i welded a perch to my waggy 44 about a month ago with no preheating and just short bursts with a high nickel rod. no cracks or anything. now i am welding a traction bar bracket to the rear 44 and want to weld it to the tube and the pumpkin at their seam. from what i understand i should weld the steel bracket to the tube then the bracket to the pumpkin. using the corresponding rods. what i don't understand is that all this talk about preheat and cracks but no pics to back anyone's claims. not trying to start shit i just can't believe everyone who has every welded to cast iron(yes i mean iron not cast steel) has preheated or gotten cracks. any recommendations?

Unfortunately I do not have amy pics.
I have had mixed results however.
On my D44 behind my (old 2.5L), I had very good results welding to cast iron. Both the Front Traction Bar and Hydro assist mount had some bead on the cast portion. Never any problems.
However, on my D60 (now behind an LT1) I did crack the welds.
Both time no preheat was done and a Flux-core/MIG was used.
I believe it is possible to do it, but might not be as strong/durable compared to a steel/steel weld.

Just my experience.

Short bursts for high nickle rod is OK, only do 1" or less at a time and let it cool to almost room temp in between. Be shure to stress relive each weld right after you finish. Hitting it with your chipping hammer while it's cooling will work. The whole pre heat and post heat thing is a PIA and you need a buddy to do that while you do the welding. You need to keep it heated over 800*, you can check that by using a magnet, the cast will loose it's magnitism somewhere around 800*.

If it's been machined it's cast steel. Although they're many different grades, it's still cast steel. Cast iron is typically reffered to as pot metal.
(yes i mean iron not cast steel)

It's a difference between what 'works' and what the 'right way' is.

Can you stick a piece of steel to a piece of cast iron with a regular MIG gun and wire? Sure. Will it have a tensile strength anywhere near that of the same joint done with proper rod and technique? Nope. Failures of that kind of weld are going to be very inconsistent, so it's not even a very 'rateable' strength.

So say a 'proper' weld would fail at 70,000 psi and your MIG/cast weld will fail at 10,000 psi. Say in your application you're only ever gonna see 8,000 psi at the joint. Yes, it works...but the inconsistency of the joint and the way it'll react to fatigue make it only a question of time before it goes.

i welded a perch to my waggy 44 about a month ago with no preheating and just short bursts with a high nickel rod. no cracks or anything. now i am welding a traction bar bracket to the rear 44 and want to weld it to the tube and the pumpkin at their seam. from what i understand i should weld the steel bracket to the tube then the bracket to the pumpkin. using the corresponding rods. what i don't understand is that all this talk about preheat and cracks but no pics to back anyone's claims. not trying to start shit i just can't believe everyone who has every welded to cast iron(yes i mean iron not cast steel) has preheated or gotten cracks. any recommendations?


i'll get you pictures of the old spindles off of our prerunner.:)

I have good results welding my upper control arm mt. directly to the pumpkin on my waggy 44.

One root pass on each side with nickel rod and 2 cover passes with mig.

http://img.photobucket.com/albums/v157/shayzj/IM003221.jpg

Shay

Forgive my welding newbyness. When you say nickle rod-are you TIG or stick? When you cover pass with MIG what kind of wire and gas?

Forgive my welding newbyness. When you say nickle rod-are you TIG or stick? When you cover pass with MIG what kind of wire and gas?

You can get nickle or high nickle wire for MIG, TIG and arc welding. There are actually some fillers specifically designed to weld mild steel to cast steel and cast iron. It is typically pretty spendy$$$.

You can get nickle or high nickle wire for MIG

Where can you get nickle wire for mig? (thats a real newb question but for whatever reason I haven't seen any around)

Where can you get nickle wire for mig? (thats a real newb question but for whatever reason I haven't seen any around)

Just do a search on yahoo or google, almost any welding supplier can get it. Like I said before....it's damn expensive, but then again you don't really need to do tons of welding on the diffs.

Just do a search on yahoo or google, almost any welding supplier can get it. Like I said before....it's damn expensive, but then again you don't really need to do tons of welding on the diffs.

That's good info, I thought you could only get it for Tig and Stick.

On second thought is they make it for Tig they must make it for Mig.

Googled a couple places... Ebay didn't have it :laughing: thats a first

Airgas carries the nickel alloy MIG wire... What gas do you use with this? Co2? C25? Trimix?

I think you want to run pure Ar with that stuff.

Just for information purposes I wanted give my two cents on the procedure that takes place when welding dissimilar metals (cast steel/iron to LCM or other carbon-based steel alloys) together and the reasons why cracks in the welds will form. When welding base metal to base metal there is typically no problems due to the fact that the chemical make-up of the two metals are the same (In some unusual applications this is not the case.) However, when welding dissimilar metals the chemical make-up is obviously completely different. This can cause a welding phenomena to occur where the weld itself along with the HAZ (heat affected zone) and base metal's sub-structure on an atomic level will be affected. To make a long story short, hydrogen atoms from the base metal are drawn into the weld and are deposited there, leaving tiny air pockets in the weld when the weld is allowed to cool without proper postheat, not just postheating (which is used to stress relieve). The hydrogen atoms will bubble up to the surface of the weld leaving paths of air voids, causing the cracking. The post heat will allow for the dilution of the hydrogen atoms from the weld and the cracking will be avoided. This is why it is important to preheat, use the correct weld rod or wire, apply post heat, and sometimes perform postheating.

I hope this helps alittle explaining why the cracking happens

Thank all of you for the info-very informative. Now for another blatantly newbyness question. Wouldn't preheating and post heating a used diff to 800 F (is that right?),I'm assuming with a torch, spread gear lube fumes and stench the likes of which few people have ever experienced? And what about warping the diff case? Seriously-haven't seen such informative answers on this forum ,at least not without a lot of attitude and misinformation also,so thank you for the help.

I work for an offshore equipment company so the things I deal with are on much greater scale (2" to 6" thick) and stricter specs, but the same principles apply. As far as the preheating and post heating (time and temp.) it depends on a few varibles. This all to get the weld perfect with no flaws which I understand is overkill for what we are talking about but I just feel that it helps to give the proper info to make sure that it is done right and the safe way. It can be done it just needs to be done correct.

i welded the traction plate to the tube then the pumpkin today. i took my time and let things cool after an inch or so. i didn't see any cracks and i peened lightly after each weld mostly to remove slag. i did not preheat either. only time will tell if the weld is strong or not but thanks for everyone's advise and about six of coor's finest i got the job done.

I'm still wondering about the pre and post heating a used diff,wouldn't this smoke up something fierce? Not to mention the sickening stench of gear lube permeating your very soul? Ok not soul.but you get my drift. How do you cope/prevent this?

I'm still wondering about the pre and post heating a used diff,wouldn't this smoke up something fierce? Not to mention the sickening stench of gear lube permeating your very soul? Ok not soul.but you get my drift. How do you cope/prevent this?

Clean the area to be welded and only preheat that area, yeah it'll smoke some,ventilation is necessary.Weld small sections at a time and try to confuse the stresses as much as possible (Don't weld in the same direction every time). After each weld post heat and slow the cooling as much as possible (Insulate and keep out breezes).....Nobody said it was fun to do it proper.:p

I have heard of people using sand to insulate after post heating.

lets hear from more people that did not preheat or postheat and have had success. there has got to be more out there.

before i had a decent welder of my own i had a shop close to home weld my outer c onto my axle tube when i cut down a 44 he let me watch when he did it.. he preheated the c to 250 degrees using a temp stick then used a mig with straight c02 then let it cool in the shop.. because of the c02 there was a little more spatter than usual but 2 years later of beatin on it and everything is still fine..im sure you can ask 10 different people on here and get 10 different answers.... most could be right..but i know this method worked for me

He probaly heated it to 250 just so it would slide on to the axle tube. I don't think those welds see alot of stress either, as long as it is welded all the way around. Braking forces are about strongest stress I can see that going through.

http://www.lincolnelectric.com/knowledge/articles/content/castironpreheat.asp

and here:

http://www.esabna.com/EUWeb/OXY_handbook/589oxy16_1.htm

the c was on already tacked in place on the axle..and that weld may not see that much stress im just giving another option...its still cast to mild steel..he added that the preheat would help the two metals fuse and get good penetration..so i would say the technique would also work on cast center sections as well..maybe just more preheat

Is it possible to oxyacetelene weld mild steel to cast? Wouldn't that partially eliminate the worry about pre and post heating the cast?

Just pre heat it to a dark glowing red...stick your bracket on there...weld it with a nickel rod...post heat it to about the same color...and finally let it cool slowly by covering it with some sort of insulating material to help remove any unwanted stresses that may have accured as a result of the welding...

http://www.pierviews.com/photogallery/jeep%20modification%20pages/shave%208.8/tn_IMG_3415.JPG
http://www.pierviews.com/photogallery/jeep%20modification%20pages/shave%208.8/tn_IMG_3703.JPG
http://www.pierviews.com/photogallery/jeep%20modification%20pages/shave%208.8/tn_IMG_3396.JPG

here are a few pics of my 8.8 shaving.
it was welded with a mig gun only. it was pre heated a bit with a soldering torch, but that was primarily to burn off the oils from the metal.
it got one pass good and hot, then 2 other wider passes.
i have since slammed it through the trails of JV for over a yesr.
so far so good.:)

here are a few pics of my 8.8 shaving.
it was welded with a mig gun only. it was pre heated a bit with a soldering torch, but that was primarily to burn off the oils from the metal.
it got one pass good and hot, then 2 other wider passes.
i have since slammed it through the trails of JV for over a yesr.
so far so good.:)


FWIW... the 8.8 is cast STEEL, not cast IRON... so running a MIG on it is not an issue... and no worries of cracking. NOT the same as cast IRON.


AW

How about nodular iron, as in a ford HP D60?

FWIW... the 8.8 is cast STEEL, not cast IRON... so running a MIG on it is not an issue... and no worries of cracking. NOT the same as cast IRON.


AW

before i had a decent welder of my own i had a shop close to home weld my outer c onto my axle tube when i cut down a 44 he let me watch when he did it.. he preheated the c to 250 degrees using a temp stick then used a mig with straight c02 then let it cool in the shop.. because of the c02 there was a little more spatter than usual but 2 years later of beatin on it and everything is still fine..im sure you can ask 10 different people on here and get 10 different answers.... most could be right..but i know this method worked for me

Outer C's are cast STEEL not cast IRON.

Cast steel is able to contract with the weld and it will not crack. Cast iron will crack when a weld contracts.

so then can you use MIG welder with the dif housing on a 88 Ford HP 60?

Ok so just got back from the shop after some experimenting. Had a 1978 ford rear D60 we wasted the housing on for experimental purposes.

Both attempts the housing was thoroughly nground and clean for the welding surface as well as the 1/4" plate (stood vertically on the housing). On the top side of the ousing we preheated till almost glowing, ran two continous 6 " beads on each side (no waiting in between), post heated for a few minutes, peened, covered it up, let it cool slowly, and peened a few times in between. After it was cooled to a temp where I could touch it we did the hammer test. We beat the living shit out of the metal and housing. Neither the housing or the weld cracked or separated. In the end it took pounding the 1/4" till it finally failed.

The next test we did on the bottom, but no preheat, or post heat, just some peening right after the weld. We also did not cover it, it cooled till test temp with in a short time (took the diff cover off also). Although the weld did not look as pretty (still a damn good weld), it took just as much of a beating and broke the same way. The 1/4" steel failed, no signs of cracks in the weld of the housing. Beat the housing for fun, still no signs no signs of cracks.

We had the MIG machine set to 3/8" (I will have to go grab the wire speed and voltage for that later today). The gas mix was 25% CO2, 75% AR. Wire was .035" ER70S. Heating was done with an O-A welding torch.

I was very surprised the welds held and the results found, especially for the first try ever to cast, hell I don't have that much welding experience to start with. From the "grinder test" we have assumed the cast is cast steel (NOT cast iron), but who knows, I could be wrong... Reason for trying is for convenience and location I want to weld my ram (single ended) mount to my diff housing. With these results I think I would trust it to not budge, and apparently PSC does it all the time when installing their kits or customers that buy their rams and have the set up done in house. My housing is a GM housing of about the same vintage so hoping the cast is the same properties and will have the same outcome :fingerscrossed:...

-Dave

To Heat, or not to Heat

In general, it is preferred to weld cast iron with preheat--and lots of it. But, another way to successfully weld cast iron is to keep it cool--not cold, but cool. Below, both methods will be described. However, once you select a method, stick with it. Keep it hot, or keep it cool, but don't change horses in the middle of the stream!


Straight from the Lincoln site, and seems to make sense. It seems like large, sudden fluctuations in temperature are what you want to avoid. Maybe running small sections at a time and allowing everything to cool would work as well.

Anyone have an idea if a GM D60 housing is in fact cast steel???

Anyone have an idea if a GM D60 housing is in fact cast steel???


Or even better, does anybody have a refrence page that will tell you what axle housings/knuckles are made of what materials?

Someone on here has a huge database of BOM info

I had a shop weld a truss and gusset plates on my 14b. We preheated, post heated and peened and the welds still cracked after beating it on the rocks.

the 60's housing is nodular iron and the nuckels are some type of iron to I dont remember what type sorry the housing is cast though and so are the nuckles but not normal cast iron like chevy's are supposedly

That is some good info. I had my mount tig to my Dana 44 so far so good. I will make sure that I keep my fingers crossed though!

I dunno, I am almost sure the D60 is cast steel, but I have been wrong before...

Also on the TIG. My friend James tried it with TIG, even with pre and post heat the TIG didn't hold as well as the MIG for some reason, it was really odd. Weld didn't fail and it didn't crack at the cast, it just took chunks of cast with it. I have to get the pics posted up I guess, took alot just for reference to our results.

-Dave