Rear differential repair

To directly answer the gen1 vs gen2 diffs: They cannot be swapped. The axles are indeed different, as is the carrier. You can swap out the diffs if you also supply the axles from the same gen LS (you can put gen1 diff and axles into a gen 2 as long as you swap BOTH the axle shafts and diff.)
 
02LincLS,

You offered and excellent diagnosis procedure in post #21.

My understanding, from searching this forum and others, is that 2002 and earlier model years, offered limited slip as an option. There have been discussions about putting an LS, in the LS. :D The consensus has been to find an '02 or earlier carrier that has posi, and swap it in. Or find an '02 or earlier "open" carrier, and sawp in 8.8 posi interals. Evidently the '03 and up carrier is different, and won't accept the 8.8 internals. This is why I was musing about putting in an 8.8 carrier, from a 90's t-bird, or IRS Mustang. I would be curious as to anyones input on, this. I'm sure others on this forum would be too.

Just by "eyeball", they look similar in mounting, but I don't know if the mounting dimensions are different. There could be an issue with axle length if the housing is too big. Ford seems somewhat smart in using common parts between platforms, (when they can, to keep costs down), so maybe this would work. Ford made 8.8 internals for both 28 and 31 spline axles. If the shaft length isn't an issue, and they fit/engage the housing properly, then you have a beefier rear end. It might come down to the fact, that the 8.8 housing just wont fit under the LS. I don't know. Just kicking around the idea.
 
To directly answer the gen1 vs gen2 diffs: They cannot be swapped. The axles are indeed different, as is the carrier. You can swap out the diffs if you also supply the axles from the same gen LS (you can put gen1 diff and axles into a gen 2 as long as you swap BOTH the axle shafts and diff.)

This is part of what I read elsewhere ^^^.

Sorry pektel, it seems you type alot faster than I do. So what's your take on the 8.8 housing swap???
 
My understanding, from searching this forum and others, is that 2002 and earlier model years, offered limited slip as an option. There have been discussions about putting an LS, in the LS. :D The consensus has been to find an '02 or earlier carrier that has posi, and swap it in.

The LS NEVER came from the factory with any sort of posi or limited slip. The basic traction control and Advancetrac took care of any wheel spin. The LS was NEVER designed to be any type of track car. If you want a track LS you'll have to make one.
 
Ok,

I stand corrected. I was also going on what a co-worker recently told me. He said his '02 had posi. Maybe he mistook the traction control for that.
 
This is part of what I read elsewhere ^^^.

Sorry pektel, it seems you type alot faster than I do. So what's your take on the 8.8 housing swap???

To do the 8.8 swap, you need:

gen 1 half shafts
8.8 housing
8.8 28 spline carrier
gears of choice

In addition to the basic parts, you will also need to fab/weld a custom front brace for the differential, and modify (shorten) the driveshaft to account for the extended length of the 8.8" housing.

The above list is only needed if you intend to install different gears than what the LS came with standard (3.31 or 3,58).

If you want to keep the stock gears, but install a limited slip diff, you only need:

gen 1 half shafts
gen 1 housing
8.8 28 spline LSD

I have a limited slip carrier installed out of an 05 Mustang GT in my gen 1. All I needed was the carrier. Well, you will need to get any materials for setting up the new diff too (shim kit, new fluid, etc.).
 
Ok,

I stand corrected. I was also going on what a co-worker recently told me. He said his '02 had posi. Maybe he mistook the traction control for that.

He could possibly be right, but he or someone else added it. An 8.8 28 spline traction loc unit (no longer made) can be bolted right into the 8.0 rear end of our gen 1 cars, reusing the stock ring and pinion. Gen 2's need to swap to gen 1 axles and housing and possibly some other stuff I forgot about.
 
I'm getting a similar sounding constant noise, it starts around 30mph and with a little vibration. I will be taking it to the shop next week to have them check it out. If I need a new diff, are they interchangeable between generations? I have a Gen I, could I install a Gen II differential?

Mine noise ended up being a bad driver side bearing. Had it replaced and noise went away. It didn't sound like when the front bearing went bad.
 
He could possibly be right, but he or someone else added it. An 8.8 28 spline traction loc unit (no longer made) can be bolted right into the 8.0 rear end of our gen 1 cars, reusing the stock ring and pinion. Gen 2's need to swap to gen 1 axles and housing and possibly some other stuff I forgot about.

So why couldn't the 2nd gen guys just use a 31 spline 8.8 posi unit from the ranger's of F150's? I have one in the shed and other than the spiders using 31 splines and I think the pin being larger diameter the rest looks the same as the 28 spline unit.
 
I have been driving with my 8.8 Limited Slip in the stock 2000 pumkin for over 3 years now. With no issues other then some sliding in the rain lol
 
IRS diffs can't handle the abuse a solid axle can. That's why the new Mustangs have gone back to a solid axle. I haven't actually looked under a new Mustang to verify this. I'm just going by what someone told me.

No offense, but that's pretty much not true. An IRS can be made plenty strong, otherwise BMW would put them in their 600+ HP and TQ 7 series, 400+ HP M3s, and GM wouldn't have them behind the 600+ HP and TQ ZR1 Vette....

It's what they're made out of that determines the strength, not the "design", on a production street car. A car making 1000+ HP that only goes 1320 feet at a time, on slicks, is a whole different animal.

It's entirely possible Ford/Lincoln had a bad batch of bearings, at the factory, that resulted in early failures reported in this thread. Or, they used inferior designed parts from the get-go, that caused failures, and subsequently corrected that.

GM had that issue with Saturn, the VUE series specifically, in which the OE assembly line wheel bearings were of a poor design - one race wasn't hardened :eek:, and as such owners had them go bad in as early as 10K miles or less. I got "lucky", mine lasted about 60K before taking a dump.

Edit - the cost of an IRS is more than a solid, that's pretty much a given, and is a consideration for vehicle manufacturers. If Ford is in fact using a SRA in some variant of the Mustang, methinks it's nothing more than a cost move, not a durability issue as they have plenty of "cheap" SRA's at their disposal from the trucks to "make fit" the Mustang chassis.
 
IRS is weaker and more problem prone. CV axles... nuff said

plus having rear ball joints that wear out and toe links that will bend if too much power is applied.

not to mention the damn rear hub bearings that go out.


its give and take. IRS 8.8 provides an improvement in handling yet is not as durable as an 8.8 SRA,

why you ask? centrifugal force wears the axle shafts as they are not supported. this is why the rear bearings go out as well.

not to mention all the joints and wearable components. making it typically heavier than a SRA

personally I think both have their place
 
CV shaft tech has come a long way....they really aren't the weak links they used to be. Yes, an IRS set up has more ancillary stuff that can fail - more joints/bushings, control arms, etc. But those aren't what I'm talking about, I'm referring specifically to the pumpkin and it's internals, which is what people are saying they're having problems with in this thread.

My E36 M, or any 96-99 M, in bone stock form with a proper tune ( proper as in no fouled plugs, bad coils, dirty injectors, etc. ) puts down over 200 HP and TQ at the rear wheels. They dyno with more RWP than a gen 1 LSV6 grosses, and a little less than what the gen 1 V8 grosses. These are stick cars too, so more driveline shock than slushboxed cars.

The failure rate of diffs and CV shafts on those cars is, essentially, statistically insignificant. There's people with mods, forced induction, cams, etc., that are putting down over 300 HP/TQ, and in some cases over 400, all through the stock IRS components while tracking the cars. No issues.

I have 170+K miles on my car, rear suspension is the same as what came off the assembly line. While I have no power adders, and don't track it, I don't pussy foot the thing around either.

A SRA is Model A technology, and while they do still have their place in the automotive world in this day and age, IRS setups are just fine and their durability is solely dependent on the components used, not the basic design.
 

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