Rear End nightmare

When I lived in Tampa, FL. my 97 F-150's differential (open 8.8-3:55 gears) was just a singing after 40 mph. I took it to a GEAR SHOP ONLY to have it rebuilt (990.00 OTD).
Long story short, after having to rebuild it (3) times they checked the housing. It was out of round (warped) just enough to make the gears sing the blues.
They installed a rebuilt differential, from axle bearing to axle bearing, and didn't charge me anything extra.
Take it to a gear shop ONLY!
It certainly wasn't uncommon for the 8.8 to crack tubes, bend the housing or start leaking at the plug welds in OBS truck applications. Sometimes they'd start weeping oil at the shock mount welds- another common area for the tube to crack. Also the limited grip CrapLok carrier would sometimes just crack because it had less meat to accommodate the clutches. As a result the open carrier was stronger and more reliable.

Now I have ZERO idea how they hold up in Mustang applications as I'm not a car guy. Furthermore the 8.8 in my '07 F150 4wd 4.6 is still ticking along with 225k miles, but I'm guessing Ford beefed up the housings or tubes a little either for the bubble bodies in '97 or the 11th Gen in '04......maybe not....I haven't researched it enough to know

Ford didn't have enough confidence in the 8.8 to put it behind 5.4 trucks -- even gutless 2Vs -- so maybe that says something
 
It certainly wasn't uncommon for the 8.8 to crack tubes, bend the housing or start leaking at the plug welds in OBS truck applications. Sometimes they'd start weeping oil at the shock mount welds- another common area for the tube to crack. Also the limited grip CrapLok carrier would sometimes just crack because it had less meat to accommodate the clutches. As a result the open carrier was stronger and more reliable.

Now I have ZERO idea how they hold up in Mustang applications as I'm not a car guy. Furthermore the 8.8 in my '07 F150 4wd 4.6 is still ticking along with 225k miles, but I'm guessing Ford beefed up the housings or tubes a little either for the bubble bodies in '97 or the 11th Gen in '04......maybe not....I haven't researched it enough to know

Ford didn't have enough confidence in the 8.8 to put it behind 5.4 trucks -- even gutless 2Vs -- so maybe that says something
The axle shop that did mine is one of the best in the state of FL. They do differentials in passenger cars, dragsters, trucks, 4X4's, etc.
You don't take an axle job to an oil change facility to have the differential R&R, (IMHO).
 
$2600 for a rebuild from a Ford dealer vs $2400 for a chong wang doo thing from NAPA?

Why’d you go that route? I realize $200 is $200, but dang man. They would have used Ford parts too.
 
$2600 for a rebuild from a Ford dealer vs $2400 for a chong wang doo thing from NAPA?

Why’d you go that route? I realize $200 is $200, but dang man. They would have used Ford parts
Its hard to trust a ford dealership to rebuild a rear when they over quote you so you pass on the repair. If Ford wanted to do it, they'd have given him a real quote instead of a "make it too much for him" quote.
If you want a rear end rebuilt, go to a shop specializing in gears. Its a hard lesson for us to learn, but you have to seek out the best people to do the job at hand.

I only knew of the shop I took mine to because I've used them to rebuild and upgrade a few transfer cases in the past. Otherwise, I might have done the same thing he did... Actually would done exactly as he did.
 
Wow-it didn't cost me much more to have the Eaton posi & ring/pinion installed in my F-450's Dana 80! Guess the only good news is the shop will keep getting reimbursed over & over by NAPA to install their junk! I wouldn't trust a Ford dealer to rebuild it either, rear end set up is kind of an art, and stealership mechanics ain't artists anymore!
 
It certainly wasn't uncommon for the 8.8 to crack tubes, bend the housing or start leaking at the plug welds in OBS truck applications. Sometimes they'd start weeping oil at the shock mount welds- another common area for the tube to crack. Also the limited grip CrapLok carrier would sometimes just crack because it had less meat to accommodate the clutches. As a result the open carrier was stronger and more reliable.

Now I have ZERO idea how they hold up in Mustang applications as I'm not a car guy. Furthermore the 8.8 in my '07 F150 4wd 4.6 is still ticking along with 225k miles, but I'm guessing Ford beefed up the housings or tubes a little either for the bubble bodies in '97 or the 11th Gen in '04......maybe not....I haven't researched it enough to know

Ford didn't have enough confidence in the 8.8 to put it behind 5.4 trucks -- even gutless 2Vs -- so maybe that says something

The 05-14 Mustangs have issues with the tubes bending under high power. It can even happen at stock power levels. Its usually solved by welding the tubes.
 
It certainly wasn't uncommon for the 8.8 to crack tubes, bend the housing or start leaking at the plug welds in OBS truck applications. Sometimes they'd start weeping oil at the shock mount welds- another common area for the tube to crack. Also the limited grip CrapLok carrier would sometimes just crack because it had less meat to accommodate the clutches. As a result the open carrier was stronger and more reliable.

Now I have ZERO idea how they hold up in Mustang applications as I'm not a car guy. Furthermore the 8.8 in my '07 F150 4wd 4.6 is still ticking along with 225k miles, but I'm guessing Ford beefed up the housings or tubes a little either for the bubble bodies in '97 or the 11th Gen in '04......maybe not....I haven't researched it enough to know

Ford didn't have enough confidence in the 8.8 to put it behind 5.4 trucks -- even gutless 2Vs -- so maybe that says something
No, but they put them in the front of 5.4L equipped vehicles ;) My Expedition had an 8.8 in the front, 9.75 in the rear.

Some applications got heavier axles than others. The Explorer (I think only the 5.0L ones) got the 31-spline 8.8, which was stronger than the 28-spline we got in the 5.0L Fox cars and also had disk brakes. A buddy of mine and I swapped one into his dad's SBC'd S-10 after breaking the craptacular GM diff. The 8.8 held up just fine on spray.

Lots of 31-spline 8.8's doing 9-10 second passes behind 500-700HP. IIRC, some guys weld the tubes because they can bend, as noted. It was a massive upgrade in the Mustang over the 7.5" peg-leg the earlier fox cars got, which I've personally witnessed walk an axle at the track, lol.

Of course the SN95 and New Edge Cobras got the 8.8 in IRS trim, and so did the '03/'04 Cobra, which had heavier axles. Some guys have done solid axle swaps to get rid of the hop, but again, 850+HP into an 8.8 pot was fine in those cars.
 
When it comes to live axle Mustangs (And Camaro's)....Getting a used one with a bent axle tube is a high probability as people love to smack into curbs with live axle Pony Cars.

I won't even quote building one without adding in checking the housing for being true using a Mittler Bros. Alingnment/Narrowing Tool.
 
At around 30k my 2018 f150 started softly singing when it’s chilly outside. It’s got amsoil severe gear lube in it, so it’s not neglected. Mines done a bit of towing. It’s a little sad for a rear end this new. My 08 Jeep had rear axle concerns - and I cooked the bearings in the 06 tundra at 150,000. I thought by going to a new ford I’d be better off. I know better than to have anyone work on it - it could be far worse. I’ve had far worse. Gonna live with it.
 
I had an 8.8 making noise in my old Mustang years ago. I took it down to the local 4 Wheel Parts and they put a bearing set in it for $400. Quiet as a mouse after that. $2400-$2600 is just nuts. I know times have changed but what the heck. A new gear set with bearings is only a little over a grand installed.
 
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When I got my ieeps rear end rebuilt last month I was given very specific break in instructions. Drive 15 min and let it cool at least 2 hrs.repeat. then 30 min and let it cool etc. Did you get any info like that?
Excellent point! Break-in is absolutely critical unless these rebuilders are lapping the r&p together like the OEMs do (extremely unlikely)
 
Or why not check and adjust the pinion dept and backlash for couple hundred? For $2600 you can get a rebuilt engine. Why spend that much on a 15 year old $4-$5K car?
Some of us like to hang on to tried/true rides indefinitely. Yes it can get a bit costly at times, but a new/used car payment these days would be a bit of a joke for me unless absolutely necessary with no real alternative.
 
My spider gear broke a tooth off when I was leaving iced driveway to dry pavement. I am just waiting for some dry weather to do the job. Have to do it outside since garage here is too narrow to pull out the axles. Want to replace seals on axles since it has 220K on them. Dodge 9.25 with 3.92 gears
 

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Just picked this up for $140 off a 2007 mustang gt (same as mine). Same ratio, so i hope it is plug and play. Zero damage on the sides and rear of the donor car, so i hope everything on this unit is good. 81k on the donor car.....we shall see. I was contemplating doing the replace by myself, but did not realize how heavy this thing is. Took me and a stronger guy than me to get it in the back of my truck.

Got a 90 day warranty from the boneyard for $11...not sure what that is worth😂
 
Just picked this up for $140 off a 2007 mustang gt (same as mine). Same ratio, so i hope it is plug and play. Zero damage on the sides and rear of the donor car, so i hope everything on this unit is good. 81k on the donor car.....we shall see. I was contemplating doing the replace by myself, but did not realize how heavy this thing is. Took me and a stronger guy than me to get it in the back of my truck.

Got a 90 day warranty from the boneyard for $11...not sure what that is worth😂
I see you are Richmond VA. A few hours from Raleigh N.C.

If you end up needing work, i can recommend East Coast Gear. They rebuild the rear in my avalanche a few years ago for 1/2 what you spent ( $1200). New posi Lock Rite( iirc) , ring and pinion gear, axle bearings. I left the truck and picked it up a day or so later. No whine, everything was perfect. They do push the lucas gear oils, but i did not use that after break in.


 
I see you are Richmond VA. A few hours from Raleigh N.C.

If you end up needing work, i can recommend East Coast Gear. They rebuild the rear in my avalanche a few years ago for 1/2 what you spent ( $1200). New posi Lock Rite( iirc) , ring and pinion gear, axle bearings. I left the truck and picked it up a day or so later. No whine, everything was perfect. They do push the lucas gear oils, but i did not use that after break in.


The LockWrong is a lunchbox locker that's weak, noisy and crappy. You probably had a GovLock if OEM which is all the above except only noisy once it engages, which only occurs once you're stuck (oops, too late)

Regardless, good reco on ECG
 
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