I am weling on a seat of Team Z lower shock mounts to my 9" rear. Is it necessary to place the housing in a jig to weld on the shock mounts?

 

IMO, no. You're not putting heat anywhere that would create misalignment between the housing ends and the center section.

 

I would. I've had a jig bar in a rear end without the alignment ends in the bearing cups and watched the tubes move 1/4 inch when welded on.

 

i really doubt your gonna warp it putting shock mounts on though. your not putting any rotational forces that could warp it like when you weld up axle tubes.

 

You guys do what you want. But I'm telling you when welding shock brackets on the housing moved 1/4". You need the bar in and the alignment ends in the bearing cups until the housing cools IMO.

 

Are you serious. You are putting heat into it and it WILL pull. Do it right, get or make a JIG. I have taken warps out of 3/8" thick steel by welding the opposite side. You can watch it move.
T.J.

 

3/8 what flat stock? i don't see how welding on a 3/8 or 1/4 bracket only half way around a piece of 3 inch tubing is gonna warp the tubes out of alignment if welded on properly sorry. go slow and do 1 inch welds and let it cool. the only way i see it warping is if you let the weight of the tube pull or compress the molten metal. thats only really gonna happen if you weld the whole piece at one time and let the entire area get red hot. so...... weld it on properly and i seriously doubt you'll have any problems.

 

Livefast1, have you ever tested your theory on a rear end? With a jig bar in place so you can measure with a dial indicator to it? I have. When I can watch the tube ends move in relation to that jig bar by .125 to .250 with tig welding heat input in a localized spot(less than the 1" you mention), then it's not my imagination. Just because you don't see how, doesn't mean it's not fact. This is a perfect example of why some cars drive dead straight at 200mph and why some cars are twitchy.

 

Nope but im sure as hell gonna try it to find out.

 

Shane this is not to be a dick this is for arguments sake. While measuring warp with a dial indicator would def be better. If i had a housing here i welded a brace on. If i put a angle finder on the left then right tube at the axle end and come up with the same number. Repeat it in 4 spots 360 degrees around. also measure it on the face of the bearing cup. Would this not also show warpage?

 

WOW! I didn't mean to start anything... I am going to wait and do it with a jig. I am going to have a friend do it since I don't trust myself welding something that will hold the weight of the car...

 

jig it...any welding on a rear end i would jig it...i have welded on rear ends before without a jig but i wont anymore...i have seem them move first hand

 

Shane Is right it will move especially if it's .188 wall tube now if it's 1/4 wall and you do it slow you may have a chance not to warp it! we can do it with a TIG and not warp it but to get penatration with the MIG and make it look good you have a chance of warping the housing!

 

Can someone post a picture of said rear end welding jig? I'm trying to picture it and am having trouble. Thanks

 

It's a straight bar approx 1 1/2" in diameter with spacers that go in the differential bearing saddles. Once the spacers are bolted in, you run the bar through. Then there are alignment ends that slide onto the bar ends and register in the bearing cup of the housing ends.

 

OK, so the spacers (bushings actually?) bolt into the housing using the bearing caps. Then, you slide this 1-1/2" diameter rod which is at least as long as the rear end is wide (50-60" for a stock width) thru one and, thru the bushing spacers, and out the other side. Are the alignment ends tapered so that they self align in the axle bearing cup?

I only ask for specifics because my diff has had the tubes welded to the housing and my car is very hard to push. I was thinking it was due to the Auburn Pro being a very aggressive limited slip, but I'm afraid the axle tubes may be warped if the person who welded my rear end didn't use a jig. It was done prior to me purchasing the car. I was getting ready to upgrade the rear to a spool and 33 splines but I may want to find a virgin rear and start fresh. I can make a jig and do the work myself if I know what the jig does and what it looks like.

 

It sure as hell can warp from welding brackets on. How much depends on how hot you get it. If using a TIG welder with lower heat you may be OK. But if you get it good and hot with a MIG welder it can move. One way to straighten a housing is to heat it up good and hot on one side. When it cools that area will shrink and pull hard moving the tube. Doing this with a housing in a jig you can vary the heat and location until the tube is straight.

 

Kind like this

http://www.crankshaftcoalition.com/wiki/Narrowing_a_rearend

 

I will bite the bullet and say i am a little worried now. Can anyone say whether or not the way i mentioned of measuring the housing with an angle will suffice?

 

Or break an axle......