I want to buy a limited slip unit for my 8.8 IRs. The IRS is from a thunderbird but I don`t have the year, the tag on rearend has 515f 3 27 88 7g23 I know its a nonlocking 3;27 gear ratio but I can`t find any specs for the 515f. Does anyone know where to find the spec ?

 

What year is it?

Do you know the spline count? If so any 8.8 L/S should work that has the same spline count. I picked mine up for my 94' crown vic axle out of a 90 mustang. Got it from one of the guys over on the corral for 75 bucks.

All you have to do is take your ring gear off and bolt it onto the housing. Won't even have to change shims.

 

this kind of interchangeability is nothing short of spectacular or even miraculous for FOMOCO!! What's the width for this axle. I know the 8.8 form an Explorer is 59.5 inches mounting flange face to mounting flange face. The center to center distance of the rear wheel wells of my '54 is 60 inches. Wheel wells are 11 inches wide.

 

No I don`t have the year I found a site that lists the specs but just not mine. All the 8.8`s listed for thunderbirds are 28 spline still not sure

 

According to that tag, it was built on July 23 2007............

 

Well crap, that could be 87, 97, or 07


I bet it is a continuation of the 51......Numbers here and is just not listed:

http://www.fordification.com/tech/rearends_ford13.htm

 

I believe all 8.8's are the same, if you have pick a part nearby lots of explorers have limited slip, all sc thunderbirds, and I have found a few
regular birds that have limited slip. a new carrier from summit will cost about $450 (just for budgeting). there is a guy online called badshoe productions that sells a great video on setup and rebuilding, he has some samples on youtube.
also the super coupes had two different ratios depending on the transmission
the car came with 3.27 or 2.73 iirc
good luck

 

I don't knoe much about the 8.8s in the t bird but I know Ranger P?Us came with 28 spline axles and the Explorers came with 31 spline. The 3L73 in the Explorer is fairly common. I just bought a compete axle with springs for $200. Above I think you meant to enter 3.27 or 3.73.

 

It is July 23 1997 manufacture date 3;27 gear I read that the straight axle carriers will not work in the IRS then others say they will still researching I have found a ford motorsports unit for around $200 new hoping that it will fit

 

I just went out and looked, it's 2.73. I have one with 3.27 in my 56 and I bought another for a project I'm working on, that's when I found out about the two ratios, I think the bird is the same as the explorer, I hope I'm not wrong because I have one of those explorer 3.73 carriers on my bench I'm planning on swapping into it.

 

With an 8.8 from a Thunderbird, either July 23, 1997, or July 23, 1987.

There is no axle code of 515F for any 1980/89 car. Suggest looking at the tag again, because 515F makes no sense.

Rear axle codes for 1980's cars begin with an S or V or W. 1990's will be similar.

 

I found that chart, my tag number does not have an S at the front of 515F I have a picture of the tag but I can`t figure out how to post it on this forum

 

Axle tag: 3 27 = 3.27-1 ratio / 88 = 8.8" rear axle / There's no S515F listed for 1980/89.

Parts catalog symbols in pic: S = Thunderbird / MF = Cougar

 

This is the tag attached to the rear housing

 

Hmmm, well I don't have the slide from the 1990/98 car parts catalog (on microfiche) that decodes rear axles. So, you'll have to stop by a local Ford dealer for the info.