Has anyone succesfully eliminated the C-Beam from their car and/or added a reinforcment to the dana 44 diff. I snapped my dana44 last weekend (broke in the front pinion area) and I'm thinking about redesigning the mounting for the diff and transmission. By the way, its a 383 with 470 hp to the wheels and I broke the diff hitting 2nd gear on street tires at the drag strip... I read that AKS racing made a cradle for the diff. Does anyone have a pic of the cradle??
Thanks
Sal

 

I asked him for photos of his brace, but never received any.

 

same here.

Though that guy is a real gearhead. I certainly believe him.

 

I'm interested in this... when I return home I plan on redesigning it. I'm going to start at the tail shaft all the way to a box cradle in the back.

 

All the C beam does is hold up the tranny tail and hence the rear of the engine, also keeps the differential pinion from moving up and down under load.

The Bat wing transmits all torque to the frame.

 

But as the OP found out it doesn't do a very good job of doing that with big torque
There is too much give in the C-Beam to hold the front of the diff in place ; the pinon climbs the ring gear until the front breaks off the diff housing
Need a adjustable pinion snubber like old school muscle cars

 

An auto will help with the breakage.

 

Any thoughts on Flow control valve.

http://www.jegs.com/i/Tilton/454/90-5000/10002/-1

http://www.clutchmasters.com/custom/...000diagram.pdf

 

470 RWHP and assuming the related torque that comes with it , might be a candidate for a solid rear if hitting the strip.
Many on here over the years have tried and failed to maintain the IRS with decent Hp and a manual.Fix one weak link and something else blows

 

I guess I should have been more clear... Very simply.. Has anyone successfully eliminated the use of the C-Beam with the IRS???

I have read all the posts of rears breaking and people saying one should put in a solid rear... I'm NOT doing it. Just want to know if anyone has tried running without the C-Beam. Obviously there would be a need for a trans cross member and front mounting the rear housing better...

 

Well you could look at some of the post by rlane5 and some others who have converted to a solid axle. From those post you could see how they built a crossmember for the trans anyhow. For the rear, I have no idea, other then to find a good chassis shop and let them build it for you. Good luck and let us know how it turns out.

 

I want to get to the bottom of this.

HOW IS A SNUBBER ANY BETTER THAN THE C-BEAM??? My 'V as a snubber and it blows.

First, the snubber is doing the exact same function as teh C beam, and in the same place on the diff housing, as the C-beam; that being, providing resistance to the housings desire to rotate backward in the frame.

Second, both the snubber and the C-beam are providing that force/resistance to movement, un the very location that the force is originated; the pinion area. So how can the diff housing break off if the C-beam/snubber is providing force on the housing, right where the force is being generated?


It seems far more likely to me, that the pinion is "screwing" itself away from the ring gear, and breaking the housing....and again, I don't see how a snubber can improve on the C-beam. Probably why you don't see any snubber-users having any better success with IRS. The method for retaining the diff isn't the problem I don't think. The problem IS the housing.

Can someone explain this?

 

[QUOTE=Tom400CFI;
[B]
HOW IS A SNUBBER ANY BETTER THAN THE C-BEAM??? [/B]


Tom, in my limited opinion, the way it may help, is to take some of the load and keep the c-beam from twisting. I have a friend, and when we took his apart, recently, you can see where the c-beam has deformed. And that is comparing it to a good one.





It seems far more likely to me, that the pinion is "screwing" itself away from the ring gear, and breaking the housing....and again, I don't see how a snubber can improve on the C-beam. The method for retaining the diff isn't the problem I don't think. The problem IS the housing.

My diff. has broke at least 5 times. I have a friend who rebuilds it for me, and his opinion is the same as yours. He says the alum. carrier is flexing under high load. I have never broke the housing like above, mine have been internal failures, clutch packs, spider gears, broken pin, broken pinion gear etc.

 

Guys running non sprung hub clutches (like mcleod) and single mass flywheels will have the most trouble with this (shock of drivetrain unloading onto slicks).

I run 1.8s w/o incident. While that may seem slow to a dedicated drag racer, I'm also enjoying the car at autox, road race, and Sunday drives.

 

I can tell you that back in 2006, I broke the nose off one D44 (before I had a snubber).

When mine broke it was on the 1-2 gear change (just like the OP) and I think a few of the others that have broken were under the same circumstances.....

I have not broken one since installing the snubber and I'm hitting it with more power and a radial drag tire - that when dead hooked, has broken everything else (stub axles, U-Joints and halfshafts).

Personally I think the C-Beam flexing (and rubber bat wing bushings) allows the diff to whip up and down under (launch/gearchange) loads and those forces are what break the nose off the D44.

There is also something to be said about managing the hit to the driveline. 90% of the C-Beam flexing problem is street clutches that hit like a ton of bricks - but theres not much you can do about, without some sort of drag racing lock up style clutch and that would suck to drive on the street.... A snubber bar is the option I chose.

My snubber bar is dead against the C-Beam, so there is no way for the C-Beam to flex and allow the D44 to move around. I also have polyurethane batwing bushings.

Now this is in my 6spd street car that has a 383 LTX slightly over 480RWHP, runs 127+mph in the 1/4 and 60ft's in the 1.7X range. As 93 Ragtop said - The C-Beam in this car is bent up so badly from before, you can see it with the naked eye and when laid side by side with a stock C-Beam it's down right gnarly.

On the otherside of the coin - I also have an 84 that is a dedicated race car. Still has the IRS under it (D44), 23* 427 SBC, TH350, PTC 4500 stall.... 10.5X28 slicks. That car 60fts in the 1.4X range every pass and in 2yrs has never broken anything - Has no snubber bar and is still using the stock C-Beam, stock stub axles, U-Joints, halfshafts, ect.... Eventhou it's faster and 60's way better, with the TH350 auto and tight converter it just dosen't hit the driveline as hard.
Will

 

Interesting replies. I completely agree that the #1 factor is how you deliver the power. Anyone can break anything. I powershifted a BW T5 for YEARS...probably made 200+ 13 second passes on that thing on 1.8 60's. Not ground breaking numbers, but we're talking a 150k mile T5 here. Never broke, never had bearing noise.

Interesting about the C-beam bending. I didn't know that was possible (in the realm of "street car power"), but apparently it is and it's happening.Couple thoughts:
1. That is lame. The thing should be able to handle 400cft-lbs and more.
2. I can see how that would apply leverage to the snout that could contribute to breaking. Sideways leverage. Maybe a steel c-beam would help? (Dizwiz suggested in another thread)


I should post a vid of my CTS-V that I made. I set my GoPro up under the thing one day and filmed the diff during basically typical starting events (1500 RPM, roll out the clutch and roll on the gas, like from a typical stoplight). The nose of the diff rises probably 2.5". It's ridiculous. There wouldn't be a harmonic "whipping" like you could get in a C4 though, with it's much more rigid assy. The V's diff is basically suspended by goop.

 

Yeah I bent mine on slicks on the street. I have 370rwtq. Soon as I drove away I heard clicking. After hunting it down, found out it was my c beam bent. The drive shaft contacted the c beam while rotating when under load.

 

OMG

Here is what I did to the nose of my Dana 44; I cut a series of small steel sleeves that fit between the webbing at the front of the differential; the C beam mounting bolts pass through these sleeves. I then completely filled in areas between the webbing surrounding the sleeves with structural epoxy (Devcon Steel) which is used for setting machinery mounting bolts.

I can't really say what the exact failure mode is, but I really believe that the C beam mounting bolts move around and place localized stress upon the differential nose webbing and then bad things begin to happen. Now the bolts are much more captured, spreading the forces they exert are spread over a much larger area, and the nose of the differential itself has been strengthened. Plus, I can cinch down on the C beam bolts without fear of distorting the front of the differential.

I did similiar mods to the rear tailshaft housing of my ZF.

I also fabbed beam mounting plates that are more robust than those I see advertised for sale.

 

I see this an older post, but I can't help but think that duplicating the snubber set-up on a C2/C3 would work. Makes me wonder why they ever went to the torque arm/C-Beam method, in the first place. I wondered what the hell they were thinking, the first time I saw the Gen 3 Camaro. Seems rather antiquated. A real step backward. Of course another method would be to mimic whatever they are doing with the Gen 5 & 6 Camaros. There is no reason you can't use an IRS, with any HP level. You may hafta abandon the original Dana unit, but there are other options. Look at the power that stock and modified Camaros/CTS-Vs/Vipers are putting to the ground. All have IRS. As an aside, there are torque arm relocation set-ups for Gen 3 & 4 F-Bodies(see photo). I've been knocking around the idea of employing one of these, to free-up my auto trans options. Since I can't find a 4L80e tailshaft housing anywhere.

 

Don't confuse a torque-arm rear suspension for a solid-axle car (like the 3rd- and 4th-gen F-bodies). Although they both control pinion windup, the torque arm is actually a suspension member that helps locate the axle and determines anti-squat and anti-lift, but doesn't help locate the transmission (the F-bodies still have a trans crossmember). OTOH, the C-beam in a C4 is not a suspension member at all and has no effect on suspension geometry, but it does substitute for the crossmember by supporting the tailshaft of the transmission.