The best method is a hope string and a good eyes LOL

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It is our attitude that will determine the outcome

This particular 8.8 was out of a 91 Mustang V8, 4-speed car. But just about 8.8 will do depending what you're looking for drive ratio.

As far as the $1500 figure goes, now that I've done it myself, I'd say it's mostly labor. While I wouldn't characterize narrowing the rear end as difficult, it is very exacting as I'm finding out. The biggest challenge is getting the axle housing flanges as perfectly perpendicular both vertically and horizontally as you can. Guys who do this as a living have jigs and such that make the assembly accurate and that's worth money. Most home builders don't have that luxury.

If I were to do it again, I'd borrow an idea offered up by Jim Stabe and bolt or clamp a long straight edge to the axle housing flange and measure for both toe in and camber. Would be easy to do with, say, a 6' piece of angle iron (aluminum would probably be easier to work with) bolted to the housing in the horizontal plane, then measure the run out at the the front and back, adjusting the housing until the measurements were the same, tack at the top and bottom. Rotate the assembly 90 degrees and repeat for camber. Then stitch between the tacks being careful not to overheat everything so you don't warp the tubes.

You'll need to start by making sure your assembly is level and will need to come up with a way to make sure the housing ends are concentric to the tubes. I did this using a modified exhaust tube reducer. As I said, none of this especially hard to due, just very precise.

Very good Bill! Behave yourself.

Ok, the 3/16" equates to a little less than 1/16" toe in measured on a front tire (the 32" radius is just under 3x the radius of a front tire - probably not enough to worry about by itself. The camber is equivalent to a little over 1/16". What that means in terms of degrees is the 3/16" equals about 0.8 degrees and the 1/4" equals about 0.9 degrees. What you don't know yet is which side or both are out of square. Get yourself a 4' drywall square at home depot. You will use it for a lot of other stuff once you have it. Clamp a wide plate to the face of the bearing end and put the square on it lined up with the centerline of the wheel bearing and extending toward the other side of the axle. The end of the blade should be directly over the center of the axle tube. Do the same on the other side. If only one is not on the center of the axle tube, that is the side you have to move. If both are off you need to move both. Measure the housing in both planes.

You can use heat and quench to pull the ends into square. Heating and quenching a spot will cause that spot to shrink and pull in that direction. Imagine which way you would have to pull a lever to get the end back into square with one pull to correct both planes. The place you would stand to pull on the lever is the spot you need to heat and quench. Heat a spot cherry red and quench it with a sponge and water and remeasure. You should see some movement. If not far enough do it again. If both planes didn't change like you thought they should, move the point to heat. If you went too far go to the opposite side and pull it back. This really works and will move the metal so go slow until you get a feel for how it reacts. With a little patience you should be able to draw it back into square.

As far as the concentricity goes, there is no easy way to measure it and fixing it would mean cutting the ends off and starting over so we both know that the concentricity is right on the money don't we!

So bribe your helping hands and start another wonderful learning experience.

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Jim

"If you want me to agree with you then we would both be wrong"

'66 MGB widened 11" with LT1 Chevy and 6 speed, C4 Corvette suspension
Pictures here Part 1 http://forum.britishv8.org/read.php?13,7581
Continued in Part 2 http://forum.britishv8.org/read.php?13,22422
Continued in Part 3 http://forum.britishv8.org/read.php?13,33108



Edited 1 time(s). Last edit at 08/13/2012 08:01PM by Jim Stabe.

Well, I've decided to redo it while the differential is out of the car.

It's not a big deal to grind off the welds and lop the housing ends off. Probably a good evening's work to make sure it's as right as I can get it. It's not like this car is going anywhere in the next 6-8 months.

This time, I thought I would get two 6' pieces of angle aluminum, drill and bolt them on center to the housings in the horizontal plane. I'll add to that the drywall square idea and should (operable word) end up with an assembly that is as close to perpendicular in both planes as a guy in a home garage can get. Once I have one plane accurate. I'll rotate the assembly 90 degrees and repeat the process. I'll use my modified exhaust reducer trick to keep things as concentric as I can, unless you have another idea on how to do that.

Any other suggestions?

Before you cut them off, try the heat/quench and see if it gets you there. Certainly easier and cutting them off won't do anything for the concentricity. It's kind of fun watching the metal move and it is a skill you will use again before you are done building cars.

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Jim

"If you want me to agree with you then we would both be wrong"

'66 MGB widened 11" with LT1 Chevy and 6 speed, C4 Corvette suspension
Pictures here Part 1 http://forum.britishv8.org/read.php?13,7581
Continued in Part 2 http://forum.britishv8.org/read.php?13,22422
Continued in Part 3 http://forum.britishv8.org/read.php?13,33108

Dave, my previous post was not intended to dissuade you from performing your own work on any complex project - in fact I applaud enthusiasts that have the inclination and ability to do such work.
In this case,though,I just see the possibility for potential quality issues with the axle and components, perhaps ending in further rework (at further expense) and then there is still the shortened and resplined shafts to rework that will most certainly have to be outsourced.
In terms of time and money invested, I believe that both would be mitigated by entrusting to a reputable axle business….
…..but, as I said in the previous post, then there would be no self satisfaction and accomplishment.
Keep us apprised of your progress……..

How far can I realistically expect them to move?

A little different method that worked for me when I narrowed my 8" ford.

I cut thru the welds on the housing end of the tube rather than the bearing end. Then I slid the tubes into the housing to the proper length. The clearance between the housing end and the tube is very tight so not much chance of misalignment there.
Set the assembly on a flat surface & use v blocks under the tubes to get it aligned, Tack weld then rotate the assembly to check for runout and weld as described previously.
It worked for me about 20K miles ago. My only mistake was taking the axles to a local machine shop to be shortened & re splined. Those suckers are HARD. Cost as much as new ones & took way long cause the guy didn't want to admit he was having trouble doing the job.
I'm not sure I would do it again (more disposable income now) but I really did want to try doing it myself.

I thought about your method when I was considering narrowing it myself. There were a couple of barriers that presented themselves 1) I would have to remove the tubes to trim an adequate amount off and while I could get them out, I wasn't confident I could get them back in. When I checked with the local machine shop, turns out there wasn't a press big enough in town to handle the job and 2) I really wanted to go with a 9" bearing (bigger, better) and c-clip elminator axles. For the bearing that meant changing the housing ends and, in the end, made the decision to cut the tubes.

After it's all said and done, I think your method is by far easier and probably results in more error free result. Hind sight is always 20/20.

You have 3/16" toe measured at the ends of a 64" bar. 1/2 the length of that bar is 32". That 3/16" is presumably split equally between the two sides (but maybe not). So you have to move the front of the bar out about .046" (.187" / 2 / 2 = .046". The flange on the axle is about 4" across which is 1/8 of the length of your lever arm so you only have to move the rear edge of the flange about .006" in relation to the front. Take out your feeler gauges and see what .006 feels like, it isn't very much. The camber will have to move about .001" more than that. You want to try and correct both camber and toe with one shrink. From what you said about your measurements, I would place the shrink slightly above the 45* point on the top rear quadrant of the axle tube. Do the shrink right on top of the weld you made. After you measure with the drywall square you may find that you need to move one side of the axle housing a little more or less and possibly in a slightly different direction or maybe not at all.

Give it a shot, you have nothing to lose. Worst case is you have to cut the ends off and start over which you were going to do anyway. If you can make it work you will have a real sense of mastery over the metal.

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Jim

"If you want me to agree with you then we would both be wrong"

'66 MGB widened 11" with LT1 Chevy and 6 speed, C4 Corvette suspension
Pictures here Part 1 http://forum.britishv8.org/read.php?13,7581
Continued in Part 2 http://forum.britishv8.org/read.php?13,22422
Continued in Part 3 http://forum.britishv8.org/read.php?13,33108

There are, without a doubt, potential and very real quality issues narrowing an 8.8 this way, a couple of which I am dealing with right now. Case in point, tonight I am creating a simple alignment gauge (courtesy of Jim Stabe) to verify and help correct some misalignment of the new housing ends. As a result, I get to try out a heat shrink method that is new to me and am, frankly, excited to see how it works. Something I didn't know about before I tackled this. More time? Surely, but well spent I believe because I will learn something that I can use in other areas of the build.

There are always risks associated with doing something like this, risks that a prudent man understands and assumes before diving in. But without them and the challenge they bring, there is no new learning. Well worth it to me because this is not always about "time and money". Sometimes for sure, but not always. I want to learn something at every opportunity even if, especially if, that means diving off into areas that have been previously untried.

Regarding the axles, I did indeed, sub them out to Moser for precisely the reasons you stated. Not only were they not something that was even remotely within my expertise, they weren't even within my field of learning.

I guess this comes down to what each individual wants out of their build. Some folks want to get the parts, get the car together, and drive the pants off it. I've done that...more than several times and enjoyed every minute of it (okay, maybe not every minute). Rather than build another car using the same learning (nothing against those who do), I wanted this one to more of my personal classroom, a place for me to try all of those things that I hadn't tried before and to exponentially increase my automotive knowledge. It has been all of that and more as it has challenged my endurance as well as my willingness to risk. Oh sure, some days, I just want it to be done so I can drive the damn thing. I get frustrated just like everybody who does this. But I wouldn't have it any other way.

Something Jim didn't mention, if you pull it to far you can go back to the same spot and heat it but not quench. Allowing it to cool naturally causes the metal to stretch back out. You'll have to experiment with it to get a feel for it.

Jim

Thanks. Good to know. I just finished setting up my alignment jig tonight. Tomorrow is the big day. First time trying the heat and quench method. Maybe a stupid question but, how long after the quench should I see (or measure) a result?

Instantly when the metal cools. If you had an indicator on the arm you could watch it move. Take pictures of your setup and let us know how it goes.

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Jim

"If you want me to agree with you then we would both be wrong"

'66 MGB widened 11" with LT1 Chevy and 6 speed, C4 Corvette suspension
Pictures here Part 1 http://forum.britishv8.org/read.php?13,7581
Continued in Part 2 http://forum.britishv8.org/read.php?13,22422
Continued in Part 3 http://forum.britishv8.org/read.php?13,33108



Edited 1 time(s). Last edit at 08/14/2012 07:23PM by Jim Stabe.

All I can say is, wow! I'm really looking forward to trying this. Thanks.

Okay, the deed is done and it was pretty damned amazing to see. If someone had told me I could see the axle tube move before I tried this, I would have thought they were nuts.

Here's the results of about 2 hours of experimentation. It's not perfect but maybe one of the Jims (Stabe or Blackwood) will weigh in on whether it needs further work. All measurements were done at 24" from center (48" total) in both vertical and horizontal planes. Front to back is off by slightly less than 1/16" with the front being narrower. Top to bottom is off by 1/32" with the top being narrower. So there is a little bit of camber and tow-in. For reference, the current rolling rubber is 24" in diameter so these measurements were 2x that distance.

It took quite a few tries to get it this close. A couple of times, I went too far in one direction and had to reheat and let it relax a bit. I also found I could correct the over-shrinks by heating the opposite side. I could probably get it closer but I think it would be more luck than my skill. Unless the consensus is that it needs to be closer, I'm going to let the assembly cool down over night, then clean up and repaint the tubes.

Thoughts? Comments? Laughter?

Told ya it works. I think you are pretty darned close. It would be interesting to measure a "pro" housing and see how close it is. How did the drywall square work out? I've never actually used one that way but it should have let you see what was going on from side to side. Hopefully everything will spin free and easy when you get the axles in there.

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Jim

"If you want me to agree with you then we would both be wrong"

'66 MGB widened 11" with LT1 Chevy and 6 speed, C4 Corvette suspension
Pictures here Part 1 http://forum.britishv8.org/read.php?13,7581
Continued in Part 2 http://forum.britishv8.org/read.php?13,22422
Continued in Part 3 http://forum.britishv8.org/read.php?13,33108

Jim,

I actually didn't end up using the drywall square (although I'm now the proud owner of one). I ended up using two pieces of angle angle iron bolted to the housings to measure the deflection. I also checked the housing to tube squareness using a framing square. Must have missed something in the instruction on how to use the framing [meant to say drywall square] square but, as I was trying to use it, it didn't seem to make sense.

Axles should get here today or tomorrow from Moser. Will be one of the sweeter deals. Bearings and studs already installed. Nice. I'm going to try and get the rear end up under the car tomorrow and install the new axles after. No sense in horsing any more weight around than I need to.

Thanks for both your advice and your encouragement on this. I know it's cliche, but I really couldn't have done it without you. I'm stoked. It was so cool to do and see.

David



Edited 1 time(s). Last edit at 08/16/2012 05:03AM by dtownsend.

You could have done it, we just got you to try.

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Jim

"If you want me to agree with you then we would both be wrong"

'66 MGB widened 11" with LT1 Chevy and 6 speed, C4 Corvette suspension
Pictures here Part 1 http://forum.britishv8.org/read.php?13,7581
Continued in Part 2 http://forum.britishv8.org/read.php?13,22422
Continued in Part 3 http://forum.britishv8.org/read.php?13,33108