CK5 - The Full-Size GM Off Road Community

hi all,

while driving on the freeway last weekend, that wobble kicked in hard and as i made my way to the right i lost the front u-joint of the rear drive shaft. made a nasty noise as it kicked up against the bottom of the truck. anyway, i had my daughter bring me wrenches so i could remove the drive shaft, lock the front hubs and drive it home which was only about 4 miles.

what i'm wondering is what damage could it have done and here's why. as i coasted to the shoulder, the motor died when the rpms got low. once i removed the shaft, it started but very slowly and sputtered at idle, you could hear it missing thru the exhaust. i had to rev the motor to keep it running and when i put it in gear it killed it.

i ended up getting towed /forums/images/icons/frown.gif any one ever have this problem or maybe can clue me to where to look. there is no visible damage. i can see that the shaft did hit the exhaust but didn't seem to break it loose. one guy at the store said maybe it pulled the manifold bolts loose since they're soft and would have been hot. i haven't had time to check close, hopefully sunday. it ran more like it was missing a plug-wire or out of time. this truck is an auto and first i thought it may have damaged the tranny, but since the shaft broke off at the xfer case, is that still a possibility.

just thought i'd check the experts before hunting around. let me know if any one has a clue of where to start. thanks!
John

you might want to check that the driveshaft didn't poke a hole in the oil pan - ouch!

I'd say check the fuel lines running on the frame rail. Have you verified there is gas getting to the engine? I doubt if the problem is that transfer case was damaged internally because your motor sputtered before you put it in gear. The transmission would not even try to spin the tailshaft/xfer case if you weren't in gear. Send more info as you get it.

When I was younger, I owned an old Izuzu P.O.S car. I knocked the catalytic converter real hard one day. It just had a small dent in it, but it was enough to clog it up. Car ran horrible and it had a zero to 60 speed of about 5 minutes. Changed out the cat and it ran like a champ again. The exhaust might be worth checking out. Maybe it knocked something loose in the muffler or something. If the truck can't breathe, it ain't going to run.

check the fuel lines and the vaccum hose going back to the tranny modulator. also check for damaged exhaust, if it's obstructed you wont get any exhuat flow. it may tend to heat up if you exhaust is pluged/damaged.

ARQ.

ok, here's what i have found so far. i'm no expert so excuse my lack of correct terminology, but a "real" mechanic friend asked me about my coil. i have a newer electronic distributor and he suggested checking the wires coming from the coil. right as he said that i vaguely remembered that back when i put in the tach dash, i had a heck of a time getting the wires to stay in. he said he used to strap them in place. in any case, i checked that and found it loose, and embarassingly, the distributor was extremely loose and way out of time. not sure if the jolt caused it to turn, that seems odd, but it was far enough off to not run at idle. i adjusted the timing after warming the engine and now i can drive it using the front drive shaft. there is also a small exhaust leak on the passenger side so i guess it did hit hard enough to loosen up a connection.

also, the greaseless u-joints were just that. greaseless. i mean these must have been dry cause they were so hot that the bolts are welded to the u-joint caps on one of them. and when it broke out, it damaged the yoke on the rear of the transfer case so i gotta get one of those also. i'm leaning toward going back to the greasable u-joints, any comments on the pros & cons of those are welcome.

also, anyone know the size of the nut holding that yoke in place? my biggest is 1-1/8" so it's larger than that. thanks for all your help and suggestions. and i got a funny look from the wife when i made a comment about "how enjoyable it is to spend some time under the truck". women just don't understand, do they?!!

more as it's back together.
-John

get some CTM joint and never have to worry about em again../forums/images/icons/laugh.gif but then ya can worry about how to pay for the damn things...like $250 each

I prefer a greaseable ujoint. Make sure you buy a quality Ujoint...one made in the US. Also make sure that any grease you put in it is rated for that application.

Hi John!

Nothing to add except it's good to see your name here again... I hope everything is going well for you these days (present driveshaft issues aside of course!) /forums/images/icons/smile.gif

The nut is 1 5/16" and you usually need a thin wall socket to get inside the yoke.

hi Greg,
yep, things are ok. after 7 months unemployed (first 3 by choice), i guess you could say i've been over-working! actually working in the engineering department of that bankrupt utility company....oh, i guess there are more than one of them, NOT enron, the other local one!
been here reading alot but not much activity on my own...until the breakdown. gotta check out your truck soon, must be way different than when i last saw it. i've been reading about the updates. we'll have to get together for lunch soon.