Just remember this - pound for pound, aluminum is not as strong as steel.

If the casting is junk (which would not surprise me here) small fissures will be created, making it that much weaker.

For the street, aluminum is great, it is lighter and wicks off heat better, but for the ultimate in track performance, other alloys or steel are the way to to go.

If someone could cast the D44 batwing in steel, they would be on to something.

 

Hey, who you calling bloke?

 

I'd believe casting the D44 pumpkin in steel would be the fix to most of the problems encountered with high horsepower C4s.

edit (I know, torque kills)

 

I purchased an adapter from RedRose and received it today...It looks great...And for all of its potential merits in the diff strengthening arena , to me those are side-benefits that made the purchase that much more of a bargain...I bought a Dana 44 chunk and needed a batwing with which to hang it in my car . My D-36 gave up the pinion for the 3.75 Richmonds due to the torque of 409 cubics with many internal mods not to mention the Mickey Thompson drag radials , etc. But I soon found out that not only are D-44s hard to find at an affordable price , the D-44 bats are obviously made of un-obtainium and would have cost me almost as much as the 44 chunk......and I was in possession of a perfectly fine D-36 batwing...Sooooo a no-brainer in the use of an adapter plate that allows me to be an Eco-sensitive recycler of aluminum. Extra strength...Thank you very much ! By the way ...the pinion merely cracked each tooth never losing any but the noises were scary....the car ran an 8.05 1/8th...1.72 60 foot....I will update with my personal experiences as soon as I have them !

 

gotta disagree.
1) 3/8'' thick flat midplate made from 6061-T651 is much stronger than a d44 bat curved cast cover and does a far better job of controlling case distortion (which is a major factor leading to failure)....adding the d36 cover to the midplate to keep the lube at home adds to the strength of the assembly even more....i'm pretty sure that the guys that build airplanes, ships, submarines, etc would prefer to leave those nasty flat bulkheads out if they didn't need em to control the shape of those cylindrical housings.
2) i take no pleasure in someone else's misfortune, but rather am pleased to have real info presented, rather than theories, and i have already decided to replace my d44 with something stronger and am pleased to learn that i am not wasting money and effort in doing that...so hooray to TA for his contribution
3)the ONLY way (theories and computer simulations be damped) to find out if a part has sufficient strength is to take it out and USE it ....thanks to TA we all now suspect that the d36 and d44 batwings may need attention...the midplate inside the gear case will help a bit because distortion of case will displace the inner mountings of the outrigger arms, surely adding to the strain in those portions of the casting
4)based on TA's input (thanx again) i already have decided that IF i change my direction and retain the d44, i will look for a ''heavy'' d36 bat (thanx joBy) or weld in a SOLID plate web into the outrigger arm structure to reduce possibility of failure

5) ''bogus'' i hate you (not really)...took a few minutes for your idea of a cast steel d44 cover to rattle around in my ear spacer...i don't have facilities to cast one in steel, but a weldment from steel is feasible.....this forum is super

 

You know, as I posted that, a welded piece would be easier to pull off... something of tubular steel and plate... it would be the cool.

Didn't someone weld up and box section a badwing?

 

RedRose...in the event that your Big block wants to eat the re-inforced Dana 44 I was told that guys like Currie or Mosier who are in the radical diff biz could build a 9" live axle to fit the vettes struts with coilovers. The 9" Ford gives you ultimate flexibility in gear ratio choices with a proven high endurance capability

 

Here's a pic you guys might be interested in of my trashed D36 cover. Its not the best picture in the world as it was still in the car, but you get the idea.





Some said when I first posted about this failure (a few years back) that it had to be due to some type of alignment problem with the car, but I can assure you the car was in perfect alignment. So assume it had to be an inherent problem with the cover. This was BTW, the second D36 I had trashed. The first grenaded internally. After the second time I upgraded to a D44.

 

TA,
pic is great...tie rod gives visual reference to prove that the S-BENDS IN THE UPPER AND LOWER members are not camera lens quirks...diagonal web member appears to have failed in tension

no sleep tonight

 

That is the weak D36 cover.
Compare to my D36 cover.

 

You mate
How many DANA 36s came from the factory with those? My 94 2.59:1 doesnt, and my 87 3.07:1 didnt either. Ive seen something like that advertized on a diff site somewhere.
How about you go all-out and make one up out of chromemoly!!

 

According to a book I have, "The Newest Corvette", they changed the design when they were improving handling on the prototypes.

I have an early 1984 with the W-shaped webs. My guess is that once the production had been running for some time someone decided that the original weak design was cheaper to produce. As far as I know all Dana44 also uses the early weak sedign.

 

Roger that JoBy yeah, i think the DANA 44 i have is simular to the 36 in terms of the webbing as you say(as in your pic, my 44 is the same as that too), i dont have a pic of that angle that i know of.

Does anyone have a picture of the Dodge Viper DANA 44 rear cover setup?? Does anyone know if it is the same or simular to the Corvette DANA 44 cover??

 

My 84 also has the older, stronger-looking diff cover.

 

Torque is a beautiful thing.....What is the casting # on that webbed up Dana-36 cover?........Bob

 

already considering that....4150 flat bar is readily available...new part to be double the strength of the existing and weight equal or less are design parameters.....first will need to obtain a sample of the existing material (aluminum comes in a myriad of strength alloys) and have a lab stretch it to see what ''isn't'' satisfactory (i know where there is an accident victim batwing)

still pouring over TA's pic....opinion at the moment (def not my 'final answer') is that failure was induced by torque, not vehicle loading....prolly not an oem goof-up (this time) given stock engine output and tire traction load limiting, but certainly of concern to those of us who may have chosen to increase either or both

project has been dubbed ''Boguswing''....related coffee and donut vouchers will be forwarded

 

You see the numbers on the picture I posted.

40874
14066827
ALDOA

 

 

Oh yeah, it is abit different isnt it

 

very large factor is invisible in pics --what alloy is used ???....strength could vary 2 or 3x easily based on alloy.... the early d36 batwing that looks stronger than the later d36 may in fact be a lower alloy and ultimately weaker (anybody have access to what alloys were used?)....both my d36 and d44 batwings show no evidence of being forgings that would be stronger than raw castings....GM price for the batwing only at well over 1k indicates either it is more than a simple casting or that GM is greedy (say it isn't so, joe)

second opinion of TA's batwing failure pic concurs that the differential attempted to rotate and outriggers were unable to control it...distribution of bending over long span would indicate that this is not a freak casting anomaly....houston, we have a problem.

meanwhile, only addressing the center section, the local machine shop can make a very limited number of midplates.