Ford 9" Rear End

[McDenny]

Hey All,
I picked up a Ford 9" rear end and it has a tag on it, I was wondering if anyone could help me determine what the info is. The tag reads as follows:

WDM - CJ 1A28
2 75 9 S314C

I was told it came out of late 70's early 80's F150. I am just looking for some info before I take it apart whether or not its a decent rear end.

Thanks,
Dennis

 

[Rick]

Hey All,
I picked up a Ford 9" rear end and it has a tag on it, I was wondering if anyone could help me determine what the info is. The tag reads as follows:

WDM - CJ 1A28
2 75 9 S314C

I was told it came out of late 70's early 80's F150. I am just looking for some info before I take it apart whether or not its a decent rear end.

Thanks,
Dennis

The 275 is your ratio and the 9 is the size of your ring gear.The rest is where it was made,what year bla,bla.

 

[ruggs]

Hey All,
I picked up a Ford 9" rear end and it has a tag on it, I was wondering if anyone could help me determine what the info is. The tag reads as follows:

WDM - CJ 1A28
2 75 9 S314C

I was told it came out of late 70's early 80's F150. I am just looking for some info before I take it apart whether or not its a decent rear end.

Thanks,
Dennis

Dennis, WDM-CJ is a 80-82 F100 or 150, it is a true 9" ring gear and a 2.75 to 1 ratio. if you measure the tubes they should be 3 1/4 inch and it will be late model large bearing. I'm narrowing one at this same time for my c-cab....Ron (ruggs)

 

[ruggs]

This link may help if it works.My link

 

[Mike]

Nice link, thanks for posting!

 

[McDenny]

Thanks for the link and info. The only way to tell the splines will be when I take it apart, correct? I will have to change ratio, do not want 2 75. I have a 8" housing that came with my car, just wanted a 9". This rear end is wider, but is it possible to use this rear end with out shortening it, I could just get different off set wheels correct?



Dennis

 

[ruggs]

Thanks for the link and info. The only way to tell the splines will be when I take it apart, correct? I will have to change ratio, do not want 2 75. I have a 8" housing that came with my car, just wanted a 9". This rear end is wider, but is it possible to use this rear end with out shortening it, I could just get different off set wheels correct?



Dennis

Dennis, To answer your first question...If you find 2 blind holes and one cone shaped hole on the end of the axles then it should be a 31 spline (this is the axle of choice since they are stronger and most can be resplined for street use. 28 spline are tapered just after the spline and cannot be resplined.
Narrowing a 9 inch is not that hard if you are a decent welder and have patience for accuracy. There are 2 ways of doing this. One is to replace the bearing housings and the other being to remove a section of the housing tube. Either is acceptable since the new bearing housings are for a butt weld (no difference since splicing the tube is also a butt weld.) In either case don't even try it without a jig. Here is a link that may help you, It is probably the best Iv'e found but does not cover everything. My link good luck....Ron (ruggs)

 

[Ted Brown]

First, nothing wrong with a 2.75 gear with a light car and more HP than needed... even with a stock V8 and plenty of 6's and 4 bangers as well...
Yes you can use a wide rear end, and run less off set in the wheel if you want the tire in closer... Look at the Leg Show, now that was a very wild looking ride, and it was WWWIIIIDDDEEEE, very wide..

 

[McDenny]

Well, I took the rearend to the shop today and started to take it apart. I stripped it down to the housing, removed the carrier and the axles. They are 31 spline axles, the ratio is a 2.75 to 1, I was wondering if someone changed the gears because of black silicone around the carrier. I am going to shorten this housing, it is 8" wider then the housing that came with my bucket. Does anyone know what gear set would fit into this carrier, or is there a website that could tell me what would fit. I was told different size carrier for different gear sets. I would like to go around 3.50 to 1. Thanks for reading.

 

[Screaming Metal]

Well, heres some more info....done by a member of another group I belong to....


Member

Join Date: Aug 2006
Location: socorro.Tx.
Posts: 897 How To Narrow A 9 Inch Ford Rear End Housing:
________________________________________
I am going to show the steps involved in narrowing a 9" Ford rear end housing. I am narrowing the following housing to accept Maverick 8" Ford 28 spline axles and housing ends to end up with a 56 3/8" wide 9" Ford rear end that will bolt in to a '65 Comet.

-First off, to clear up some mis-conceptions, a rear end is NEVER measured from backing plate to backing plate. That measurement tells you absolutely nothing because there are so many different backing plates, brake offsets and brake shoe widths. ALWAYS measure a rear end from the outside of the axle flange to the outside of the axle flange.

-Here are some terms, vital measurements and facts:

-28 spline 8" and 9" Ford axles are the same spline.

-You have to cut at least 4" out of 8" or 9" Ford OEM axles in order to shorten and re-spline them. Some of the older axles cannot be shortened at all. You cannot remove 1", 2", or 3" from any stock Ford 8" or 9" axle.

-Axles are always measured from the outside of the axle flange to the end of the splines.

-Brake offset is the measurement from the outside of the axle flange to the inside edge of the bearing retainer flange + 1/8". (the 1/8" is the thickness of the brake backing plate)

-Most small bearing 8" and 9" Fords have a 2 1/2" brake offset.

-Most big bearing 9" Fords have a 2 3/8" brake offset.

-These brake offsets are the most common, but there are always exceptions, so your best bet is to measure what you have.

-Centered pinion rear ends will ALWAYS have a left side axle that is 4" shorter than the right side axle.

-Rear ends that have the same length left and right side axles ALWAYS have the pinion offset 2" to the right.

-The "dogbone" is a tool that shows where the edge of the axles end up when bolted in the housing. It allows measurements to be taken with a bare housing when narrowing a housing.

-The space between the two axles is ALWAYS 1 1/8" on 8" and 9" Fords whether the rear end has an open diff, posi, locker, spool etc. This measurement is the same throughout all years of production.

The rear end housing that I will be using is from a late 60's early 70's Ford pickup. It is the small web housing, but it has 3" O.D. housing tubes that are .188" thick. It will handle lots of abuse:


I will be using the small bearing axle ends from the 8" rear end. They have already been cut off and faced in a lathe to 2 3/8" in length:


The 8" axles have a 2 1/2" brake offset:


The left side axle measures 25 5/8" from the outside of the flange to the end of the splines:


The right side axle measures 29 5/8" from the outside of the flange to the end of the splines:


Here is the housing after all the brackets were cut off and ground smooth. It has been cleaned with a stiff wire wheel:


The "dogbone" is placed on the housing studs for measurement:


-Now for some math to determine where to cut the housing:

-29 5/8" right side axle length minus the 2 1/2" brake offset minus the 2 3/8" length of the housing end = a 24 3/4" housing cut measurement.


So we set the housing on the chop saw table and we measure from the edge of the cut off wheel to the right side of the dogbone:



......and the end of the housing is cut:


-Now for some math for the left side:
25 5/8" left side axle length minus the 2 1/2" brake offset minus the 2 3/8" length of the housing end = a 20 3/4" housing cut measurement.

The housing is set on the chop saw table and we measure from the edge of the cut off wheel to the left side of the dogbone:


....and the housing is cut:


We now have a very narrow housing waiting for some housing ends to be welded on:


A dummy centersection is set up with aluminum mandrels in place of the bearings:


This is the 1 1/2" diameter stainless steel alignment bar that will slide into the centersection:


The centersection is bolted into the housing and the alignment bar is slid in place:


Another aluminum mandrel is used to place the housing end on the alignment bar. The face of the centersection is leveled and the bolt holes on the housing ends are also leveled. The housing end is tack welded in four places 90 degrees apart and then fully welded:





Here is the finished housing. When assembled, it will measure 56 3/8" wide, narrower than any 9" ever offered from the factory:


These terms, measurements and procedures can be used to narrow any 9" Ford housing to accept any length axle whether they are stock or aftermarket. Notice that we built a housing to utilize axles that were on hand, but we can also figure any housing width and determine what length axles to order for it using most the the measurements above along with a couple more.
________________________________________

 

[Screaming Metal]

Gosh darn it.....the pics didn't post.....

 

[Screaming Metal]

lets try this....

well....since the privacy software is working.....if you read carefully....you get the jest of it....

 

[McDenny]

I actually saw that post and was reading it earlier, very nice job he did.

Here is another question, 2.75 to 1 gear ratio, wondering how that would be for a ratio. I am going to have a TH400 trans. I was thinking 3.50 to 1, but now I am second guessing thinking that may not be a bad ratio. I do need to find a locking spool though. TH400 are low, and to be honest, I am running a BBC.

Thanks,
Dennis

 

[Screaming Metal]

You've got to remember....your not pushing nowhere near the weight of a normal car.....1600-1800 if its a bit on the chunky side. Well....since we're all performance folks here....he's something for comparison.

Get a Econo-Altered...basically a T, put a stock smallblock chevy in it, a powerglide, and about some 4.56's to 4.88's in the rear....and if she's hooking at all, she'll be running about mid to hi 10's @ about 135 mph. Nothing fancy or magical, its just your not pushing any weight at all and with those gears....the motor winds agianst the only resistance, thats the gearing.

Same thing with a BBC and a T. Theres alot of guys here that run them, with tunnelrams, blowers, nitrious, maybe both!....do they need it, no. They could easily run in the 10's, and if they were hooking good, probably 9's, with a good tuner on hand.

With a BBC thats healthy, I myself wouldn't run anything lower than a 3.50 or a 3.55 rear gear, and thats with the tallest rear tires you can find to put out back. Anything lower, when you step on it hard, it isn't gonna move, its just gonna spin.
Big power in a light car, go with a taller gear (numerically lower number)....

I don't think you want to run a spool, its your car though. Its gonna try to 'push' thru the corners, its gonna try and 'crab'when turn a sharp corner. Limited slip would be plenty, or a bonafid posi-trac....
With a spool, you'll get into a lot of undue tire wear....if you put anymiles on it what-so-ever....

 

[McDenny]

Thanks for the input Screaming Metal. It all makes sense when you put it that way. Just wanted to do something different is all. The only problem I may have is I am not sure what size gears I can put into that carrier. I was told that changing gears in some cases is limited because of the size of the ring and pinion and clearance issues. I am still looking into that. I was looking into 3.50 or 3.55 and a posi or limited would be nice. I am trying to find some info on carriers to see if I can find what gear sets will work it what carrier.

 

[Screaming Metal]

Thanks for the input Screaming Metal. It all makes sense when you put it that way. Just wanted to do something different is all. The only problem I may have is I am not sure what size gears I can put into that carrier. I was told that changing gears in some cases is limited because of the size of the ring and pinion and clearance issues. I am still looking into that. I was looking into 3.50 or 3.55 and a posi or limited would be nice. I am trying to find some info on carriers to see if I can find what gear sets will work it what carrier.

Do a search here....its been thrashed out a few times here on the boards....all the guys should chime in and give you all their experience by tomorrow.....

We should hear from Ted, Mike, Putz, One finger....they'll give ya the scoop....What Ted says is gospel....in my book. He's forgotten more than most of us will ever learn....

 

[blownt]

the real culprit in picking gear ratios is how tall the tires are. Big difference in how it runs between a 27", 29", 31", or 34" tall tire. I got 34" tall dirttracks and running a 4.30 gear. Personally, just my opinion, I would not run anything less than a 4.11, but I like the FUN factor at the stoplight along with torque converter and full manual TH400. I'm sure there are others that will disagree.

 

[Screaming Metal]

the real culprit in picking gear ratios is how tall the tires are. Big difference in how it runs between a 27", 29", 31", or 34" tall tire. I got 34" tall dirttracks and running a 4.30 gear. Personally, just my opinion, I would not run anything less than a 4.11, but I like the FUN factor at the stoplight along with torque converter and full manual TH400. I'm sure there are others that will disagree.

Yea Blown, I love the excitement too. ought to feel the pull of my new motor....its a inline 6 cylinder....4.625 bore x 4.5 stroke, with 4-71 induction on it.I changed the trans....trying to get a 5 speed overdrive to act right....motors fine, trans guy has his work cut out for him....

 

[McDenny]

Well, I found out today I can run 3:50 to 1 ratio in that carrier. I am going to shorten the housing myself. I am going to shorten it so the the center section is in the middle instead of offset. The pinion would then be offset, but the center section would look center. I am going to take 5" from one side and 3" from the other. I dont think the angle of the driveshaft will be that bad, it will go at a angle to the rear end, but it shouldn't effect it too much. We have a drivesshaft shop in house that we make driveshafts. I am not sure how the shortening of the housing will go, but I will keep you posted, wish me luck

 

[Screaming Metal]

Good luck! Its not hard, just read the articles and stay with those guidelines.....you'll get alot of satisfaction out of doing it yourself!
If ya need any advice, we'll be standing by....but with a few qualified folks around, it should go smoothly.