rear end shortening

[67 Evil Eleanor]

I guess the proff is in the end result. If the bearing falls in, it has to be in line. I just take out what I need to shorten the housing, cutting the end off first then the next cut is off the tube. I usually scrib a line on the tube with a straight edge to keep things lined up and check it after the spots. I by far am not an expert on this, but it works for me. I used this method for my track car with no problems so far. I have seen the aftermarket people use a long "true" rod to check alignment from bearing thru carrier to bearing. Then take a tourch and straighten them. From the comments and what I've seen, these housings were not that accurate to start with. Anyone know what the pass rate is using these strict standards.

 

[351w_swap]

when you consider that I had almost 900 into the versailles and wanted to shorten it, I dont think i am going to spend any more money on the 8.8 than the versailles even if i bought the spool/custom axle/c-clip eliminator package from moser.

 

[1320stang]

Thats what I'm trying to tell you, you're talking over 2' before you hit the carrier with the end of the axle, if that's 1/4" out, that's .01+ per foot, you can't see that. Typically the axle tubes are bent where they go into the center section. I've seen 9", 12 bolt, 8.8" and Dana 60's that the tubes are bent on. I've known my chassis guy for almost 20 years, I was roommates with him before I got married and spent many an hour helping him out at his shop. He mainly builds SSO & Outlaw 10.5 cars now, these cars are running 7.20s to 6.80's on 10.5W tires making over 2000HP with SBFs.

 

[lauras70mach1]

You can't make sure a rear is true without a jig.

 

[1320stang]

But you can get lucky. Contrary to the saying, I'd rather be good than lucky. I'll have probably $40k+ in my Fairlane when it's done, it'll be jigged. If I was throwing a car together for Pinks, I might forgo the jig.

 

[351w_swap]

I went back to the junkyard today to check out the rear end. He has two explorers with the rears in them. One is a 98 and the other is a 96. I was disappointed to find out that the engine in the 98 is a 4.0 and i couldnt get the 96 hood up. Does anyone have any clue what I am looking at for gears, trac lok?, or even the housing? I have never seen an 8.8 because i have never dealt with a newer ford, am I looking at an 8.8 or could it be a 7.5? is there any other pitfalls of the 4.0 rear end I should be aware of? Thanks

 

[ratio411]

Gotta look at the tag on the rear end.
It will hang off one of the cover bolts.
You should see a few sets of numbers, but the one you are looking is spread out.
It will have the gear ratio.
Look something like:
3.______7 3

That is what you should see for a 3.73 pegleg, as an example.
If it has limited slip, it will look:
3.____L___7 3
Engine shouldn't matter.
I believe any disc rear in an Exploder will be 8.8".

Edit:
I have learned my lesson with Fords. Gotta know what you are looking at and ignore what's under the hood.
The last 10 years I have popped the hood on every Granada/Monarch I ever found in a yard. If it had a 6, I kept walking... If it had a v8, I crawled under the car and looked to see if it had a 9" rear.
Lesson learned:
I never found a 9" rear until I found a car that the hood would not open on... I checked it and found a 9" rear.
While the yard guys were removing the rear for me, I saw that the car was an I6! I never would have found the 9" if I could have gotten that hood up. I would have kept walking. Who knows how many 9" rears I missed!
I would also steer away from 6 cyl car front brakes because someone told me once that they had smaller discs than 8 cyl cars! Now I know that isn't true... I grab them all when I find them now. While they are still dirt cheap in junkyards for the time being.

 

[351w_swap]

I got it figured out. The center section on a 7.5 is integrated into the housing while it is removable on the 8.8. There wasnt a 8.8 in either, I guess I am back to square one. I did find out that the junkyard guy only wants 125 for a 31 spline 9 inch while i was there and I know he has it because I there is hills of axles in that place. Maybe ill get lucky and find one with trac loc and 3.70 gears in it so all i have to do is replace the clutches, shorten the housing and respline the axles. Oh yea, and the thing that started the thread: the brakes. There is a circle track store near by that sells weld on brackets to use what I was told are "metric gm brakes", maybe I will just buy some cobra brakes and conversion brackets for it.

 

[96 DOHC Cobra]

Explorers only came with 8.8s from the fatcory. If they don't have one, then it's been swapped out. They're all 31 spline, and about 90% of them have 3.73s and traction lok.

 

[351w_swap]

Are you sure about that because I went to the local auto value today where one of the guys is a local racer and he seems to have answers to most of my questions. He looked it up on their computer and said that they came with 7.5 and 8.8 and it was about 50/50 on which one it was.

 

[96 DOHC Cobra]

If any did come with 7.5s, I'd have to see it in person with verifiable proof. I've looked at well over 100 Explorers in wrecking yards, and I've never seen one with a 7.5 rear. The smallest engine they came with was a 4.0. All the Rangers and Aerostars that came with 4.0s got the 8.8 rear. Why would the Explorer be different?

 

[ratio411]

I have never seen a 7.5" with discs myself...

Also, the 8.8" does not have a removeable 'chunk' like you were told.
Here is a comparision, the 8.8" rear is top of pic, with 7.5" rear cover at bottom.
The 7.5" cover is round on the sides, while the 8.8" is straight.

 

[351w_swap]

ok, guess i was wrong. They must have been 8.8. I plan to extend this build out over a substantial amount of time but the next thing is the rear end and rear suspension. I want to build a twin turbo 408 stroker that I am hoping to get 6-700 horse power out of. Should I just go with the 9 inch and take the brakes off it and buy the 8.8 for the better brakes? I dont want to spend that much money and I dont know if i can get rid of the rest of the 8.8 but I guess i might have to do that.

 

[67 Evil Eleanor]

Just spent a couple of days at a reputable race shop. They are Ford
Bluebloods all the way. Remembering this post, I ask them what kind of rears they use. They stated that they used a built 8.8. The C-Clips have to go thou. Their cars they race are making between 1000 and 1100 HP with no failures. On my home-made housing shorting method, I don't use a "Jig", I have seen them move and be off sometimes even after using a "Jig". I'm not saying that this is a better way. A jig is certainly better and easier, but you still have to check your work, as they can move either way. Actually, this was on TV a few years ago from one of the big players in the aftermarket services. They even they check them after they weld and make adjustments as necessary. The key to the end result is to check your fit as they do. If you are off no matter how you do this, you will have to straighten it anyway. Good luck what ever you do. Oh yeh, I friend of mine spent about $1200 with the "best known", on his 46 PU just have the bearing fall off in less than 5 miles. When he reported this to them, they of course denied any wrong doing. They still have his money and we had to fix the problem ourselfs. They were off on the left side tube and the bearing retainer and bearing would fall off with a pull of your hand. He was lucky he stoped for a heat issue and seen the oil before the damn thing came out on the road. Go figure.

 

[1320stang]

A jig is certainly better and easier, but you still have to check your work, as they can move either way.

That's what I said before....

Without a jig, how do you know if the rear end is square or not? Even after welding, it's recommended that you check the rear for warpage due to heat.

What I don't understand is, without a jig, how do you check your work? I mean, you can eyeball your line-up bar to see if it's bowed, my buddy stands his up in the corner in a cloth sleeve so that it doesn't bow. You can't eyeball down the housing to see if it's warped or not. I don't know how it could move in a jig. I could see the jig being hard to remove due to the housing being warped after welding. My buddy sets the rear end up on stands and rolls the rear while he welds it. One pass.

I'm done. I'm not saying you can't do it your way, and I'm not exactly saying it's wrong to do it that way, I just don't feel it's precise enough, my opinion, nothing more. I don't condone anyone doing it that way, it's not as much a problem if someone stays on top of their maint. program, but if people don't do anything until something breaks, there's a good chance of someone getting hurt, and it might be the guy in the other lane who has no say in it.