IM STILL HERE

TKOPerformance wrote:

Considerable experience.  I won't use anyone else's gears and I've run two of their limited slips and been very happy with both.  Personally though I think I'd upgrade to 31 spline axles.  Be sure to get rid of the crush sleeve as well (use a solid spacer instead). 

Thanks for the feedback, I thought they looked like pretty high quality pieces. They come fully assembled with solid spacers already installed, which is one of the reasons I'm getting the full assembly - I don't have access to the tools (and know-how) to make those measurements (backlash, preload, etc.) anymore. I can press on the yoke, but that's about the limit of what I can realistically do on one of these. I know all the off-roaders and racers like higher spline counts, but for my car 28 will be fine, plus I'm trying to avoid unnecessary spending so that I can afford the things that really matter to me.

Last edited by LoveToFlyGuy (4/18/2023 9:10 AM)

BobE wrote:

I have an Auburn posi unit in my 9”, and am happy with it.  I recently changed to 3.70’s (from 3.89) due to a noisy rear (pinion bearings were bad).  I’m not sure of your driving habits, but with the T-5 trans, I wouldn’t go below 3.50s. While I have 28-spline axles, if you are in need of getting new axles, I would go for 31-spline, just to be safe.  Note to verify that the axle bearings may need to be changed to the ‘large’ bearing to accommodate the 31-spline axles.

Thanks. I've mellowed somewhat in my 5th decade on this planet, so I'm not a super aggressive driver, but I do like to step into it on occasion - scares the daylights out of the Mach-e drivers
Are you running a T5? I have 3.89 gears that I was planning on using, but re-did the math and thought that toning it down a little would still give me plenty of bottom end power, but also give me a much more comfortable highway cruise, hence the 3.50 decision. If I didn't already have the 28 spline axles, I would definitely go with the 31 spline.

TKOPerformance wrote:

If its a Fox Mustang T5 then 3.50-3.70 is about the perfect gear with a reasonably sized tire.  I have a Fox Mustang T5 with 3.50s in mine. 

I hear not wanting to spend unnecessarily, but consider what gets destroyed when you break an axle.  The gearset, possibly the housing, etc., etc.  Also, if they are stock 28 spline axles how old are they?  The stock heat treat wasn't really all that good, and axles do fatigue over time.  Nothing wrong with economy, but beware false economy. 
 

Yes, the T5 is from an '86 Fox Mustang and that's what caused me to re-evaluate the 3.89 gears I was going to use - it's great to hear that you're getting good performance from 3.50 gears. What size wheels/tires are you running? I've been planning on going with 17" wheels, but I'm not committed to that yet - I still have 14" wheels on it right now.

I appreciate the advice about the axles, and you made a very good point. After more than 15 years, I can't remember where (or what) they came from, so I don't actually know how old they are. At this point, I've ordered that third member ($1216 from CSP Racing with free shipping), so I'm committed to the 28 spline axles, just maybe not the ones I already have.

I would get a set of Moser replacement axles at the very least.  I have a set in my IROC, which are only 28 spline (largest available for the 7.5" 10 bolt).  They've held up well.  The problem with drivetrain parts is they are fine, until they aren't.  You typically get no warning, just a loud bang and an expensive repair bill.  After breaking a bunch of stuff in my youth I started to if anything overbuild the drivetrain in my projects.  Insurance always seems expensive until you need it. 

TKOPerformance wrote:

I would get a set of Moser replacement axles at the very least.  I have a set in my IROC, which are only 28 spline (largest available for the 7.5" 10 bolt).  They've held up well.  The problem with drivetrain parts is they are fine, until they aren't.  You typically get no warning, just a loud bang and an expensive repair bill.  After breaking a bunch of stuff in my youth I started to if anything overbuild the drivetrain in my projects.  Insurance always seems expensive until you need it. 

I slept on that thought, and managed to convince myself to go shop for axles... Do you know of any brands that should be avoided?
 

I have Moser 28-sline axles.
If you're going to open up the T5, the Tremec website has has a service manual available to download.
I also found Paul Cangialosi to be a T5 helpful source; https://www.5speeds.com/word.html
 

BobE wrote:

I have Moser 28-sline axles.
If you're going to open up the T5, the Tremec website has has a service manual available to download.
I also found Paul Cangialosi to be a T5 helpful source; https://www.5speeds.com/word.html
 

Yeah, I think I'm going to do that since I have no idea what condition the internals are in. I rebuilt the 46RE in my old Durango a few years back, so this shouldn't to too bad. I figured that as long as I'm replacing everything else in the drive train, I might as well do it properly and give the T5 an overhaul as well. I watched a YouTube video with Paul & Eric the car guy rebuilding a T5, so I'm convinced that I should do it, and confident that I can do the job.