Help Narrowing a 9" Ford

Use a jig. Determine if the housing is offset or not, then cut each tube accordingly. Although you can cut the welds and reuse the original housing ends, I prefer replacing the ends when narrowing a housing. Never cut and re-weld an axle. Axle prices have come down so far in price, there's really not a need in re-using a stock axle.

Build it once, build it right, fill it with oil and forget about it. Any shortcuts you take now will eventually haunt you in the future, and usually at a time when you're 100 miles from home on a Sunday and have no cash in your pocket.

 

I got my alignment bar here: http://www.metalsdepot.com/products/coldfin2.phtml?page=cdround&LimAcc=$LimAcc

I use a 1-1/2 x 6' shaft. $162.36.

My line-up blocks came from http://mittlerbros.com/rear-end-narrowing.php

Yukon Cut-to-Fit axles:

http://www.ringpinion.com/PartsList.aspx?SearchMode=Diff&TypeID=4&DiffType=Ford&DiffID=277&Diff=Ford+9%22+%289+inch%29+-+31+Spline&CatID=20&Category=Axle+-+Rear+%28Both+Sides%29

 

Here's what I used. I haven't had a chance to verify straightness, but v blocks and a dial indicator would take care of that.
http://www.speedymetals.com/pc-1565...quivalent-turned-ground-polished-000-001.aspx

 

Yes, mine is a truck rear end with the centered differential. Since I am putting it in a Model A won't I want to keep the diff in the center? After all it does not hurt anything in the truck and the cross-member sits directly over the axle.

Moser is quite reasonable on the splining. Less than half what an axle set costs.

Mike

 

I used McMaster part # 6061k27 $71.07

 

All of you have given me quite allot to chew on. I ordered my bar from Speedy Metals

http://www.speedymetals.com/pc-1565...quivalent-turned-ground-polished-000-001.aspx

It is stressproof 1144 turned ground and polished. The 72" bar gives me plenty to hold on to and was quite resonably priced at $121.31. I am expecting it to arrive on Monday.

If you like I will post photos of my progress. Perhaps it will help out others.

Mike

 

That one is only 42" long. It is fine if you are doing narrow rears.

Given 2-1/2" brake offset brakes, for instance, that would limit you to a 47" WMS-to-WMS rear axle.

6061K97 might be a better idea.

 

seen lots of ways to narrow, most require a jig, interestingly Ive seen guys break the tubes loose from the center and cut to length, reinsert then weld. still should be done in a jig.

What length do you need, mounting to mounting? rangers 8.8's have drum brakes decent gear selection and trac lok if you look around.

If youre dead set on a 9" youll spend much more getting it all set up, dont think you'll ever hook hard enough in a light vehicle to need it compared to an 8.8 but your choice.

Ive done it both ways, Im sticking to takeout 8.8's unless its seeing drag strip (slicks) duty.

 

Never upon never use a chop saw on any shaft of any kind that you want to send a machine shop. The chop saw heats and hardens the cut end of the shaft when you do that. Got my ass chewed out royally by the local machine shop when I cut a pto shaft off and took it in to have a keyway cut in it a few years ago. Trying to save a buck cost me having to buy a whole new shaft.
Plus as someone else explained the machine shop uses the center mark on the end of the shaft to center it in their lathe when they do the machine work or they would chuck the splined end in the lathe.

 

After reading through all these posts , I can't believe some of the crazy shit people are doing to a rear and expect it to last or even hold up under a load ! I worked for Ford for many years and would have never tried to do what some have posted here for shorting a rear ! As for cutting and welding an axel , I would never do that one or tell someone to cut a weld an axel ever ! Shorting a rear house is fairly simple as long as you use a jig of some sort . Some of the ways some have shortened rears really scares me ! As for axles , you can buy Moser's for about $300 now so why even consider shorting the axel you have that has had who knows what already done to the rear you are rebuilding . New axles will always last longer than a used one that someone cut a welded up !
Just don't be cheap or cut corners and have a professional do the rear for you . That way if something goes wrong you have someone to go after that you paid to have it done right the first time . These back yard rear re builder that someones brother , cousins , uncles , friend has done before is just not worth it ! The prices have come down a whole lot so why cut corners to save a few buck doing a rear the 1/2 ass way ! It just plain doesn't make since !
Just my opinion !

Retro Jim

 

Mike,
Centered diff or centered pinion shaft? Hardly any of the factory rears had the pinion shaft centered. For looks you would want to keep the diff case centered. If the car is low and has a tunnel in the floor it is probably centered, so you'd want to center the pinion to keep the driveshaft lined up with the tunnel.

Massive amounts of bullshit info on this thread. Mittler is the best choice for an alignment kit, but I used an old piece of turbine pump line shaft (and bushings) for years with no problems. That stuff has to be pretty straight! A lot of the kits out now are designed to do one end at a time (short bar). BAD IDEA!

Just my $.02...

 

The lowly 8.8 is stronger than you think. I have put them under 4x4 rock rigs, running 35" tires, locking differentials, and astronomical at-axle torque numbers (due to gear multiplication), with good results.

For high-torque applications, the tubes should be welded to the pumpkin, with high nickel rod. I have seen them spin.

 

X2 on the 8.8" They come in 2 flavors 28 spline (Mustangs and Rangers) and 31 spline shafts in the Explorers and Mountaineers. (all of them not just the V-8's)

I have them in more than a few Jeeps and buggies, my YJ had one with 35' MT's 4:88 gears on a Detroit Tru-trac with a 134:1 crawl ratio. I have the tubes welded, only broke one shaft. I was in 1st gear 4Low was climbing a rock got the wheels spinning then got a bunch of traction snap goes the axle. Keith

 

You might also check the width on Broncos up to 76, Mustangs and 57/58 fords also. The 8.8 is excellent too

 

AMC 20's out of Wide Trac CJ's might work as well.

 

seems you guys know your 9" i have a 9" out of 70 ranchero it has a 351c in it ( dunno if that matters for rear or not ). the price is free as i own the racnhero.... was donated with the house.. is this a decent rear end? this car was a victim of the gas shortage, converted to propane, then parked with low millage so the rear is gonna be new as i would expect from a used rear..
chris.

 

WOW! Interesting reading here! Some very misleading. My jig consists of two 1.75" cold roll bars, one 48", one 72", a dummy 9" case with bushings permanently installed and bushings for both big and small Ford axle bearings. Any decent machinist can make the bushings. If you want to see how far out of whack your housing/axle tubes are, put a case in it with bushings installed, slide your bar in, and then slide a bearing bushing up to the housing/axle bearing end, you may be shocked and dismayed about how far out of whack your rear end housing really is in stock condition. Buy one of the plates that Mark Williams [and others] sells, it bolts to the housing where the case mounts using the case studs, has a slot where the pinion center is to hook your tape measure so you can lay out length, cut lines, placement of suspension components etc.

I like to straighten the tubes up before I go to far, keeps everything consistent. I prefer to weld suspension stuff to the housing/tubes before the welding the ends on [stuff moves when you weld it] that way I can throw the bar back in one last time to check for straight. And i don't mess with resplining axles!

Good luck, John

 

I am pretty sure that I have the BS in this thread filtered out. I want to say that I appreciate everyone's advise on this. I am a competent mechanic, welder, and machinist. I know how to set up pre-load on pinions correctly and set gear lash and check patterns using Prussian Blue. This is not my first rear end assembly and all I have done stayed together well with no noise. As far as an 8.8 verses the 9" goes... The engine I am using is a 1957 368 Lincoln Y block. It makes about 300 HP and 415 ft lb of torque. Based on my understanding the 9" can handle this stock quite easily. Plus the 9" Comes with drum brakes and the correct bolt circle for my old ford wire wheels. One less thing to do in the machine shop! I have no plans to bob the axles myself now. Mosier only charges 150.00 round trip to modify my axles. I am sure they will be fine. Yes they could lived a hard life but they are straight and show no spiraling on the skin. Plus leting a "professional" do the job comes with no guarantees. I am remembering a time when I asked the local Chevy garage to line up my '57. After they did it the car was no better it was worse. I took the car elswhere and he fixed it in 15 minuets and only charged me 20.00. I went back to the Chevy dealership and politely complained and was cussed at by the service manager untill I was in my car pulling out of the lot.

Mike

 

same set up i use and yes most factory housings are out of alignment