Rear Driveshaft Universal Joints

[leathermaneod]

Well if they are stock then I guess maybe good quality non greasables are better than I would have given them credit for. You think they are stock since they are spicer? I know spicer is the original brand, but can't you buy replacement spiders? I figured these had been replaced before.

Edited May 22, 2016 by leathermaneod

[dripley]

Mine all have 374k on them. Keep thinking I ought to change them but they are tight and other things have taken precedence over them.

[Me78569]

11 hours ago, leathermaneod said:

Well if they are stock then I guess maybe good quality non greasables are better than I would have given them credit for. You think they are stock since they are spicer? I know spicer is the original brand, but can't you buy replacement spiders? I figured these had been replaced before.

I bought OEM spicers when I did mine.  Typically if the OEM part lasted 150k+ I always try to use them again.

[Mopar1973Man]

Sad to say I lost all my stock u-joints way back at about 60-80k miles. Mine were all dried out and ground up. Been running grease-able u-joints and just grease them up every oil change. I contribute my early failure to the fact of all the offroad driving, dirt and dust, then flip side in the winter time all the water and mud. The little rubber seals are pretty weak for keeping debris and water out. So every 7-8k miles pushing fresh grease in forces out debris and water. Where most of you are on the pavement and easy to get those kind of miles out of the u-joints.

[leathermaneod]

If I had known the original spicers lasted that long I may have gone with them even though I do prefer to always get greasable parts when I can. I would probably get the joints done by someone if I did it again too lol

 

How long have your greasable joints held up Mike? Im curious to see how mine do being they are SKF. I'm also worried about that one with the seal that I cut, I'm hoping regular greasing will make them last a long time....

[Mopar1973Man]

Where I had my rear drive-shaft taken out for the carrier bearing the shop only replaced one u-joint. Wasn't that the needles bearings was bad just had some end to end movement which would impact balancing the shaft. Like we both agreed twist checking it felt fine. The only way you could detect the end play was remove the shaft and pull in line to the trunnion arm then you felt the slight movement.

[dripley]

2 hours ago, Mopar1973Man said:

Sad to say I lost all my stock u-joints way back at about 60-80k miles. Mine were all dried out and ground up. Been running grease-able u-joints and just grease them up every oil change. I contribute my early failure to the fact of all the offroad driving, dirt and dust, then flip side in the winter time all the water and mud. The little rubber seals are pretty weak for keeping debris and water out. So every 7-8k miles pushing fresh grease in forces out debris and water. Where most of you are on the pavement and easy to get those kind of miles out of the u-joints.

I agree with you 100% on the longevity I have seen with mine. My truck is on the highway 97% if the time.  Conditions on the site are not the best when we first start out but for the most part on the CFA's I build I show up and park the truck. No need for it on a 1.5 acre site. The Love's is different with a 25 acre site too much ground to cover sometimes. Never done alot of 4 wheelin. It is fun though.

[KATOOM]

Everything has a typical service life span and as we all can contest through various threads and discussions in these forums, various components can easily go well beyond.....or fail a lot sooner.  So I say sometimes its a crap shoot understanding why something fails or why it doesn't.

 

And I drive my truck in all kinds of conditions too and get many cords of wood every year or drive the back fire trails. (Propane is too expensive to heat a house)  So meaning dirt roads arent uncommon for my truck either as I collect enough lumber to keep my family warm.  Even though its used as a truck, I dont beat it up.....

 

And the weather around here is very dry and gets hot in the summer and rubber things cant seem to last a summer around here without drying out.  I get tired of replacing bike tire tubes.....

 

What does tear up u-joints is lugging the driveline, doing abuse things like burnouts, and overly high driveline angles.

[leathermaneod]

So this has kinda turned into a complete fail for me. Today driving the truck around something doesn't feel right. The shaking I was talking about before isn't as bad, but there are others at different speeds. So I pretty much decided to take the shaft back out and get it balanced. Well I got under there an found one of the retaining rings barely still in place. Some of the joints also tightened up on me again and don't move as freely(I spent a lot of time trying to get those clips in and then having to bang on the yoke trying to get the joint to loosen up). Anyway the shaft is now in the back of my civic (thank goodness it's a two piece) to go to the shop tomorrow. I figured I'll get them to look at it and possibly even re replace all the joints . Thankfully they aren't too expensive. Then I can also get their opinion on the one joint that was kinda loose and have it balanced. Unfortunately this just is not as simple as press the old one out and press the new one in 

[Mopar1973Man]

Nothing wrong with having a professional drive-line shop look over the drive-line and verify its straight and balanced.

[leathermaneod]

Yeah, just makes me mad that I screwed up what should be a simple task, and wasted $60. Oh well, lesson learned. Hopefully that one yoke isn't screwed up that the joint was kinda loose like that, idk how it could be if those were the original joints, it's not like it was rusted bad or beat up.

Edited May 23, 2016 by leathermaneod

[Mopar1973Man]

You be surprised how many time I've put together u-joint and in inadvertently kick a roller bearing to the bottom and then end up crushing the bearing in the cap. Makes for a tight u-joint. At least a rear shaft is easy to do. The front shaft with the cardigan joint is a big PITA to deal with. Even on the 96 I managed to bend one of the yoke ears and screw up the centering of the joint. Don't feel bad...

[leathermaneod]

Just curious, how do you tell if you've kicked the needle down in the cap? I understand the joint gets tight, but how tight? And I suppose if it won't loosen up by tapping on the yoke....

 

I've always thought that front one would be a pain, it's even hard to get unbolted with the cross member in the way. I will definitely take that one to a shop the first time. Was the one you bent fixable, or did you have to replace it?

[KATOOM]

You generally can tell if a needle dropped into the cap by the fact that the caps wont sit up against the seal and also wont want to seat in the yoke ears very easily without having to press them harder.

 

And dont sweat having a shop take a look.  No harm no foul and at the very least next time you'll remember what to do or not to do.....or you'll take it to the shop again.

 

And yeah.....dont even try messing with the double cardan joint.  If you thought the regular u-joints were a bugger then try seating two u-joints and the center spring loaded ball all at the same time inside a tiny little housing.

[leathermaneod]

Well I got the driveshaft u joints replaced and the shaft balanced today by my local Fleetpride, and got it all back together tonight. Not sure if they are a chain or not? Anyone ever heard of them? It seems like they do a lot of big trucks, and apparently specialize in driveline. They told me they only use Spicer and Neapco U joints. They only had the Neapcos on hand in greaseable, but they assured me that they use them all the time and that they are just as good as Spicer. The guy there told me that as far as he knows, the u joints from Napa are chinese made and not manufactured to oem tolerances. He said that was probably why one of my joints was a little loose. He said he has seen a lot of bad napa parts lately.... anyway they got the job done very quickly and only charged $120 for the new joints, labor, and balancing. I thought that was very reasonable. By the way, the shaft was balanced and did not require the addition of any weight. I did think it was slightly odd that some of the joints are slightly tight, and not tight like hard to move, just not loose like the old ones were, or like the ones I put it were some of the time lol. And one of the new ones is a little tighter on one side of its travel. I'm hoping everything is all good. I guess if it balance out it should be fine. My only other concern is a couple of the retaining clips. I'm paranoid now since that one of mine almost fell out. I have some pics of the ones I'm not sure about. 

 

hard to tell but on the end you can see its not totally seated

 

 

Compared to this nice one...maybe its just not possible to get them all perfect?

 

Not sure if these matter or if I'm being way to paranoid. I did get them to tap one in better before I left, and one of they guys looked at one of these and said it was good....the other was wrapped up real nice in plastic

 

What do you guys think? leave them be and just check up on them and make sure they aren't coming out? or try and tap them in? I didnt want to go banging on anything after the shaft was balanced and have a joint tighten up like I experience they other day....I would hope these guys are a good bunch. They seemed very knowledgable and gave me plenty of time to tell them my story and my concerns. They even got the joints in so that all the grease fitting point the same way! I was pretty impressed at that lol

 

Another question. You can see in this pic that my driveshaft comes out of the rear diff on a slight angle, why is that?

Edited May 24, 2016 by leathermaneod

[notlimah]

Id imagine your clips will settle in once you start driving the truck. 

 

Not sure about the rear diff driveshaft angle.

[KATOOM]

All those clips look perfectly fine.  Dont touch them.

 

Neapco are supposed to be a relatively quality u-joint but you know which ones I would have chose.   I'm guessing they gave you a warranty too.

 

As for the driveshaft angles, they're like that to offset one another.  As a u-joint turns and the caps oscillate in movement, they create a harmonic vibration.  So two u-joints are always set in exact opposite angles (sometimes through various multiple shafts to make up those apposing angles) so that the harmonics created by one u-joint will be canceled out by the other.  This is why the pinion angles are not set at zero angles unless there's a double cardan joint on the other end of the shaft.  Point being is yours are fine.

Edited May 24, 2016 by KATOOM

[leathermaneod]

Lol yes I know which ones you would have chosen. I just really like to be able to grease stuff like this. I always look for greasable whenever possible, be it sway bar links, ball joints, u joints ect. I know I will keep up with greasing them so to me it's the better option. Who knows if it actually is or not, but it's what I like and I didn't want to wait around for others when he very confidently told me that the neapcos are just as good, and I don't see what reason he would have to lie. Why would he care which he sells, especially when it's a small job. 

 

Thanks for confirming that those clips are good btw. I appreciate it. Also thank you for explains about the driveshaft angles. That's very interesting. So the cardan joint is because the front drive shaft is perfectly in line with yoke that comes out of the front diff? That's what you meant by it being at 0°?

[Haggar]

Be careful, we are starting to mix some of theories of operation and terms.

 

A single cardan joint  that has an exit angle different than the input angle (the front half of a normal drive shaft  (forget carrier bearing atm)) will have a relatively constant input velocity (as constant as our diesel can produce) but the output of the shaft will have a constantly variable velocity. ( If measuring the velocity and acceleration of the output of that single shaft will make a sinusoidal output graph. with two high and lows per revolution)  If you could feel it with your hand, it would be "jerky" or cause a vibration.  The greater the angle of the shafts, the greater the amplitude of the output velocity differential.

 

The addition of a second joint exactly opposite phase of the first joint, will smooth or dampen the angular velocity difference back out.  So theoretically the rear differential will "see" a nice constant velocity input.

 

As the angle approaches zero...(if there were no parallel offset of the rear of the engine and input pinion) the cardan joint would be a poor choice.  The cardan joint needs to bend so the rollers inside will roll.  If the joint didn't bend all the load would stay on the same needles and eventually brinell the races. 

 

In our system, the front universal going to the carrier bearings should be pretty straight.  (I don't think the angle is zero, but it is very small) (yes poor use of the cardan, but I think all the oems just live with it from a logistical and cost perspective.)  The angle is from and corrected by the other two cardans. 

 

In the front, the system is pretty much the same, but due to the very short shaft length, the double cardan joint does most of the bending and the input to the front differential is fairly straight.  (unless you have added a lot of frame lift, without rolling the front pinion.)   So it is "like" our carrier bearing system in the rear, just no room for a carrier bearing.

 

We can go into driveshaft whip too if you want...

 

I hope this helps a bit!

 

Hag

[KATOOM]

Your input is appreciated Haggar.  I just try to keep it laymans terms as possible.  Some like that.....some may not.

 

And true, lots of people misunderstand the differences between a u-joint and CV joint and tend to call the the same.

 

As for the pinion angle with a DC joint, yes, its never "ZERO" per say because ZERO is had to achieve and there's always angle changes as the suspension moves.  But generally the rule of thumb is you want the pinion angle as little as you can to assure that u-joint doesnt cause a vibration.

 

I've built drivelines for higher HP 4wd trucks and I've used a DC joint on the rear driveshaft.  Worked great for shortbed trucks.