14-Bolt 1410 Yoke and U-bolt Kit

By Bill "BillaVista" Ansell
Photography: Bill Ansell
Copyright 2004 - Bill Ansell
(click any pic to enlarge)

Introduction

Everyone knows by now what a fan I am of the mighty GM 10.5" ring gear 14-Bolt axle. It's an especially good choice for the budget builder because it's so stout in stock form. That is...except for one really weak Achilles heel. In stock form, most, if not all 14-Bolt pinion yokes use "straps and bolts" to retain the driveshaft U-joint.

This can be a serious driveline weak-point, AND a huge PITA for a couple of reasons.

First, the straps themselves are the weakest and flimsiest method of retaining the U-joint bearing caps. They are barely acceptable for a street rig (the design is poor, and unevenly clamps the bearing cap causing accelerated bearing wear, as you will see) - but they simply suck in real-world abusive 4x4 applications. This means your kick ass drivetrain is only as strong as this one flimsy, poorly designed piece of stamped steel. That sucks!

Second - unlike other yoke strap kits - the 14-Bolt version is unique and a real PITA to find. In fact - the proper strap is almost completely impossible to find anywhere but a GM dealership - where of course they will make you pay for them dearly! Not only that - but for some reason, most of the major parts store houses are completely unaware of this - so that if you go to any and order a strap kit for a 14-Bolt (or more accurately, GM 1 ton truck - they never know what a 14-Bolt is!) they will gleefully sell you one - which if you're a hapless soul like me - you won't realize is totally wrong and wont fit at all until after the store has closed Sat p.m. with an early morning Sunday run coming up. It is some frustrating when your whole rig is down because of a stupid little U-joint strap kit!

Third - the design of the strap retention style means that the yoke itself is threaded to accept the bolts. This can be a large PITA if you should shear a bolt head off or beat it badly enough that you can't get a wrench on the head. In contrast, when U-bolts are used, all threaded parts are on the U-bolt and nut, which can easily and cheaply be cut off and replaced - rather than having to mess with removing bent or broken threads and/or repairing the internal threads in the yoke.

I recently went through just this - and discovered the solution - or rather it discovered me. Jess at High Angle Driveline (from whom I got my driveshafts) sent me an e-mail to say he just may have the solution I needed. So I called him the next day and he told me about the custom 14-Bolt 1410 yoke he has available, that comes with sturdy, better designed, more even clamping, and most importantly - available anywhere U-bolts instead of straps. Wicked cool - just what I was needing....except...

My only concern was - what about my new 1350 series driveshaft? Do I have to use some funky, uncommon half-and-half conversion U-joint to go from 1350 at the shaft to 1410 at the pinion yoke? This would really defeat the purpose.

The answer was no - the 1410 pinion yoke is available in kit form with a new 1410 driveshaft slip yoke! Perfect. The added advantage to this is all the benefits of the 1410 U-joint (stronger, greater angle capability) over the 1350, as shown in the following chart:

U-joint series	Joint width (W) (inches)	Cap diameter (D) (inches)	Maximum Angle	Continuous rating (lb-ft)	Short Duration rating (lb-ft)
1310	3.219	1.062	30	130	800
1350	3.625	1.188	20	210	1240
1410	4.188	1.188	28-37	250	1500

Here are all the details:

The Weakness:

Beat on your driveshaft for long, especially in the rocks, like this, and soon enough you will discover the Achilles heel of the mighty 14-Bolt. The stock pinion yoke straps suck, and are just not up to the task.

	After a while they look like this.

	Not very impressive, and a lousy weak link in the drivetrain.

	You can see the galling where the cap has begun to spin, after the strap has stretched and deformed.

	That's what a used one looks like next to a new one - no wonder they don't hold the U-joint bearing caps well after some use.
Worse yet:
	Even new ones do a lousy job of retaining the caps. They contact the cap in only 2 places, the "high spots". Look at all the open space between the strap and the cap, indicated by the yellow arrows.

	When you remove a strap that's not been beaten, it's easy to see the wear marks where it clamps the cap. That's a pretty lousy design in my opinion, and doesn't do a good job of evenly clamping and retaining the cap. Not only that - but the lack of contact area only exacerbates the problem of loosening straps and poor cap retention. The result is, to compensate for the poor design, people over-torque the retention bolts to try and keep the cap in place.

	This in turn unevenly loads and distorts the bearing caps - leading to accelerated wear of the needle bearings and premature U-joint failure. Great - just what you want at the business end of your drivetrain! Here you can see the wear marks on the U-joint cap itself.
The Pain in the A$$:
	And if that weren't enough - to add insult to injury - the proper straps are a pain to find. No parts store I have ever tried, from NAPA to Car Quest ever has them. That leaves only the GM dealership, where the strap (GM p/n: 3920486) will set you back $3 EACH! and the bolts (GM p/n: 458300 or 14018700) another $2 EACH.

	As for all the local and big chain parts stores. They will all gladly sell you a "strap kit" for a "1-ton GM rear axle" or "GM 10.5" rear end" or a "14-Bolt full floater" or a "1980 Chevy K30 1 ton 4x4 " or whatever else you have to say to them to get one - but, in my experience (NAPA, Car Quest, Canadian Tire, and a couple of local independents) they are all WRONG, and won't fit at all. The top strap is the one the parts stores will sell you, the bottom the GM part.

	You can clearly tell from the pics that the width, height and profile are all different.

	No way that strap is even going to clamp the cap as well as the piss-poor factory design - talk about from bad to worse!

	In fact - in most cases it's impossible to get the thing to even fit, as the bolt hole spacing isn't even right. Explaining this to the counter jockeys draws only the inevitable blank stares. I for one, am WAY to old for this aggravation - and get more than a little grumpy when something this stupid keeps me from a run!
The Solution:
	Enter the High Angle Driveline 14-Bolt 1410 yoke kit. The kit solves all the problems at once, and is a nice strength and angle-capable upgrade to boot. The kit includes a new, custom, 1410 pinion yoke for the 14-Bolt, a new (optional) driveshaft slip yoke - with brand new Spicer life series 1410 U-joint installed, and of course the U-bolt kit to replace those godawful straps!

	It ships in the usual bullet-proof container - complete with 3/4" thick wooden end caps held in place with drywall screws!

	Here is the pinion yoke.

	It starts life as a Spicer part number, but is then machined by High Angle for this application.

	Back side view.

	The new driveshaft slip-yoke that comes optional with the kit if you need it. This allows the use of a true 1410 series U-joint, while letting you keep your original driveshaft. It comes complete with dust boot, grease nipple, and a 1410 series Spicer Life, solid, non-greasable, sealed, U-joint installed.

	Here's a shot just to give some perspective - this stuff is HUGE! 1350 is for wimps !! :-)

	Here are the parts loosely assembled on the bench. You can already see how far superior the U-bolt cap retention is to the strap style - even without the size, strength, and angle capability upgrade of the 1410 joint and yokes...

	... look closely at how evenly the U-bolts clamp the U-joint bearing cap; and compare this to the picture of the strap clamping above!!
The Comparison:
	The old slip yoke next to the new.

	1350 U-joint (right) vs. 1410.

	The old pinion yoke and the new.

	1350 series 14-Bolt pinion yoke (stock) on the left, High Angle Driveline 1410 series U-bolt pinion yoke on the right.

	How the old 1350 yoke and strap combination retains the U-joint caps. The straps are new in this pic, note the gaps at the yellow arrows.

	The High Angle kit installed with U-bolts retaining the caps. Check the even clamping around the bearing cap (yellow arrows).
The Install:
	Remove the 4 bolts securing the old straps.

	Make a mark on the driveshaft (red arrow on extreme left of pic) so that the new slip yoke can be installed in phase. If your old yoke doesn't have an alignment mark like mine did, make your mark line up with the centre of the cap bore.

	In order to ease removal of the slip yoke (to avoid a hydraulic grease lock) I unscrewed the dust cap from the slip yoke and removed the grease fitting. Then tap the yoke off the shaft splines and remove the old dust cap.

	Install the new dust cap first, then ...

	...align the new slip yoke with the mark you made on the shaft and slip it on over the splines. Because of the anti-wear coating on the splines it takes a bit of fiddling to get it to go on. Once the yoke is on, screw the dust cap onto the threads.

	Next move to the axle and remove the pinion yoke. The pinion yoke nut is 1.5" so you need a big socket and either a 3/4" breaker bar or a healthy impact gun to get it off. Once the nut and washer are off, you still need to get the yoke off. I started it with a cheap 2-leg puller until it ran out of authority...

	...and then I "persuaded" it the rest of the way off with the ol' hammer!

	Line the new yoke up with the pinion splines the same way the old one was, so that the driveshaft will easily fit back into it, and tap it on. I used the 1.5" socket to tap it on straight. I then liberally coated the pinion threads and the old nut with Loctite thread locker, reinstalled the old washer and nut, and did them up with a 3/4" drive ratchet as tight as I could by hand with my hand about 8" down the handle.
I should note that this is NOT the proper way to replace a pinion yoke, because the 14-Bolt uses a crush sleeve to set preload. The strictly proper way to do the job of replacing the yoke would be to measure and re-check pinion bearing preload (instructions are contained in the 14-Bolt .pdf manual in the 14-Bolt bible article in the tech section) or even install a new crush sleeve, and then use a new nut and washer. I would certainly recommend this approach for any street driven truck. The job isn't too bad either since you can remove the pinion section from the 14-Bolt housing if you're going to go as far as installing a new crush sleeve. That said, I was in a hurry, and the Wolf is only ever trail driven.
	Once the pinion yoke is tightened in place, install the new U-bolts and lock washers then tighten the nuts evenly. Check to sure everything is aligned, properly seated, and evenly clamped.

	The final step is to grease the slip-joint in the driveshaft. Because the slip joint purge hole is welded up to prevent the ingress of water and muck, don't just pump till you can't pump anymore - you will fill the whole cavity and likely cause the slip-joint assembly to hydro lock. Just a few pumps will do.

	And you're done! The U-bolt replacement kit is Spicer part number: 3-94-18x
The Result: For your trouble you get: No more stupid little straps (Hooray!) Bigger, stronger yokes Massive 1410 series U-joint - stronger and greater angle capacity Stronger, more even U-joint cap retention Easy to replace (even when damaged), commonly available U-bolts And best of all... NO MORE 14-Bolt Weak Link !! Important Note: The 14-Bolt 1410 Yoke is not a "universal" kit. Since I was already running a High Angle Driveline 1350 CV shaft, the conversion was simple and straightforward. However, if you have a different driveshaft, there are a few things to consider. In order to match the slip-yoke to your existing driveshaft you will need to know the major diameter (outside diameter), length, and the spline count of the splined section on your existing driveshaft. Have this information handy when you call High Angle. Note that in the case of some light-duty 1/2-ton rated driveshafts, it is not possible to match the massive 1410 slip-yoke to the existing splined section. In this case, the best option is probably to replace the entire shaft. I've added this note just to make you aware of the possibilities and so that you can have the necessary information at hand when you call Jess at High Angle Driveline.