So my NP241 DHD, with the two piece tailhousing decided to grenade-

Buddy sent me a DLD to put in for the time being. I installed it, and noticed that the two retaining notches on the pinion yoke had sheared off...I figured it may or may not hold, with the ujoint straps, but I tried to drive it into work...and promptly slung the driveshaft off. The ujoint caps flung off, and the driveshaft dropped.

So, I drove it home in 4 wheel drive, and parked it. Ordered a new pinion yoke from Rock Auto, and overnighted it. Got it installed tonight, new ujoint, and got the driveshaft in. I took it for a test drive, and I now have a bad vibration as soon as I hit 3rd gear, before I really get into it...under light acceleration, it starts getting bad.

in 1st and 2nd, as long as I'm out of the throttle, it's ok, but as soon as I start to get speed, the vibration gets worse.

I tried taking a video of the rear pinion, and it's hopefully loading to youtube right now, so I'll get the link up.

edit:

I noticed 2 things tonight and thought of a 3rd, that could potentially be a problem-

1. When I installed the ujoint in the driveshaft, for the pinion yoke, I couldn't get the ears to loosen back up. I tried the normal-hit the ears with a hammer, to loosen the joint back, but that failed. I figured I'd throw it in and drive it easy, to see if it would loosen up. I'll have to pull it again to see if it does.

2. The DLD is definitely shorter than the DHD... I took pictures to show how much the slipyoke fits on the Tcase output shaft-it's about 1.5 inches.

The 3rd thing I thought of, was could I have unbalanced the Dshaft when it slung out?

I'm at a loss right now. Been driving the wife's Jeep to work, so we're down to one vehicle until I can get this figured out. The gears shift fine, truck rolls smoothly at low speed, I just can't figure out what's going on with this thing.

You have one definate issue causing a vibration and that is the fact that you do not have enough slip yoke on the shaft, it is almost out to the danger zone limit and can cause the drive shaft to jump rope from that point and second you could have a bent driveline and should be taken to a shop that specialized in balancing them. If you are going to stick with the DLD you are going to need to make or find the correct length driveline, The proper dimension for the driveline length install the slip yoke going into the t-case all the way and pull it out 1inch "Some say 3/4 to 1-1/2 inches " and measure the flat surface of u-joint cup to th same of the rear pinion yoke.

That's what I was afraid of...I'm assuming the DHD and the DLD slipyokes are the same length? I do have a DLD slipyoke. Otherwise, it looks like I'm buying a new DHD, since I've got a 1 piece drive shaft. No lengthening that.

my question, how did the TC grenade on ya?

I'm not 100% sure, but I'm pretty positive it's due to the fact that I lost 4 Lo last year trying to yank out a couple guys from the marsh...I never got it fixed, since 4 hi still worked, and i didn't have the money at the time. Now I'm regretting it. My guess is that the chain worked it's way loose, or something came off inside, and decided to come out.I guess I'm going to have to get the driveshaft checked for straightness, to make sure it's not bent, and either look at a new T Case or hope I can find a longer slipyoke. Apparently, finding a new, 2 piece factory driveshaft for a DLD trans is almost impossible...I thought maybe I could convert back to stock for a bit, and allow myself the time to rebuild/replace the DHD. Guess that's not happening...

If I remember right the output shaft is smaller on the DLD as well.Brand new t-cases used to be had for around 1100-1200. Good used ones a bit cheaper.Front drivelines being out of balance or a badly worn slip splines on it or a bad CV joint in the front of the t-case are all main culprits of dynomiting a case like that.

If I remember right the output shaft is smaller on the DLD as well. Brand new t-cases used to be had for around 1100-1200. Good used ones a bit cheaper. Front drivelines being out of balance or a badly worn slip splines on it or a bad CV joint in the front of the t-case are all main culprits of dynomiting a case like that.

It cant be anything to the front of the tcase affecting it, as I'm running a free spin conversion, so the front drive train isn't moving at all at speed. Its looking more and more like I may be going with a new tcase...rock auto has the cheapest price for a remanufactured one; I priced a rebuild kit, rear housing, and complete two piece tail shaft from Quad 4x4, and it was about the same as a reman from Rock Auto. I did try to find a new two piece rear driveshaft, for a 2500 manual with the DLD, but I came up dry. I'm going to pull the driveshaft tomorrow, and look at the slipyokes, to see if there's any difference in length. With mine being the two piece tail shaft, the spline count and OD of the output shaft between the DHD and the DLD are the same. If I had a one piece tail housing DHD (1997 models only, with the speedo gear on the tail housing) the output shaft would be bigger, with a different slipyoke.

Pretty sure I just now figured out what's been turning my tcases into an expensive lunchbox.... Don't have any pics, but the mounting bolts that hold the trans to the bellhousing- The bottom one on the drivers side was good, the top one on the drivers side had backed itself out, and was hanging out with the clutch slave cylinder tubing, the top passenger side had sheared the head off, and the bottom passenger side, well, let's just say its MIA... I'm pretty sure a liberal application of antiseize, and torqueing exactly to spec and not checking it later by the PO is exactly what caused this....They will not be getting antiseize this time, it will be Loctite, and I'm installing them the same way I did it on my truck-with the impact, till it stops. and then bump it a few more seconds. I've never had one back out that way.

ouch, the only thing i use antisieze on are the front hubs.like dipping yer brake pads in grease...

Wait, what? I'm not supposed to pack my brake calipers with grease? Thought you were supposed to pack them just like a wheel bearing?

ouch, the only thing i use antisieze on are the front hubs. like dipping yer brake pads in grease...

Wait, what? I'm not supposed to pack my brake calipers with grease? Thought you were supposed to pack them just like a wheel bearing?

Funny you guys bring this up........I have this exact thing going on right now with my pontoon trailer with drum brakes and bearing buddies. My pontoon trailer brakes have been acting funny and chattering badly, so I pull the plugs and go to set the bakes up and what I found was exactly that, grease packed brake pads. The trailer is about 5-6 years old and I pump up the bearing buddies once a year and now I found out where all the grease went. Stuck my brake adjustment bar in and it came out a grease ball, took a light and looked in al the adjuster slot holes and all I see is grease.

So today started out great...got all the parts this morning, and went out this afternoon to put it all together, for the last time. New bolts in the transmission, to bolt the transmission to the bellhousing. Found the right size, and they went it tight. Replaced the Ujoint on the back of the rear driveshaft, at the pinion, as I didn't like what I was dealing with before. Ujoint went on perfectly. Filled up the transfer case with new fluid, no leaks, everything was tight. Went over everything one last time to ensure that I hadn't forgotten anything. Went for the test drive. Had a little bit of wobble at first, I attributed that to the fact that the MT's have been sitting for almost a month now, I'm not used to them, and the truck ran rougher than the Jeep. NOT the case.At higher speeds, the vibration seemed to get worse, then taper off, but as it tapered off, it is now being replaced by a noise...almost sounds like a rattling noise. My best guess right now is the clutch...especially considering that the transmission had to have been slamming back and forth into and out of the bellhousing, with only one bolt holding it in place. I can't think of anything else in the truck that would sound like that. The only thing is, the clutch shifts perfectly, engages and disengages, and even when I push in on the clutch, I can still feel the vibration as well as sometimes hear the noise. I know I gotta get the driveshaft checked, I'm just wondering, could the clutch have gotten warped, and if it could have, would it be causing a driveline vibration? I'm really getting tired of having to do all the work to it in the dirt outside the garage, because it doesn't fit in the garage...

Get that driveline checked out! I would not do anything else until you get it looked at. You gotta get that ruled out before doing anything else. It only takes the slightest bit out of balance for a driveshaft to give off harmonic vibrations, etc.

Went for a test drive today, sans rear driveshaft. Got up to 4th gear, everything was driving smooth, so I'm pretty sure now its the shaft. my next challenge now is to find a machine shop here local that can test it...hopefully find one on Monday and get the shaft dropped off.

Having worked at a truck shop "Inland truck parts and service, ITP for short" with a specialty driveline shop where we built them from scratch as well as complete rebuilds straightening ect, I am not a fan of the machine shop laith method as we got them in regularly and they were still quite a ways off, a good man can get them close at best. Find a shop with a Dynamic spin balancer, they spin them up to whatever they are rated to spin, normally 5-6k rpms, then they know what end is off and how far off it is. They are similar to a tire balancer only they spin way faster.

100% what w&f said. You need a driveline shop not a machine shop. This is also assuming the parts in use suffered no damage and therefore excessive wear and resulting slop from having been run with MUCH less engagement than is necessary. Tapatalking in traffic

I know its not ideal by any means, unfortunately, unless I ship it somewhere to have it checked out, I don't have another choice locally...and because of work, driving anywhere over 30 minutes during the week is out of the question....I can only hope they can check it...

- - - Updated - - -

The machine shop called me back today, said I needed a new driveshaft...They had it on the lathe still, when I showed up with the payment. Turned it on, and there was an obvious wobble in the end of the shaft...don't know whether it was bent, twisted, or what, but it was definitely bad. They're building me a new one, balanced for $250. I know my neighbor has used them before, and he didn't have any issues with the ones they built him, so hopefully it works. I can't afford to spend any more than that right now anyway...pretty well tapped out in the bank account between the transfer case and this.

New driveshaft is in, its 1.75 in longer, so it sits further in, and its straight. No more wobble, no more vibration. Ts good to have my beast up and running again!