Build / Recommend a New Diff, 2010 Crown Vic Police Interceptor

[HankHill]

Kinda second question about this, with more info...

2010 Crown Victoria Police Interceptor. 94k miles. Mint Mint, Mint condition.

I ruined the lsd in my car driving like a moron on ice. Was stuck on hill on a highway on Christmas during a 2" pure ice storm (did not know highway was so bad when leaving) Car behind me also stuck and my CV was sliding back towards his car the ice was so bad. Rather than hitting him, I got ****** and floored the **** out of it up over the hill for about a quarter mile. Road was salted halfway down over the hill. Smelled diff oil later in the trip and continuously after trip. After car drove like **** in corners and seemed to have drag when turning. Fill plug on diff was removed and oil looked like mercury. Was told clutches and gears were probably shot. I have an 8.8 axle with 3.27 gears and a shot LSD. QUESTION: I want to get a well performing and durable diff. I have the desire to take the car up over 250k miles (done it before) and want a diff that will last.

I have the ability to build a new dream axle, all new components. I am replacing all bearings, gears, seals, diff cover (drain and fill type). But I'm stumped on which type of diff to get. I drive very aggressively and plan to drive the car several times a year, at a mach EVOC course.
I've looked at LSD's from Ford Performance with carbon clutches, and Torsen Diffs. Ford Per. LSD's are about $600, and the Torsen's run around $800. Is the extra investment worth it? I like the idea of no clutches to wear over time, and for an extra $200 is it worth it in the long run? Are Torsens that much better than LSD's? How about Auburn Diffs?

I'm looking for advice, opinions and experiences. Your input means a lot to me, and will hopefully get me to the goals I mentioned.

BTW: I found a local off road shop that does all types of axle work too. Estimated price is very much cheaper than other shops around here. Plus since the shop does diffs and gears all the time, I trust their work.

 

[el Nuke]

Have you look into going the Wavetrac route for the LSD functionality? I’ve heard nothing but good things from the Dodge LX folks that have tried it.

 

[Gimpy1]

Have you look into going the Wavetrac route for the LSD functionality? I’ve heard nothing but good things from the Dodge LX folks that have tried it.

A wavetrac? Those are like $1200 why not get a Kaaz and go all out.

 

[HankHill]

Have you look into going the Wavetrac route for the LSD functionality? I’ve heard nothing but good things from the Dodge LX folks that have tried it.

Seems like a *little* bit too much money for me. I know I said dream rear, so thanks for the input, seriously.

 

[Kuato]

I'd go Torsen, the $200 you save gives you nothing to wear out except the fluid. LSD you'll be repairing every so often.

 

[DuckRyder]

Didn't i post the link the Filthy MS comparison of diffs.

I would put a TrueTrac in it if it was mine. I don't however think the FRPP is a terrible choice, but if you're buying a complete new diff spend the extra for a TrueTrac.

IMO

 

[HankHill]

Didn't i post the link the Filthy MS comparison of diffs.

I would put a TrueTrac in it if it was mine. I don't however think the FRPP is a terrible choice, but if you're buying a complete new diff spend the extra for a TrueTrac.

IMO

I didn't see the link, sorry. yeah, at $6xx I think I'd just go with the Torsen. Did some reading on the true trac though and it seems like an awesome upgrade for my jeep when I finish!

 

[SwampSurvivor]

Torsen is the way to go if you want some sort of limited slip!

 

[HankHill]

Torsen is the way to go if you want some sort of limited slip!

thats where I'm leaning right now. I just want to get a ton of opinions so I can choose wisely.

 

[HankHill]

Torsen is the way to go if you want some sort of limited slip!

By the way my '99 XJ made it to 205k miles before it rusted to death. The floor pans and rear wheel well frame curves were repaired one already, POR-15'd and rhino lined. Still rusted though.. It was a monster, fast, amazing in the snow and cornered well .
Every day I wish I did the repairs on it, but I was at a busy point in my life so I let it go. Upgraded injectors, intake, everything possible for that rig. I always look for them and would kill for another one.

 

[nthach]

Torsen - no “special” fluid required, no clutch packs to worry about. Next option would be an driver-controlled locking diff.

 

[DuckRyder]

 

[SwampSurvivor]

By the way my '99 XJ made it to 205k miles before it rusted to death. The floor pans and rear wheel well frame curves were repaired one already, POR-15'd and rhino lined. Still rusted though.. It was a monster, fast, amazing in the snow and cornered well .
Every day I wish I did the repairs on it, but I was at a busy point in my life so I let it go. Upgraded injectors, intake, everything possible for that rig. I always look for them and would kill for another one.

Mine's at 214000 but doesn't get driven a lot any more at all. Just a trail rig. When I got it, Cherokees weren't considered real Jeeps and were not a desireable vehicle.

Now to find one in semi decent shape, you're looking at spending at least $5000. I had one on my short list for vehicles along with a panther, but finding a decent panther is a lot easier and cheaper than a Cherokee! The panther is surprisingly good in snow

 

[buck91]

Can’t imagine you did any actual damage, maybe worn LSD clutches at the worst (if they weren’t already shot). The 8.8 is pretty decent. I used to beat the tar out of my 94 CV and the only time the rear end gave me issues is when I ran over a sewer culvert at speed….

I put some carbon fiber clutch packs in my 96 Mustang and they held up and performed well for a good decade of intermittent abuse. Not sure if they are still available. A lot of CV guys like the true trac as an upgrade from the OE track-lok did also. I actually put an Eaton posi in my truck (9.75) about 5 years ago and it’s held up amazing. Finally feels more like a LSD than a locker! Super stiff, even with a high dose of FM.

 

[Asterix]

Clutch LSDs are very tunable from undrivably grippy to basically worthless. You can find a sweet spot where it has the grip you want but is acceptably smooth and quiet. It's easy to adjust the grip with fluid as long as you have too much to start with. Yes, the clutch plates will wear out, but it takes a very long time.

The big disadvantage of any helical LSD is if you lift a tire by doing something like bouncing off a berm, it will suddenly act like an open diff. Also, if one tire is on ice and one is on pavement, the ice-side tire will spin, just like an open diff. In that situation, you can lightly apply the brakes to move force to the pavement tire.

If you're going to play on the racetrack, I suggest you get a clutch LSD and play with the grip. Helical LSDs are not at all tunable.

 

[Langanobob]

I haven’t follwed Formula 1 racing for years but at one point they were running Torsen style differentials, maybe they still are. Not sure if what they used equates to what we can buy over the counter though.

 

[HankHill]

Clutch LSDs are very tunable from undrivably grippy to basically worthless. You can find a sweet spot where it has the grip you want but is acceptably smooth and quiet. It's easy to adjust the grip with fluid as long as you have too much to start with. Yes, the clutch plates will wear out, but it takes a very long time.

The big disadvantage of any helical LSD is if you lift a tire by doing something like bouncing off a berm, it will suddenly act like an open diff. Also, if one tire is on ice and one is on pavement, the ice-side tire will spin, just like an open diff. In that situation, you can lightly apply the brakes to move force to the pavement tire.

If you're going to play on the racetrack, I suggest you get a clutch LSD and play with the grip. Helical LSDs are not at all tunable.

Awesome info... I have no berms on the courses to bounce off of, its a old airport with cone leaders. I am leaning to the Torsen, but I'm really getting great information here... I appreciate the hell out of it!!

 

[HankHill]

Can’t imagine you did any actual damage, maybe worn LSD clutches at the worst (if they weren’t already shot). The 8.8 is pretty decent. I used to beat the tar out of my 94 CV and the only time the rear end gave me issues is when I ran over a sewer culvert at speed….

I put some carbon fiber clutch packs in my 96 Mustang and they held up and performed well for a good decade of intermittent abuse. Not sure if they are still available. A lot of CV guys like the true trac as an upgrade from the OE track-lok did also. I actually put an Eaton posi in my truck (9.75) about 5 years ago and it’s held up amazing. Finally feels more like a LSD than a locker! Super stiff, even with a high dose of FM.

Like I said the oil came out looking like mercury. I can't imagine that just the clutches would cause that much metal.. I have never experienced oil like that, and it seems like its all metal with oil as a secondary.
The car currently feels different when turning, kinda like an understeer condition.

Carbon fiber clutches are still available at AMAZON! if you can believe that

Based on all the awesome informative info I've received, its down to two choices..
1. LSD with carbon clutches
2. Torsen

 

[buck91]

I’d still be surprised if the dif is shot. Maybe bearings which you should do while your in there if it’s high miles and you’re replacing/upgrading the LSD. Torsen/trutrack is supposed to be a nice upgrade but if you don’t want to spend the money maybe check out your factory track lok after teari by it down first.

 

[HankHill]

I’d still be surprised if the dif is shot. Maybe bearings which you should do while your in there if it’s high miles and you’re replacing/upgrading the LSD. Torsen/trutrack is supposed to be a nice upgrade but if you don’t want to spend the money maybe check out your factory track lok after teari by it down first.

Yeah, I will. The shop thats doing the work literally specializes in diff repairs, so I'll also take his opinion into heavy consideration.