Gap in Slip Yoke Splines

[salans7]

I'm currently looking into a rear driveshaft for my truck, but It's a little confusing as I'm going to have one made since my driveline combination is unique and used driveshafts won't match what I'm trying to build (nor do they ever seem to be in good shape). I'm running a T19/BW1356 from a 1987 F350. My rear axle is a 1988 10.25 full floater which uses a 1350 u-joint, and I would like to keep the same at the slip yoke like the 1988+ trucks seem to use (a 1987 F350 driveshaft uses 1330 u-joints per Ford).

When I look at some slip yokes, there is a noticeable gap in the splines of the slip yoke which makes it difficult to determine whether these will work on my truck. Most of these are listed as a 30/31 spline, but I'm hesitant to buy online without knowing the reasoning for the gap (ease of removal?) and whether these yokes will still work with a 31 spline output on a BW1356. Thoughts?

[ArdWrknTrk]

I think they will.
The missing tooth is to keep the universal phasing when two shafts are used in conjunction.
It's a normal 31 spline pattern with only 30t

Ford is notorious for using combination (bastard) U-joints.
My 87 with a 10.25 & 1356 came with them, but I have a Yukon 1350 yoke now.

[ArdWrknTrk]

Oh, that listing should be T-19.
460's never came with a non-synchro 1st gear....

[mat in tn]

good morning, Jim.
I'm reading along this morning, and I get the comment about the 31/30, gap etc. but would you please explain the "phasing with two shafts"? I feel as though I'm missing something here and I don't mind learning something new.

[ArdWrknTrk]

I'm assuming that is a universal slip yoke.

Back when Excelsior Machine Works was still around.
Power train specialists, bearing house and driveshaft builders, for almost anything.
When they would build shafts they always impressed that it was critical to have all universals cancel each other out, and balance as a complete assembly.

Without the missing tooth you can't be sure it only goes together one way.

[mat in tn]

so that assumes that the male has a matching irregularity. that make sense. otherwise, it is just an indicator, and it seems that there would be a better place to mark it. many slip yokes that I have used have this "missing tooth", yet the transmissions do not. its minor but the missing tooth is missing mass/weight and balance comes in at that point.

[salans7]

ArdWrknTrk wrote

Oh, that listing should be T-19.
460's never came with a non-synchro 1st gear....

That's just typical poorly written parts catalogs by Ford. lol.

Thank you for confirming it will likely work. I figured as such since I can picture the 31st spline in the gap of that slip yoke, but I just want to make sure I get the right Dana/Spicer slip yoke at $100-$150 a piece.

[ArdWrknTrk]

I bought from JBG, they show it online but dropship direct from the mother ship.  


To Matt, Yes, when Excelsior built matching shafts they could only fit in one orientation.
Having the one spline missing doesn't appreciably weaken it, but does mean it can be sold for all applications.

1350 size. They're showing as out of stock, but have the right number:  https://shop.broncograveyard.com/BW1356-Transfer-Case-Slip-Yoke-For-1350-Series-U-Joint-3-3-5431X/productinfo/31671/

[ArdWrknTrk]

Spicer won't have it until the end of September, but Denny's Driveshaft has the Neapco equivalent, or Amazon has China, Prime by tomorrow...

https://www.danaaftermarket.com/spicer-automotive/automotive-driveshaft/slip-yokes/part/3-3-5431x-drive-shaft-transmission-slip-yoke/3-3-5431X?catalog=PIMS_NA&partType=PART

[salans7]

I already have a few options for that specific Dana number in my Ebay cart, but they're all $100+. I'm not that worried about the price since JBG would likely tag $30 worth of shipping onto their price. And if Dana won't have it until September, I doubt JBG will either. But at least their website shows out of stock unlike when I ordered my firewall reinforcement, only to find out it was on back/order with no ETA, and then it ended up releasing literally a week later.

[ArdWrknTrk]

I don't think Jeff's carries any Dana/Spicer stock except maybe universals.
Whenever I order parts from them it comes direct.

That link shows available 9/30/24

[Invisibleman13]

The gap is called a "Blind Spot", it's used as an alignment reference on slip shafts. Some transmissions have them too. I have seen them on GM transmission slips.

[salans7]

Thanks!