U-joints

[Three Peaks]

This is one of those things I really never gave much thought to until now when I need to have my driveline shortened.
After looking online for u-joints, I realize now there are tons of choices at all the parts stores- from $8.99 "performance" joints to the $59 Lakewood units.

Assuming this was your car- 393 stroker, 500+ FWHP, IRS rear, T5, mostly street driven with an occasional track day thrown in. No serious racing. Which U-joints would you pick? Cheapest, middle of the road, etc......

I'm leaning toward the NAPA units that are greasable and labeled "performance" at around $24.99 each, but I have no clue if they are any better/worse than any of the $11.99 units or $50 units?
What's your 2 cent's worth?

Thanks,
Bob

[patrickt]

Originally Posted by Three Peaks

What's your 2 cent's worth?

Go with Spicer.

[blykins]

You can get Spicer at Napa. I used them in my Cobra....I used the 1350 1-ton truck pieces.

[patrickt]

And some subscribe to the theory that your rear U-Joint should be weaker than your front U-Joint so that you have a "planned failure point."

[blykins]

Good idea.....then you won't have to describe to us how it feels to pole-vault a Cobra...LOL

I'd go big if you can find the weld/slip yokes to fit. 1350/1350 or 1350/1330.

[Bobcat]

Hey Patrickt .... "planned failure point " ?? Is that like slightly pregnant ??
But I do understand the theory and not wanting to be a pole vaulter !

[patrickt]

Originally Posted by Bobcat

Hey Patrickt .... "planned failure point " ?? Is that like slightly pregnant ??

Leaving off the safety hoop and blowing a U-joint is a good way to keep you from getting anyone pregnant. Seriously, having blown U-joints I can tell you that you almost instinctively throw in the clutch. That helps if the rear U-joint is blown, but not on the front.

[CJ428CJ]

Go with the Spicers. This is what a broken u-joint can do: http://www.clubcobra.com/forums/all-...ary-noise.html

[Jerry Clayton]

Spicer SPL series

[treblig]

have you broken one yet!! If not then go with a standard U-Joint. Your only talking 20 bucks come on dude. But if you twisted a drive line then you need to re-think the HP. U-Joints fail due to no maintenecne or wrong drive line phasing.

[Three Peaks]

Well, I couldn't find Spicers around here so I bought some Precision Ujoints and took them over to the driveline shop. He refused to use them as he said they won't balance out at least 50% of the time. So, he is going to supply me with some Spicers and away we go.
Thanks for the input guys,
Bob

[1985 CCX]

Reviving of an old thread!

I am buying Spicer but my question is specific to half shafts. I have a Jaguar rear end set up and think it might be time to replace 26year old parts.
Question:
a) Grease fitting?
b) Non-grease fitting?

SNG Barratt offer OEM Jaguar Spicer replacement with grease fitting both stock and HD. Now I have more power than a Jaguar but I am also half the overall weight? The argument can go both ways. The greaseable unit is OEM replacement for halfshafts. Any Thoughts???????

Thanks
Jeff

[Jerry Clayton]

See if you can get the spicer spl units---they aren't greasable but will go 200k in a 1 ton diesel truck--best unit out there

[patrickt]

Not long ago I searched the Dana/Spicer site to see if I could find any tests or studies that compared the two types of U-joints for strength. While there is loose anecdotal evidence that non-greasable U-joints are stronger, there were no definitive papers to be found. The inconvenience of greasing axle U-joints is pretty minor (IMO), so strength and fit are really the big issues. I don't know if the non-greasable U-joints are exactly the same size or not as the OEM ones. FWIW, my outboard-braked rear from ERA with their custom half-shafts all have greasable U-joints; that's true for the driveshaft as well. I would think that if the non-greasable U-joints had a significant advantage they would probably have gone with them -- but I don't know.

[Jerry Clayton]

the non greasable spl joints have much higher quality seals, a stronger cross and more exact fit---the ones with grease fittings have lower quality seals, needles, weaker cross and are CHEAPER----the reason they are used---the spl are used in most OEM shafts for the reason that they last longer and warrenty costs are reduced---

You have a drive shaft and axles within a foot of your as_ , which ones do you want????

[patrickt]

Here's another viewpoint from Jim Allen, the author of Jeep 4x4 Performance Handbook:

[Jerry Clayton]

On a Jeep , that wouyld see a moderate amount of off road playing, I would probably use a high quality greasable joint if the engine was stock or of moderate horsepower---the dirt and water extraction during the greasing process is highly overrated as you will only purge one of the four corners( the one that the seal pops first)

The miles that get put on one of these cars , lubrication will not be a problem that comes into play---strenght is

The shorter the driveshaft the greater angular difference from misalignment issues

But-----I'll let you choose what ever time bomb you want to put by your right hip---

Jerry

[patrickt]

Originally Posted by Jerry Clayton

But-----I'll let you choose what ever time bomb you want to put by your right hip---

A 5% strength difference makes greaseables a time-bomb?

[Jerry Clayton]

In the case of a 447 in FE engine---yes and the clock is ticking with every clutch release

And the strength difference between a 1350 spl series joint and one of your greasable ones of whatever size is way more than 5%--the torque capacity of a greasable joint is probably more than 5% depending on whether you have the zerk hole in compression or not---I've seen several driveshaft failures and they were mostly all well lubed

Its your choice and yours alone on what you choose but I hope that this exchange has opened some eyes as to choices to be made other than ""shall I get the $8 joint or the $25 joint?"

[patrickt]

Originally Posted by Jerry Clayton

Its your choice and yours alone on what you choose but I hope that this exchange has opened some eyes as to choices to be made other than ""shall I get the $8 joint or the $25 joint?"

We're not discussing cheap u-joints, only Spicers. You know I respect your experience, but so far I have only found two written texts that actually discuss the strength difference between two Spicer u-joints of the same size, one greasable and the other sealed. The first was the handbook I cited and the second was an article in Four Wheeler that, apparently, had a metals engineer test the u-joints and he reportedly "showed the strength difference claim to be a myth." Unfortunately all I can find are references from people who have read that article, not the article itself. Perhaps you know of some authoritative text that shows sealed u-joints to be significantly stronger than greased ones? You would think that if that was true then Spicer would certainly tout that in their advertising, right? Remember that Jeff's question was premised on the fact that he had already chosen Spicer and that these u-joints were for the rear only, which are easily reached to grease. With that said, let me ask you this, if there was indisputable evidence that there was no significant strength difference between greasable and sealed would you still opt for the sealed units?