Metal manipulation on a Ford 9" rear diff

[torker]

I narrow quite a few rear diffs for hot rods etc. Here's a trick I use that may interest some here. After cutting and trimming, boring the ends etc. this is what you often end up with after the jig is installed

The end is a bit more than 3/16" out. The housing has tweaked over the years. Here's how I get rid of that.

I run a heavy weld bead on one side and then decide where I want to apply heat to help pull it. The circled areas are where I want it to pull. It's heated to a dull red and allowed to cool. Here's what I get after this....perfect alignment! The whole thing done with out a grunt and usually with a cup of coffee in one hand...lol!

An old fabricators trick. We use this to pull/move some really big steel....20"XXX wall pipe...thick plate etc. I still marvel at the power you have in your hand!
Russ

[3 Phase Lightbulb]

Cool.. How did you decide where you wanted to distort it back to running true? It also kind of looks like axle housing is tapered at the end?

-Adrian

[torker]

Adrian...it's sort of an aquired knack...mostly from screwing up til you learn how to do it.
You're right...the housing is tapered. This is a terrible housing to work with. They smash it flat on the top and it is double tapered. It's from a mid 70's T-Bird...not my favourite.
The truck housings are far easier to work with. This rearend is going in my ol' Willys pick up.
I have another on the go that's going into a Cherokee.
Russ

[This message has been edited by torker (edited 08-05-2005).]

[wierdscience]

Good deal,I know what you mean about pulling.Ever notice the weld beads top and bottom on house trailer frames?They weld beads on them down the center of the flanges to pull a reverse crown on the neked frame before they start adding wieght building the house on top.Some I have seen actually have 4" of crown pulled in them.

[torker]

Darin...yup..I've seen lots of that. A place I worked we built big 40 foot long log decks from 8X10 1/2" wall HSS. A lot of crap got welded to these and some would bow up over 6". This was with two, back to back and a 6" block in the middle, and the ends pulled together with a crane and come alongs. Man did they pop when you cut them apart. There used to be two of us that could straighten these with a rosebud. Took about an hour to pull them big buggers back. The other guy is the one who taught me how to this. That was many moons ago.
Russ

[Duct Taper]

When you weld spring mounting pads on the axle housing, what do you do about shrinkage and bowing?

[3 Phase Lightbulb]

<font face="Verdana, Arial" size="2">Originally posted by Duct Taper:
When you weld spring mounting pads on the axle housing, what do you do about shrinkage and bowing?</font>

Personally, I'd bolt up the axle to whatever suspension you plan on using with the correct diameter U-bolts:



-Adrian

[torker]

duct taper, Good question. Think about a spring perch and how it's made. Looking at the front view, it's an upside down U. You weld the sides of this. If there is any pulling the perch itself will absorb the little bit you'll get with a weld around the diameter. This has never been a problem. Of course you could make it a problem if you slop a real heavy bead on it like I did where the tube enters the housing. But why would you? A 1/2" weld on all four corners will hold a spring perch.
The big problems lie with some of the heavy bracing we do to these housings for extreme competition vehicles. You have to brace the dickens out of the housing before welding and often have to use the torch to relieve the welded areas after the fact.
Adrian...that's how I prefer to weld perches on if I can. Most housings I do are sent out so I don't have the vehicle to bolt them to.
Russ

[GregC]

I would never use the springs as a guide for the spring perches - is that what is being suggested? The springs are seldom that true with one another.

[torker]

GregC...have you ever actually checked the spring perches from a factory rear end? There are some I've seen that are canted in two totally different directions. Besides... this is how it is normally done to set the pinion angle on a rear diff. How are you going to do that before hand if the (as you say) springs are so far out of whack? To get the angle set true you need the weight of the vehicle and the "difference" in the springs all in place beforehand.
I'm often asked to weld these on for out of town orders. I always recommend not doing this but guys who don't fabricate or weld will use shims instead.

[Nutter]

Nice post!

I've had the same problem with Dana 60 rears when I weld 9" ends on them. Always bent. I've just jigged it up straight and butt welded the ends on. There's plenty of meat in a D60 tube, so the misalignment didn't hurt. I figured that it would be OK as long as the end was aligned properly with the carrier bearings. I will have to try to straighten the tube next time just to see if I can make it work.

[This message has been edited by Nutter (edited 08-05-2005).]

[torker]

Nutter... Bears (in Canada), a division now of Strange...sell the Ford style ends that are meant to be butt welded on all tubes. Thats what I used for the 60's in my mudrails.
You are right. They are easy to line up even if the tubes are out of whack. Here's what I do...
Cut the end and make sure it's square. Easy with a 60!
Stand it up, drop in the axle, ends and dummy bearings. Swing the axle around and measure the quadrant distances. Calculate the center and tack it in place. Tack it some more until you are sure it won't pull off to one side. Remove innards and weld away.
Sound right?
I like doing them that way. The ends up here are $70 so I use the Ford factory ends for stuff like this. Not as much meat to work with though.
Russ

[Nutter]

I've used similar ends from Dutchman and Moser.

Your method of alignment sounds like it should work perfectly. You just made me wonder if I really need the pucks and rod that I use

[ibewgypsie]

Hey,, Howdy..

Another machinist with a coal scoop, I won't be the only one here now.. I make some heavy duty chips here.. About five gallons is a good day here.

Nice dealie on the 9incher.. do you spline them too? I tried to heat treat the last ones and had to file for hours..

David

[wierdscience]

Hey,the handiest tool I have found for this type work are those torpedo levels with the magnet base and the adjustable level.

That 44 special frontend I did I had no less than two hanging on it before I cut/welded anything.

Oh I did notice one difference between the Dana 44 Ford end and the Dana 44 Chevy.The Chevy has a smaller diameter tube,but one that's a lot thicker,like 5/8" wall,the Ford has a larger od with a 1/4" wall.


Hey,ever use a section of retangular tubing and a soapstone compass to layout a back brace for the 9"?