C409

This adapter lets you use your Dana 36 cover/batwing on a Dana 44 rear. There are a lot of Dana 44 rears available without the cover/batwing.......I have an alternative to expensive , hard to find Dana 44 batwing differential covers......Use your Dana 36 cover instead with an adapter plate made of high strength 100% CNC machined 6061 aluminum plate. The adapter adds strength to your Dana 44, provides the proper spacing for the strut rod brackets, and is used as a template for locating the holes for mounting the D36 cover to the D44. I have been running this adapter in my own car for quite a while and all I can say is that it works .....it has gone 7.82 in the 1/8th and 12.72 in the 1/4 MANY times........Forum price $ 175.00 shipped to the lower 48

Pete K

Very interested. Do you take paypal? And what is the plate thickness?

Iroc57

Good thinking

C409

Special thanks for development to forum member Red Rose

Mr. Magoo

For some reason I cant see the pics?

Can you send them to mmcgrade@unicorr.com

I'm interested in your 44 for sale also.

C409

Pics sent to e-mail address..........

Pete K

Sorry it took me a week to get back to you. Work fuggin crushed me again.
Shoot me a good e-mail for pay pal, and I will send payment.

Pete K

I somehow missed your last PM. Sorry about that.
Payment of $150 sent to the e-mail addy provided.
TIA

C409

Thanks Pete.........Now who else wants to save money while adding strength to their Dana 44

anesthes

How much does this move the pumpkin forward? What is the impact of the cbeam bolt locations?

-- Joe

C409

Nothing moves....the strut rod bracket bosses on the D 36 cover are smaller than those on the D 44 by the thickness of the plate.....no changes to any mounting dimensions including the C-beam....Thats what makes this so easy to do....the most difficult thing that has to be done is drilling the holes in the D 36 cover Oh and don't forget to pop the plastic vent out of the D 36 before drilling or you go right thru it.............

The C-beam and driveshaft need to be dealt with just the same as a conversion using the D 44 batwing

hexane

I was once thinking about doing something like this on my 87 but wouldn't you say that there would be more stress on the D36 rear cover because of all the drilling? What is the thickness of the plate? How about the structural integrity? Would it be sacrificed because of less material holding it together? That is actually what I'm now getting concerned about...

C409

.....There are 5 additional holes being drilled into the 36 cover.....
these holes are .406 diameter.....the large holes for the strut rod brackets do not change at all.....however, logic would suggest that there would now be more stress or less strength.....BUT you are adding a 3/8" thick piece of structural aluminum between the diff and the cover to reinforce the now weakened cover replacing whatever was removed by those 5 holes.....There are essentially two 1/2" diameter bolts at the ends of the wing that hold the WHOLE diff into the chassis there are four 1/2" dia bolts clamping the diff, the adapter plate and 36 cover together PLUS the 5 drilled holes I think your concerns are understandable.....I too am quite cynical....but as stated above I have had this set-up in my own daily driven , and often raced corvette for over two years with NO adverse affects or problems......BTW with drag radials I'm running 1.7X 60' times with 3.45 gears and the torque of a modded 409" small block.....I'm VERY confident in the structural integrity of this adapter plate and the resulting modifications to the 36 cover

A95Y

You don't have to drill the c-beam or change the driveshaft, supposing you have a D36 and are converting to D44?

C409

If you are changing from a Dana 36 to a Dana 44 you will have to shorten the driveshaft & re-drill the C-beam.....to the same dimensions as if you were using a Dana 44 batwing.....the adapter plate with the D 36 batwing keeps eveything in the same alignment as the D 44 batwing.....sorry for any confusion I may have caused

WVZR-1

Just thoughts!

Excuse me but I don't see where this "alternative" does anything but "float" between the D36 cover and the D44 differential. It would be a major accomplishment to machine the "alternative" in all five locations without "wide tolerances" to match the OD of the 10mm bolt shank that's used to assemble the cover to the differential. The camber bracket (control arm) bores are the "only" direct mating alignments retained and they just provide clamping not machined "alignment"!
Every bore on the D36 cover requires modification for the install. The threads in the D44 differential are made when a "tri-obal" self tapping fastener is used to attach the cover the "first time"! You've got now two mating surfaces that require sealant and it doesn't seem likely that the threads created by the "tri-obal" bolts on the differential would tolerate the required torque to maintain the sealing characteristics. It seems like a "leaker" for sure.
The thought is perhaps good but the D36 cover would require "machining" of all the required bores not just drilling by the installer to qualify as an "engineered" piece. It certainly isn't a piece that I would "beat-on"!!

Your install seems to contradict my thoughts!

redrose

"friction" connections using bolts are recognized as "structurally sound", even in the presence of paint, etc...100+ story high buildings depend on these "friction" connections, many with fewer fasteners than the vette rear, often made in inclement weather, most made using only "turn beyond snug" torque.

if you want to really "nail it", match drill the mid/adapter-rear case between the bolts after fitup for force-fit "locater pins"

WVZR-1

That would add considerable "confidence" to the build! That's done on even well built conventional D44's. It seems from the snapshots you would need to pin the "alternative" to the D44 differential and then pin the cover to the "alternative". I don't see anywhere you could pin all three parts with a single drill operation.
You could pin the "alternative" to the differential on each side where you use the spreader adapters to spread the case. You could use 4 pins if you wanted. There would be "NO" drill operation on the D44 differential. Then you wouldn't be doing anything to alter the D44 differential. The cover pinned in two locations to the "alternative" would do pretty well.

**It's a long ride home and I gave this "alternative" considerable thought and I didn't edit my posted thoughts but I just really don't see it's value. The differential housing and the cover are all machined surfaces and meant to seal against one another with sealant. The "alternative" is "NOT" a machined surface and none of the drilled holes in the D36 cover in the snapshot display a machined "boss" for the flange of the bolts to apply equal torque to the area required. You've "flogged" it pretty good I'd say but I just don't grasp the "alternative" very well.

**I also thought I was posting in your other thread in "tech" but I guess I had inadvertently clicked on your link to this "for sale" thread. Had I seen or noticed this earlier I would likely have deleted all of my comments here and moved them to the "tech" thread. Sorry!

C409

Thank you for your wonderous thoughts.....I have been running this setup on my car for over two years and have never had a moments doubt about its sealing capabilities , or its structural integrity.... Its primary use is to avoid having to buy a D44 cover in the event that a D44 presents itself to one of you without the original cover.....I had this same problem and was faced with buying a D44 batwing only on Ebay for $650.00 from Ikerds Corvette or recently on this forum for $375.00 ...I opted for the plate and was convinced that there may be others faced with a similar $$$ situation and so I invested in producing it en masse......FYI this alternative has seen frequent visits to the local drag strip.....has earned a runner-up plaque at one of last years Corvette Challenge series races at Bradenton M S park where the car ran consistent 12.8s .....It has travelled from Clearwater Florida to Cleveland Ohio and back and made a quick trip to Key West and back.....no leaks....ever....Any and All are welcome to come and inspect the installation and my car....Wednesday is test & tune night at the 1/8th mile strip down the street.......................... ......... So , as I understand ? your thoughts.....the threads in the Dana 44 rear for batwing attachment are cut by the "tri-orbal" bolts used by the factory during the initial installation of the cover and are not threaded by any machining process ?? and you are not concerned about removing and replacing them ???

WVZR-1

I made these comments also:

Using RTV sealants is generally accepted for "machined" mating surfaces and your "alternative" doesn't actually supply any "machined" surfaces and I would assume that with a "plate only" between the differential and the cover it would require substantial additional torque applied to the hardware to maintain the seal. How much additional?

Were the "alternative" machined on the sealing surfaces to a consistent dimension I would think it require likely less.