 5/8 thread.
And on a race car stuff is looked at constantly for maintenance/etc while a street car?????????????????
It's not about the force you can apply from the steering wheel. The force applied is calculated from the perspective of the tire.
Given a ststic frictional coefficient of one, dry rubber on asphalt, and an expected maximum mass of 90% car weight, and the surface area of tire contact: that will give you the maximum force the tie rod end will see.
The calculation is the same for the rear tire except now the load is shared by two links, not one, resulting in an algebraic quotient of half the force applied.
Effectively, you are arguing against a part which, in application ,is going to receive half its rated stress load.
Consider also, the static frictional coefficient is always greater than the kinetic frictional coefficient.
Meaning: once the force applied exceeds the frictional force, the additional force is simply transferred to the wheel as motion, (spinning tires), and the force applied to the links will actually reduce.
Firebird 77 ---I'm not going to continue arguing about these parts-----------The OP I believe sees my point and is not continuing to carry on-----I have been involved with more than one race car, and from experience of looking for the bet route to go with components comes several roads to go down-------and never once to this day have I ever used something that was designed for a lessor load in suspension or steering, also power drive lines----------
I don't deal with opinions, perseptives, he said she said, internet trash talking forums, ---------
So, if you want a resume of my qualifications, experience, exsamples of race records, car shows, magazine center pieces, etc, etc, feel free to ask---------but plesae don't try to side track a conversation about constructing a road sharing vehicle with substandard components ----
I'm only discussing the math.
Could you explain the advantage of the swedged tubes?
Obviously, the larger diameter produces greater cross sectional strength in the center, but doesn't the narrowed diameter create a stress point?
Doesn't the mechanical swedgeing process work harden the material, which would further weaken the material at the diametrical transition?
Well, Driver50x, you've certainly struck a chord with your choice of parts!;)
And I will have to echo others and question the selection. But I cannot say it will fail and when as I simply don't have a spec to show me a load rating. If you've had experience with these parts used in this fashion, then I / We may learn something new. I'd suggest use the ends from a large truck rather than a vega!?!?! :eek::eek::p
Van, not Vega.
I pushed it outside this morning, so I could stand back a ways and get a better look at it. :)
Attachment 68820Attachment 68821Attachment 68822
So how long did you set there, holding the imaginary steering wheel and making "car sounds"??? rofl..
You know we've all done it at least once! 8-)
Good for you, you're making it happen.
For some reason a guy has to do that once in awhile. It gives the allusion that it's almost finished.:LOL: It sure looks good from here.
It looks nice! Do you plan to go with a pick up type bed or a turtle deck?
Yep, it rolled in and out super easy. It must be close to done right?!:LOL:
My wife seemed pretty amused that I was outdoors taking pictures of it.
I am going to build a wood stake pickup box.
Please check your 4 bar angle alignment.
I know in the picture the pinion is angled down. I had not yet taken the time to adjust the correct bar lengths.
Please check it through its travel (up/down). My calcs may be wrong, but it appears your geometry out of sync causing the differential to excessively tilt as it goes through its swing.
keep in mind on this light of a car the travel will likely 3 in or less .
JMHO, ideally you want to minimize any differential to motor angle changes, excessive (or misaligned) angles will eat u joints, bearings and transmission tail shaft bushings. Only trying to help, and again, JMHO...
That's a good idea. I'll unhook the spring and swing the rear end through its travel to see how much it actually changes.