Going from 28 to 31 spline

[Marauder Rick]

simple question: Whats needed to be done for this conversion to be successful? How important is it to get a tune afterward, or do i even need a tune?

Here's the skinny: Im planning on going from stock to Cobra 31 spline traclock diff w/carbon clutches.

[ImpalaSlayer]

you dont need a tune

you need the axles and the diff, thats it

[Mr. Man]

you don't need a tune

you need the axles and the diff, that's it
Doesn't he need the tuner to reset the speedo to the correct calibration?

[Pops]

Only if he does a gear change.

[Dragcity]

Putting a new differential in will likely require it to be set up again. Out goes the 28 spline diff. Pull off the ring gear and pop it on the new Cobra 31 spliine diff. That has to go back in the housing. New spacers may be needed, the pinion depth MAY have to be adjusted to match the original wear pattern - right. ?

New axle bearings is also a recommendation. New axles may not play well with old bearings.

Never easy, is it?

[DOOM]

Doesn't he need the tuner to reset the speedo to the correct calibration?

No! He's not changing his gears.

Same thing I just had done to my car.

[Mr. Man]

So in other word his wheels will spin the same number of rotations but his differential will be beefier for doing long smoky burnouts. Got it. Thanks for the clarification guys.:)

[DOOM]

So in other word his wheels will spin the same number of rotations but his differential will be beefier for doing long smoky burnouts. Got it. Thanks for the clarification guys.:)

You got it! :up:

:beer:

[Marauder Rick]

So...what im hearing is that this process is "plug-n-play" right? change axels, change diff, add fluid, add modifier, and drive away?.........sounds simple

[SpartaPerformance]

You may want to start here. 31 spline kit (https://ssl111.webhosting.optonline.ne t/spartaperformance.com/merchantmanager/product_info.php?cPath=32&products_id=328)

Some modifications to add Vic axles may be needed

[ImpalaSlayer]

So...what im hearing is that this process is "plug-n-play" right? change axels, change diff, add fluid, add modifier, and drive away?.........sounds simple

yes sir :burnout:

[Marauder Rick]

You may want to start here. 31 spline kit (https://ssl111.webhosting.optonline.ne t/spartaperformance.com/merchantmanager/product_info.php?cPath=32&products_id=328)

Some modifications to add Vic axles may be needed

are our axels a different size than cobra ones? what would i need to modify?

[ImpalaSlayer]

are our axels a different size than cobra ones? what would i need to modify?
yes they are different but that link mentions nothing about cobra axles. cobras have IRS and are completely different

[Marauder Rick]

yes they are different but that link mentions nothing about cobra axles. cobras have IRS and are completely different

touche my friend

[SpartaPerformance]

They're not Cobra Axles. Mustang axles are too short.

[DOOM]

CVPI 31 spline axles! :rock:

[DOOM]

http://www.summitracing.com/parts/FMS-M-4204-F318C/

http://www.summitracing.com/parts/FMS-M-4210-C/

And my dyno shop got me the FORD axles for $190.00 ea.

This is what I used.
No modifications needed.

[Marauder Rick]

so...there's an ex-sherriff CV at my local junk yard. can i just snatch them off of there? Im guessing that CVPI means crown vic police interceptor.

[Dragcity]

Just be sure to check your pattern. Different differentials may have different tolerances. Myself. I would not call this a plug and play swap out.

[DOOM]

Im guessing that CVPI means crown vic police interceptor.

Yes that's what CVPI means.

It has to be an 05 & up rear that you need.

In 05 31 splines were standard issue in all panthers.

[Marauder Rick]

Yes that's what CVPI means.

It has to be an 05 & up rear that you need.

In 05 31 splines were standard issue in all panthers.

rock auto has 05 CV 31 spline axles for $107. what about those.

[DOOM]

rock auto has 05 CV 31 spline axles for $107. what about those.

Are they OEM ???

[yjmud]

I got replacement 31er's for 65 a piece

[Marauder Rick]

Are they OEM ???

yes sir http://www.rockauto.com/catalog/raframecatalog.php?carcode=143 0667&parttype=10439&partkey=1327984&a=FRc1430667k1327984-2563649


I got replacement 31er's for 65 a piece

do you know where they were from?

[Marauder Rick]

check this out http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=360316830605&frommaketrack=true&viewitem= this project is getting cheaper and cheaper thats $192.00/pr

[DOOM]

check this out http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=360316830605&frommaketrack=true&viewitem= this project is getting cheaper and cheaper thats $192.00/pr

I'm not sure if these are OEM. :dunno:

[Marauder Rick]

they have a number listed. I'll giv'em a call and aska few questions and post the outcome 2morrow. Anything specific that i should ask i.e. part #, constructed material, brand, whether it is a direct OE replacement?

[musclemerc]

Rick, DO NOT buy Dorman axles....

There is a set of "O" rings that are on the OEM's but is NOT on the Dorman's. Most will say "it wont matter" but I sent my Dormans back after finding this out. If you put the OEM "O" ring on the Dorman, you wont be able to get the axle to the"C" clip.

[Speed]

I plan on doing this down the road, heres the info I got from -Matt-. Add the listed
installtion pack and let it rip.

Tousley Ford (listed prices was year ago).
1-877-593-2526

Cobra 31 Spline Diff w/CF (2R3Z*4026*AA) - $190.22
31 Spline Axles (6W1Z*4234*A) - 183.51 ea

[musclemerc]

^^^oem...ftw!