S.A. Upgrade...How to make your own HP-passenger side D44...

[4speedfunk]

Back to the original post...

Made some great progress today on the D44 HP axle project. Fortunately I have a GM Dana 44 housing laying around so I can reference any critical dimensions I may need. As noted...the stock GM Lo-pinion housing is a perfect match for the H3, so I plan to mimic the tube-length exactly. This will allow me to use stock-length GM shafts, and save some money. Anytime I can use off-the-shelf parts, I will. Not sure yet if I'm going to use Yukon or RCV shafts. Sort of leaning toward the Yukon because I can keep my 19-spline outers. RCV shafts come with 35 spline outers, and that requires you to buy their $300 drive slugs, I think. I don't really know since they refuse to answer emails or voice mails. (Another reason the Yukons are looking better).

Because the new tubes will be cut from slightly larger 3" OD/.500" wall DOM...some lathe work was needed to get them to properly "plug-in" to the Ford casting. Also, an internal "cup" needs to be machined into the inboard end of each tube so a seal could be installed. I got all this done to the short-side tube today, and got it pressed-into the pumpkin. That turned out to be pretty simple. We'll see tomorrow how it works with the longer side. I do not have access to a press that is tall enough...so it might get interesting. I used a .006" interference fit on the short tube. This was done to make sure the tube fit nice & tight into the casting. We put a torch to the casting to expand it, and the gauge still peaked at 11-tons during the pressing. This seemed like quite a bit to me, and I may have to knock that fit down to .003" for the other tube...especially if I have to drive it in with a sledge.

So far everything going as planned. I'll post up some pics tomorrow night.

 

[atvspeed4]

Back to the original post...

Made some great progress today on the D44 HP axle project. Fortunately I have a GM Dana 44 housing laying around so I can reference any critical dimensions I may need. As noted...the stock GM Lo-pinion housing is a perfect match for the H3, so I plan to mimic the tube-length exactly. This will allow me to use stock-length GM shafts, and save some money. Anytime I can use off-the-shelf parts, I will. Not sure yet if I'm going to use Yukon or RCV shafts. Sort of leaning toward the Yukon because I can keep my 19-spline outers. RCV shafts come with 35 spline outers, and that requires you to buy their $300 drive slugs, I think. I don't really know since they refuse to answer emails or voice mails. (Another reason the Yukons are looking better).

Because the new tubes will be cut from slightly larger 3" OD/.500" wall DOM...some lathe work was needed to get them to properly "plug-in" to the Ford casting. Also, an internal "cup" needs to be machined into the inboard end of each tube so a seal could be installed. I got all this done to the short-side tube today, and got it pressed-into the pumpkin. That turned out to be pretty simple. We'll see tomorrow how it works with the longer side. I do not have access to a press that is tall enough...so it might get interesting. I used a .006" interference fit on the short tube. This was done to make sure the tube fit nice & tight into the casting. We put a torch to the casting to expand it, and the gauge still peaked at 11-tons during the pressing. This seemed like quite a bit to me, and I may have to knock that fit down to .003" for the other tube...especially if I have to drive it in with a sledge.

So far everything going as planned. I'll post up some pics tomorrow night.

EDIT: Just looked into this the tubes are a heavy press fit from the factory and can be in a range of 0.003" to 0.009"! That seems like alot to me but I guess mild steel tubes into a cast iron housing is a different animal than the parts I usually work with.

 

[4speedfunk]

Great info. Thanks for the numbers...sounds like I'm right in that range (I thought it was alot too). I've never pressed anything this big and potentially explosive. I used a fifty-ton, air-assisted press, and I never read over 11 tons on the gauge but, I stood behind a ballistic barrier when I pulsed the foot switch. This is nothing like pressing studs and bearings...its downright scary. At the end of the day today we cut a piece of tube to go inside the pumpkin. It fits perfectly into the carrier bearing saddles, and I'm hoping it will reinforce the case when I press (or hammer) the other tube in tomorrow. We have to stand the axle upright on its end, and then force 11 tons of pressure down onto it. My concern is that we could possibly deform the case if it were empty inside. All of this would be a waste if we bend or crack the casting during assembly.

The tubes bottom-out into the casting at a 3.5" depth...a large contact area and quite a bit of friction. I've seen some guys on the net using alignment bars and such but, the 3.5" long receivers sort of straighten things out as you press the tubes in. I don't see the point of an alignment bar. I will check the run-out of course...before and after welding, to make sure the tubes are installed true.

 

[RamRod]

Very cool!

I am enjoying the (insert fake word to discribe its cool factor) "adventurousness" of this project!

 

[4speedfunk]

Oh yeah...another great day! I love it when a plan comes together.

Here's the progress from yesterday. Short-side tube was fabbed and pressed into place. Also you can see the temporary tube bolted into the saddles. In the background you can see the stock GM low-pin that I used for reference. One thing worth mentioning is that the GM low-pinion casting has the same internal dimensions as the Ford high-pinion casting, in terms of width and tube lengths...


Today we picked up where we left off. We cut the tube to length and turned the inboard O.D. to fit the housing...then the I.D. to fit the seal. After that we flipped the tube in the lathe we turned the outboard end to accept the inner C. After getting the tube done...we brainstormed about how to press it into the pumpkin. The total height needed was 56"...taller than our press. Myself and another big guy decided to drive the tube in by using the mass of the casting itself. We got the tube started and put a piece of 2"x10" lumber on the concrete. Then we started raising the axle and dropping it straight down...thus driving the tube into the casting. That worked for the first 3" or so...then it got real tight. The "drops" turned into "throws" and before long we were slamming the end of the tube down onto the wood block with everything we had...


This works amazingly well! We had pre-marked the tube so we could see when were were getting close. The last 1/8" or so was a beyotch...but we eventually got it all the way to where it needed to be. It came out very nice...


Now its time to weld the tubes to the pumpkin. And then the C's to the tubes. After that...time to build!

 

[08H3]

That's great! We were over thinking getting that tube in the other night. If all else fails, just slam it into the concrete! Looking good!

 

[MaxPF]

Oh yeah...another great day! I love it when a plan comes together.

Here's the progress from yesterday. Short-side tube was fabbed and pressed into place. Also you can see the temporary tube bolted into the saddles. In the background you can see the stock GM low-pin that I used for reference. One thing worth mentioning is that the GM low-pinion casting has the same internal dimensions as the Ford high-pinion casting, in terms of width and tube lengths...
View attachment 9734 View attachment 9735

Today we picked up where we left off. We cut the tube to length and turned the inboard O.D. to fit the housing...then the I.D. to fit the seal. After that we flipped the tube in the lathe we turned the outboard end to accept the inner C. After getting the tube done...we brainstormed about how to press it into the pumpkin. The total height needed was 56"...taller than our press. Myself and another big guy decided to drive the tube in by using the mass of the casting itself. We got the tube started and put a piece of 2"x10" lumber on the concrete. Then we started raising the axle and dropping it straight down...thus driving the tube into the casting. That worked for the first 3" or so...then it got real tight. The "drops" turned into "throws" and before long we were slamming the end of the tube down onto the wood block with everything we had...
View attachment 9736 View attachment 9737 View attachment 9738

This works amazingly well! We had pre-marked the tube so we could see when were were getting close. The last 1/8" or so was a beyotch...but we eventually got it all the way to where it needed to be. It came out very nice...
View attachment 9740 View attachment 9741

Now its time to weld the tubes to the pumpkin. And then the C's to the tubes. After that...time to build!

Another method for pressing tubes in is to make a tool for the job. You get a piece of 1-1/2" 5/16" wall (or thicker) DOM, roughly 1" shorter than the pressed-in length of your axle assembly. Drill and tap the ends for 1" fine thread, and thread in suitable lengths of 1" fine thread grade 8 allthread. Add a couple 1/2" thick plates with 1" holes drilled in them, a couple 1" nuts, and a big-ass wrench, and you have a tube press fixture. MAke sure to use plenty of moly grease on the allthread.

 

[4speedfunk]

Max...I had the same idea...pull it together, instead of pushing it together. That was our "Plan B", and we didn't need it.

 

[atvspeed4]

Another method for pressing tubes in is to make a tool for the job. You get a piece of 1-1/2" 5/16" wall (or thicker) DOM, roughly 1" shorter than the pressed-in length of your axle assembly. Drill and tap the ends for 1" fine thread, and thread in suitable lengths of 1" fine thread grade 8 allthread. Add a couple 1/2" thick plates with 1" holes drilled in them, a couple 1" nuts, and a big-ass wrench, and you have a tube press fixture. MAke sure to use plenty of moly grease on the allthread.

Thats such a good idea! wish I thought of that before messing with the 10 bolt

 

[MaxPF]

Max...I had the same idea...pull it together, instead of pushing it together. That was our "Plan B", and we didn't need it.

It was probably more fun doing it your way :wink:

 

[4speedfunk]

It was probably more fun doing it your way

Yeah somehow neither of us went to the E.R. -LOL

After a couple hours of surfing and trying to get real answers about the "welding tubes to the pumpkin"...I discovered that this is a raging debate among welders, fabricators, and car guys. I found a million different opinions, and didn't care for any of them but my own. Long story short...the pumpkin is cast STEEL (not cast IRON), and the tubes are STEEL. So I chose to use a wire that was STEEL. Its that simple. Forget hi-nickel. Forget 7018. Forget Stainless. Forget peening the welds. Forget all the other crazy ideas I found on the net. I'm just not convinced that any of that stuff is necessary.

Two things I found did make sense to me. (1) is pre-heating the casting. (2) is wrapping the weld with fiberglass to slow the cooling process. I did both of these, and it worked like a champ. You don't need to get crazy with the pre-heat...I'de guess 350-400 degrees (nowhere near glowing, as some suggest). Crank up the amperage and let r rip. The fiberglass wrapped worked about 100 times better that I thought it would. Seriously...it took 4 or 5 hours for this thing to cool down!



I had a buddy do the welding. He is not known to be a welder. Man was that the truth! He made an awful mess of it, so I chucked the whole thing in a giant lathe (yes, with the pumpkin spinning around) and shaved the nasty weld down to something more acceptable. This also gave me the benefit of looking deep into the weld and it had very good penetration, so I know this method works good. BTW run-out on the tubes was less that .030"...probably much better than any factory tube installation.

I'll be welding the C's myself.

 

[Bigunit]

I didn't think think that Dana made cast steel housings. I thought that Dana only made cast iron production housings.

Sent from my DROID RAZR using Tapataint

 

[4speedfunk]

I can't speak for other center sections but, this one appears to be all steel. So are the inner-Cs. Not sure about knuckles...probably iron.

Grab a grinder, and make a pass on the outside of the pumpkin. If you can launch sparks 6 to 7 feet across your shop...its steel. If it only shoots em 1 foot...its iron. For comparison, go try the same exact grinding disc on an old engine block. You'll quickly see what I mean about the sparks. Cast iron does not throw near the sparks that cast steel does. I heard this net-rumor and tried it myself...seems to be correct.

I'm sure welding tubes to center sections will continue to be a raging debate (Google it). For my purposes...I'm perfectly okay with this technique...

[video=youtube;1rZPHfDU4fE]https://www.youtube.com/watch?v=1rZPHfDU4fE[/video]

 

[RamRod]

The good ol' spark test!

i have seen some funny thing when you mix a farmer and welder.... Like big globs of bubble gum welds trying to weld cast iron to some steel tubing.... For what they were doing with it (fixin' patio furniture) it did the trick haha

I keep saying it, but again I like the work your putting into this! Years down the road it might be enough to convince me to SAS my T!

 

[MaxPF]

The pumpkin is indeed cast iron, not cast steel. However, it is NOT gray iron, but rather nodular iron. That is why the spark test looks like steel. FWIW, high nickel CI engine blocks and newer blocks made from compacted graphite iron (CGI) also spark similar to steel.

Nodular is a different beast from gray iron. It is ductile and quite a bit stronger. However, welding presents many of the same issues as gray iron. The biggest problem is that it still has a lot of carbon, just like gray iron, so the filler rod admixture picks up a lot of that carbon. If steel rod is used, you end up with a weld puddle full of brittle martensite, which can crack upon cooling. Even if it doesn't crack, it can end up with a lot of internal stress unless it is cooled slowly or post-heated to at least 1000 degrees but below the transformation temp of the admixture. Peening immediately after welding helps, as it puts compressive stress in the weld bead. Cracks only occur under tension, never compression.

You can use nickel rod, which doesn't become brittle when it absorbs carbon. I use a rod called Eutectic 680 (now called Eutectrode 680), which is designed for joining dissimilar difficult-to-weld materials. I knock the flux off the rod, clean it with Scotch-Brite, and use it as TIG filler. I make 1" stringer beads and immediately peen them with a needle scaler. No pre or post heat. I have never had a crack or failure of a nodular iron weld done this way. The filler material has a tensile strength of 120ksi, which is stronger than either the nodular iron or the DOM steel tube. I welded the tubes of my D60 to the pig with this alloy.

 

[4speedfunk]

I welded the tubes to the pumpkin strictly for leak protection. The press fit and rosette welds are more than enough to hold them in place. The rosette welds function is more like "molten pins" that attach to the tube itself, and not really for joining the casting to the tube. This welding conversation can go on forever. There are hundreds of people on the net...with hundreds of opinions...and they all swear to God that they know best on how to weld castings to tubes. Equally they all seem to have varied opinions on what pumpkins are made from. Its one of those internet searches that brings up so many opinions...that you basically get nowhere. So, with all the information and mis-information...I chose to use my own resources and common logic to get this far. I have zero worries about this housing.

I have tacked my inner-Cs on this morning with my pinion angle 5-degrees up from horizontal, and caster angle 5 degrees leaned back. I use the term "leaned back" because I have found numerous diagrams and opinions on which way is positive & negative. Frankly, the terminology doesn't matter to me. So...to bypass all confusion, opinions, and scolding...I just use "leaned back". Regardless of which side of the fence you're on with the terminology..."leaned back" is idiot proof. I'm an idiot on this stuff...and I find comfort in basic terminology so other idiots like me can understand it.

Just like welding castings...opinions on caster vs. tire size are all over the place. I'm afraid to go as high as 8-back like some say...also afraid to go less than 3-back, due to death wobble concerns. I have two GM Dana 44s to reference from. The one in my truck seems to be sitting with pinion at 5-up and caster at 2-back. The truck drives great and the wheel returns to center. However I do notice some weird geometry feelings when turning tightly and accelerating. Nothing un-safe or anything...just a strange feeling as the wheel returns to center. The other GM Dana 44 is on my bench and its sitting with pinion at 5-up and caster at 5-back....more like what most folks say it should be. I can only attribute this difference to the vehicles they came from, and maybe that's why they are slightly different. As for the new hi-pin?...I can make it anything I want. The yoke will be 4 inches higher and that makes a huge difference in the front driveshaft angle, and the amount of pinion angle I need. It will be very flat, and only needs 5-up. I sort of took a stab at the caster...and decided on a fairly mild 5-degrees back. My front suspension is fully adjustable and I can rotate the housing 5-10 degrees with link bars to find the sweet spot. But I can't change the angle between pinion and caster after I weld it up. So, I'm trying to stay in the middle of the range to give me the most flexibility.

Dare I ask how to weld the C's to the tubes?

 

[MaxPF]

I welded the tubes to the pumpkin strictly for leak protection. The press fit and rosette welds are more than enough to hold them in place. The rosette welds function is more like "molten pins" that attach to the tube itself, and not really for joining the casting to the tube. This welding conversation can go on forever. There are hundreds of people on the net...with hundreds of opinions...and they all swear to God that they know best on how to weld castings to tubes. Equally they all seem to have varied opinions on what pumpkins are made from. Its one of those internet searches that brings up so many opinions...that you basically get nowhere. So, with all the information and mis-information...I chose to use my own resources and common logic to get this far. I have zero worries about this housing.

Opinions on casting materials are irrelevant. The info I have comes straight from a Dana spec manual

 

[4speedfunk]

Yeah...that manual is flying all over the net. (along with other several other "factual" publications). If you look hard enough...you can find proof to support anything. No disrespect to anybody...but some net conversations have no ending, and no definite answer. This is one of em. The only advice I have on this is...do some research...ask trusted resources...throw-out 90% of what you hear....pick one of the many techniques...weld the way you see fit. At best, 30% of welders will agree with you. At worst, 99% will think you're nuts. I'm not a hack, and I'm not disagreeing at all. I'm just not convinced there is only one specific solution. For every properly-trained master welder spouting facts from the Dana manual...there are hundreds of mouth-breathers driving around on perfectly good, back-yard welded housings. Some of them use downright terrifying techniques, (that are wrong in anybody's eyes!). But they are still driving around and not loosing sleep over it. I simply don't think its that big of a deal...and barely worth this conversation.

Just for fun...I'm going to try an experiment. I'm gonna drop this housing past a very large, nameless, production shop (with scores of master welders). These guys do stuff for NASA, Rolls-Royce, Caterpillar, Amtrak, etc. I will not tell them anything, other than "I want these inner-Cs properly welded to the tubes". I will not mention OPINIONS or FACTS. I'll just let them do it completely blind and without all the b.s. I've found on the net. These guys probably have equipment that will tell them what material it is (although I sort of think they will already know, even without testing). But, I'll see what they recommend...see how they do it...and report my findings. I can already say without question...30%-60% of net-welders will think they are wrong, and this topic will continue down the same path its been on since inception.

The really great part, however...is that I'll be done, and I can step out of this mind-numbingly boring subject forever! -LOL

 

[gfbh3t]

4speed if you really want to know what metal your dealing with call around and see what scrap yard has a Niton XRF analyzer, Called a Niton gun on the job. And in about 4 seconds they can tell you exactly what your dealing with we have one for work so I know it will work for sure.

 

[4speedfunk]

Thanks G...I knew there must be some sort of Batman "atom analyzer ray gun" out there.

I took the housing to four separate places yesterday and had six welders (of all calibers) look at it. All of em said "Just crank it up and weld it". Not one of em said anything about special rod or techniques. One guy at a race shop says he does them all the time for circle-track dirt cars, and says that straight-up MIG steel wire works great. I even asked them about pre-heating and such, and they all just shrugged their shoulders at me. I get the feeling they thought I was some sort of anal-retentive freak, for over-thinking the issue. By the time I pulled out of the fourth place...I was in complete agreement with them.

I'm sure most of these welding on-line techniques are valid, and clearly these guys know way more about it than I do. But, this ain't rocket science...no matter how hard I try to make it so. I'm firing up a buddy's Miller 252 this week, and welding the Cs myself. I plan to have a TIG buddy do the small fillet weld on the outboard edges of the Cs, simply because its a small weld and I don't want to glob-it-up with a MIG. I have zero concerns.

 

[atvspeed4]

Thanks G...I knew there must be some sort of Batman "atom analyzer ray gun" out there.

I took the housing to four separate places yesterday and had six welders (of all calibers) look at it. All of em said "Just crank it up and weld it". Not one of em said anything about special rod or techniques. One guy at a race shop says he does them all the time for circle-track dirt cars, and says that straight-up MIG steel wire works great. I even asked them about pre-heating and such, and they all just shrugged their shoulders at me. I get the feeling they thought I was some sort of anal-retentive freak, for over-thinking the issue. By the time I pulled out of the fourth place...I was in complete agreement with them.

I'm sure most of these welding on-line techniques are valid, and clearly these guys know way more about it than I do. But, this ain't rocket science...no matter how hard I try to make it so. I'm firing up a buddy's Miller 252 this week, and welding the Cs myself. I plan to have a TIG buddy do the small fillet weld on the outboard edges of the Cs, simply because its a small weld and I don't want to glob-it-up with a MIG. I have zero concerns.

Here is a post that might be worth looking at #731

http://www.zr2usa.com/mboard/index.php?showtopic=51031&&page=37

Chris is a certified welder that has been in the business for a long time. He recently bought this buddy and has been going through it repairing things. Its not the weld that is of concern it is the metal surrounding it that changes grain structure and weakens. This isn't an opinion thing. Look at the pictures and be careful is all I am trying to say. I can get more pics of failed welds on the 10 bolt housing using standard steel mig wire when I get home if you would like. Shock loading the parts caused the material next to the weld to break away.

 

[4speedfunk]

I know I know...I've seen a bunch of em. One thing to remember about what I'm doing compared to alot of failed welds I've seen posted elsewhere...is that the tubes (both ends) are inserted and pressed into cast receivers on each end. That's a big deal because the weld isn't subject to taking 100% of the load. Sure, its purpose is to attach the two pieces but, in my case...both ends are driven into castings with 11 tons of pressure! One of my inner-Cs was so freakin tight...I joked to a buddy that it didn't need welded! I have seen failed welds on inner-C's...so don't kill my buzz by posting them.

I'm convinced that for my situation...its MIG and steel wire. Period. Myself and everyone I PERSONALLY know feels plenty warm & fuzzy about what I'm doing. I'm not sure I would feel this way if were attaching a piece of plate to a casting (iron?) like in your photo. I can't really tell what it is...but the weld seems fully penetrated on the plate, and merely lying on top of the casting with no penetration at all. Also the surface of the casting looks very porous, like cast iron. This makes me think its cast iron and not cast steel...in which case, what you say makes perfect sense. All of my guys say that welding to cast iron is a huge no-no...no matter what the filler is.

My stuff is steel. I think my pumpkin is cast steel and the inners are forged steel, (sorry Dana tech manual). So, I'm not sure my situation has anything in common with the one in your photo. I have done test welds on the C's and pumpkins, and they accept, flow, puddle, and respond just like plate steel does with standard MIG steel wire. For the helluvit, I tried the same tests with an engine block (that I know is cast iron), and it does not take steel wire at all. It reacts completely different, and you can knock off a welded piece with a single blow from a hammer. Not only that but, when you leave it out in the rain...it turns that deep red-ish orange rust color that is shown in your photo. BTW...what is that photo of?

 

[atvspeed4]

That was a 14 bolt rear with a truss.

 

[4speedfunk]

Call it DONE! MIG with steel wire for the large inboard welds. TIG with T-304L stainless for the small fillet weld on the outboard edges of the tubes...



No pre-heat. No fiberglass wrap. No peening.

 

[06 H3]

First time tig welding?