9" rear in a jailbar truck

[GB SISSON]

Originally Posted by cas3

Sorry I don't have a specific answer, but yes I know there is a small bottle of special additive to use to make the clutch pac happy. Google 9" ford, there are several places that specialize in 9"ers and I would bet the answer is there

Thanks Skip. Yes I've been doing my research and see numerous explanations of how it all works. No or not enough friction modifiers in a limited slip axle causes clutch chatter and vibrations, especially in low speed, low torque cornering. For instance a little old man steering his homemade wooden car into a gas station. The friction modifier, (us limited slip guys just call them 'FM's) actually reduce the friction in the clutch packs so the clutches slip smoothly while going around corners. I am confident this is what I'm hearing and feeling on those sharp corners.
Shortening up the parking brake cables was the last difficult task, and I made it more so by having the cable installed into the backing plate with it's ball end in the fork already. This was to assure correct length. All the cable work was done with the clevis/threaded end vice gripped onto the running boards, which I will say, Did make an excellent workbench.

[Scotty's 52 F3]

Sounds like you got it figured out Gary so maybe you already know this. Throwing it out there anyway.

Some of the gear lubes on the store shelves will have the limited slip additive already added but it will say so on the label. If you filled with oil that does not contain the additive you can buy just the additive and save draining your fresh oil. The additive is pretty smelly stuff.

Even after you add it, it takes a few miles to get soaked into the clutches and start working.

They ARE nice to have over an open diff. And not quite as harsh as a locker.

[GB SISSON]

Yes, thanks Scotty, I'm getting educated in yet another new realm. Just made a run to napa and got the additive to mix in with yesterday's GL5. I found some photos on line of ford trac-loc differentials and compared them with a photo I posted on this thread after I uncrated the 3rd member fron Lanny. Sure matches up to be a ford trac loc. There is plenty written online about the noise and vibrations when the clutch pack does not have the friction modifier and it chatters on slow cornering. Supposed to add it to warm differential so the cabinet work will have to wait til I go for a warm up, then the mix, then the test drive. Sucks to be waiting for cabinets from Mt Pickett Woodworking... But a guy has to have his priorities straight.

[GB SISSON]

5:40 am, 2 cups of coffee in and I'm heading down to the cabinetshop to make up for lost time. The additive did the trick and wife and I drove the woodie out to dinner, then up the winding mountain road in the state park, followed by a run down to the old boatyard at Obstruction Pass. Thanks to all who helped make this happen.

[51504bat]

Sounds like you're all set for the big Fourth of July parade! I'm sure Woody is looking forward to riding on the front grille for all to see.

[cas3]

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How's the brakes?

[GB SISSON]

Originally Posted by cas3

How's the brakes?

Excellent! considerably larger in the rear and the parking brake holds way better. Gear ratio is the same, so the new axle doesn't bring any new thrill to the ride, but the huge increase in torque from the 221 to the 276 (not to mention the 5 spd tranny that went in with it) still brings a smile to my face every time the old wagon is pointed at a hill! To me the entire drivetrain has now been brought up to modern standards. Which way is the mainland?

[mhsprecher]

Quite the thread.

I have a 45 JB that has a bad axle. I have replacement axle and have been contemplating taking the rear out and rebuilding it. I can't say that I have a lot of enthusiasm for the project and have thought about a replacement axle like you did. I have no idea how difficult it would be to find a 9 or 8.8, but the swap seems more complicated than I had envisioned. Not that replacing the axle in the old banjo is a walk in the park, either.

I have a friend who has a JB with a replacement axle. The prior owner and the guy who helped him with the project have both passed on, so I can't consult with them. I can visit the truck next month and see how it looks.

[GB SISSON]

Originally Posted by mhsprecher

Quite the thread.

I have a 45 JB that has a bad axle. I have replacement axle and have been contemplating taking the rear out and rebuilding it. I can't say that I have a lot of enthusiasm for the project and have thought about a replacement axle like you did. I have no idea how difficult it would be to find a 9 or 8.8, but the swap seems more complicated than I had envisioned. Not that replacing the axle in the old banjo is a walk in the park, either.

I have a friend who has a JB with a replacement axle. The prior owner and the guy who helped him with the project have both passed on, so I can't consult with them. I can visit the truck next month and see how it looks.

I feel really good about this swap. The confidence gained from doing this work is well worth the price of admission. The components went together just like many here said they would. In review, for a 'bolt in' you are looking for a rear axle from a '57-'72 ford F-100. If you knew it was ready to go on the inside the swap would be less complicated, but I was using a known rebuilt pumpkin and installing it in a fairly well used housing/tube/brake assembly that needed all the usual seals and outer wheel bearings. The pumpkin from Lanny has settled into a perfectly quiet and smooth rolling assembly after the right dose of the friction modifier kicked in and a few short trips for ice cream. Now it has about 600 miles on it and I couldn't be happier.

[rustynut4247]

i had a 46 pickup and used a 67/72 axle worked great . only that i had to do is move the spring perches and at the same angle and the brake cables were just the right legnth

[ford38v8]

Originally Posted by GB SISSON

,,,The confidence gained from doing this work is well worth the price of admission.,,,

Now there's a quote I can relate to.
As a 17 year old know nothing kid, I had speed shifted my '39 Ford Tudor one two many times, and trashed my cluster gear.
Having received sage advice (pull the rear end), from the local junk yard, I rebuilt that transmission and never looked back.
Happily, I've had greasy fingernails all my years since, and wouldn't have it any other way.