Need Help With SOA on front axle.

[aaronveve]

This is my problem. I have a 71 Jeepster with
dana 27. I welded new axle spring perches just opposite of the factory ones for the SOA. With the perches on and axle installed the differtial seems to be pointed to far downward for the driveshaft to work right. It runs out of articulation, and the u-joint yokes touch when it still needs to pivot more. I know that a longer driveshaft will be needed for the SOA.

This Jeep will be for Highway use along with off-road. I can see if I was to turn the differtial up and point it towards the transfer case that it would cure the problem. By doing this I know this would mess up the castor/ camber, I have seen a " cut and turn" done but would like to do something else before doing that. I'm looking for the easiest way to solve this problem.

[HOWDY]

One thing that will really help is to convert to a 1 piece drive shaft. You will need 2 1310 yokes (10 spline) to replace tiny origionals and a used cj front drive shaft (I don't remember what length). Remove origional pencil sized shafts and carrier support from tcase. Save bolts, put thread locker on them and put them back in with a couple of extra washers for spacers to retain the case oil. Swap out yokes, measure for shaft, and find used or make new shaft. Cheap easy upgrade for strength and better angles. Almost forgot depending on your combo you may have to do some exhaust or crossbrace tweaking but I had no problems with it. Good luck!!!!

[WalterX]

Did you just eyeball the perches? If you get the perches off just a couple degrees, by the time you get the axle on it will really show up. It sounds as though you need to remove the welds, put everything together and turn the axle to the proper angle, then spot-weld. My buddy did this very same thing. It’s extra work, but with everything together and weight on the vehicle it made a difference.
He was actually doing a few other things at the same time, but this seemed like a logical way to go. You could try degree shims?
Rotating the axle a little to help the angle won't hurt anything unless you plan on engaging the front at highway speeds. There's no vibrating if you keep it at 2 MPH. You still have to deal with shaft length/travel.

Anyone. Can you do a 1-piece axle and still keep the old shifter? Would the new shaft be too close to the carrier bearing on upward travel? I just went to the 1-piece/twin stick without ever thinking about that. If you are good at fabrication you could probably make a new mount for the shifter that won't interfere. If I remember correctly, the top half of the carrier bearing housing is the bottom cover for the shifter housing and the bottom half of the carrier bearing is the mount to the tranny. If you remove the carrier bearing setup, then you need to fab a bottom shifter cover to tranny mount. Does that sound right?

[badbrad]

Have converted to a one piece driveshaft with SOA and no interference problems. It is an automatic and we just removed the bottom half of the carrier bearing support, leaving the top part (which is also part of the shifter housing) in place.

Another option if there is interference or you do not have SOA, is to just cut a flat bottom plate replacement and drill 4 holes, easy enough. That way you can make another improvement by adding a grease zerk to the bottom cover. Then it is easy to add grease to the shifter ocassionally and keep it freed up. Someone did this to one of our Jeepsters and it seems like a good idea.

The brace from the shifter to the transmission pan is a seperate piece and can be reused with a replacement bottom plate. You will have to use washers or a spacer to make up for the thickness of the original bottom plate with the carrier bearing support (original is about 3/8" or so thick instead of the replacement sheet metal piece on ours). Again, this only applies to an auto transmission, the manuals did not use this brace.

Brad.

[aaronveve]

The perches were welded just opposite of the others, with tape measure to center distance on each end of perch then tacked in placed. So I do know the perches are right.

Wtih the axle bolted in place you can tell the angle would be the same above the springs but now below the springs for the SOA.

I don't have a carrier bearing for the trans case output shaft going to the front axle. The driveshaft is connected to the yoke coming from the trans case and then goes directly to the front axle with a slip yoke on the driveshaft.

So I need 1310 yokes plus driveshaft to make it work, is there anything else that anyone can think of with this conveersion. I just completed the disc brake conversion for the front axle. Thanks

[LCAC_Man]

I won't profess to have any knowledge of the Dana27 but I've done a few SOA's (44's and just finished a 60), and many required correcting the pinion angle to get a decent lower u-joint angle/clearance.
A possible quick fix would be to install some caster shims under the springs to raise the pinion, but that's only if you've got some caster to give, you'll need to keep at least 2 degrees (tipped back toward the rear of the vehicle) to maintain any type of return to center on the steering.
Outside of that cutting and turning the Inner-C's to allow you to set the pinion anywhere you want it is the way to go.

[stevesc1]

Based on what you are describing you may already have a one-piece drive shaft conversion which probably already has 1310 yokes. You can take measurements of the yoke diameter and width or just compare it to the rear. If the yokes and u joints are the same size as the rear then they are 1310s, but if they are noticeably smaller then they are the original size.

[badbrad]

Have not done the one-piece and 1310 conversion on a D27, so I am not sure how hard it is to find or if the yoke even exists to do this on the D27.

But I can tell you that it works for us on a Dana 30 and there is no interference. Stock height front springs, SOA, one-piece drive shaft. When it was installed, I had to change the output yoke on the transfer case to match the driveshaft and the D30. Like you describe, our SOA perches are welded parallel to the stock ones.

Brad.

[aaronveve]

Ok. Rechecked the the perches everything seems correct. I pulled the output shaft yoke off the trasfer case and it has ten splines for the different yoke " 1310". I haven't pulled the yoke off the Dana 27 yet but if the yokes are bigger, with some more side to side movement I believe it might work.

If someone knows about the yoke interchange on the Dana 27 let me know. Oh does anyone have any used 1310 yokes you would be interested in selling let my know also.
Thanks

[kevinmcg]

if i can find (2) 10-spline cv style front yokes from 76-79 q-trac transfer cases, i will ship you mine for free