U joint straps vs caps?

[RubberFloorMat]

so in pulling out the driveshaft on my new-to-me 78 blazer to get the trans out, I observed that the rear U joint was held in by some pretty weak looking parts store strap kits. I've been around a ton of cars and trucks but never had a strap kit on any of them. Where should I look for caps? The universal summit racing Moroso caps are like 40.00. Anyone running something else?

 

[Stomis]

Im curious to see this question clarified. It seem remember in the 4wd world everyone likes the straps but in the race world everyone likes caps....

 

[obijuank5]

I say straps are probably pretty good. held up OK here. 1350 dana 70 rear with BBC 4:1 and 40s.

 

[RubberFloorMat]

Im curious to see this question clarified. It seem remember in the 4wd world everyone likes the straps but in the race world everyone likes caps....

Agreed. I've had a few performance cars and they all had caps, just wondering what the consensus is.

 

[AJs72K5]

Caps are taller. Perhaps a clearance issue under articulation?

 

[Hogback Fabrication]

The billet caps do limit angle a lot. Cool idea, but not great on a 4x4.

Some straps are better than others. Some yokes only cover ~1/2 of the cap and those don't seen to hold up very well under hard use.

Others have most of the joint in the yoke with the strap only covering a little bit of the cap (and hence, the strap is near flat). Those hold up much better.

 

[FOR MUD]

The biggest problem I have with cap is the bolt heads getting bunged up on rocks making them hard or impossible to remove. I even had a few of them that were bent. At least with the straps their easy to cut them off if need be.

 

[diesel4me]

Most of my older GM trucks used u-bolts to hold the u-joints to the yokes...later ones after the 80's used straps...I don't think either is any stronger than the other,both seem adequate...

 

[78K30]

I'm a fan of the U-bolt style of retention. Simple and hard to mess up. The rear of my F250's both used torx bolts to hold the caps on, the previous owner had been kind enough to round them all out as well . I drilled the yokes out to accept ubolts and never looked back.

 

[Hogback Fabrication]

I'm a fan of the U-bolt style of retention. Simple and hard to mess up.

I've heard that the reason they switched to straps is that the u-bolts can be over-tightened and crush the needles in the u-joint and burn it up. The straps can't crush the cap no matter how tight the bolts get.

The u-bolts are definitely the stronger and more reliable setup, just have to make sure to not over-tighten them.

 

[F.S.F.W]

I say straps are probably pretty good. held up OK here. 1350 dana 70 rear with BBC 4:1 and 40s.

How did you tighten them down that tight???

 

[F.S.F.W]

I've been running straps for quite a while without any problems.

 

[78K30]

I've heard that the reason they switched to straps is that the u-bolts can be over-tightened and crush the needles in the u-joint and burn it up. The straps can't crush the cap no matter how tight the bolts get.

The u-bolts are definitely the stronger and more reliable setup, just have to make sure to not over-tighten them.

Quoted for truth!

 

[paratrooper307]

How did you tighten them down that tight???

I'd guess the reason straps or ubolts work fine is because of how the loading forces work. All the force (rotational) is on the yoke. The straps bear minimal force when the driveshaft rotates. The only job of the straps is to keep the u-joint seated in the yoke. The force required to do that is minimal, hence the relatively meager construction of the straps/bolts.

 

[Blue85]

I drilled the yokes out to accept ubolts.

This is generally considered a no-no, as the whole yoke casting is different between the strap and u-bolt type. What other machining was required? See http://www.pirate4x4.com/forum/gene...bolt-strap-yoke-drill-out-convert-ubolts.html

The girdle style must be stronger, but even if you don't have much angle in the joint (like at the rear axle pinion with a C/V shaft) the driveshaft yoke has to be built to match. You can see below how it wouldn't work.

 

[78K30]

This is generally considered a no-no, as the whole yoke casting is different between the strap and u-bolt type. What other machining was required? See http://www.pirate4x4.com/forum/general-4x4-discussion/520239-14b-1350-bolt-strap-yoke-drill-out-convert-ubolts

This was on a sterling 10.25 and worked quite well. the hole spacing was just right for the U-bolts and the back side of the yoke was flat for the nuts and washers to land on. I'm not one to cobble things but it worked excellent on that particular yoke. Some yokes it wouldn't work on, in this case it did. Would I recommend it to someone else? No I would not, but it has lasted for the last 10,000 miles issue free.