I had a 29 spline unit apart and did some measuring, in the case to show everyone what is involved in converting a 23 spline unit to a 29 spline unit.
For the hard parts, you'll need:
29 spline input shaft.
Large input shaft front bearing and outer snap ring, and small (super thick) front bearing retaining snap ring.
29 spline coupler.
Input shaft seal (dual lip)
Front adapter gasket, might want to use a thick one here.
Quad 4x4 makes a "kit" with all the needed parts included:
http://www.quad4x4.com/cgi-bin/commerce ... key=662001Disclaimer: I used one of my el cheapo dial caliper, I would recommend measuring all the new parts and what not with a proper metal dial caliper and depth gauge. My measurements are a rough estimate as to what's all needed.
Machining to be done:
Input bearing bore on the case will have to be machined to approximately 3.550" to accept the larger bearing. The input shaft front bearing is 3.543" in diameter. It doesn't have to be a tight/press fit, but don't want it loose either. It should take light persuasion from a soft faced hammer.
Front adapter or "bowl" as Bill and I call it, will have to be machined to accept the larger seal, bearing and two snap rings.
Large outer snap ring groove, 3.775" to a depth of 0.100".
Bearing groove, 3.550" to a depth of 0.200".
Small (thick) snap ring groove, 3.050", to a depth of 0.350".
Seal bore to 2.685"
The cost for each bowl to be machined was $50.
I didn't get a quote to get the case bored, I would guesstimate somewhere between $50-$150.
Now here's where it gets a little interesting. I recently had two small input bowls machined out to the large bowl specs. No biggie there, buuuut where the input seal rides. Most of the casting is machined off, leaving just a small, sharp lip. One of the bowls was off my 91, and it had about 0.300" of material remaining. The other bowl I had was off a 85 W400, it had 0.250" to .0.270" of material remaining. The dual lip seal has a thickness of 0.500". The big input bowl has a seal surface of 0.800" for the seal to ride in.
Pictures.
Outer snap ring groove
And depth
Bearing groove
And depth
Bearing retaining snap ring groove
And depth. NOTE: this depth is from the land above it, need to add 0.200" to it to get the total depth.
Seal surface
Small (thick) snap ring
Bearing
Large snap ring
This shot shows how much of the snap ring would protrude from the case, and how much DOESN'T go into the bowl, hence the need for the thicker gasket
Another shot of the bearing and two snap rings
Original big input bowl seal surface
Machined out small input bowl to big input bowl specs, notice the input seal surface
Inside of big input bowl, and how much material is there
And inside of machined out small input bowl
Case input bearing bore
That's all for now, I got to head to work, I will update this some more when I get some time tomorrow morning...
Enjoy!!!