I need a six by six u joint.

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Deere boy
Posts: 11
Joined: September 10th, 2018, 12:21 pm
Body Type: truck
Model Year: 1928

I need a six by six u joint.

Post by Deere boy » March 23rd, 2019, 5:42 pm

I've added a dual high to an A chassis which has a six spline output shaft and the drive shaft is also six spline. So far the only one I've found is off a believe a slightly later car and the tube that meets the drive shaft is too short. Is there someone who builds a 6x6 U joint? The outlet tube needs to be about two inches.

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RustydoubleA
Posts: 108
Joined: June 18th, 2014, 10:22 pm
Body Type: express
Model Year: 1930
Location: N. Calif.

Re: I need a six by six u joint.

Post by RustydoubleA » March 28th, 2019, 11:35 pm

I don't think that you are providing enough information on what your intentions are.

Putting the underdrive transmission in a Model A chassis is sort of strange unless you are making a slower doodlebug or trying to turn the underdrive around to make an overdrive. It is WAY too tall to make an overdrive out of a 1 1/2 to 1 transmission. I would bet that it would be NOISY as well. I have put these underdrives (as an underdrive) behind a AA 4 speed truck transmission in one AA truck and another AA truck with small Model A axles. In the small axle AA truck, I had to "make" a rear universal joint out of taking apart a couple of the later car and truck joints, doing some machining of two of the cross "bearings", and assembling the mess together. Half car and half truck X joint. I am wondering why you need a X joint with a longer "tube" on it. I guess that you could try cutting the tube off of another X joint and welding it onto the one that you are using to make it longer. The center of the X joint needs to be perfectly centered in the X joint housing/clamshell assembly.

I also put an underdrive into a 26 T speedster with Model A axles and a 42 Ford 4 cylinder truck (9N tractor) engine (3200 rpm at rated HP). 37 Ford transmission, then the underdrive, and then the shortened Model A rear driveshaft/torque tube. Used all stock X joints for that. Rear axle has 3.78 to 1 gears in it, so the underdrive may have some use on a long steep hill, shifting to underdrive I should be able to keep 45 mph instead of 25 mph in 2nd gear. Still working on the speedster, I have not driven it yet. I am putting the speedster together on the cheap, using parts that I have around. I would never consider putting an underdrive in any of my stock Model A cars/pickup, as 3.78 to 1 gear with a used Borg Warner overdrive works great with a 2000 rpm engine. A lot of people are swapping out their BW overdrives for the Mitchel overdrives, so you can get their old one for $500 to $800.

Deere boy
Posts: 11
Joined: September 10th, 2018, 12:21 pm
Body Type: truck
Model Year: 1928

Re: I need a six by six u joint.

Post by Deere boy » March 29th, 2019, 8:45 am

I'm building a speedster using as many John Deere parts as possible, but the drive train is model A. When I first took it for a test drive with just the model A 3 speed, it was too fast. By my calculations, first gear was probably 9mph. That's not safe for tooling around at a tractor show or driving it on a trailer. So I added a dual high. The output on a dual high is six spline and it goes to a 6x10 U joint. I, of course, had to get the drive shaft and torque tube shortened and I made sure to tell the machinist that the driveshaft needs to go from six spline (normal on a car) to 10 spline like the U joint I sent along. Somewhere along the line, he decided that shortening the drive shaft from the back end was easier. He then realized his error and found be a 6x6 U joint from something. It fits, but it is only about 4 1/8 inches from end to end and when you add the inner cup-or whatever you call the thing the torque tube pushes on, it is too short.
I am pursuing a couple of leads, but I may end up having to find another 6x6 and have him cut a piece of the tube off and weld it on the end.

Bob C
Posts: 1285
Joined: April 24th, 2003, 11:50 am
Body Type: Mail truck, Stake tr
Model Year: 1931
Location: SO CAL

Re: I need a six by six u joint.

Post by Bob C » March 29th, 2019, 10:10 am

The Model A driveshaft is 1 1/16" and the AA is 1 1/4" so you can't respline the A driveshaft to 10 spline.

Bob

RustydoubleA
Posts: 108
Joined: June 18th, 2014, 10:22 pm
Body Type: express
Model Year: 1930
Location: N. Calif.

Re: I need a six by six u joint.

Post by RustydoubleA » March 29th, 2019, 2:16 pm

Hi, That diamond shaped dog sleeve mount on the rear of the underdrive is not for adustment purposes, because the X joint must centerline exactly with the centerline of the clamshell/bell stuff. That sleeve mount bolts to the 28/29 AA crossmember which is a fixed distance from the engine mounts (or the rear of the transmission). You may have positioned your crossmember a couple of inches off. Also, Is the inner driveshaft positioned properly with the torque tube bell? Or, maybe your entire driveshaft/torque tube is 2" too short for the wheelbase. Are you sure that the diamond shaped dog sleeve mount is not on backwards? If you have all the dimensions correct, everything should bolt up. Extending the X joint splines may seemingly "fix" one problem, but the real problem will show up on your test run!
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Deere boy
Posts: 11
Joined: September 10th, 2018, 12:21 pm
Body Type: truck
Model Year: 1928

Re: I need a six by six u joint.

Post by Deere boy » April 1st, 2019, 7:02 am

At present, the "bell" or whatever you call the end of the torque tube would push against this brace. Without the bell-cone thing that the torque tube is supposed to push against, the Universal joint will fit. Of course it can't push against this brace. I need about another half inch, like the 6x10 U joint I already have.
Image

Bob C
Posts: 1285
Joined: April 24th, 2003, 11:50 am
Body Type: Mail truck, Stake tr
Model Year: 1931
Location: SO CAL

Re: I need a six by six u joint.

Post by Bob C » April 1st, 2019, 8:15 am

That part you are showing looks like the cross member for a Reeves frame extension
so you may be dealing with some non Ford parts.

Bob

RustydoubleA
Posts: 108
Joined: June 18th, 2014, 10:22 pm
Body Type: express
Model Year: 1930
Location: N. Calif.

Re: I need a six by six u joint.

Post by RustydoubleA » April 5th, 2019, 9:11 pm

Hi, Your cast iron cross member is just a support for an intermediate driveshaft for a frame extension. It cannot take a thrust from the torque tube loading without shattering into many pieces. You need to install a 28/29 AA cross member. The cross member needs to be an exact distance from the engine mounts in order to center up the x joint inside the bell/clamshell assembly. The diamond shaped rear underdrive mount bolts to the crossmember and the underdrive nests into it.

To gain the lowest speed (this is what you are looking for), use an AA truck 4 speed transmission and find the special bearing retainer/x joint that bolts the AA 4 speed to the small model A car drive shaft. This will let you connect the 4 speed directly to the underdrive without any modification.

Then the output of the underdrive uses the regular car front half of the x joint, and if you use a small A rear axle, you can just use the complete car x joint. If you use an AA rear axle, then you must take the front half of a A x joint and wed it to the rear half of an AA x joint. I have done this several times.

There exists the special AA truck X joint that can be taken out with the engine and axle in place. Photo in the next reply. This has a longer nose on it. But something is wrong if you must use this.

I have done this modification THREE times, putting these underdrives behind the 4 speeds and using either A or AA torque tube/driveshafts. I did not extend the x joints. I used all stock stuff, except for two that I swapped the rear half of a stock AA joint to the front of a stock A joint. If the x joint is not centered properly within the bell/clamshell, a clunk clunk and high vibration will result. You may have to do some fine tuning by sliding that cross member fore and aft until the vibration fades, use elongated holes cross member to frame. Weld it in later. You can also shim the underdrive diamond mount aft a bit as well. I think that the AA half of the x joint rubbed on the inside of the bell, and I had to grind the "flash" off of the OD of the x joint for clearance.
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RustydoubleA
Posts: 108
Joined: June 18th, 2014, 10:22 pm
Body Type: express
Model Year: 1930
Location: N. Calif.

Re: I need a six by six u joint.

Post by RustydoubleA » April 5th, 2019, 9:19 pm

Here is a comparison of the stock AA x joint and the special take apart AA one. You should not need this long one. It does not belong in any bell/clamshell assembly. It was only for use from the 4 speed transmission to the intermediate shaft, no torque bell.
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RustydoubleA
Posts: 108
Joined: June 18th, 2014, 10:22 pm
Body Type: express
Model Year: 1930
Location: N. Calif.

Re: I need a six by six u joint.

Post by RustydoubleA » April 5th, 2019, 9:27 pm

Some of my pictures did not transfer, so here goes. A view of the other end of the 4 speed to Model A x joint. the front of the 29 cross member looking aft. How I attached the rear AA truck springs to the A axle. I used old fire hose to shim the space. Lastly the 4 speed to the underdrive connection. It works!
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RustydoubleA
Posts: 108
Joined: June 18th, 2014, 10:22 pm
Body Type: express
Model Year: 1930
Location: N. Calif.

Re: I need a six by six u joint.

Post by RustydoubleA » April 5th, 2019, 9:27 pm

Some of my pictures did not transfer, so here goes. A view of the other end of the 4 speed to Model A x joint. the front of the 29 cross member looking aft. How I attached the rear AA truck springs to the A axle. I used old fire hose to shim the space. Lastly the 4 speed to the underdrive connection. It works!

RustydoubleA
Posts: 108
Joined: June 18th, 2014, 10:22 pm
Body Type: express
Model Year: 1930
Location: N. Calif.

Re: I need a six by six u joint.

Post by RustydoubleA » April 5th, 2019, 9:55 pm

Not all pictures are transferring. Picture of remains of Mixing and matching x joint parts. Most of those early x joints are worn out so I use the newer ones. Notice the flanges on the cross member in some of the pictures.

You can notice my 8 1/2" driveshaft extension in some of those pictures. I welded a flange around the stock bell and cut another driveshaft/torque tube to 8 1/2", added the flange and another bearing inside and bolted it up. I may have welded a 48 Ford driveshaft coupling to the short shaft and slid it into the rear shaft. If I were to do it again I would extend the torque tube housing and cut/weld two driveshaft halves together.

I have a 31 AA doodle bug that I put early sheetmetal back on it. It has the low speed axle, but I want it to go slower and have one more (worn) underdrive unit to install in it. With the bolted on rear axle, welded A frame on the front, and the heavy Manley Crane on the stern, I am not looking forward to doing it.
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RustydoubleA
Posts: 108
Joined: June 18th, 2014, 10:22 pm
Body Type: express
Model Year: 1930
Location: N. Calif.

Re: I need a six by six u joint.

Post by RustydoubleA » April 5th, 2019, 9:55 pm

Not all pictures are transferring. Picture of remains of Mixing and matching x joint parts. Most of those early x joints are worn out so I use the newer ones. Notice the flanges on the cross member in some of the pictures.

You can notice my 8 1/2" driveshaft extension in some of those pictures. I welded a flange around the stock bell and cut another driveshaft/torque tube to 8 1/2", added the flange and another bearing inside and bolted it up. I may have welded a 48 Ford driveshaft coupling to the short shaft and slid it into the rear shaft. If I were to do it again I would extend the torque tube housing and cut/weld two driveshaft halves together.

I have a 31 AA doodle bug that I put early sheetmetal back on it. It has the low speed axle, but I want it to go slower and have one more (worn) underdrive unit to install in it. With the bolted on rear axle, welded A frame on the front, and the heavy Manley Crane on the stern, I am not looking forward to doing it.

RustydoubleA
Posts: 108
Joined: June 18th, 2014, 10:22 pm
Body Type: express
Model Year: 1930
Location: N. Calif.

Re: I need a six by six u joint.

Post by RustydoubleA » April 6th, 2019, 7:04 pm

Hi, I reread your question and reply, as well as looked at the cross member that you have. I replied above with too many words! You are mating a Model A three speed transmission, with the underdrive, then to the Model A car drive shaft. You will use 2 STOCK Model A car x joints to do this correctly. The three units bolt up nicely. No modified anything. I have done this exact thing twice using Model A car drive shafts. (and twice using 30/31 AA driveshafts).

You have something spaced wrong. That cast iron cross member that you tried to use may be too thick, spacing the bell too far back from the underdrive. The original 28/29 cross member is just over 1/8" thick. If the centerline of the bell/ clamshell assembly is sitting 1 or so inches back from the centerline of the x joint, then a binding will occur causing clunking and vibration. Note that the x joint is bolted to the underdrive shaft and cannot float to find a center.

Since you had the drive shaft and torque tube cut shorter; I suspect a problem there. Is the end of your driveshaft roughly even with the edge of the bell? (as in my first set of pictures). They are normally 1/8" longer, but if it is even or an 1/8" shorter it won't hurt anything. If the shaft is recessed an inch or so (because the machinist messed up) then it will not work because the bearing surface on the driveshaft will not be running on the correct shaft surface, and you will need a specialty x joint that does not exist. If the wheelbase is not critical, then shorten the torque tube. If the wheelbase cannot be changed, then have another inner driveshaft made up.

Sometimes (all of the time) it takes 3 or 4 tries to be successful at making strange things that work correctly. Actually, it usually takes 2 tries to get a stock thing working correctly. It's always better to correct the issue by correcting the issue, instead of modifying something else for correction.

I sort of feel that you are not stating all of the information that you have at hand which leaves me only guessing what your real problem is. That's probably why I am the only silly one on this forum offering some avenue of resolution. But then, all that you are asking for is a X joint that does not exist.

Good luck with your project, Steve.

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