Ball and Trunnion Conversion

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JWestfall
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Ball and Trunnion Conversion

Post by JWestfall »

My 71 Wagoneer has a ball and trunnion joint on the driveshaft connecting to the Dana 20. Does anybody have a part number or source for a bolt-on flange yoke to attach to the t-case so I can convert to u-joints all around? I have seen a few for older cars, but I don't know if they match up with the Dana 20 bolt pattern. thanks
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Stuka
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Re: Ball and Trunnion Conversion

Post by Stuka »

You can buy brand new yokes from several places. You will need a new drive shaft as well, and you will need to measure for its length after the new yoke is installed.

Your D20 should have a course 10 spline output.

This is basically what you need for the t-case side: https://collinsbrosjeep.com/dana-20-t-c ... 10-spline/

Does your D44 also have a ball and trunnion.
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ

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JWestfall
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Re: Ball and Trunnion Conversion

Post by JWestfall »

Thanks for the link. I was hoping to find a flange yoke that would bolt right up where the ball and trunnion did for much easier installation. I know they make them, I just don’t know which one mates to the D20. The axle end is a regular u-joint yoke.
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Stuka
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Re: Ball and Trunnion Conversion

Post by Stuka »

Oh, post a photo of your current setup. I know you have before but I don’t recall the details of hand. You may just need a drive shaft with the bolt on side for the u-joint, which is also very common. And is how Jeep did it (my 75 had this setup).
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Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ

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JWestfall
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Re: Ball and Trunnion Conversion

Post by JWestfall »

ball and trunnion.jpg
This is not mine, just a picture from the internet, but it is the same thing. It bolts to a round "plate" that is on the transfer case.
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tgreese
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Re: Ball and Trunnion Conversion

Post by tgreese »

Look at the '62-73 J-series parts catalog here - https://oljeep.com/edge_parts_man.html

In the illustrations, the flange is shown at Gr 18 - L 1 (group 18 plate 1) and the drive shafts are at Gr 9 - L14. It looks like the later Spicer-type flange at 18.115-1 is a Jeep PN 933734. I found that part as NOS in an old listing on eBay https://www.ebay.com/p/2202377853?iid=114928689577 - looking at the later book, that number is good at least through 1979. I'm surprised it's not more widely available.

You'll still have to have a Spicer-type driveshaft made. Looks like the Spicer driveshafts were used with manual transmissions, and those will be the wrong length for your application. If a '71 has the Detroit style shaft thatg you have, it seems unlikely there were ever any Dana 20 Wagoneers with the Spicer shaft and automatic. If it existed, it would have to be a '72 or '73, since the full-time Quadratrac was optional in '73 and standard from '74-on with the automatic. If you found a driveshaft from a manual Wagoneer, you could have it shortened to fit the automatric. However, a specialty driveshaft shop should be able to make one for you if you give them the dimensions.

A good driveline shop may be able to rebuild your Detroit shaft.

Just examples -
https://4xshaft.com/
http://www.highangledriveline.com/
There's a shop in Pahrump that's owned by one of the members on IFSJA. http://www.ifsja.org/forums/vb/showthread.php?t=189326 Maybe he's a member here too.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
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JWestfall
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Re: Ball and Trunnion Conversion

Post by JWestfall »

ball and trunnion conversion.jpg
This is a picture from the web of a conversion someone did for an old Ford (I think) showing the old driveshaft and the new. I know I will need a new driveshaft, but you can see the new flange yoke bolts up with four bolts to the transfer case. It would be a lot less labor to do it this way.
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tgreese
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Re: Ball and Trunnion Conversion

Post by tgreese »

JWestfall wrote: Fri Sep 02, 2022 8:27 am ball and trunnion conversion.jpg
This is a picture from the web of a conversion someone did for an old Ford (I think) showing the old driveshaft and the new. I know I will need a new driveshaft, but you can see the new flange yoke bolts up with four bolts to the transfer case. It would be a lot less labor to do it this way.
Try the Pahrump shop linked above. He would know what's available to adapt your existing flange.

JMO - replacing the existing flange does not seem like much of an ordeal, if the Spicer flange is available.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.

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JWestfall
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Re: Ball and Trunnion Conversion

Post by JWestfall »

Thanks for the links. One of those shops is only 1 1/2 hours from me so I will give them a call.
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kjandb
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Re: Ball and Trunnion Conversion

Post by kjandb »

OP, I'm curious if you ever found the correct flang yoke that bolts up to your existing d20 setup? My '71 is going through the same thing.
'71 Wagoneer - 4" BJ's Leaf Lift - early 360 - Avocado Mist ???
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Re: Ball and Trunnion Conversion

Post by sierrablue »

Mine has the '74-'79 front end in it (I know it's off a '74-'76 but that's irrelevant for this), but it seems to have a factory yoke, maybe it's from the '74ish they pulled it from though. It's u joints on all joints though.

Is there a reason you can't just swap to the output/driveshaft from a later one?
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
-Front shoulder belts (rears eventually)

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There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.

Topic author
JWestfall
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Joined: Fri Feb 05, 2021 12:39 pm
Location: North Eastern California

Re: Ball and Trunnion Conversion

Post by JWestfall »

When I ordered a new driveshaft the shop supplied the flange to bolt right up to the T-case. Sounded like it was a pretty common conversion for them.
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