Rebuilding a 2004 Sport Trac 8.8 axle

[SN95GT50]

New project, retrofitting an Ford 8.8 into a Jeep TJ. Hoping to get help from the Ford people along the way.
.
Let me introduce you to my Jeep:

• 2005 Jeep TJ Wrangler X
  
• Inline 4.0L 6 cylinder
• 3.08 gears with Dana 30 front and Dana 35 rear, both open differentials
• I have a 3" lift with 31" tires
• A few other little things

The Jeep is my daily driver and doubles as my weekend four-wheeler. Tired of being left behind by others with bigger wheels, better gears and better differentials. In the spring I will be regearing or replacing the front axle and adding an autolocker to the front and upgrading to 33" tires.

Instead throwing money at the weak Dana 35 I decide to replace it with a Ford 8.8 that I found out of 2004 SportTrac. The axle has 4.10:1 gear ratio and TracLok, I believe this axle will have 31 splines as well, can someone confirm the 31 spline? Hven't pulled the axles yet.

Started tearing the axle down over the weekend, pulled the brake calipers and rotors and opened up the differential. I tried turning one of the axles with an 18" breaker bar and the other one turned the other direction, that's not a good sign, pinion did not turn at all. Finally put a couple bolts in the pinion flange and put the breaker bar in there and the pinion broke free and then turned pretty easy, that's better.

So, my first question, how difficult should it be make the LSD slip? Sounds like I should be replacing the clutches, but, not sure. I believe the axle had between 120 and 140k miles on it. Anyway to test the LSD to confirm it needs a rebuild?

Assuming I need a rebuild, can you guys recommend which kit to get? I look forward to any advice you guys can throw my way! Thanks in advance.

John

 

[fastpakr]

Ford motorsports sells a carbon fiber clutch kit. As I recall it was about $100-110. The part number M4700C comes to mind but I may have made that up. Lots of rebuild walk through pages online and YouTube videos.

 

[SN95GT50]

Ford motorsports sells a carbon fiber clutch kit. As I recall it was about $100-110. The part number M4700C comes to mind but I may have made that up. Lots of rebuild walk through pages online and YouTube videos.

What material is the factory clutches? I've seen ceramic and now carbon fiber. What are the advantages/trade-offs of each.

Thanks,
John

 

[fastpakr]

I haven't seen a definite answer to that, but it's the setup they use from the factory on the more powerful/heavier Mustangs (GT, GT500, Cobra). My suspicion is that it lasts longer under hard usage. There are some other discussions at this site and others that you can find with a search. No real complaints that I've found, just consistent solid engagement.

By the way, to answer your question about 28/31 splines, it should definitely be 31. I've got one out of an '02 that I'm working towards installing in a '99 Ranger.

 

[SN95GT50]

Made some progress the last couple of days. pulled the cover and everything looks good, no spare metal floating around. Diff fluid was pretty dark. Confirmed the gears are 4.10s

. Cut off the two passenger side brackets, need a grinding disk to remove the remainder. Did a little sanding to make it shiny and removed the parking brake cables. I bought a 10 pack of cut-off disks, four are gone, should have enough to finish the job. Fun little project for after work.

 

[fastpakr]

I'm surprised you're going through so many cutoff discs. The first one I broke out is still going after removing both spring perches and the shock mounts.

Do you have a plan for cleaning the housing? I haven't hit on a good way to do that yet.

 

[SN95GT50]

My cut off discs are from Harbor Freight, need I saw more .

Not sure on prepping the diff, as porous as it is, I don't think it will take much. I plan to put a base down of POR-15 with a rattle can top coat.

Plan to finish the bracket removal this weekend and get the axles pulled and everything off the end for pulling seals and bearings.

Haven't purchased new brackets yet, may wait for black Friday.

 

[SN95GT50]

Are you planning to weld the axle tubes to the diff?

 

[fastpakr]

Ruff stuff has a kit for $125. I just ordered that when it was 20% off. Perches, mounts, plates, u bolts, and nuts.

http://www.ruffstuffspecialties.com/catalog/merchant.mvc?Screen=PROD&Product_Code=88SS-31


I'm using HF stuff too. The $10 grinder has long since earned its keep on this project.

 

[fastpakr]

Are you planning to weld the axle tubes to the diff?

No. Probably a good idea that I'll regret later.

 

[SN95GT50]

What are you installing yours on?

 

[fastpakr]

99 Ranger.

 

[SN95GT50]

Here is the kit I'm probably going with, probably without the Truss. I do like how the truss lines everything up. Got a litle more work done last night, ground what was left of the brackets down to even with tubes.

 

[crankyjew]

Nice project! good find on the 8.8, they're not as easy to find these days as some would lead you to believe.

I've swapped a 01 Explorer 8.8 into my 1992 Ranger SAS. I'm running 35's with zero issues.

Explorer axles are frequently fairly beat up- many explorer owners weren't exactly passionate about maintenance, or caring about their vehicle. They're called exploders for a few reasons.

All explorer axles are 31-spline. Make sure yours is straight (sight down through the tube, through the pumpkin) and hasn't twisted one of the tubes (check the plug welds).

Ruffstuff is a phenomenal company, I used all Ruffstuff brackets/u-bolts/mounts on my build. Highly recommend.

I used a Harbor freight pneumatic needle scaler to knock the big crusties off of my housing, followed by a couple of different wire wheels on a grinder. Wear a GD faceshield, respirator, and ear plugs...

Concerning your diff carrier:
First, are you positive it's a LSD? I've seen axles labelled wrong before. If not, consider an aussie locker.
If it is a LSD, and worn out, have you considered a Powertrac No-Slip? Similar skill and time required, so much more capable off road.
If you're into the LSD however, I'll second the Ford carbon-fiber kit. The stock clutches are organic and are set up from the factory to engage very mild. You can set up a new set of clutches to engage (almost) as positively as a real locker.

 

[01STrunner]

Ha I did the opposite. I put a Jeep axle in my Sport Trac. It was a HD Dana 44 for the front though. I didn't see anyone confirm it for you, but yes the Tracs (and explorers) have 31 spline axles. Most rangers have 28 spline but there are exceptions. You'll be happy with the 8.8 in your TJ.

 

[SN95GT50]

I would love to stumble upon a Dana 44 front I can afford, bonus would be the 4.10s.

 

[SN95GT50]

Got the brackets removed and ground down, removed some rust, still have some to go....


Photo by John Larsen
Photo by John Larsen
Photo by John Larsen
http://i284.photobucket.com/albums/ll23/sn95gt50/88 Upgrade/Pass Side.jpg

 

[SN95GT50]

See anything I should be concerned about?

Got the brackets removed and ground down level with the tubes.

 

[SN95GT50]

Took a little break, got back to it tonight. Pulled axles out, seen videos of people doing it, but surely mine won't be that easy, pleasantly surprised took just a few minutes. Put everything in the diff back together and removed everything bolted on the ends of the axles. Will need to do a little more sanding so the welds and paint has something to stick to. Next week is black friday, hoping to score a deal on the mounting brackets and TracLok rebuild kit.

 

[SN95GT50]

Who is your go to for Ford supplies. Looking for a good price on the M-4700-C Carbon Fiber TracLok rebuild kit. I have dealt with Summit Racing before, looks like they want $112 for the kit with free shipping. Anyplace else I should look?

Thanks, John