Arms on a toyota

[91yotaprerunner]

I am getting ready to rebild the arms on my toyota. I used mild steel for my first time. I was only 16 at the time though and now i know that its probly not the best to use. Should i use Chromoly or DOM tubing. Also i have a miller mig welder and will mig welding be ok for welding the arms or should i tack everything together and take it elsewhere to have it TIG welded. The last question is is it better to use heims or bushings at the pivot points for the upper arms and strut for the lower arms.

[motoxscott]

Your design and layout should dictate the strength, not solely the materials you use. Most strength comes from tieing everything together properly and gusseting high stress/load areas. MIG welding will work fine as long as your MIG welding is good. Do you have plans to make tubular or boxed arms?

You have any pics of the arms you already built ?

-Scott

[91yotaprerunner]

i havent decided on tubular or boxed arms yet. Which one in peoples opinions would be best. Im open to all suggestions. I do have some pics of the arms. I know they arent the best, but i was 16 when i made them and had never touched a suspension before. I only got 12 inches of travel out of them but i know where my mistakes where, the main problem was the upper arms and the plate the ball joint attached to, it put the ball joint in a bind too soon. the other problem was the steering, i need to go to heimed steering because they are 5+ per side. the pic only shows the lowers, i can try to get some of the uppers tomorrow

[SLR]

GO 4130N PLATE .187 .125

[racer951]

I'd say 4130, boxed or big tubing...taking them to get tigged would be a waste of money in my opinion.

[91yotaprerunner]

I also wanted to ask if its really necessary to use uniballs on the lowers. I plan to use uniballs on the upper. Ive seen toyotas get 18 inches of travel with stock ball joints so do i really need to use the uniball on the lower.

[WFODAN]

WOW!!!

18 inches out of a stock balljoint ?? Must have been painted blue .

[matt_helton]

yeah dan. i think its technically called "True Blue", if im not mistaken. lol

[matt_helton]

this is what happens when you make a-arms out of mild steel. .120 wall 1.5" HREW. now my arms have lasted for 2 years now of serious abuse and the right upper just folded over the weekend. right at the end of the gussett. just metal fatigue, i guess. some re-designing is necessary. see pics...

[matt_helton]

another pic......

[matt_helton]

last one..........

[91yotaprerunner]

I also plan to be going to a coilover shock so i was wondering if there is any advantage to moving the strut support on the lower arm to the rear of the arm.

[matt_helton]

i think you are best off leaving the strut arm on the front sides of the lowers as it is in stock form. i think its better to have the arm and mounts being "pulled" on instead of "pushed" as it would be if it was off the rear of the arm. besided the "strut frame" is a great way of tying the sub frame up to the front cross member and makes a great skid plate mounting area. i dont really see why you think a coil over setup has anything to do with wether the strut arm is fore of aft of the lower control arm. , un less i read that wrong, but i would still keep it in the front.

[91yotaprerunner]

well depending on how the strut is designed on the lower arm it can be put right in the way of where the torsion bar would run to mount to the lower arm.

[matt_helton]

yeah, you are right. you can mount it in the rear on the same axis as the torsion bar. and i have seen a few trucks built like that. but your question was if there were any advantages to moving it to the rear, and i dont think there is like i allready stated above about the whole "strut frame" thing. why make more work for your self and ad more weight to the truck when you can run it off the front and make one design function in 2 different ways. unless you just want it to look different than everyone else. do what you feel is necessary, but id run it off the front for strength and function.

[91yotaprerunner]

I would rather run it in the front, i was just trying to get some opinions on it because i have seen it done a couple times and just wondering if there was any advantages. i will most likely keep it in the front so its less work i have to do to mount the new arms. plus like u said earlier i can tie the skid plate into the strut frame and give better protection under my truck.

[curt]

A couple of things to think about...If the support is in the rear, you can probably make it go further out to the end of the arm without clearance issues which would reduce the leverage on that arm. As for upper control arms, we've been using plate arms for the uppers for 4 or 5 years now and they are bullet proof. We came up with a design then had it cut out of 3/8" thick high tensile steel and we're running one of the originals and the ther side had been going for at least 3 years. The good thing is they can be welded by anyone and get the durability, the bad is you need to have access to a plasma cutter to get the plates cut when you want to make changes to the design but there's no way they will break....Curt

www.race-dezert.com/ubbthreads/download.php?Number=68683

[91yotaprerunner]

well i actually do have a plasma cutter, my parents helped me purchase a welder and plasma cutter and now i no longer have to rely on friends to help me get the welding and cutting and etc. done. those arms are definitely interesting and ill consider that type of a design when building my uppers.

[matt_helton]

hey curt, you probably dont remember me but i met you and your wife, patty way back in the day at a poker run in barstow. probably 96 or 97 i think. i met you guys and you had the old 4wd race truck out there at the power lines behind slash x. and mark naugle BCG1 was with you guys. i met you guys through a friend named Kyle Hetfield from SB., white IFS yota w/ red bumpers. my yota way gray at the time with blue bumpers..........its a long story, anyways. what i wanted to say is how do those upper a-arms not bent under harsh braking???? i remember the old downey arms, the first downey arms that had that design and they had problems with them bending under braking loads. the only difference i see in the arm is the pivots and the uniball at the end. ok, and its not gold zink plated http://www.race-dezert.com/vb3/attachments/old/images/graemlins/smile.gif but seriously, am i missing something?????????? how do those hold up??

[ntsqd]

The strut links want to be in a tension arrangement, as they are in the front. Moving them to the rear puts them in compression and requires that they be larger OD and probably thicker wall (if not bar stock) to avoid buckling.

The lower arms need to be designed with the coil-over's bending loads in mind or most likely they will bend at the c/o mount.

The biggest single advantage of Chro-Mo is weight, you can use less of it to get the same strength. You're far better off to design in the strength than to rely on the metal for it. If you have Chro-Mo TIG welded you should also have it Normalized. And not by a welder with a torch.
Welds are on-site castings. MIG welding Chro-Mo means that you now have mild steel 'castings' holding your Chro-Mo pieces together. Put that way it sounds rather silly to do that doesn't it ? It should. I'd use 1020 (not 1018) DOM.


Pop quiz, what does "BCG" stand for ?

[matt_helton]

BEER, CHIPS, AND GAS

[drtdevil93]

instead of giving a technical reply to the tig-chromo comment, ill give a real world example. my entire chassis is chromoly and mig welded, and has never developed so much as a crack. no welds broke. the only breakage ive ever had was on the steering centerlink, and that was tig welded. it didnt break because of the weld, but you get the point.

erik

[tedmales]

"my entire chassis is chromoly and mig welded, and has never developed so much as a crack. no welds broke. the only breakage ive ever had was on the steering centerlink, and that was tig welded. it didnt break because of the weld, but you get the point."


was it heat treated?

[curt]

Matt, wow 95-96 is a way long time to remember, not to mention I'm crappy with names.Post a pic of the truck, I never forget a truck http://www.race-dezert.com/vb3/attachments/old/images/graemlins/wink.gif I remember the trip mostly cause it was about the last time I was in Barstow since we gave up on SCORE. VORRA always schedules a shortcourse race on the same weekend and we haven't missed one in the last 5 years....Our uppers work fine and as I said have lasted virtually forever. The only reason we bent one was a Patty got a left front flat in the 2nd lap of 8 and decided to push the truck anyway so with all the jumping and hard braking in the hairpins it bent the arm about 1-1/2 forward probably due to the braking and heavy loading on that corner(it was the outside corner on the tight turns) The original idea we're using came from an old E&C Spring design that we extended and modified. The only downside is the 14" of travel, I've been massaging them for the last couple of years and can't figure out how to get to the 18" that I'd really like to get. Camburg is going to help me look at my angles and lengths after this season to see where the extra travel might be gotten from. I wouldn't run a tube arm unless I had to, although they are way easier to make in a one up situation where the plate are easier to make in volume.

As for the old chromoly vs DOM argument. Chromo is better, there really is no question that the metalurgy is superior for strength. I would think it's great for fabrication under a controlled environment, keep in mind desert field repairs with the old car battery and coat hangers might give you a less than favorable result. That being said I still don't believe the average beginning fabricator, that needs to ask the question, has the skill to use the stuff, overheating is a problem and how many not perfect notches did you add extra filler to cover the gap? My crew and I've built the last 3 trucks we've raced with favorable results but we haven't felt good enough nor do we have the PROPER equipment to work with the stuff with any kind of comfort level.

Everything we've built is DOM or A36 plate except the upper arms(which I can't remember the specification). For the last 2 years we've run a minimum of 23 pro arena events, 5 shortcourse races, and 3 desert races(short ones@200 miles) each year and for 3 years before that we ran 5 shortcourse races and somewhere around 500 miles of shortcourse testing and the truck is still holding up very well. Fabrication is all design and materials, the better the design the less materials needed and vice versa. Be realistic with your skills and fabricate based on your ability, most of us will never achieve the skill of a Camburg or similar high end fabrication shop so we must work with what we have.

[ntsqd]

"Beer, Chips, Gas"; That's the obvious one. What else does it stand for ?

I'll take a lot of heat for this statement, but if you're determined to use Chro-Mo and can't/won't Normalize it (not just heat treat - Too generic) after welding then you should Oxy-fuel weld it. That is what it was designed and intneded to be welded with. After welding with Oxy-fuel all you need to do is let it cool in still air. No need for normalization, but fitment still needs to be tight and you have to use the right alloy filler rod. Coat hangers won't do.

99% of the itme a TIG welded joint fails in the HAZ becasue of either overheating or no pre-heating, or lack of proper post welding treatment.
To that molten puddle of metal in the arc zone the solid metal just 1/64" away looks like an iceberg. That iceberg supercools the molten metal and 'freezes' it in an extremely brittle crystaline structure. Normalization allows the metal to re-assume the more ductile structure formed by slow cooling or Oxy-fuel welding.

[matt_helton]

sorry Thom, i guess i failed your pop quiz. i only met mark naugle and curt hayos once or twice and that was about 8 years ago. i guess i wasnt "in the loop" as far as the unobvious acronym for BCG.

[Mintychip]

</font><blockquote><font class="small">In reply to:</font><hr />
I'll take a lot of heat for this statement, but if you're determined to use Chro-Mo and can't/won't Normalize it (not just heat treat - Too generic) after welding then you should Oxy-fuel weld it. That is what it was designed and intneded to be welded with. After welding with Oxy-fuel all you need to do is let it cool in still air. No need for normalization, but fitment still needs to be tight and you have to use the right alloy filler rod. Coat hangers won't do.

[/ QUOTE ]

I'll second that. I went to the Oshkosh EAA (Experimental Aircraft Association) Air Show/Fly In this year and went to a few seminars on welding to see how the home built aviation crowd looks at it verses how we do. The guy giving the lecture said the same things that you were saying and I was shocked after reading all the pro-Tig comments on this board.

[tim_krueger]

matt thought you were gonna post a pic of sy 1.1
heres the best one i got
back side from slims house way back in 96 i think
oh the good old days

[drtdevil93]

ted- no the part was not heat treated. when chromoly is tig-welded, mild steel filler material is commonly used, this makes a the strength somewhat uniform (the mild steel becomes about the same hardness as chromoly after welding.) the part must be heat-treated if you are tig welding chromoly with chromoly filler (the filler becomes harder than the rest of the part, and breaks there). and, like i said, the part breaking had nothing to do with the weld. it actually broke in the middle of the tube, about 3" away from the nearest weld.

erik

[matt_helton]

curt, heres a pic from back in the day. let me know if you remember it.

[matt_helton]

and of course the infamous BCG1. pic was taken that poker run weekend.

[matt_helton]

and i couldnt resist...................your old yota that Patty took me for a hot lap in. what a blast. http://www.race-dezert.com/vb3/attachments/old/images/graemlins/laugh.gif

[matt_helton]

ps. sorry to hijack the thread.

[tim_krueger]

heres the best pic of sy 1.1
sorry he hijack the thread lol

[V8Ranger]

Thom, I agree with your statement that 4130 should be normalized after welding but I'm unclear why normalizing or another heat treatment process is not needed if the material is oxy. welded. Obviously the oxy process is going to have a larger, less concentrated HAZ than the tig process but brittle martensite is still going to be formed in the HAZ. From my understanding regardless of the welding process, the material is going to become brittle at the joint which requires it to be normalized.

[ntsqd]

That truck has changed a little since then. BTW BCG1 himself, doubt the truck, will be at the Expo this weekend.

Big Chested Gurls

[ntsqd]

You're right there skirting around the edge of the answer. Oxy-Fuel welding puts enough of what I call "background heat" into the part to allow a cooling rate that doesn't result in the brittle structure. In other words, if the oxy technique is correct the welder is 'Normalizing' as he/she welds the join.

The filler rod alloy used is critical to the succes of the weld. I do not believe 4130 rod is recommended as it results in an unsatisfactory weld metal. Aircraft fabrication uses it, but they go to comparitively exotic lengths in their welding process'. Carroll Smith says Linde Oxweld #1 (or Equiv.) on parts that won't see heat treating, and Linde Oxweld #32 on everything else.

[curt]

Well for once I don't remember a truck ;( It really looks like the one we're racing now before the last couple of makeovers. The old race truck is still in the family, my brother drives it and the one we race was originally owned and built by BCG3-Todd Spicer. Curt