Ok, I have been struggling with this long enough and need some help from the experts. I bought what I thought was a 9" Ford rear end from a 1969 Mercury Marauder that had the 429 in it. Aside from the crash course I'm getting in this situation, I know virtually nothing about rear ends. Why not narrow one and change the ring gear & pinion then right! Anyway, I took all of the measurements needed from the unit being together, then disassembled it to get the measurements required for the shortened axles. All good , done, next. I then purchased the kit and gears needed to change out the ring gear & pinion. Still good... I'll skim over the part where I got the amounts needing to be removed mixed up on the axles and had to send them back to Moser. One for exchange, one for cut & re-spline. (Good vendor by the way) They got me out of this spot for what I consider minimal cost. As some of you have figured out by now, I am now to the point of replacing RG & P and they do not fit this carrier. Turns out this is a 9-3/8" rear that was used on very few cars with high torque motors and I think a few 4x4 trucks. It seems that this rear had only a few ratios available (mine 2.80) and none that would be used with a straight drive car. It's my understanding that a 9" 3rd member will drop right into the housing, but is there anything else I will need to take into account to use my already shortened axles, other than it accepting 31 spline? One concern I have is axle length, since I've already been down that road once. Any help would be appreciated, KK
I am not a Moser axle fan,had one break out side the bearing allowing the wheel to come off,this was when my Comet was a high 11 second car with M/T ET streets,they may be OK on the street!!A 9" carrier will interchange with the 93/8" version,I did this on a 93/8 out of a Lincoln that we used under a 57 Chevy Pickup. ROY.
Damn, just could have got a K code stang housing, they re-pop them, or a 57 Ford Wagon 9" and they bolt right in a 64-65 Falcon/Comet..... http://www.mustangsunlimited.com/it...tegory=Differential+&+Related&CatKey=EMUSTANG
This one is actually going into a 57 Chevy, but I did all the narrowing before I found out that it wasn't a 9". I just need to know if there any variables I need to take into account while looking for a replacement 3rd member. Like, do all 31 spline Ford axles share the same diameter? Is the pinion offset on the 9" & the 9-3/8" the same? etc...
Been using Moser axles for years, never a problem and they have great customer service. B.T.W.: I'm going fast in a heavy car with 31" x 14" wide slicks. Oh and small bearing ends too.
All 31 spline axles use the same diameter,so any 31 spline carrier will work.I don't remember checking the pinion offset when we did the swap,but the truck did not have any vibrations.The rear seemed plenty strong[street use only] as it held up to a 671 blown 406 SB Chevy,turbo 400 combo! ROY.
To answer the questions, Yes all 31 spline Ford axles are the same diameter at the spline. Yes you can bolt a 9" carrier where the 9 3/8" was and NO you won't have any issues ~ Well you may have issues, but it won't be with this swap.
I don't know much about rears (of the automotive variety) my self but I found this websight very helpfull! http://www.kevinstang.com/Ninecase.htm When you google for 9 inch and its the first website that comes up you know its good!
Sorry HR maybe I mis-read your post. When I read this part I figured you were referring to a Ford 9" as a whole. Yea I mis-read it and assumed and you know what that means...... God I hate this internet stuff!
FYI...While shortened and re-splined 31 spline Ford axle(s) are pretty strong [just crusing around mild stomping] they will not handle good bite/healthy abuse like slicks at the strip..I was breaking them with a sbf engine of maybe 300hp just trying to dial the suspension in...
I would think that Moser axles would hold up on a street car with a few occasional runs down the strip but we'll see. HR, it sure has been fun watching you work out your "issues". LMAO!
We ran 31 spline Moser's in a 9" w/4:11 gears in a 56 Chevy with radail tires on the street and a couple drag passes with a 485HP 383 stroker motor and a 350TH and it never had an issue!
For a decent starting point - look at late-60s to late-80s Ford 4x4 trucks and broncos. They will quite often have 31-spline, 3.50 ratio, traction-lok rears. Look at the outside axle flange - if it has 3 holes in a straight line, chances are it's a 31-spline axle (unless you're looking at big land yachts from the early-mid 70s or disk brake rears). If it has a big open double-D, it's a 28-spline axle. When I used to go junkyard trawling, I'd just look at the axle end and if I saw the 3-holes, I'd then make the effort to find the tag on the rear...otherwise, I didn't waste my time getting dirty.
The Jalopy Journal
