9" axle parts, soon to be Marauder axle

[lifespeed]

Here are some Ford 9" axle parts soon to be the base of a torque arm rear suspension in the Marauder. The fabricator has the parts and an example (bracket donor?) Panther axle to work from. It might not be much more than a month before I'm driving a smooth, quiet car with precise yet comfortable rear suspension.

Strange HD pro aluminum studded differential case with oversize pinion bearings (plural, the 9" has bearings on each end of the pinion), Trac-loc T1 carrier and aluminum driveshaft yoke.






Speedway Engineering Grand National axle housing, aluminum hubs, steel axle drive plates, aluminum rotor adapters, inner axle seals and bearings. Gun-drilled axle shafts aren't shown.






Look at those bearings!!! Proper tapered rollers with adjustable preload. Just like the good old days, but larger. They'll never need replacing.


A custom version of the Maximum Motorsports torque arm will be mounted underneath the housing. The bolt-on 8.8" axle brackets are replaced by something neater and welded.

A splined, hollow sway bar will also be employed. I'll be reducing the rear sway bar rate slightly from the Addco 1-1/8" X 0.25" wall tubular rear bar cancel slight oversteer, although I think the Metco urethane bushings in roll bind are partly responsible for this issue.

[lifespeed]

Here is a thread about wheel widths and offsets that resulted in the axle width 3/4" narrower than stock, with 40mm offset 20 X 8.5" wheels widened to 10". See the first post in the thread for wheel photos.

I have changed my mind on keeping the air ride. I'm going to switch to coil springs as they are the only way to get a linear rate. I will employ an air bag overload for towing and heavy loads, but they'll only have 2 - 3 psi in them when not needed. I'm not sure if this can remain automated or will be manual with a gauge. It might be all I can use from the factory system is the lines and solenoids.

[MOTOWN]

Looking forward to seeing this come together, a little skeptical of gun drilled axles on a street car.

[lifespeed]

Looking forward to seeing this come together, a little skeptical of gun drilled axles on a street car.

They don't carry the weight of the car in a floater. It is the default configuration for most all race cars and they seem to be reliable.

[FordNut]

Beautiful!

[chief455]

Beautiful!

really, having had several torque arm GM F-body cars, I rather enjoy the u/l control arm/watts link.
No suspension theory experience, have no idea what you are going for.
I'm sure it will drive awesome, and those are some beautiful parts.
I've run forged, 31 spline gun drilled axles on the street before for 2 summers and no issues.

[lifespeed]

really, having had several torque arm GM F-body cars, I rather enjoy the u/l control arm/watts link.

Let's not paint torque arm suspension with the broad brush of GM F-bodies

The trouble with 4-link is it needs the rubber bushings to deform in roll, it has inherent bind. Think about the side view of the control arm axle bushings moving through two different arcs. No problem when both sides compress equally, but in roll they try to twist the whole axle housing. Instead the bushings deform. Then I put in Metco control arms and Watts links. Solves some problems, creates others. Snap oversteer is an issue. It isn't really serious, but that kind of unpredictability at the edge isn't a good thing. And it degrades ride quality, kind of like having a larger, inconsistent sway bar. Don't get me wrong, the Metco stuff is decent and I'll likely keep their Watt's link.

The two types of live axle suspension with minimal roll bind are three link and torque arm. And three link puts the third link in between the two back seat passengers. So the realities of a passenger car dictate torque arm suspension. It's not a done deal yet, hopefully no major surprises.

Edit: Here is a link on the different characteristics of rear suspension designs.

[chief455]

very interesting stuff! Hopefully the effort has positive results. It sure is a sweet 9" rear

I modified all my GM torque arm cars with adjustable lower control arms, torque arm and panhard rods with greased bushings. It greatly improved the feel over stock parts and allowed easy pinion angle adjustment and centering of the tires to the body after ride height changes. Combined with larger sway bars, those cars really handle!
That said, with just aftermarket control arms, sway bars and improved shocks/struts - the Panther is amazing to me for it's size and weight.
I think you'll be pleased either way.
Cool idea to try.

[lifespeed]

What part # U-joint is in the pinion flange of the Marauder driveshaft? I have to match a 1350 U-joint cup in the 9" yoke. Maybe the slightly longer third member and the removal of the Marauder pinion flange will match up perfectly in overall length and let me re-use the stock driveshaft.

High speed vibration will probably force me into a better driveshaft eventually, but I wouldn't mind at least trying the stocker with an axle with good bearings.

Edit: Rock Auto seems to reference both 1330 and 1350 U-joints, not sure which it is.

[chief455]

Mine are both 1330, front and rear

[justbob]

What part # U-joint is in the pinion flange of the Marauder driveshaft? I have to match a 1350 U-joint cup in the 9" yoke. Maybe the slightly longer third member and the removal of the Marauder pinion flange will match up perfectly in overall length and let me re-use the stock driveshaft.

High speed vibration will probably force me into a better driveshaft eventually, but I wouldn't mind at least trying the stocker with an axle with good bearings.

Edit: Rock Auto seems to reference both 1330 and 1350 U-joints, not sure which it is.

Stock is 1330 which is easily available in 9" yokes. IIRC they make a short and a long so that might help you. Not sure if your going to find anything but old school U bolts but that worked fine for decades..

My personal favorites for driveline parts is The Driveshaft Shop and Yukon gear. I split a Spicer front yoke clean in half..


Builder Of Badassery

[lifespeed]

Stock is 1330 which is easily available in 9" yokes. IIRC they make a short and a long so that might help you. Not sure if your going to find anything but old school U bolts but that worked fine for decades..

My personal favorites for driveline parts is The Driveshaft Shop and Yukon gear. I split a Spicer front yoke clean in half..

I'm sure they make 1330/1350 adapter U-joints, I used one years ago. I have a Strange aluminum 1350 yoke on the pinion with an extra large retainer and pinion bearing, so I'm committed to their yokes. Shouldn't be an issue, and I don't know what the chances of the stock driveshaft being the correct length are anyway.

[chief455]

I'm sure they make 1330/1350 adapter U-joints, I used one years ago. I have a Strange aluminum 1350 yoke on the pinion with an extra large retainer and pinion bearing, so I'm committed to their yokes. Shouldn't be an issue, and I don't know what the chances of the stock driveshaft being the correct length are anyway.

even a local parts store has always had a 1330/1350 crossover joint. they also have straps for the 7mm? bolts to the billet yoke I had, or old school u bolts for through holes..
Last 9" swap I was surprised how easy this was at the local store.

[justbob]

Boom.

http://m.summitracing.com/parts/str-...FdgRgQodnMgAlw


Builder Of Badassery

[lifespeed]

I'll check the shaft length before buying that U-joint. And I'll get the billet caps instead of the pedestrian U-bolts as well.