how many people on here have fabbed their own 9" and still used the tq arm? how many have fabbed their own 9" period? how hard and how much I am thinking about trying it or bringing it somewhere. also what exact length? I want to use 4th gen width but need either 3rd or 4th gen length #'s. as 4th gen is 4" longer either would work also what is everyone using for brakes? I am thinking maybe LS1 disc rear brakes? anyone on here tried this combo?

 

I have made several 9" for race cars. It is pretty easy to do if you have the correct tool. Keeping the housing straight is a must. Also welding in the proper order is important too. I purchased a Currie housing for my 82 Z28. When I got it I chack it for being straight. The drivers side was over an 1/8" off and the passerger side was a 1/16". I was very upset with the lack of qualtity. This is not to dish on Currie but WTF!

Anyway I ended up cutting the housing ends off and putting new housing ends on so that the housing so that it was correct and straight. The mounts on the 9" to mount the torque arm are very simple. Just two thick DOM tubes welded to the top and bottom on the housing. I'll get you some pictures over the weekend so you can see. You can probably purchase the torque arm mount from Currie or Moser. This is a big hunk of 1/2" plate that will bolt onto the tubes that get welded onto the housing.

When I ordered my rear axle I had a custom length one built. So my width is not going to be of much help. The nice thing about building a custom rear axle is you can do just about anything that you want. I am using big rear disc brakes with no parking brake as of yet. Being my car is being built to run in the Silver State races and see street use I was not too concerned about having an e-brake. One thing that is nice about building things is if your going to use something like the LS1 rear disc brakes all you have to do is order an axle set up for that size of housing flange. Since it is custom anyway usually they do not charge extra for special items like that.

 

when you did your own did you mig or tig weld them?

 

I have always Tig welded them. You can control the heat much better with a tig weld. I am sure that you could mig weld a rear end together.

When I have built housings usually it has been a 4130 sheet metal housing. I have done two of the larger truck housings for friends 4wd's.

As an FYI there are three main type of stock 9" Ford housings. This early housing was used from the birth of the 9-inch in '57 through 77 on some applications. But it's weaker than the later housings because it used a butt weld to join the axle tubes to the center. In aThe early style that looks just like the 8" ford.

The later housings that came out around 68 have much of the axle tube sticking inside of the center section.This also provided triangulation so the center section could distribute and handle more power and a greater load. There were two axle bearing sizes and the smaller style that has the ends of the housing that taper down and hold a smaller axle tube. Then there is the HD truck housing. This housing is the best as it has a thicker axle tubes.

In the pictures attached you can see the main difference between the early and late housings.

 

wow you know alot more about it then I do. how much would you charge me to do one? just the bare housing. and it would be able to be shipped through ups I think. LMK if interested I am less than impressed with a few others I have spoken with. also if you have access to a tig than you have me beat.

 

Well I can do one but it can't be shipped UPS. It needs to be shipped truck freight.

In all honesty it is more cost effective to just purchase one. By the time you go get a housing out of a junk yard (if you can't find a van housing then you have to remove the factory axle tubes and retube it so you have material to work with and also can get the correct axle length), order parts (housing ends), create the brackets, ((usually you would use the stock rear axle brackets (spring perches, lower control arm mounts, panhard brackets) unless you going to have all HD ones made)) Then it gets even more expensive. weld it up, your in it alot of time. After all it is all labor!

I would call up Moser and get a quote. If your really in a bind I can fab something up.

And yes I have a tig machine.

 

pm me with some kind of price and we may do some business anyway. I will check on shipping.

 

I currently use an early style housing. It has 3" tubes which are what the majority of all aftermarket suspension brackets are based on. When I get around to installed a narrowed diff, I'll be using a later style. The late style has 3-1/4" tubes and the tubes are 1/4" thick. I finally found someone who has an alignment jig that I can borrow when I'm ready to weld my tubes back into the housing. From rough measurements, my narrowed diff will be 44" from axle flange to axle flange. Third gen stock is in the 63-65" range.

 

I started with a moser 9”, stock brackets, stock, 3rd gen width. If I was going to do it again, would change a few things.

I would order it 1” to 1-5/8” narrower, it would let factory, 0 offset front rims fit like the stock rear rims on the rear. The 5/8” range there is the difference I’ve found between the assorted factory rear rims. This would let you run the same offset rims front and back as well as give you a lot more properly fitting (as in with the tire all the way in the wheel well) off the shelf rear rims 15x8” and bigger, especially 15x10’s (I have 0 desire to run 4th gen or corvette rims on it, and no matter what you do you have to run spacers for them at least in the front so I see no reason to go with a 4th gen width).

I’m also not sure that I would order it with the third gen brackets on it. I’d probably get the cast TA adaptor piece, and the 3 mounting tubes, I might get them welded on, but I’m not sure about the rest of the brackets, I’ve decided that I really want slightly different geometry and am only using the brackets that they put on it to locate the new brackets.

 

I was also thinking about just using stock width and using adapters all the way around. that way I could keep my factory rims too. what is the major drawback to stock suspension setup? seems like a decent setup to me.

 

Nothing major, it's just not exactly the way I want it... just call me **** retentive.

 

I installed a 8.5 10 bolt in an 88 irock. No welding on diff. I used a clamp around the snout made of two peices of 6" by 4" 2" wide alum. Bolted together with 4 .5" bolts. Took a lot of grinding to get the fit. Then bolted the torque arm to the clamp. Car is street driven and ran 11.79 at 116 mph with 1.58 60 ft. with a little nos.

 

I am starting a twin turbo 18 degree motor. I doubt a 10 or 12 bolt will hold up. gonna take a while because of cash though.

 

Hey Brian, do you happen to have any good pics of your bracket? I've been thinking about this because I hate to spend $2500 for a moser right now. I would appreciate any good detailed pics and/or drawings you might have.

 

was looking at some site and saw that moser was using 3.25 tubing and switched to 3 is this a typo or just cost savings at work again on there part? also how hard is it using the stock 10 bolt brackets on the 9" housing? also is there any offset required for the torque arm bracket or just install the bolt tubes on the driver side and weld on? ready to start on this before I even start my motor. figured rear first then tranny then motor. cheapest to most expensive. also I would love any pics anyone has or can get. thx
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hey comp788 was also wondering the later style housing you have pictured is that a stock housing or moser?

 

do you have any pictures of this, sounds interesting. i am thinking about putting a 12 bolt in my camaro and everyone on here pretty much says the only option is to buy an aftermarket one for 2500 bucks which really isn't an option considering i'm not rich. i know there has to be a way, its just one bracket, i'm not giving up that easy.

 

That picture is of a stock housing. The aftermarker ones are all made that way unless you get into a fabricated sheet metal housing like the hard core drag racers use.

 

I've been doing some more research. I know the diff I use is very close to the width of a third gen. Close enough that within an inch isn't going to make a big difference.

I was under the car doing some measuring today to see how much I'm going to need to cut. My current diff housing is 56.5" wide. Add in the 2-1/2" axle flange on both sides and you get an axle flange to axle flange width of 61.5". A third gen diff is very close to this width although I don't have the exact measurement of one.

From doing some research on what's available for narrowed diffs, a 40" wide housing is the most common. Doing a bunch more measuring, I can see making this width fit the tires nicely under the car keeping the outside of the front and rear tires roughly in the same track. I'm also going to correct the pinion centerline since it's over to the passenger side by 1-1/2". To cut my diff down and get everything lined up, I need to cut 7-1/2" out of the passenger side tube and 9" out of the driver side tube. That would make the final width from axle flange to axle flange 45" not the 44" I rough guessed at. Not a bad guess really when you consider all I did was put the new tires and rims behind the car and eyeballed where they looked the best.

A 12 bolt will hold up as well as a 9".

All aftermarket suspension mounting hardware, 4 link brackets, ladder bar brackets, coilover mount brackets etc are all designed for a 3" tube. If your diff has 3-1/2" tubes, all the mounting brackets need a new radius cut in them to fit over the tube. Why not just provide the diff with 3" tubes for consumers to easily use all the brackets that are available. Make 3-1/2" tubes an upgrade option. It's not like a street or street/strip car needs 35 or 40 spline axles where it needs the large diameter tubes. Even my car only needs 31 spline axles although upgrading to 33 spline would be nice. That would mean buying another spool.

I've also noticed the panhard bar is a terrible setup for drag racing. As the diff moves up or down during launch, etc, the panhard bar actually forces the diff to the right in it's arc. We're talking extreme up and down travel of 2+ inches. My new narrowed diff won't be able to use the panhard bar and I'll be installing a diagonal link.

 

Here is a pic a guy sent me. I just got a free 8.5 10 bolt and am going to run a spool and 33 axles. I know of guys running high 8 at 154mph granted this is with a spool but A spool is no worse then a locker and well no posi is going to take anything over 550hp for very long. I say screw $2500 rears. Brian I would realy like to see how you made your bracket I plan on copying this one.

This was his prototype is just neds a little more welding and tweaking to make it tuff

 

Both my stock 83 drum brake axle and my moser “third gen width with big ford ends setup for 4th gen disks” axles are 56” even from flange to flange.

A 9” is intrinsically stronger then a 12 bolt because of it’s design, larger gears, larger housing, pinion support, heavier casting, larger beargings… Of course, 28 or 31 spline axles are pretty much standardized so if you’re running a set of 28 spline axles it won’t matter which you have, your weakest point will be those axles.

If you’re capable of doing a proper job welding those brackets/setting up that rear, you should be more then capable of spending 2 minutes grinding out 1/8” out of each side of the bracket to make it fit. You spent more time typing that then it should take to make them fit.

35 and I think even 40 spline axles work fine in a 3” tube. Yes, I agree that most fast cars out there don’t really need more then 33 spline axles, but if you’re looking at 9” parts you’ll find that that severely limits you WRT to differential selection, where 35 doesn’t. since 28, 31, 33 and 35 all cost the same if you’re having stuff built, at that point there isn’t much reason not to go with the 35’s, unless 31’s are more then strong enough for anything you might ever do to the car.

Um, HUH??? Have you actually looked at one? Did you pass geometry and trig in HS? First, 2” difference on most f-bodies roughly moves it through the center of it’s arc resulting in NO relative motion to the body. Second, assuming you started with the PHR parallel to the ground, 1” change in axle height results in rougly .01” (yes, 1/100”) change in axle position side to side. I defy anyone claiming that the rear axle moves too much with a PHR or that “you have to put an adjustable PHR on the car if you lower it” to even measure that difference accurately/repeatedly on the car or in any way be able to tell from looking at it. The casting variation from one side to the other side of the tire rubber is probably at least 5x that.

There are posis that will hold more then 550hp reliably, as will a traditional locker…

There is no way in hell that bracket will hold any significant HP for very long. The sheet metal used for most of it is way too thin, those welds are sad, don’t look to have proper penetration and are not in locations where they result in significant strength. About the only part of that that I would consider done right is the ring around the pinion. Otherwise, the rest of that bracket should be heavier, formed out of bent steel and instead of tying into the ribs on the housing which is just asking to rip them off should have similar sections to the pinion ring that wrap around the axle tubes right where they come out of the center section, then the whole deal, the housing, tube and bracket can be welded together to keep everything nice and strong.

 

The pic is some guys prototype as I said. Your missing my point a spool is bulletproof and cheap at the same time. I never said a locker won't hold 550hp I said a posi won't did you pass gramar school reading class? I plan on improving on this design.

 

I am thinking of going with the 8.5 also. Sure would like to see somemore TA mount pics.

 

Sorry superirocz, I won’t waste my time trying to help you again… you just go with that design. Tell us how far down the track you make it on your first pass with some sticky tires.

 

I just don't like the remarks about high school. "Did you pass geometry and trig in HS?" I just don't think it does any good and you obviously don't like it when it directed to you. As for the bracket it just a place to start as I said my setup will be alot beefier.

 

I like that bracket design a little more than Brian Weatherby's design in the other thread. Personally I prefer it welded rather than clamped, but that's just me. It is a solid, well made piece though, looks like clean workmanship and all that (Brian's).

This, I agree, shouldn't have been welded to the tabs, more to the center housing. Also, I wouldn't use MIG (looks like mig), I would have used a high nickel arc welding rod. A cast iron, or "weld-all" type of rod, if you will.
I just assumed it was welded as if it was mild steel, and that would be a crack waiting to happen. I would also do a proper pre-heat, and post heat on the whole thing (not sure if this guy did, just saying that's what i'd do).

hey crossfire, if you had to use 3" diameter cut brackets (1.5" radius), on a 3.5" diameter tube (1.75" radius), wouldn't you need to remove 1/4" more material (difference in radius?) not 1/8"?

Stephen, how did (or are you) going to cut the tubes? Chop saw, band saw? Just idle curiosity.

What metal is used on that bracket superiroc? Looks like 1/8"? Personally I think 3/16" would work, no sense in overkill, the type of loading it's needing to withstand isn't bending on the thin axis (if made right), so 3/16" should be plenty. (For a car with reasonable HP that is...)

Open ended question - Just how much force does a torque arm actually see? I'm looking at the guys pulling front tires off the ground with a stock stamped steel one, so i'm assuming it's not ALL that much. It's not the sole component forcing the car to wheel stand is it?

 

I don't want to chop up my current diff because it will still have a good resale value. I'd love to find another old style housing with the 3" tubes to cut up. I do have a late model housing that I've cut. I cut the tubes right at the weld on the housing then knocked out what was left of the tube inside the housing. All you would need to do then is cut the tubes to length, press them back into the housing, use an alignment jig to make sure they were square and weld them back to the housing. The problem is that the late model housing uses the large diameter tubes and the housing itself is very wide meaning lots of bracket modifications to get them to fit. Early housings are nicer to use but are getting very hard to find unless you buy an aftermarket one. Places like S&W and Comp Engineering still sell early 9" housings. I was at one of the local wreckers (Bucks) and they had a pickup box full of 9" housings. All late models.

When I do finally cut up a housing, either the one in the car or hopefully another one I can pick up, I'll just cut the ends off and either reweld them on or weld on some new ones. I use the Ford big bearing style ends with a Set 20 bearing and 1/2" bolts. Worst case is that I'll just use the late model housing I have and do lots of modifications to the brackets. I'm still looking for another early housing.

When I cut the tubes on the late housing, I used a 14" chop saw. Accuracy wasn't required because I just cut the welds off the housing. When the shortened tubes slide back into the housing, a new weld wouldn't care if the housing was cut a few degrees off or not. The tubes are slid in about 2-3".

 

Superirocz, I gave you correct information and also corrected a downright stupid misconception about PHR’s around here that I don’t care to ever see repeated again. Yes, you caught the brunt of it _this time_ but you also took it farther than most people do.

If the design is so stupid and a diagonal brace is better, then show us how.

You wasted mine and everyone else’s time and added nothing useful or constructive in your post.

 

Link somewhere? I can’t find it…

Cast iron is a weird animal… the trick to welding to it is realizing that you’ll never get the expansion and contraction right so to design your joints where it doesn’t really matter and they’re not structural. If you look around you’ll find that structural connections always are done at large, oversized bosses that usually go entirely through the casting, where the load can be well distributed and in compression (castings tend to be strong in compression and weak other wards). The thin ribs sticking up are nowhere near as strong as steel, the joints are not in compression, and welding material to them in 3 dimensions is just asking for cracks/failure because of different expansion/contraction rates. You can get around that by building a flexible structure, but who wants something flexible to hold a TA?

Actual technique is more dependent on the welder. You’ll find someone that doesn’t like every method out there for one reason or another. Preheat/no preheat, peining/no peining, that filler or this filler, TIG, Stick, MIG…. There is actually a specific, cast iron filler for MIG just like there is for Stick and TIG (good luck finding any of them) but the general rule of thumb is that any higher grade alloy will to some extent prevent cracking so if in doubt even 308 or 309 SS wire will work (much higher nickel content then the base metal), for stick a lot of people like “super missile weld” and for TIG any of the mostly nickel rods like Ni99. The more nickel the more compatible overall the weld will be with that base casting WRT to expansion rates and especially in the weld zone where the metals mixed). That general rule works for just about everything, not just cast iron, but I can tell you that a lot also depends on the exact piece that you’re messing with. I’ve run across pieces that I could weld with anything and it was fine (within the structural constraints of the base casting), and then others that just didn’t work no matter what and ended up brazing it. FWIW, I’ve had the best luck with MIG and the worst (as in never got a functional weld) with TIG, which is just the opposite of what it should be if you had someone with a lot of theory and no experience predict the outcome.

Yes, but does anyone actually make 3.5” tubes on anything that is intended to be used in a car? Moser and a few others when they went oversized went 3.25”, and since that was mentioned in the previous sentence in the post that I was responding to I stuck with it. If you’re bending a ¼” wall, 3” tube then you either need to redesign your suspension or add some specific bracing to the rear.

In my case I’ve always used a horizontal, down feed bandsaw and a jig/stand to get them perfect, of course, with the nice machined ends that you can get from moser that practically can only go in right or not, you don’t really need to get it perfect, I’m just **** retentive that way. Well, I’ll take it back, the first time I put new ends on a mustang axle I did one side with a 4.5” abrasive wheel in an angle grinder and the other side with a sawzall…, worked fine, I’d bet that 95% of people couldn’t tell after it was welded.

I’d suggest at least 3/16” CRS, thinner or HRS will want to bend anyplace where it does not have a bend or 90* in it to give it rigidity. All of it will tear off that cast housing, taking some of the housing with it.

In theory, a pure TA suspension shouldn’t have any up/down loads on the LCA’s, so ALL the force lifting the front end of the car (or trying to lift the back while braking, wheel hop…) goes through the TA. As the LCA mounts move downward and the front link on the TA does more and more sliding more of the force gets transferred off the TA and to the LCA’s.

The stamped steel TA was never designed to lift the front of the car on the drag strip. That being said, take a look at how much steel it has in that plane. As long as you prevent it from twisting it is very strong in the up down bending direction.

FWIW, if you’ve seen how moser connects the TA to their housings that should give you some idea how much force they see. A few TA manufacturers refuse to warranty their TA’s when used with a moser or moser style mount, because they believe that they move around too much, come loose and brake TA’s, if you agree with them then you’ll need to design something stronger then their heavy wall, massive casting, large bolt mounts (I’m not sure that I agree… if that was the case coating the 3 big bolts with some high strength locktight should fix it. I believe that the real problem is people setting pinion angles incorrectly since there are some very fast cars that stand on their back bumpers running that same basic design).

 

Heh, couldn’t find it with a search but it was near the top of the list on the board… I’ve even posted to that thread but not since the pics were posted and haven’t seen a notice in my email about it…


https://www.thirdgen.org/forums/fabr...brication.html

 

ah you beat me to it, I just went to find the link and give it to you, but then noticed you were the last poster so...

Yea, the reason i'd use stick is because I can go grab a handful of high nickel rods, say for $10, and grab it in the stinger and go. Mig i'd need to buy (well, a mig welder first )but then a huge spool of the wire, and yea, it's hard to find. I think the stick rods are more common.
anyway...

ok, well i'm thinking of the stock torque arm, mostly in the rear mounting area. 2 bolt holes through ~1/8" thick material. I'm thinking if indeed it was lifting the front of the car, it should tear the holes in the TA into nothing at all... but alright, if the LCA's help out, that makes sense.


CRS, yea, I can agree on that, looks nicer too

Yea, I think personally i'd like to make up a steel TA mounting bracket, and weld it on, rather than Brians method. Granted, the setup in this thread isn't a "perfect" example of how i'd do it, but it's on the same playing field. Brians method seems to work quite well, is SOLID, and looks well made (the AL brackets are machined quite nicely, the place where the socket capcrews are, in particular lead me to believe they were milled, not "hand drill in the backyard"). It just worried me having to balance the clamping force with pinion gear drag, and JB weld always makes me uneasy.
Anyway, those are just my rambling thoughts.

 

pm'd ya with a couple?'s Crossfire

 

I found this thread on welding axle tubes on a 8.5 10 bolt. I think this could be applied to fabing up a TA mount on the diff. alot of good info on weling steel to nodular cast iron.


How to weld axle tubes on GM 8.5" 10-bolt - NastyZ28.com

 

Good posts I've been learning alot.. I got a 77 8.5" 10 bolt from a Trans Am that I'm shaving tomorrow. I'll post pictures of the process. Have to design a torque arm mounting technique, but there was one half way up the page using two heim joints and a couple of chromolly bars.. very cool

Does anyone run one of these rearends currently, and can you attest to the strength of this unit? They look fairly beefcake to me.. but hey.. who knows eh

-Brett

 

hey man do you have any pics of your setup please. i am going to install an 8.5" 10 bolt and thats the only thing puzzling m,e is the torque arm setup