31-spline swap-in parts?

[GetMeMyStogie]

My spider gears are on their way out (heavy galling, not going to last much longer), and I'm looking for a solution.

A few other threads mention swapping in 31-spline axle/side gears, spider gears and axles as a direct drop in. My questions are:

1. Has anyone confirmed this to be actually doable?
1. From where to source brand new gears? Vendors & part numbers?
1. What vehicles can I use to cross-reference for the axles, either new or used? Part numbers?
1. What vehicles can I source used gears from? Part numbers?

No guesses please, I'm looking for the specifics that are not really clear in the other threads.

[RubberCtyRauder]

Did you look at the sticky thread in the DIY forum? Parts list and all

[mustangeddie]

31 spline axles from mid 05 -11 Grand Marquis or Crown Vic are the correct length. The 31 spline spider gears do not work in the 28 spline carrier they are bigger and the cross pin which goes through the spider gears is bigger. 28 spline cross pin is .750, 31 spline is .875.Any 8.8 31 spline carrier will work in the Marauder housing. I'll have to dig but I think I have a set of Marauder specific 28 spline spider gears & a complete Marauder posi.

[GetMeMyStogie]

Did you look at the sticky thread in the DIY forum? Parts list and all

That sticky replaces the carrier itself. But a few members mentioned swapping in just the spider gears. Let me dig up the posts...



https://www.mercurymarauder.net/foru...ink_source=app


https://www.mercurymarauder.net/foru...ink_source=app

Looks like just one guy saying it's possible. [mention]justbob [/mention] , everyone says it's not possible - how sure are you, bud?

[RubberCtyRauder]

Post above says 31 spline spider gears do not fit in 28 spline carrier. I would change it all out. Mine was changed at Mo's Speed Shop in 2014

[mustangeddie]

The Marauder has spider gears that are specific to only the Marauder. No other spider gears 28 or 31 spline fit the Marauder carrier and 31 spline spiders only fit 31 spline carriers due to the size of the center pin. You need to change the carrier if you want to put in 31 spline axles.

[offroadkarter]

Is it really worth it economically to try and rebuild the stock diff with 31 spline spider gears? What mustangeddie says is right, for whatever reason the Marauder had its own unique set of spider gears that weren't used in any other Ford. Either buy a full fresh 31 spline Cobra/GT500 trak-lok from Ford, or if you really want to pinch a penny and do this on the cheap, find a factory tow package 95-01 Explorer which has a 31 spline 8.8 rear end and should have a 3.73 trak-lok unit. You'd need to get a clutch pack kit to rebuild the LSD at that point I am sure.

[BLACKMARAUDER04]

I replaced mine with a Detroit Locker and changed my axels to 31 spline at the same time.


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[Comin' in Hot]

The carbon clutches and upgraded S-spring are about $160, you can get a whole 31 spline trac-lok diff on Ebay for $269 already assembled.

LINK>>>>>> Ford Performance 8.8" 31 Spline Rear Traction Lok Differential Carbon Plates | eBay

[GreekGod]

You can install an OEM clutch-type differential, as has been mentioned. They work well and seem to be long lasting.

Otherwise, you can make a much more permanent repair. by installing an Eaton Detroit Trutrac or an Eaton Detroit Locker. They do not wear out (no friction plate clutches). The "Locker" is more for racing (it is required in NASCAR competition), but is streetable. The Trutrac is much more street friendly, and is a true limited slip differential.

Never ever never use 28 spline axles where 31 spline are available ...

re:
https://www.eaton.com/us/en-us/catal...ferential.html

[BLACKMARAUDER04]

Correction: I have a Eaton Detroit
Trutrack.


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