Fix my 8.5 or Ford 9inch that I found

[pontiacgp]

you don't have to look for anything else. Rear ends will always let you know something is wrong with the noise they make and when you take it apart you'll see heat marks on the metal or bearings. I'd just change out the clutch packs and put it back together.

 

[khan0165]

Re: Ford 9inch, "Direct Bolt In", tell me what to ask!

that is the old style, I was able to remove and inspect the clutch pack on my 8.2 without have to remove the carrier or the crown. It is rebuildable, the large keyways cut in the carriers are where the clutch packs are, you can see the tabs in the picture, one pack on each side of the carrier. There is no small retainer holding the packs together like on mine. All you do is remove the carrier by taking the 4 5/8 bolts off the caps. Mark the caps so they go on the same way you took them off. When you removed the carrier, you'll probably need a pry bar to get it out, make sure you keep the backlash shims in place so you can put them back exactly how they came out. Then you remove the crown gear, the bolts have a left handed thread. Next you remove the pin so you can remove the pinion shaft. Next the S spring is removed, then the two pinion gears can be removed with their thrust washers, next the side gears come out and then the clutch packs can be removed.

thanks! this helps ALOT!
few questions... when you say

Next you remove the pin so you can remove the pinion shaft.

is this the pin seen in the middle of the S spring? this pin has to be removed to take the S spring out. But I don't understand why the pinion shaft has to be removed for this? What are the two pinion gears? Are these the two gears up against the clutches? Are the thrust washers what hole the clutches against the gears?

 

[crotchss]

I got the clutch kit from Summit part #ETN-29403-00S, I guess it was $110. They also have a kit with carbon discs for $150 part #ETN-29426-00S.

 

[pontiacgp]

Re: Ford 9inch, "Direct Bolt In", tell me what to ask!

few questions... when you say

Next you remove the pin so you can remove the pinion shaft.

is this the pin seen in the middle of the S spring? this pin has to be removed to take the S spring out. But I don't understand why the pinion shaft has to be removed for this? What are the two pinion gears? Are these the two gears up against the clutches? Are the thrust washers what hole the clutches against the gears?

this is a picture of the pinion shaft and the pin that locks the pinion shaft in place. the two gears that are on this shaft are called the pinion gears, the pinion gears have the thrust washers which act as a bearing between the gears and case. The clutch packs are behind the side gears which is where the axles comer thru and are held in place with the c-clips

 

[pontiacgp]

I got the clutch kit from Summit part #ETN-29403-00S, I guess it was $110. They also have a kit with carbon discs for $150 part #ETN-29426-00S.

that's good to know, thanks

 

[khan0165]

thanks pontiacgp, that's really helpful. I think I'm getting the idea...
... now I just gotta arrange a temporary rearend for the GP.

thanks crotchss for those part numbers. Is the carbon clutch system worth the hype?

- Update on the 9 inch -
I asked the seller all the questions you folks recommended... dimensions, brand type and condition of internals, if it's a oem housing converted to fit a G or a aftermarket housing made for Gs. I asked him about the brake setup, what type it is and brand.
...

The guy doesn't know much about the rearend, he said he bought it from someone for his car, and doesn't have the time to install it. He doesn't know anything about the internals, except that it's a 3.55 ratio. He says "the housing has been made to fit a G body and has the same width". So I assume it's a oem housing converted to fit a G? probably shortened? Says the Ujoint will work with my current driveshaft and the wheel bolt pattern is standard chevy. The axles are setup for a SSBC bolt on brake kit, which he has and can sell seperately.

...
At this point, I want to call him and clear up some more details. However, more attractively, he has said he'll take $750 because he wants it gone before winter.

 

[pontiacgp]

I posted in your other thread I have my 7.5 that you could borrow but I'm not that close to you. It's got oil and brakes and ready to go. Your drive shaft is an inch shorter than what the 7.5 uses but your will work, I ran a GN drive shaft with a 7.5 for about a week

 

[khan0165]

so I spoke with the 9 inch seller to clear things up...
Same story... he bought it from a guy who used to drag race a 600hp GrandNational. I bought it to put it in his 400hp GN, and it was built to handle 800hp.

He has no idea about the internals. It is a 9 inch out of a Ford car, that was shortened and modified to fit a Gbody. Apparently it will work with my Ujoints, and has 5x4.75 bolt pattern.

He said he paid $2000 for it, 1k for the diff, 1k for the brakes. He has the brakes that he wants to keep.

... all that said... I think it's too much trouble for nothing. My car can do fine with a 8.5, and I really just need a temporary diff while I tear open the 8.5
so I've decided to pass on it the 9 inch

... if anyone wants it, he'll take $750

 

[Crazcnuk]

no gear howl or hum, no vibrations, nothing out of ordinary. The issue I am having is slip... at the track, on slicks, it will sometimes have trouble locking both wheels. And, on peel, I've noticed it sometimes does not leave even lengths of rubber marks on the road.
I'm don't know much, but it feels like bearings and other mechanical components are okay... But clutches are gone bad.

sorry I couldn't grab any pictures... but from visual inspection, gears seemed to have even wear, broad accross each tooth. Everything looked very clean, nothing out of the ordinary.
... I don't know what else to look for.

... I can open it up again to check more things. How do you check backlash? The video doesn't explain where to point the dial indicator...

is there anything else I can inspect while I'm there? ... without removing any components?

thanks again,

Slip would be the clutches, if they are worn out. It is unusual for that to happen, at a track, though. sitting in the luanch box, pointed straight ahead, yuor wheels should be clean, and hot, and you shouldn't need a posi. I don't know how long the clutch packs on that model should take to lock the diff. I put in a locker for that 'once in a blue moon' when what your describing happens.

Many racers use lockers, for this reason. With a locker there is no lag while the diff locks. Mine is a Lockrite model. It has worked fine, but it was made for a 4x4 truck. I doubt I am putting very much load on it launching at the track.

 

[khan0165]

it doesn't slip on the launch... it works well there...
... I've noticed the slip when I do a burnout. Sometimes, if it doesn't get enough moment off the go, it'll only burnout one wheel. Or often, the car squirms around like both wheels aren't spinning at the same speed.

... slip has only been experienced on burnouts... The unit works well other wise.

and what I was describing before, was a test I performed... I did this to see if both wheels were locked equal amount of time. So I lined up, and hammered the gas off the line, and left a big #11 patch on the road. Then went back and measured both patches... the left one was a little shorter.