19 spline or 30 spline???????

Alright, I am going to ask this question once more and I hope I will get a general overall picture that what I am doing is the best way to go. As probably everyone knows I have been wrestling with what to do with my Dana 44 19 spline rear. Last week I thought I solved the problem by getting custom made axles from Dutchman or Sand hills. Looking at the cost for these axles and new seals, bearings, spider gears and so on and so forth I remember a gentleman on this forum who said he had a 1970 1/2 Dana 44 30 spline 3.73 out in his shed that was in great shape and would sell it to me if he still had it. A day later he called and said he did so we made the deal. Now my questions are, from everything I read a 30 spline was much sturdier than the 19 especially on a V-6. I do not want to put a locker in the rear because I would say I am about 65% on road and 35% off road. I do have the Power Lock that was on the 19 spline and again I read and informed it would work in the casing as long as you change out the spider gears, new shims and clutches. You are the Jeep Gods up in Kaiser Willy's Overland with all the knowledge and wisdom from all the combined years of hands on and repair, word of mouth and sometimes just hit and miss. Let me know if going with the 30 spline is a better choice than chasing the 19.

Robert

 

30 spline flanged much stronger...end of axle discussion.
Set it up however you want it to be set up: axle ratio, limited slip etc.

 

I gather you're going to buy the d44 flanged axle. I believe they are 30 spline axle shafts. I do not know if a swap from 19 spline to 30 spline is something that can be done on a power lock case. I do know you can order a new one from R&P for about 450 bucks that is 30 spline. I just did that and installed it with new gears and bearings in my D44. It is involved to set up gears on a differential yourself. I did it and it seems to work fine but it took me a while to get it right. If you plan on using the power lock you presently have you will need to set up gears when you transfer it over if you can even swap out the spiders. You cannot mix and match pinions and ring gears either. You will need set up bearings, dial indicator, calipers and other assorted hand tools. You cannot use 19 spline case bearings as setup bearings on a 30 spline case because they are not the same ID.

 

It is the axle shaft diameter that makes a 30 spline axle stronger than a 19 spline shaft and not the spline count alone.
In truth, involute type splines are much stronger than straight splines.
Both the 19 and 30 are involute type splines.
Within reason the exact spline count is not so important.

That said; the axle shaft strength required is mainly effected by engine torque, then tire size and also the type of differential.
Personally I prefer Spicer Powr Lok in all my axles because I drive all types of pavement and terrain.

You cannot run the 19 spline Powr Lok in your offset flanged D44 without changing the side gears.
Converting a 19 spline Powr Lok for 30 spline shafts is doable but the parts are not cheap and it does not produce the optimum 30 spline Powr Lok.

The V-6 CJ's with 19 spline axle shafts have a time proven record.
That said; if you drive with quick throttle stabs on terrain providing variable traction the axle shafts can be broken.
If you drive a V-6 with so called "common sense" you will never break a 19 spline axle shaft.
By far the worst scenario is to spin the tires wildly on any wet /slippery surface then suddenly get full traction with BIG WIDE tires on a dry granite slab.
So there you go..... another argument in favor of skinny treads.

 

Oldtime you are mostly dead on in your posts. About 30 years ago I broke an axle shaft in my '61 3B, with a Powerlock on a flat paved road. It must have been abused before I got it. (OK, I may have some part in this). I still have an extra Powerlock unit in the garage but I don,t know which series it is. I suspect it is for a 3:73.

 

I would also agree with Oldtime above , especially his use of the word " Common Sense" in reference to how the vehicle should be driven..........If a person has the right gear ratios both in the rear axle and the transmission and use's them as mentioned above regardless of a reasonable tire size , gear and axle manufactures would soon be out of business for lack of need to buy there products.

 

Put the axle manufactures out of business ?
Haa Ha Ha ! That's absolutely hilarious !

Truth is... if we look deep into our prehistoric past it logically becomes evident that the wheel was only invented whenever the axle was conceived.
Before the axle shaft/wheel; man's method of cargo conveyance was no more advanced than the sledge or travois.

I forgot to mention...The earlier 19 spline shafts were "milled" to form while the later 30 spline shafts are "rolled" to form.