New question about Rzeppa axles and bushings.

[Carls_jeep]

As you know I am putting Rzeppa axles in my Jeep to replace the Bendix axle that failed. I ordered parts from Walcks and finally told Carl to send me everything he could think of to put the Rzeppa's in my 1951 CJ3A Dana 25 axle housing.

it seems I have a condrum which leads to a quandry as to how to solve a problem and ultimately a dilemma to solve.

What I have is what bushing to install for the Rzeppa axles. The first photo is of a bushing that is supposed to be installed in the axle housing. However the small diameter between the large diameter and the tapered area is 1.565" diameter while the axle housing is only 1.377" diameter. That bushing will NOT fit in the axle housing and leads me to believe it's not the right bushing to support the axle shaft. However, I can make a bushing to drive in the housing to fit that axle shaft to support it.

There is also the question of why the angled area on the bushing. Does that bushing shoulder on the axle housing and control the end play? If you look at the fourth photo you will see the area for a bushing is a long way from the area where the bushing would ride against the axle shaft if it goes that far and it should not. That is because the axle end bumps against the shaft the sun gears ride on in the ring gear carrier and limits how far in the axle can go.

Since I have the carrier out to replace the inner seals I have not determined the depth of insert of the axle into the steering knuckle area. Perhaps for that reason this is a premature observation and question.

The other issue is the large bushing in the second photo that is installed in the axle housing. I have tried fitting that bushing against the Rzeppa axle with it in a 23 degree angle to determine it's relationship and the bushing interferes with the axle at that angle if the axle is centered in the housing.

If I use the large bushing it will move the axle shaft away from a centering position and possibly bind the axle up. The bushing will also ride on the smaller splined area of the axle and give no support. I don't need or want any binding and prefer a centered axle shaft at that point.

Here is where the dilemma starts. Since the large bushing is not going to work if I want the axle shaft to be centered in the housing during turns and the smaller bushing will NOT fit into the axle housing my only alternative is to manufacture my own bushing to, #1-center the shaft in the housing and, #2-to control end play of the axle shaft. I can machine a bushing that will drive into the housing and with a small enough shoulder to control the end play of the Rzeppa and not interfere with the articulation of the axle while it free floats in the drive hub as explained below.

Carl said that since the shims for the Rzeppa are not available most people just leave the axle nut loose on the end of the Rzeppa and put the cotter pin in and allow it to move freely. The outward movement is limited by the shouldered bushing in the spindle housing. He said many times the threaded end is cut off so lockout hubs can be installed and it just floats freely in the lockout hub splines. I can machine the axle housing bushing long enough limit the end play of the axle with just a little measuring, well, maybe a lot of measuring. Couldn't be harder than anything else I have done.

There is another alternative, if I make a bushing to fit the axle housing to center the axle without an extended shoulder and just leave the axle nut at the outer end loose the the axle movement is contained in the axle drive flange. That will eliminate all the difficult measurements needed to make the bushing for the axle housing. How many see that as a solution like I see it?

I use drive flanges because lockout hubs contribute to transfer case wear/failures and were never intended to be used on these WWII type transfer case designs. That has been discussed extensively here so look it up if you want to.

Now the question to all, have you even looked at this issue? Have you just stuffed the parts in and hoped for the best? If so what happened? Let me know if anyone has been able to drive a 1.565" diameter bushing into a 1.377" diameter hole, I would be interested in knowing how that turned out. If you used one or both of the bushings how did your end play work out? Did your axle survive for very long.

Discussions are always fun and past experience is very enlightening.



http://s82.photobucket.com/user/yeathatshim/media/P4010002_zpsdmatpq66.jpg.html?sort=3&o=3

http://s82.photobucket.com/user/yeathatshim/media/P4010011_zpsleentixb.jpg.html?sort=3&o=0

http://s82.photobucket.com/user/yeathatshim/media/P4010005_zpskqgpkq7i.jpg.html?sort=3&o=2

[Carls_jeep]

This is a cut and paste from the CJ2A site.

I intend to call Walcks Monday and ask about it. The fact is there is no support in the axle housing to keep the axle in alignment with the spines in the carrier housing. Consequently there is no support of the constant velocity joint in the knuckle area but there is support in the area of the spindle housing and the drive flange.

Also, with the bushings supplied for the axle housing there is no control of the end play of the axle and I believe it's not needed there. One thing I didn't mention is the clearance for the bushing that is supposed to go in the axle housing has a clearance of .025" between axle and bushing but that bushing will not fit into the axle housing. The bushing that goes in the spindle housing has an axle to bushing clearance of .015".

Having been a machinist most my life and worked on a lot of machinery and rebuilding them I don't like unsupported shafts, especially long shafts with a lot of stress on them. It simply is not a good idea.

I have about decided to make a bushing for the axle housing without a shoulder to limit end travel. The end travel is limited by the spindle bushing shoulder and the axle nut on the end of the axle. I will make it with .025" clearance to replicate the clearance of the provided bushing for that area.

To be honest the Bendix axles in my Jeep have been in there since new because there was a Bendix axle tag on the steering knuckle. The Jeep has about 100,000 miles on it, I am guessing, and the Bendix axle is not a constant velocity axle and is more like the Spicer axle in motions it produces. Since those axles lasted as long as they did I am real curious about just how the Dana 25 works as it does. There are signs that both sides have been apart in it's past life.

It's not hard for me to see that the Rzeppa design is the better of the Bendix or Spicer and is still used in constant velocity joints today. It's unfortunate that the Dana 25 Rzeppa axle is not still made.

The Rzeppa design needs a closed knuckle for lube while the Spicer can be in the open. a double cardan most closely replicates the Rzeppa axle and is also used on heavy duty front end 4 whl drives.

I didn't really expect many comments on this thread and it is intended to get people thinking about the subject of the right axle shaft for the Dana 25 and a good installation.

[Carls_jeep]

I've decided to not make a bushing for the housing and start putting it back together. If it ain't broke don't fix it.

[mtnman37879]

Best advise ever! "If it ain't broke don't fix it!" unless you're in the Government then your mantra is "fix it till it's broke"

[Carls_jeep]

LOL, that's true.

[Carls_jeep]

For anyone interested I found some front wheel seal numbers.

National 40566S

SKS 21101

[Carls_jeep]

The axle job is done. Rather than leave the axle nut loose to allow it to center I followed the manuals way. It told about how to shim the Bendix axle using the nut type and then it said it using the Rzeppa axle just install a .060" shim between the axle and the flange and put it together.

I machined two shims and put it together torqued the nut and it works just fine.