Driveshaft. First major breakdown.

[eightbanger]

Today while overtaking at speed a real bad noise started coming from under the truck, I hit the brakes right away, and started to head for the side of the road the noise got worse crashing and banging and what sounded like metal draging along the road then something bounced out from under the truck and landed in the slow lane...Yes it was the rear half of my driveshaft, it had broke out of the u-joint straps on the rear end...why or how? I have no idea.
Classic parts has new u-joints and straps, but i'll have to post a WTB in the parts for sale for another drive shaft as this ones a bit banged up.

[lofly'a]

YIKES.......don't have a clue what caused it but hope you had no other

damage. looks like one of the u-joint caps seized and gave up. maybe it

happened cuz you and all the other drivers were driving on the wrong side of

the road....... sorry i couldn't resist.

[eightbanger]

I know...Funny thing was regardless of my tailgate being open hazard lights flashing and that silly warning triangle that my father in law gave me perched in th bed, people still pulled up and sat behind me waiting to turn right at the lights. I gave up after the 10th idiot, and left them to work it out for themselves.

[WorkinLonghorn]

That happened to me a million years ago and I think I had to replace the companion flange in back there too because it got a little bent. Can't remember the cause. I think on mine the pinion angle was WAY to steep and the u-joint eventually fell apart,lost all the needles and then did what yours did.

[tcb-1]

look at the bright side Nigel, that big block had probably been twisting hard on those old, stock u-joints for a while now. you were more than likely going to need them replaced sooner than later. at least the drive shaft didn't kick up through the bed floor or you DIDN'T HAVE A WRECK!!

I'm sure someone will have a good used drive shaft for you here. I'm just wondering how much a drive shaft build at a custom shop in the UK would be as opposed to getting one from here in the States then having it shipped?

good luck, Mate!!

[eightbanger]

Originally Posted by WorkinLonghorn

That happened to me a million years ago and I think I had to replace the companion flange in back there too because it got a little bent. Can't remember the cause. I think on mine the pinion angle was WAY to steep and the u-joint eventually fell apart,lost all the needles and then did what yours did.

WorkinLonghorn, this may sound really dumb but can you tell me what is meant by pinion angle? you may as well tell me what needles are too while i'm asking. the more I can find out the less chance there is of this happening again. I hope.

Originally Posted by tcb-1

look at the bright side Nigel, that big block had probably been twisting hard on those old, stock u-joints for a while now. you were more than likely going to need them replaced sooner than later. at least the drive shaft didn't kick up through the bed floor or you DIDN'T HAVE A WRECK!!

I'm sure someone will have a good used drive shaft for you here. I'm just wondering how much a drive shaft build at a custom shop in the UK would be as opposed to getting one from here in the States then having it shipped?

good luck, Mate!!

Hey my buddy, I am worried that when I had all this stuff removed a short time ago having my trans re-done, that maybe I changed something...you know the way when you fix one thing you disturb something else in the process. Doug if I actually found a guy here that worked on driveshafts, gauranted he would not know where to begin when I say the magic words....it's from a 71 Chevy truck.

[tcb-1]

Nigel,
you should give the drive shaft shop a try though. take in what you have. you never know, yours might be okay with a good balance.... unless it's trashed beyond balance.

when workinglonghorn is talking about pinion angle he talkng about the theoretical centerline through the rear axle to the drive shaft centerline. example: when you lower the rear of a truck, the pinion angle changes to the point that you may need to put insert a 2 degree wedge between the axle and the control bars. this allows the rear u-joint to run at the proper angle.

since your truck hasn't been lowered much, you shouldn't have a problem with the pinion angle.

[Skirkpat]

A driveshaft is a driveshaft, I bet they can fix you all up on that side of the pond...if not, I will donate a driveshaft to keep you going, you pay to ship and tell me where to send it.

[TonyJohnson]

That's why drag cars have drive shaft loops. It can go very wrong...

Back 20 years ago I was driving my '62 International pickup down the highway when the driver-side front wheel decided to shear off at the hub. I was going about 55 or so and the hub dug into the asphalt and the truck literally stood up on its nose, sliding 25 feet with me suspended above the steering wheel, crapping my pants. It finally made it to a point where the rear fell back down and the thing stopped, but it left a huge trench the entire way across two lanes to the shoulder. I walked away from that truck and never looked back. lol. It might still be sitting there....

[WorkinLonghorn]

Yeah,what tbc-1 said about the pinion angle. On mine,it wasn't a matter of lowering or raiseing the truck ,but what happened was the diff housing rotated on the axle tubes so that the conpanion flange (the one in the back that the driveshaft is attached to) was pointed way up,which puts lots of strain on the u-joint.
The u-joints are made with small roller-bearings,sonetimes called "needle bearings". When these needles fall out there is lots of slop and it will eventually fall apart. That's what happened to mine,but I didn't have a 454 either! Just a very high torque 350 extreme RV cam.
Did you notice any strange clunks or other noise or vibration before the failure?

[69GMCLonghorn]

Originally Posted by lofly'a

YIKES.......don't have a clue what caused it but hope you had no other

damage. looks like one of the u-joint caps seized and gave up. maybe it

happened cuz you and all the other drivers were driving on the wrong side of

the road....... sorry i couldn't resist.

Ok, that's some funny stuff! I needed that!

[eightbanger]

Originally Posted by Skirkpat

A driveshaft is a driveshaft, I bet they can fix you all up on that side of the pond...if not, I will donate a driveshaft to keep you going, you pay to ship and tell me where to send it.

That is an extremly kind offer mate...Thank You Skirkpat!

Originally Posted by TonyJohnson

That's why drag cars have drive shaft loops. It can go very wrong...

Back 20 years ago I was driving my '62 International pickup down the highway when the driver-side front wheel decided to shear off at the hub. I was going about 55 or so and the hub dug into the asphalt and the truck literally stood up on its nose, sliding 25 feet with me suspended above the steering wheel, crapping my pants. It finally made it to a point where the rear fell back down and the thing stopped, but it left a huge trench the entire way across two lanes to the shoulder. I walked away from that truck and never looked back. lol. It might still be sitting there....

Tony that was a horror story, my son was reading your post with me and we both looked at each other and went....S******T!!!!

Originally Posted by WorkinLonghorn

Yeah,what tbc-1 said about the pinion angle. On mine,it wasn't a matter of lowering or raiseing the truck ,but what happened was the diff housing rotated on the axle tubes so that the conpanion flange (the one in the back that the driveshaft is attached to) was pointed way up,which puts lots of strain on the u-joint.
The u-joints are made with small roller-bearings,sonetimes called "needle bearings". When these needles fall out there is lots of slop and it will eventually fall apart. That's what happened to mine,but I didn't have a 454 either! Just a very high torque 350 extreme RV cam.
Did you notice any strange clunks or other noise or vibration before the failure?

Now I understand, Cheers!.....and curiously I had noticed something different in the feel of the truck this last week or so, a low droneing noise at low spead, and my gas pedal would was bouncing ever so slightly up and down under my foot at low RPMs soon as I gave it some it went away, I wonder if that was a sign that the shaft was getting loose and sending vibrations up through the engine?

It seems there is a guy here who will have a look at my driveshaft, he works on commercial vehicles though, and he did say that as it was American that his adapter plates (whatever they are) will probably not fit mine when it comes to balancing it. It was funny when I rang him to explain....I was talking to him and refering to my "Driveshaft" when he then stopped me and said "do you mean Propshaft" (that's how it is refered to over here)oh yes I said I forgot I was British

[breeh]

I would ditch those style of u-joint caps and get the actual threaded strap type (with nuts of course). The type that you have are notorious for failure. This is the style:

[eightbanger]

Breeh, I never knew there was a different type available...who has them?

[breeh]

You can get them from Jegs, Summit, or in the US at an auto parts store. Drivetrain shops usually have them as well.

[brad_man_72]

i dont think it would be worth the trouble of having a free shaft shipped to you when you would still have to take it to a driveshaft shop to have it ballanced as an assembly anyways. take in your old shaft, see if they can reuse any of the old parts such as the weld yokes or slip yoke. now is a good time to get the front shaft checked out also u-joints and carrier bearing.

i would stay with the strap style u-joint retainers, as u-bolts are easily overtightened causing premature u-joint failure and you would have to drill out the threads in your pinion yoke to be able to use them anyways.

[eightbanger]

Originally Posted by brad_man_72

i dont think it would be worth the trouble of having a free shaft shipped to you when you would still have to take it to a driveshaft shop to have it ballanced as an assembly anyways. take in your old shaft, see if they can reuse any of the old parts such as the weld yokes or slip yoke. now is a good time to get the front shaft checked out also u-joints and carrier bearing.

i would stay with the strap style u-joint retainers, as u-bolts are easily overtightened causing premature u-joint failure and you would have to drill out the threads in your pinion yoke to be able to use them anyways.

I understand were your coming from Brad, the only thing thats worrying me is the condition of the end of the D/S where the u-joint is, it is quite bashed up and I may not be able to fit a new clip to hold the replacement u-joint & bearing. Your right on the u-bolt question I had not noticed till I looked closer that the u-bolts won't work unless I drill out the bolt holes on my pinion.


I have another question if anyone can answer.....do I need to buy specific u-joints that are compatible with a BB454 &TH400?????
Also I had not realized till today that one of the tabs on the pinion yoke has sheared off so now I need to buy a new pinion.......

[oldblue1968chevy]

dayumn


my u joint broke and the driveshaft was still ok for draggin the asphalt 50 ft lol

[Classic Heartbeat]

My suggestion would be (if you cannot get yours fixed) is to find one in the states. Have whoever you get one from send it to a reputible driveline shop here in the states and have it completely rebuilt, ballanced, and new carrier bearing installed. There are many reasons to do this. First off witch you are in the United Kingdom so anything sent wrong like the front end of a driveshaft that has not been ballanced with the rear of yours will be a waste of shipping dollars and a good amount of time. Secondly, if the splines in the driveshaft are worn out or close to it, the driveshaft will vibrate and you will have to rebuild it anyway. (again you are across the pond so shipping dollars and time a huge factor there.) Also have them send you a new set of straps to bolt the driveshaft back to the rear end. (because) Unless you drill out the rear end yoke for the "U" bolt style straps, or replace the rear end yoke with one that accepts them you won't be able to use them. If you replace the rear end yoke, be sure to have them send you a new pinion seal. Also make sure that if you replace the yoke, that the pinion bolt is put back exactly where it was when you started. If not your rear end will be short lived and you will find yourself needing to rebuild it also. WES