Anyone know where I can look up a cross reference between passenger cars and trucks? There is a Crown Vic carrier with 3:55 gears for sale, but it makes no mention of size (8.8 or 9.75) nor does he mention spline count. I have e-mailed him with these questions, but I am wondering if I can look it up in case he does not know. I called my local Ford service department and the best I could get from them was " we think it will work but you realize the gears aren't going to be the same." My initial response was going to be " duh, you think?" Instead I said "thanks" and decided to get some help from here. All I want is the carrier if it will fit, I am going with 3:73's new bearings etc. The price is right, I just don't want to buy it if I am not sure it will fit. Thanks.
Rick

 

You don't let them change your oil do you?

 

I recently had to find a new rear axle for my truck and searched every junk yard in North Carolina, spoke with countless mechanics, and several Ford techs. The crown vic should be an 8.8, and the carrier should work if you are putting it in an 8.8. The 8.8's and 9.75's are not compatible with each other. So if you have a 9.75 don't buy it. If I were you though I would buy a new eaton or an auburn carrier instead. They aren't that expensive and you know what you are getting. Unless you know the history of the car I would go with a new unit.

 

01 XLT,
LMAO, no, I don't let them touch it. I buy parts there every once in a while and do the work myself.

hobackF150,
Thanks, he told me it measured 9 inches and counted 30 splines so I believe you are correct, it sounds like an 8.8. I have been on vacation so it may not even be for sale anymore. Not a problem, I also agree with you about a new Eaton LS. That is actually the way I want to go.
Rick

 

I agree, and Eaton would be a lot better. But, compared to some of the prices of other things, they are expensive. Last time I checked my pocket, $500 bucks was pretty high. You can get a Ford LS for half the price.

 

Hey Offroad,
Good to hear from you. I know, I know, between fans I haven't installed yet, blower parts and regular maintenance items( I changed out my A/C compressor and did a brake job complete with new spindles last month) funds are getting temporarily tight. Here I am wanting to put in a centerforce dual friction set and a LS rearend. I still check E-bay daily hoping to find a decent deal. Speaking of which, have you installed your new gears yet? Can't wait to hear what your seat of the pants meter impressions are when you get them installed. I thought about just installing 3:73's right now but I am going to wait until I can get some sort of LS to go with them and do it all at once. When you are talking about a Ford LS for half price, do you mean a new unit from the dealer or finding a used one? Guess I'll keep shopping around for now.
Rick

 

I heard that the Ford Motorsport HD LS Differentials made by Auburn are one heck of a lot stronger than the Eaton units. Is this true. The FMS differentials are also about half the price of an Eaton unit. The Eaton unit also limits you to using mineral based oil. I guess you can't run a synthetic if you wanted to.

 

mf150,
I am really starting to confuse myself on this one. I get differing opinions from friends on who has a better LS, FMS or Eaton. I know the Ford is less expensive, but I don't know if that translates to cheaply made. I didn't know that about the mineral oil or that the Ford units were made by Auburn. I guess I will have to do a little more research.
Rick

 

Hi-

I'm trying to hash this out, too. It looks like Ford Motor Sport has two LS makes. One is called the OEM Tracloc, the other OEM replacement is for the the heavy duty applications. This other is made by Auburn, and it's called the Auburn Heavy Duty LS.

I have been informed that Auburn not only makes its Heavy Duty unit, but it also makes a top-of-the-line Audurn Pro, which is suppose to be comparable to the Eaton units.

Some on here have said that there is more to be desired as far as strenght goes with the Eaton units.

I guess we're both on the market for "the best" Posi/LS unit, so keep me posted if you here anything.

I'm going to be staying away from the Eaton unit because they do not allow synthetic usage with their LS units. I like running Red Line 75W-140.

 

FYI to those who want to know:

There are only two versions of 8.8 carrier, 28 and 31 spline. All passenger cars that I know of came with 28 spline, light duty trucks (F150's) come with 31 spline. You need a 31 spline and my bet is that is not in the donor car rear.

Auburn posi is a cone type with no clutches, noisy around corners (it clicks) and when the cones wear off, you buy a new one because it can't be rebuilt.

Eaton is a better clutch type design, but is pricey.

Ford Traction-Lok is best bang for the buck. It is rebuildable and can easily handle most tasks you can hand it. Unless you are making more than 400 HP or trying to tow 10,000 lbs, you ain't gonna beat the old trac-lok.

BTW, you can add one or two extra clutches in the ford unit to make it hook better, all us Mustang heads do that. New one can be had for $230 everywhere.

Fluid additive is call "friction modifier", we affectionately call it whale s**t because it is derived from whale product, take one sniff and you will understand, IT STINKS!!! But you have to use it.

 

mf150,
Looks like we are definately on the same quest. I may be wrong here, but I am shooting for a LS because I thought the clutches load up differently than a posi and you don't get that clunking or clicking sound while cornering. I wish I had known about the synthetic thing before I bought my little Amsoil preferred customer membership. I just ordered $200.00 dollars worth of oil, gear oil, and tranny fluid for the wife's van and my truck, all synthetic of course. I think I may call and get a total price together on the Ford unit, carrier, gears, install kit or parts and whatever else is needed. I'll post it here when I get it tallied up.

Fast Pony,
I bought an ATI from Crash, but even considering a 50 shot of nitrous I would think I will be safely under 400 HP? I hope. I didn't know you could add clutches to the Ford. I thought you had a choice of a three or older four clutch design, take it or leave it. Thats a pretty cool option. Do you need to add the whale s**t with synthetic gear lube? I'm like mf150, even though it costs a little more I like running synthetics in my vehicles whenever possible. Just a personal preference, I wouldn't dream of starting that debate for the 500th time. This is why I hate Chevy's, I missed a shift to third racing a new Tahoe on the way to work a couple of months ago, and now I'm spending all this money on mods because I am still pissed about it.
Rick

 

Yea, it's a little know thing, most people don't think about it. The ford unit is pretty stout if set up right. Most people don't realize you can add extra clutches to the direct drive drum in the transmission either, but you should on a build up. I have an older truck (93), but most things in the Mustang world apply to our trucks as well, so I use that knowledge to make my truck "mo' better".

Yes even with full synth, you still need the friction modifier for the clutches. It's cheap, stinks like hell, but it's cheap, any ford dealer has it.

The only real weak link in the 8.8 is the c-clips that hold the axles in, but for street work you shouldn't sweat it. It's only at the drag strip with constant beatings that they can fail and let an axle go.

 

My local dealer stocks the Ford Racing friction modifer (blue) even though, they are not a FR dealer. They say the stock Ford parts modifier (orangeish brown) is not as good. They are a very good dealer, so I believe them. You are right about the smell. PU, boy does it stink.

 

lilricky2-
the gears are suppose to be installed this monday. I should of had them installed a couple of weeks ago, but I had the wrong set of gears. I did buy the used LS, but it's missing the pinion shaft. So, if I don't get that part on monday, then the gears are going in without it. I'm desperate for the gears right now. I'll let you know on the difference it makes.

 

Fast Pony-
I didn't think that the ford LS had clutches. I just had one installed, and if I looked at it correctly, I didn't see any. Just gears.