Im wanting to do a c4 corvette IRS swap and know how to do it but my question is will the differential hold up to my TT LS2's torque? Also is the c4's dayna 44 the same internals as a regular straight axle dayna 44? and if so couldn't i just use a beefed up dayna 44 differential, and where could i find one? Im all sorts of lost and just want answers. If i cant find anything ill just stick with my, less of a cool factor, ford 9''

 

See if any C4 torque monsters are breaking them with higher power

The T-bird alum housing 8.8 IRS isnt a weakling either, something to consider

 

Yea I was thinking about that. I wonder if the t bird diff will fit in the batwing of the C4 suspension. Too bad they can't just make a ford 9'' rear diff that fits in a c4 vette suspension. Aaahhh someone should make a conversion!

 

The C4 Dana 44 is called a Dana 44 HD, the C3 (80-82) unit is called the Dana 44 ICA, they are NOT the same. the C4 unit uses a dana 60 sized pinion, the same as the viper D44 HD diff. Anthing can break but it's a stout diff. The C4 unit uses a C beam mount, not a pinion mount so you'll have to fab something for it. Nothing exchanges w/ a D44 solid axle.

 

So the viper has the same diff and basically the same internals? Can the viper diff fit in the c4?

 

I've seen that done. The batwing on the viper version is narrower, and the c-beam mount on the viper d44 for 1992-2002 (2003+ is a different case and uses cv joints) is on driver's side, as opposed to the passenger side for the vette. That could be helpful when fabricating a mount. The viper diff cover doesn't have provisions for toe control, as the viper has always used a rear SLA setup, vs the 5 link vette setup.

There is a guy in philly that used vette knuckles, and control arms with a viper diff:

http://www.r3vlimited.com/board/showthread.php?t=119358
http://www.youtube.com/watch?v=XvxLdSQxwP0



Viper Diff

 

Well 2 to one I plan on buying the whole rear suspension so ill have the c4's diff cover. I wonder if I could just use the vetts diff cover on the vipers diff case. The bolt holes should be the same right?

 

Not necessarily, but it's possible. Try before you buy if you can. Your going to a salvage yard, not buying this over the internet right? GM, and Dodge had different castings for the D44, obviously, just look at them side by side. Maybe the wholes will line up, but that's more coincidence then by design.

My understanding of the viper diff's is try and stay away from the Gen I units ('92-'95), get one out a ('96-02') as they are more reliable.

 

I really hope this works. I don't want to cut up my car and not be able to go back to stock design if this torque issue does not work out. Besides that thought I am vary excited. Now I just need to pay off my tool bill at work and buy the rear end.

 

Also does.anyone have an exact measurement between the 4 link bars? I think its like 44'' or something close.

 

what's your primary use going to be for this car?

 

Its a vary vary vary exspensive show car that I have built and restored, torn down and rebuilt and now torn down again and rebuilding for the 3rd time. I just have too many engineering ideas and visual modifications stuck in my head lol. I drive it probably about 15 times a year and take it to the track, both drag and road corse, for fun. I belive in building things that are fully functional and will perform very well.

 

Ok, I just wanted to make sure. Just an FYI, the side yokes are retained by C-clips on that rear end, in addition the half shafts are the upper control link. Some sanctioning bodies may not permit that in drag racing at certain trap times. As a failure of the half shaft will generally cause the wheel to tilt top in. However, if you were going like hell down the track the wheel may leave the car altogether. If you're using sticky tires with this set up you could chew up stub shafts, and u-joints very quick.

As far as road racing, such a mod might put you in to a class with custom built six figure super cars or some other class where you just won't be competitive. Check to make sure what your classing will be, before you go to all this trouble.

If you have the skills to put one in, you have the skill to put it back the way it was. But, that's hell of a lot of work, and you can save yourself some trouble by knowing before hand that your going to be screwed at the track.

 

No no lol. Its not competitive racing. Its called midnight madness at gateway raceway in stl. Its $25 to race/ drift all night. Its just a fun thing to do where all the little tuner car, muscle cars or full drag cars just line up and race for fun. Sometimes they open up the road course

 

 

These are some pictures of what my camaro did look like just for kicks.

 

And this is what it looks like now after the third go around so far. Not been doing much work on it. Suppose to move into a warehouse next week so maybe then I can get some work done.

 

you're 99% correct. The actual diff carrier itself can be swapped. When I got my D44 it actually had a regular non HD ring and pinion in it. The previous guy TIG welded a collar on the pinion so the larger head bearing would fit, that was the only mod required, the end bearing on the pinion is the same for HD or standard.

ChevyRS-305. I see you are in Indy, I live in South Bend. You should come up some time and see my IRS...

https://www.thirdgen.org/forums/susp...uspension.html

 

Actualy I moved back home from college and now live in southern illinois. Haven't had a chance to change my profile

 

Without the mod it doesn't interchange. It may have been done by Toms differentials, I think he was at one time (And maybe still) selling modified pinions so you could use a normal dana 44 pinion and ring gear set instead of the dana 60 sized pinion so maybe that's what happened to yours.

The super Dana/Dana44HD uses a Dana 60 sized pinion, where the C4 D36 & the C3 D44 both use the smaller sized pinion. These 2 use the same sized pinion but different sized ring gears. The carriers are even interchangeable (I have a C3 D44 w/ a C4 D44 carrier with the 8,5" ring gear)

C3 D44
________________
Pinion Shaft Diameter: 1.375"
Pinion Spline Count: 26
Ring Gear Diameter: 8.5
Ring Gear Bolts: (10) 3/8 x 24 RH
Cover Bolts: 10

C4 D36:
________________
Pinion Shaft Diameter: 1.375"
Pinion Spline Count: 26
Ring Gear Diameter: 7-9/16"
Ring Gear Bolts: (10) 3/8 x 24 RH
Cover Bolts: 8

C4 D44 HD/V/Super
________________
Pinion Shaft Diameter: 1.625"
Pinion Spline Count: 29
Ring Gear Diameter: 8.5
Ring Gear Bolts: (10) 3/8 x 24 RH
Cover Bolts: 10

The C4 D44s are not all alike either. Supposedly the early housings are stronger. There are 3 versions, the differences can be seen by the ribs in the C beam pad and the other stiffening ribs. The early batwings are stronger also.

The C4 D36 is easily identified by that it has a single top mounted cover bolt, the 44 has 2 bolts on the top, much like the C4 unit.

the C4 and C3 housings and batwings are not interchangeable between either C3 D44, C4 D36 and c4 D44.

The camber brackets for the C4 (2 separate pieces) will bolt up to the C3 unit, the C3 unit's single large bracket will not bolt up to the C4 unit because there's a bulge in the casting.

C3 D44




C3 D44 w/ C4 D44 case (see no c clips to retain center pin)




C4 D44



C3 vs C4 D44



3 versions of the C4 D44 case

 

I have another question for the OP. Are going to back half this car, or try and use the original frame rails and sheet metal?

 

Oh no its not a drag car. Here is a pic of what I have done. Fyi im going to make all new controll arms and link bars and tie rods out of 4130 chrom moly and rod ends from ballistic fabrication.

 

It doesn't have to be a drag car to back half. You could start clean sheet with the rear of the car, a lot more work of course, but then you could use C5/C6 stuff instead. Before anyone says it, no you don't have to use the transaxle.

 

Lol im not going to back half my car. And the transaxle is the best part of the C6 with the rear mounted trans.

 

I was just curious as to how far your going with this. In regards to the transaxle, it is good for weight distribution, that's true, but being the best part of that suspension is debatable.

In comparison to the C4, some of the better qualities of the C5/C6 rear assembly are the SLA setup, and the CV-shafts. Toe and camber can be maintained better through the range of travel. The cv-shafts provide better ride quality as they don't change speeds as the angle changes, and introduce vibration as u-joints do.

The c4 rear isn't terrible, it's ok, it just isn't as good as the next generation. That all being said the C4 is easier to fit in to a variety of chassis's with minimal cutting.

 

Like I said its my show car. Ill drive it to car shows and sunday church every once in a while.

 

The last gen viper units use cv shafts yet the diff is mostly the same. You could swap the stub axles for those that are used to bolt up the CVs and convert it that way.

 

You mean use the 2003+ Viper Diff in place of the C5/6 diff & transaxle? The Street Shop does that.