What year did they fix the 8 3/4 problem

[Kern Dog]

Kern, you solved the dilemma. Keep ordinary street tires on em, and they will live a long and happy life.

Not really ordinary....They are great for cornering and braking but not for straight line action....

 

[33 IMP]

Cmon Kern, you know what I meant,lol. Keep the slicks and drag radials away, they'll live a long and happy life. I've gotten away with slicks on mine for a lotta years, but I only have about 500hp and a 727.

 

[1 Wild R/T]

Cmon Kern, you know what I meant,lol. Keep the slicks and drag radials away, they'll live a long and happy life. I've gotten away with slicks on mine for a lotta years, but I only have about 500hp and a 727.

That 727 is your cushion, add a trans-brake & you'll want a Dana but if you have seen & blown up at least 20 of them junkers, then either you don't know how to set one up or clearly it's the wrong choice for the application.... Not everyone needs a Dana... We aren't all driving 4000 lb 9 second race cars...

 

[33 IMP]

That 727 is your cushion, add a trans-brake & you'll want a Dana but if you have seen & blown up at least 20 of them junkers, then either you don't know how to set one up or clearly it's the wrong choice for the application.... Not everyone needs a Dana... We aren't all driving 4000 lb 9 second race cars...

I love my transbrakes, but both the cars with brakes have nines, and are a LOT less than 4000 lbs! My 62 will get a Dana when the 520" victor motor goes in. No transbrake in that one though.
I haven't broke an 8 3/4, but I'm smart enough to replace it before I break it if I think an upgrade is necessary.

 

[chtampa]

Never had a problem with oil blowing out of the vent and if there was a problem, all it took was for the vent hose to be looped....

69's came with a vent hose? If the engineers had remembered that they wouldn't have issued a service bulletin.

 

[oldbee]

Point is with an 8.75 you drop out the pumpkin and swap it... You don't touch the set-up.... I have a 2.76 peg leg, a 2.94 Sure Grip, a few 3.23 Sure Grips, a couple 3.55 Sure Grips, a 3.91 Sure Grip & a 4.10 Sure Grip... I need a 3.73 Sure Grip... Like I need another hole in my head...

Years ago, we did a pumpkin swap with 3 cars & 6guys. 2 hoists & 3rd car right behind on the ground. Went like a charm. It was on a Friday night after the shop closed.

 

[Dipstick]

I believe most 8 3/4" failures are at the gear teeth due to the inherent deflection of the pinion under load.

 

[Cranky]

Exactly... that bigger round thing and deflection...

In a nut shell, all of them have some amount of deflection. Even a stock 9 isn't all that great in that department

The secret that I try to adhere to is, preload the **** out of the side bearings. Build some anti deflection into it.
Not that I claim to be an expert.

I snug em pretty good but how tight is too tight?

69's came with a vent hose? If the engineers had remembered that they wouldn't have issued a service bulletin.

Not that I know of but never really had problems pushing gear oil out but do like having a vent hose vs just that stock vent cap.

I believe most 8 3/4" failures are at the gear teeth due to the inherent deflection of the pinion under load.

The first time I dug into a 9", it surprised me at the bearing setup. That little nose bearing and the support for it was really lame looking to me. A stock 9" isn't as strong as a lot of people believe. If you want a strong one, you have to go aftermarket. Also, the majority of 8 3/4 failures in drag racing is because of people using street gears.

 

[33 IMP]

Agree, a nine is only as good as the parts used, like anything really. A stock nine gray iron center isn't very strong. Ford 2 pinion posi (whatever Ford called it) is quite a bit weaker than an 8 3/4 clutch. The 28 spline axles are smaller and weaker than stock 8 3/4.
I've got a nine in my car, that I wanted to never have to worry about. Strange 33 spline axles (small bearing housing, 35s wouldn't fit) 33 spline strange spool, nodular case Daytona support, and progears. I have about a grand in it due to friends who had a nine-specialty rear-end shop. (Ford lovers,, but I liked em anyway). I doubt I could do it now for TWICE that.

 

[Crackedback]

All 8.75 ratios use the same ring gear across all the cases. Pinion is different. Weak spot, ring gear... and the dr side cap.