Installed Tom Woods Offset U-joint!!!

[Broncoholics]

With the flex in the front end of my 68 Bronco(wristed radius arm), I decided to try Tom Woods new offset U-joint http://www.4xshaft.com/

Take a look at the site for additional information.

When I lifted my Bronco from 3.5" to 4.5" (front only) I noticed the front CV style driveline was getting rather steep. I jacked up the bumper and let the tires hang. I couldn't turn the driveline by hand. @-) Dropped it way down until I could turn it but there was a bad bind every 1/4 turn. Took it off the axle end and found it only hung a few inches lower than the yoke. It will drop another inch but it will not turn at all.

I run a NP435/205 so I lowered the crossbrace to help the rear driveline angle. Now the front yoke is just heading up hill a degree or two so a CV style driveline just wasn't cutting it. This isn't the case for most Broncos out there.

After doing some research on Tom Woods new offset u-joints I needed to run a single ended driveline on both ends. I had one so I purchased the u-joint ($65 delivered).

Below are photos of before and after and what the u-joint looks like.

Never did a measurement comparison but its got to be 5-6" of droop further than before.

I had to take off the oval shaped CV style yoke on the t-case and replace it with a square style that takes u-bolts. Looks ljust the same as the axle yoke.

I had to go dumpster dive for hours looking thru used yokes. Once I found one that matched the splines I took it. I don't want to count another spline if I can help it! :wacko: The seal was a different size so I had the part store match one up. I did find some u-bolts for a Corvette which fit the oval style yoke but the u-bolts strap over the inside cap of the u-joint instead of the outer area where its stronger. A driveline shop said it was OK but I have my doubts and searched out the yoke. Maybe I was a lucky find. Infact I don't even know what rig it came off of as I went thru a pile. Not sure if D20 t-cases have a square yoke available but probably.

I did do some slight gringing to the inside edges of the driveline and yoke to allow more movement. I had to grind the yoke no matter what as I could feel the ears touching as they came around. Now its nice and smooth!

You can't beet their "Gold Seal Warranty". Full replacement if it fails. If it does damage to your driveline they will fix it at no charge, you just pay shipping.

Can't beat that, my hat is off to Mr. Tom Woods!

Most Broncos will not need this unless you have tons of flex up front.

The driveline will not move up or down hardly at all. When one tire is up and another down keeps it centered. Jumping or hitting a bump hard will allow both sides to drop together resulting in failure in my old CV driveline.

As my axle drops it rocks down and inwards (arch pattern) so as the axle drops the yoke is still pointing at the t-case. For odd setups where the yoke on the axle is sitting level you could run one on both ends to help.

 

[Broncoholics]

Does anyone know what the part # might be for the square style 1310 or 1030 yoke for say the NP205 & Dana20 t-cases that are commonly found on Broncos? Might make it easier for those that want to do this modification without going dumpster diving for hours and not finding it.

 

[Broncoholics]

OK I went to a driveline shop in Seattle and had them match up the yoke I found in the junk yard. They have no clue what its off of either, it was sized up.

Spicer Part# 2-4-4191-1 New costs $70 used is $10.

U bolt strap Part # 2-70-18X

Hope this helps. If you are to do this I'd go buy the correct one and match it up at the junk yard and return it to save cash.

You need a new seal or have a machine shop mill down the yoke so you can use a stock seal. There is a difference with the two yokes. The new square yoke is 1/4" shorter. It also allows the splines to come all the way thru vs. the old had a ****** to stop the yoke with a rubber seal inside. Hope the new one doesn't leak. I added a washer to the inside of the yoke and drilled it out to fit the thread size and put the seal back in. I used the old nut and added lock tite. Should be fine but I'll be busy until next week to test drive.

 

[Broncoholics]

After talking to others on a few sites a guy sent me this: http://www.4x4wire.com/tech/pinionangle/

What do you guys think?

He thinks I need to lower my pinion angle down since the t-case yoke is near level. Plus now I am running single ended u-joints. They speed up and slow down and can cause a vibration. I never drive fast in 4x4 unless in the dunes and have shift on the fly and use 4x4 only when needed.

I can see the articles point and will see what other say like Tom Woods. Thinking of changing the c-bushings from 6.25 to something lower to correct the pinion angle if I have to. Tom never said anything about this. Maybe the offset u-joint helps from a standard u-joint.

Before I used to run this single ended driveline and the pinion always pointed at the t-case with no vibrations. Maybe I was lucky. At that time I was running a D20, rancho coils and no wristed arm. I upgraded to a NP435/205, long travel coils and a wristed arm.

I'll let you know the out come...

 

[Broncoholics]

Talked to Tom Woods. Yes, its best to have equal angles at both yokes when running single ended u-joints. He said if the driveline is working in the location its in now without bind its going to be fine until higher speeds which this u-joints is not meant for anyway. The front is only place I'd run one.

I also let him know they need to add into their web site and directions:

Going from CV style DS to off set u-joint will require a single ended DS and a new square style yoke. These square yokes might not be available for all t-case setups out there so do some research. The 205 that I run doesn't show one available at any part store I went to. The one I found must be off another rig and t-case with the same spline count. This will be a huge imporvement over what I had. I kept bending the DS at the slip shaft due to the DS binding up. Now I just need to find a 4' rock around the neighborhood I can drive the rear tire up and let the front (driverside) drop to test if it binds up or not. So far jacking up the bumper and letting the suspension hang it turns smooth. Should be interesting. I will not have time until next week to test this though... (