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blew up another ujoint....help!!

Citizen Rider

Citizen Rider

1/2 ton status
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Plano, Texas
Blew up the ujoint i swapped in thursday after i blew that one up cause the Ubolt straps where too tight. Well i just got home from blowing up the same ujoint. Its the one at my 203 transfer case on my rear driveshaft. When i installed it we made sure not to get the straps too tight. Just snug enough to hold. From what i could tell in the dark and in the middle of a busy street the joint body is blowing through the side of the caps. If you look at the caps in this pic you will see how there is a big gap blown out of the side-
DSCF0475.jpg


The one i blew tonight had no discoloration from heat or anything. Just a large chunk blown out of the side of the cap. The ubolt straps are just at the edge of where they have blown through. I now have a small peice of the yoke missing from where the joint flew out of the caps.

I do not know what is causing this all of a sudden. Im not pushing huge amounts of power. Im taking it really easy on how much i push on the skinny pedal. My angles are damn near perfect. Its no where near what it would be binding.

Any ideas?:mad:
 
what size joint are you using? looks like 1310.
you say your angles are good, but what are they?
any vibration?
driveshaft slip yoke wore excessivly or binding?
what kind of grease are you using?
 
1310 joint.
Angles not sure of what they are but no where near its max running.
No vibs that i know of. Before the lift i never felt any vibs. Now i have TSL's and a bumpier ride, but no vibes to my knowledge.
No clue about the slip. I pulled it off tonight to look at ujoint better as my gf's dad was on his way with a wrench. Was slightly hard to get off. Then i had to press the shaft on the ground to get it back in. Felt tight to me. But im no pro at this.
Grease i am unsure of what was in it. Koldsimer on here had it as a spare he had and swapped it in for me thursday when i blew that one up.

All ujoints exept for rear shaft at tcase and front at axle are just over 1 months old. The rear at tcase was put in thursday and front at axle was put in friday....
 
The picture i posted is of the one from thursday. The one from tonight i have not got a picture of. The pic is just a reference of what the caps look like.
 
How many miles did you get on this joint before it went? Was it only the two legs that are held by the u-bolts again? I know there wasn't much grease in the caps when we put it on your truck. Like I said before, make sure that you are greasing your u-joints as often as necessary. For me, that's extremely often- every wheelin trip or every few hundred miles. Get some good grease and use it often. I think your angles are ok and you should be able to get by with 1310's, we just need to figure out the routine needed to keep them alive. If you get a few minutes, read up on the u-joint tech over on pirate. Pay real close attention to the failure analysis portion of the article. Oh yeah, give me a call so we can go wheelin today!
 
Hey, I just realized why it blew up. Remember when you were putting the driveshaft back in and you tightened down the u-bolts on your yoke? I asked you how tight you got the nuts and you said that you got them real tight. Even though we backed them off and re-torqued them, it looked like you had them way too tight at first. I bet this deformed the caps which led to the early demise of the joint.
 
I don't think over tightening the u-bolts is the issue. I don't think it's even possible to over tighten them enough to deform the caps. I'll send Jesse a link to this thread, maybe he can add some insight. :wink1:
 
Angles not sure of what they are
Click to expand...

That says it all right there! Why would you even keep throwing U-joints at it without even knowing this? You are probably twisting the sh!t out of your U-joints because of excessive driveline angles .
 
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well after some late night thinking. The thought of a 1310-1330 might fix my problem.

The ubolt straps are closer to the top of the cap then centered. A 1310-1330 joint would put the straps right at the center of the caps. I havent been to see the truck today but i cannot recall if the joint was tight between the "ears" on the yoke that keep the caps in place.

There are NO signs of the Yoke or dshaft where there has been contact between the two. I WOULD post pics of my angles if....1. I had the blazer infront of me....and 2. THERE WAS A UJOINT IN IT! Currently the blazer is 30 min. from my house and im trying to figure a way to get it home.

PLUS, i got to figure out of the chunk that was takin out of the yoke on the tcase is going to cause any other trouble or if i should find a yoke also!
 
1-ton said:
That says it all right there! Why would you even keep throwing U-joints at it without even knowing this? You are probably twisting the sh!t out of your U-joints.
Click to expand...

Why would i keep throwing ujoints not knowing this???

Maybe cause thursday was the first time it threw a joint, OBVIOUSLY cause of a heat issue. Then i started driving it again SATURDAY thinking it was fixed. Sat. Night it blows again. NO HEAT SIGNS. Not overtightened. I got then till they where just snug, not tight nothing. Just snug enough the nut couldnt go anywhere. I got maybe 50 miles MAX outta this joint.
 
I'm sure we can figure it out. Give me a call tomorrow and we will see what we can come up with.
 
Your sig says you have 6" of lift... Did you cut your perches off and roll the pinion up at all? Did you lower the t-case? Are you still at stock wheelbase? 6" is pushin it on a stock wheelbase K5 with a stock, non-cv shaft, without rolling the pinion up and/or lowering the t-case. If you have done none of those things, it's bad angles- no doubt. It's not possible to tighten a ubolt enough to deform a cap. What does it take...a 1/2" wrench? I don't think you could get enough leverage on it to deform a cap...Even if you could, you'd twist off the u-bolt or strip the threads before that happened.

Bad angles= vibration. Vibration= heat. That u-joint got hotter than shiit, (obvious from the heat marks:eek1: ) which burned the grease away, which burned up the needle bearings, which caused the trunions to rattle around in the cap and blow out the side of the cap. :doah:
 
From what I remember seeing, his angles looked acceptable. I would guess that if it is an excessive angle, it's at the case. I didn't take a good look though so I could be wrong. It could be one of those scenarios where I had my mind made up about the cause of the problem causing me to overlook other possibilities.
 
It looks classic for the diff yoke damage we see / change the diff yoke and buy a good joint it should go away- Jess
 
Rear lift block is tappered pointing pinion up. Case is at stock possition. Was seeing how it would work without it as i know lots of people without the case dropped running around 6" of lift.

Drivelineman- What would changing the yoke on the diff do when both ujoints broke at the tcase?

Shaft is being sent to be rebuilt or replaced in the morn. Be set up for the lift and and angles. Figured this was the best way after its smacked the concrete multiple times and the yokes on the shaft where mis-shapin now. Ill have it back weds. and we shall see how that goes.
 
Driveline man is on it, but you need to change the yoke at the 203. I was experiencing the SAME EXACT problems as you. Even with the utmost care in torquing down the u-bolts, I'd only get MAYBE 300 miles out of a u-joint. They always blew just like yours, only the ears under the straps of the np203 output yoke. Hell, if I search, I could probably find my original question from a few years back. I had stock lift and good angles, but the joints kept blowing. t got to where I got the slip joint end of the driveshaft from the junkyard and had it all set up with a new joint, so the next time it blew, I would just have to swap the slip joints, and strap the ujoint back in. I started using Spicer joints, and I was getting maybe 800 mile between blowouts. Anyway, at some point I installed a milemarker part-time kit, and I got a new yoke while I was at it, the old one was beat to hell. That was thousands of miles ago and I check my joints for play regularly, they're still tight.
 
Citizen Rider said:
Rear lift block is tappered pointing pinion up. Case is at stock possition. Was seeing how it would work without it as i know lots of people without the case dropped running around 6" of lift.

Drivelineman- What would changing the yoke on the diff do when both ujoints broke at the tcase?

Shaft is being sent to be rebuilt or replaced in the morn. Be set up for the lift and and angles. Figured this was the best way after its smacked the concrete multiple times and the yokes on the shaft where mis-shapin now. Ill have it back weds. and we shall see how that goes.
Click to expand...


You know lots of people...Who? I've also read about many people that have had your probkems with just a 4" lift. Every truck is different.

Pretty sure Jesse/drivelineman knows what yoke is in question. He's been doin this stuff for awhile. :bow: A typo is a typo.

If your yoke is jacked up, then you need to replace it. Plain and simple. Don't keep using the same old yoke. Repalcing/rebuilding the shaft won't do any good if the good ears on the joint that blew up were in the shaft...You need to replace that t-case yoke. You should prolly lower the t-case a bit too. The tapered blocks help your pinion angle, but do nothing for the angle at the t-case.
 
Im replacing the case yoke as it has a chunk out of it. Not going to chance it with a chunk out of it. If i cant get a stock one off of another 203. Where could i get a better one?

The ears where beat to he11 from slapping the ground multiple times and it was most likely bent from that also. And when i get it on im going to go through and grind down the ears and whatnot to eliminate what binding i may have. But we will see when i get it back. If i have to drop it i will, but im shying away from it for the time being. Do some exploritory surgery and get it all worked out.

I have no doubt that drivelineman knows his stuff. But from what he said, it made no sense.
 
I wouldn't go for a junkyard yoke, get a new one, the real deal. There has to be a driveline shop around you. Walk on in and tell them what you need, might want to bring your old yoke with you. I think they run about $30 or so.
 
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