9" rear in a jailbar truck

[GB SISSON]

Originally Posted by Scotty's 52 F3

The width is the same and the cap diameter is the same but the cap bolt centers are different?

Are we talking cast caps or straps? I'm having a hard time visualizing this. Dang Gary, you're SO close.

On my existing yoke (47 jailbar) there are neither cast caps or straps. They are small u-bolts that my best description is... Picture a piece of 5/16 " rod, like 2 1/2" long. Now thread both ends about 1/2" in. Next pound the center of this rod flat on an anvil. Maybe 1" worth of flat. Now bend it into a u-bolt with 1 3/8" or 1 5/8" centers on the threaded ends. Maybe this description is a 'strap', but on my '92 F350 flatbed the u-joint is secured by an actual strap like small bar stock with a hole at each end and a hump in it. Then allen head cap screws threaded into its yoke. No wonder that old Chinese guy said a picture is worth a thousand words.

[Randy in ca]

Originally Posted by GB SISSON

On my existing yoke (47 jailbar) there are neither cast caps or straps. They are small u-bolts that my best description is... Picture a piece of 5/16 " rod, like 2 1/2" long. Now thread both ends about 1/2" in. Next pound the center of this rod flat on an anvil. Maybe 1" worth of flat. Now bend it into a u-bolt with 1 3/8" or 1 5/8" centers on the threaded ends. Maybe this description is a 'strap', but on my '92 F350 flatbed the u-joint is secured by an actual strap like small bar stock with a hole at each end and a hump in it. Then allen head cap screws threaded into its yoke. No wonder that old Chinese guy said a picture is worth a thousand words.

-
There's at least 3 different pinion yokes (that I'm aware of - maybe more) for 9" differentials. Only skimmed thru this video but it looked like it would help you figure out what you're dealing with in that regard.

https://www.youtube.com/watch?v=xKiokoEYAQA


This seems like the style of u-bolts you're describing - again some differences in the sizes:

[GB SISSON]

Randy, That is a great piece of information! Really narrows the search. I saw some Ujoints that were 1310 on one cross and 1330 on the other. so that's what I'll look into today. But maybe a 1330 is wider....? Like I mentioned there is a 'big cap' 1310 out there just might be what I need. Last year at this time I had a driveshaft built when I installed the T5 from an S-10. I told the guy I wanted it 'T5' on the slip yoke and '47 ford 1/2 ton' on the rear. So My existing rear U-joint is now a 1310 in both directions. Perhaps instead of a 'conversion U joint' from 1310 to 1330 I need a 1310 that has the 1 1/8" big cap on one cross. Lanny had this 3rd member built as a spare for his race 40 ford race car, so I can't go by make and model while searching for this joint. At first I was searching for a u joint for a 1971 F100, but really, that's just the housing.

[GB SISSON]

Just got off the phone with Driveline Services in Bellingham. They built my driveshaft last year. Looks like I need a conversion joint. Both are 3 1/4" wide, one has 1 1/16" caps, other has 1 1/8". They have one in stock and should have the the u-bolt straps too. Owner will call and confirm when he gets in. UPS from Bellingham normally arrives next day. This joint is a spicer #5-7439 and the straps are as in the post above 2-94-58x. Hope this helps the next guy someday.

[cas3]

If I remember correctly, you have a parts store on the island, how good is he? Remember
the old days when they had a row of books about 10 feet long, and the man in charge could find anything. Since you have all the math done, maybe they can help. I'm sure there are lots of yokes available for the 9", but thats more of a project

[Scotty's 52 F3]

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I gotcha actually. "The devil is in the details" is another saying that applies. Looking forward to your solution. I always enjoy your threads.
Scott in AZ.

[cas3]

Wille would say, "on the road again, just cant wait to get on the road again"...

[Lanny]

Hello GB, just a note to say that my '40 Ford coupe race car had a 9" Ford
rear end out of a 1957 Ford pickup and that is what the spare pumpkin
with the 4:1I gears I sold you was. It would fit most all 9" housings, but
there were a few Different Yokes used back in the day...
Give me a jingle GB, If there is any questions I can help with. thx, Lanny



.

[GB SISSON]

Thanks! The driveline shop called and said they made only four different yoke sizes for the 9" and from my rustic, long winded description of what I was looking for he seemed quite sure he was sending exactly what I'm needing. He already had them boxed up and labeled for Fed Ex

[Als48]

Was your torque tube length OK GB? Or did it need shortening?

Al Hook

[GB SISSON]

Al, Beginning in 1942 the pickups got an open driveline. No torque tube. But in order to address your question, the driveshaft should not need to be altered in this situation. The driveshaft I am currently running was built a year ago to accomodate a T-5 transmission from a chevy S10. This altered the length and type of yoke from stock. Now we deal with the back end. It's hard to measure how far the yoke extends forwards especially on the current stock axle. Then factor in different axle tube sizes to butt tape against. I feel quite confident I am really close to same number and of course slip yoke travel is important to keep in the zone. I won't know for certain until axle is mounted in the vehicle. Fingers are crossed on this one.

[GB SISSON]

Hoping to start the swap in the morning. A lot had to happen to get the woodie back into my good work bay. Finished the work on the skid steer last week. This week it's been getting that old figurehead project out of my way. The owner is a very busy guy and I need him to make a bunch of decisions about how to procede from this point. Scheduling a trip out here can be difficult. Now I see he's out of state for a month so decided to mount the rotisserie on an old trailer frame I had so she's moveable. I will put her in a shed on the lower property until I have confirmation on phase 2. In the photos she is in 'travel mode'. About a foot lower than working height for better center of gravity. Hoist her up with the overhead winch and put the pins in the top holes and she can rotate 360 degrees. With the old gal outa the way I did a good cleanup and got the other old girl in and jacked up on a pair of large mis-matched jack stands. I wanted front up a bit too so blocked and chocked the front wheels too. I think I have all the needed parts and have loosened and tightened back the u bolts etc for no surprises. I'm sure there will be a few. There always is..... My main hope is for no alterations to that driveshaft. The 4th Of July parade is looming and we have more family than ever eager to be involved. Even my baby sister with her husband, 2 sons and grandchild, all the way from someplace called Brighton on the coast of England!

[petehoovie]

Originally Posted by GB SISSON

Hoping to start the swap in the morning. A lot had to happen to get the woodie back into my good work bay. Finished the work on the skid steer last week. This week it's been getting that old figurehead project out of my way. The owner is a very busy guy and I need him to make a bunch of decisions about how to procede from this point. Scheduling a trip out here can be difficult. Now I see he's out of state for a month so decided to mount the rotisserie on an old trailer frame I had so she's moveable. I will put her in a shed on the lower property until I have confirmation on phase 2. In the photos she is in 'travel mode'. About a foot lower than working height for better center of gravity. Hoist her up with the overhead winch and put the pins in the top holes and she can rotate 360 degrees. With the old gal outa the way I did a good cleanup and got the other old girl in and jacked up on a pair of large mis-matched jack stands. I wanted front up a bit too so blocked and chocked the front wheels too. I think I have all the needed parts and have loosened and tightened back the u bolts etc for no surprises. I'm sure there will be a few. There always is..... My main hope is for no alterations to that driveshaft. The 4th Of July parade is looming and we have more family than ever eager to be involved. Even my baby sister with her husband, 2 sons and grandchild, all the way from someplace called Brighton on the coast of England!

[GB SISSON]

Thank you Pete! I thought I would note before someone else does that the makeshift jackstand in the foreground is welded onto that old chevy rim.

[cas3]

My goodness that rear end all painted up pretty hardly fits the MT Picket program! Just kidding of course, looks great. If you know anybody with a wood shop nearby you could cut a piece of wood the correct length to jamb in between the brake pedal and the seat to bleed the brakes by yourself. Thats how I've always done it, since either I have no friends, or its done when they are all sensibly in bed already. Take your pick

[GB SISSON]

Now that it's installed I have been noticing that both wheels definately turn in the same direction when I rotate one side while up on the jackstands. From youtube it would appear it is a limited slip differential and where I live I consider that a good thing. I used regular 90-140 gear lube for my test drive about 25 mile round trip to town as it never occured to me it may be limited slip. It runs smooth and quiet down the road (did 50 on some straight-aways). When I got to town and slowly turned into a parking lot there was some shuddering with vibrations back there on slow, tight turns, right or left. When I got home I shot everything with my infrared heat thermometer. Yoke was 120 degrees, tailshaft of the T5 was 115 degrees, drums all around 80-85. That seems perfectly fine. All bearings feel smooth and free. I'm sure all the parts are good, but wondering about the need to add a special additive or a different gear lube altogether. I know almost nothing about limited slip or positraction other than they have a clutch pack of sorts and take different lube requirements. Please school me on today's findings. Thanks, Gary

[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

[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.

[Lanny]

Hello GB, I had bought that 9" pumpkin from a friend who had built it.
I wanted it for a spare for my 1940 race car. I just knew it had 4:11 gears
but never cared if it was limited slip or not. We just raced at the local tracks
with our restored old race cars, mostly for fun and a good time.
Here's a picture of my old restored '40 with 276 flattie with dual carbs.

Click on Pictures to Enlarge.

[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.