I bought a D44 from a corvette salvage store on ebay. The rear was described as a busted D44 from a 86 stick car with no markings on the rear, but the decal in the car said 3.54.
I got it cheap, and also purchased the "C" beam and drive shaft to convert my auto to the D44.
The damage did not look bad, and this is what I did to repair it.

Here is the ebay pics-


Here it is at my door-


And here is the damage (from a t-bone to the pass side)-

As you can see, the second hole is broken off that mounts the "C" beam. The seller said that it could be run like this and had sold many to other people who have successfully ran them in this condition. I decided to weld it...
I started by cutting grooves to improve the penetration of the weld-


Using a Miller welder with an aluminum spool gun, I started burning into the case and building up the weld by briefly pulling the trigger and letting it cool. I followed that with a stitch weld-

By placing a steel bolt in the hole, I don't have to worry about filling it in with weld...
Here it is completely welded-

Afterwards I ground the welds down to look more eye appealing.
Later in the evening, I power washed the rear and began dismantling it to get it ready to install-

I began looking for markings to verify the gear ratio. Since there were none, I turned the axle and counted the drive shaft revolutions...
Hmmm? just over three? I thought this was 3.54?
So I remove the batwing-

How come its never easy???

 

Great repair job, I wish you lived in Arizona. I think all 4+3's were 3:08 (3.07?). Was your old ratio 3.08?

 

Looks like a nice fix. I had some similar damage to our 44 and we will see how the fix holds up. If yours came from a stock 86 it would not have a 3.54 unless it was installed after the fact. The 3.54 was an option in 89 and I think the reason for it was mainly the Corvette Challenge. Good job

Al

 

Forgive my ignorance about welding, but why the cross hatch before welding? You can tell you're a meticulous builder, it almost looks you measured each cross in the cross hatch. Nice work.

 

43 and 14 tooth count are stamped on the ring gear. 43/14 = 3.07

Check the batwing carefully. Looks like side load on the cbeam broke the rear hole out, which would've torqued the hell out of the batwing too. The left side might be bent forward or the right side might be bent back, or maybe cracks where it meets the case.

 

Tell us how much money you saved!

 

Nice work, the stampings are the same on my 86 4+3, 3.07 ratio.

Quick question that you might know the answer, I have a Hobart welder can I replace the wire w/ Al wire and do the same, never tried that I always used the TIG at work.

Great job on the weld.

 

Nice salvage job!

 

Nice job, I saw the rear end on e-bay but didn't have the welding equipment or the nerve to take the chance! Looks like you did okay even if the ratio isn't exactly what you wanted, way to go.

 

First of... Thanks for all the kind words...

The cross hatch is to get better "bite" into the aluminum. The broken raw area of cast aluminum is grainy and the weld might pull off.

"Quick question that you might know the answer, I have a Hobart welder can I replace the wire w/ Al wire and do the same, never tried that I always used the TIG at work."

I believe it could work if you reverse the polarity and switch to straight argon gas. I think the problem might be that the aluminum wire might not be strong enough to be "pushed" the distance to the gun.

As far as saving money... I probably saved around $1000 dollars buying the broken one. Ive seen them for sale around 1800. I also got the "C" beam and driveshaft all in one shot, so that was a big score in my book. I payed $611 for the complete rear, $125 for the "C" beam and $150 for the driveshaft. The worst thing was shipping, $220.
I did look at the batwing and it looks straight, but I will give it a closer inspection...

I wish I had known about the 3.54 option available starting in 89...
That might have saved me the disappointment. Monday, I will contact the seller and question him about the gear ratio thing. Perhaps I can get a few bucs back to help pay for the new gears?

 

Sounds like you can change the gears and still come out ahead! I actually like the 3.07 behind the autos.