hexrain

94 2wd straight axle pickup

I'm posting in this forum because I need feedback and no one goes to the 2wd forum.

Changed clutch because it began to slip bad. Drove for a day and a half and noise started. Clanging clunking and grinding sound between 47 and 55 mph.
Took off driveshaft and saw metal dust and slivers of metal on yoke and output shaft.

I did a Zuk mod 3 months ago and had no problems that I could tell.

When changing clutch I replaced output shaft oil seal, and admittedly mangled it a bit. It has little dents all around it. Please search for my other posts for some background info and to see how high the truck sits on the springs.

Now to the questions. Could the oil seal not being in correctly and/or being dented allow play in the slip yoke? Could my pinion angle and increased torque be causing it? Could my yoke have already benn worn and just shows now with more torque. Please help. I'm desperate to get my truck going again. It's been down for 2 weeks.

highonpottery

iTrader: (1)

is the oil seal actually leaking? you'd see/smell oil flinging around that area. metal flakes usually means unlubricated friction. very possible your ujoints were going bad before and the changes you've made recently did them in - especially since you've changed the operating angle via your ZUK mod. also, why do you think you have more torque now - because your new clutch grabs better?

hexrain

I replaced u joints first thing. Yes I think the clutch has been slippings since I got it 3 months or so ago because my accel and power up hills is much better. So definitely more torque to driveshaft. My seal leaks with driveshaft off. I replaced with clinch but did a ˟˟˟˟ty job and it still leaks. Not so much with driveshaft in. Is it normal for oil to come out with driveshaft off?

highonpottery

iTrader: (1)

no oil should be making it's way past the seal (that's why we use them) especially when it's not moving - as-is, you could park your truck on a hill and potentially have all your trans oil leak out. replace the seal and drive it in the correct way with either a seal punch, a large socket, or some other tool to keep it flat and from deforming.

skypilot

iTrader: (1)

Or the yoke is badly worn and no seal is possible due wear.

hexrain

Could the increased torque be why it suddenly showed how worn it is? And if it is worn out, what about the output shaft. Would both need to be replaced? Replacing output involves taking apart tranny right?

hexrain

And if the yoke and shaft are worn, why is it only grinding and clanging at 50 with hard accel. That's why I suspect the Zuk. Like maybe splines are slipping because it's pulling out.

highonpottery

iTrader: (1)

could be any of those. well, since you have the driveshaft out, why not take some measurements and see if the splines are too short like you think? seems like a 2 min verification.

hexrain

i dont quite understand. i think the zuk mod might be pulling the yoke out at 47-55mph with the increased torque. but how would i go about measuring them? i dont knowwhat measurements are normal. im just trying to figure out what this freakin noise is. im about to break down and take it to a mechanic... but i suspect a large bill.

dropzone

iTrader: (6)

how about posting pictars of what you are dealing with.
if you jacked up the crap out of the back with the added coil springs you may have fubarred you pinion angle.

hexrain

Search my threads. I don't have picture of pinion angle but you can sort of see how high it is. I'm not sure how high above stock I went because I was already sagging super low

highonpottery

iTrader: (1)

nobody really wants to search people's threads and spoon feed info -- if you want help it's best to post the pics/supporting evidence in the thread you're getting help in so everything is in one place.

I did see the pics of your ZUK mod and to me you raised the rear considerably over stock without adjusting anything else afterward. pinion angle, LSPV adjustment, etc are some fairly important things to maintain when changing suspension around. i didn't see measurements, but it looked at least 2" higher than stock to me...and possibly 4-5" above what it was previously in the saggy state. just that change in height is definitely changing operating angles of everything and could be a combination of multiple issues effected by the changes.

i really don't understand why you did the ZUK mod in the first place, instead of simply adding to your leaf pack which would have kept it closer to stock height, but allowed more weight capacity. as you've seen, the cheaper route is not always the best solution and can end up costing more in the end.

hexrain

Thanks highonpottery advice is appreciated. What can I say, I'm a cheap guy and saw how much people were hauling with the Zuk. That being said, ow I need to fix the problem.

I have been wondering if the output shaft is made of more durable materials than the yolk. If my yolk is trashed does that mean the output is as well? Does anyone have a line on where I could buy just an output shaft for w56? Google came back with nothing.

highonpottery

iTrader: (1)

i think it's part 33321, W55 and W56 output shaft:
i would call up a transmission shop or dealer to verify correct part number. maybe just call a trans shop to see if they have one sitting there.

hexrain

i took the ZUK mod off to se what happened. noise still there and now a low pitched noise as well. feels and sounds like vibration. i took a video under the truck while driving, but it didnt seem to be shaking. maybe a little at the accel at 50 but maybe just normal. im not sure.

hexrain

I am still no closer to figuring out exactly what is going on. Still looking for an answer S to whether output needs to be replaced if yoke is worn as well. I have checked pretty much everything thAt I know to check and I'm still getting nowhere. So frustrating.

skypilot

iTrader: (1)

If the rear transmission seal is still leaking after replacing it, you need a yoke. Now there is bearing in the tailshaft that holds the yoke in alignment, that may be toast too.

hexrain

update. pretty sure the timing chain was the culprit. deep railroad lines on the TC and an inch of play in the chain. i think it was reverberating through the whole drive train and sounding like it was coming from everywhere.

skypilot

iTrader: (1)

Well; that's one for the record books.

I would have never even considered that.

hexrain

yeah i had known the whole time that it needed to be taken care of. when i first got the truck i found the timing chain write ups and explanations of what it sounds like. i thought i heard it smacking every once in a while when i was engine braking. i thought low RPMs was the only time it happened, but mine is definitely on acceleration. as i figure it, the chain was already hitting and when i changed the clutch (which was hardly grabbing at all the whole time i owned the truck) the increased torque to drivetrain and resistance from the grabby clutch was making more slack in the chain, which was loudly smacking the TC. it looks SOOOOOO bad. i have deeper railroads than the people who have pulled their timing stuff because it already broke. like 1/8 to 1/4 of an inch more! it must just be the angle of how it was hitting that it didnt eat through to the water jacket. i cant actually say for sure that this is the ultimate cause until i take it apart and button it back up, but i am 95% sure from looking at it that this must be it. so to anyone else who is getting really intense noises coming from an unknown place, CHECK YOUR CHAIN!. just a few brackets to take off, PCV hose, and 2 vacuum hoses and you can take the valve cover off. it is worth it.