I'm having a buddy of mine weld up my bolt on subframes this week along with some other welding work and I was thinking of having him weld the axle tubes to the center section for added strength. Are there any special precautions that needs to be done when doing this, like do I need to drain the fluid first? I've done everything else so far to try and strengthen the rear up, thought this might help a little before I hit the track again next month.

 

are you running the 10-bolt rearend. I can't remember exactally but if it has an inboard seal you wouldn't want to do it because it will definatally melt. I wouldn't reccomend doing this anyway. you could cause the axle tube to warp or you could melt the seals or a number of things. And I don't think it will really make a difference.

 

Yes it's the stock 10 bolt, I've heard some people have done this to help strengthen it up more. I didn't know if the rear had to be apart to do this or if it could be done all assembled.

 

I fail to see the advantage of this on our torque arm suspension. All rotational torque is transmitted from the center section, through the torque arm, to the transmission/chassis.

am I missing something

 

There on no seals near wear the welding is taking place. The only seals is on the end of the axle tubes and on the input shaft.

As for draining the fluids and such, your call. If he is a real good welder you should be ok but if blows through the tube you might have to clean it up from the inside.

 

Ken, my buddy is a mechanic and is a very experienced welder, he would probably use his "tig" welder or the wire fed kind, not the torch so I don't think there would be a problem going through the tube.

Buttercup, even with the torque arm their is still a lot of twisting force on in the rear during a hard launch causing the tubes to flex. Welding the tubes to the housing helps reduce flex and the chance of breaking the axles from what I hear.

 

Well lets hash this out. I like being educated

My reasoning is that there is simply nothing to apply torque to the axle tubes. I can see the lower control arms possibly applying some torque depending on their mounting location, but it'd be rather insignificant. The only real loads I can see would be lateral loads, but with drag racing this isn't a problem.... and hasn't proven to be a problem for road racers that I'm aware of. All forward loads are transmitted from from the lower control arms which are mounted close to the driving wheels. The rear will rotate about the centerline of the car on hard launch but I don't see how welding the tubes near the center will eliminate flex over the length of the axle.

It's easy enough to lay a bead down but I'd love to see some hard data or theory if anyone has it. I'd weld mine up while I'm under there

It's probably a moot point, the carrier or gears will almost always break before an axle anyway.

 

I'm no expert on this subject, I just heard welding them can help strengthen up this weak rear. Maybe someone with more expertise than me can chime in on how effective this would be.

 

That's cool

It couldn't hurt anything unless the welder doesn't know what he's doing.

 

You are talking of having them welded to the carrier itself, correct?

No expert here, but I had mine welded when the rear was out for gear change. My opinion is ANYTHING you do to keep the rearend a solid, one piece unit, is going to help prevent pinion/ring gear flex.

It's just one of the LITTLE things you can do to help the little rear end live.

 

Yes, I mean welding the tubes to the carrier housing or "pumpkin". Last year was the first time I was really hard on it, made about 30 launches with DR's and it held up fine. I've got some bigger tires and more HP this year and I'm just worried about the little 7.5, hoping this will help extend it's life a little longer before I fork out the money for a 12 bolt