2004 DII drivetrain vibration mystery

[drewhinkle]

Put on some new tread and noticed a fast-paced vibration and roar that starts at about 75mph. Not violent, just annoying, similar to crappy tires that are feathered. Took it back to the tire shop (Kauffman) and they road force tested them; all were okay and none out of round. Even so, they agreed to replace the unidirectional tread pattern with an omni pattern at my request, even though the service manager didn't think the tires were the source of the vibe. He was right. Took it to "The Shop" in Norcross, GA and they couldn't find the source of the problem, either. The only other things worth mentioning are that the truck has 100k, the T-box has a slow leak, and a tranny drain-and-fill didn't help. The trans fluid looked clean when drained. Also, The Shop replaced a leaking rear wheel hub recently so I asked them to recheck it to see if it went bad. Vibe noise/feel doesn't change after shifting into neutral and coasting. Vibe present 100% of the time when speed is over 75.

I've read all of the old posts about vibrations, but I can't seem to really get any answers for my specific problem. Any ideas? Drive shaft?
:banghead:

 

[KyleT]

Driveshafts? Rear flex joint? Don't go that fast cause if you have to stop quick you won't?

What wheels are on it? Lifted?

 

[LRNationals]

http://www.discovery2.co.uk/propshafts.html hope it helps

 

[drewhinkle]

The suspension is bone stock, KyleT. 18" Hurricane wheels. Brake rotors are Napa Ultra Premium that were just resurfaced whilst on the vehicle, pads are EBC green stuff. 80 is my cruising speed in Atlanta.

 

[wheelen disco]

Check the front drive shaft before you find out the hard way that it was the problem. Search d2 + cracked transmission + prop shaft/drive shaft.

 

[pjkbrit]

My money is on the front driveshaft. My 04 had EXACTLY the vibe you describe at 72-76mph. Make sure you have not lost a balance weight ...if you see a rusty square on the side of the shaft, this is where the balance weight used to be!!

I solved the issue with a jubilee clip "weight" placed near the rear DC joint...transfer box end. Took a little trial and error but now I have a very smooth ride. (My prop also has greesaable joints so if yours is OEM at 100K you NEED to replace the sealed joints anyway and have the prop balanced by a shop that can do this well).

 

[ukoffroad]

my guess is front driveshaft or rear rotoflex.

 

[drewhinkle]

Thank you all for your generous help. The Shop wants $525 to replace the prop shaft with an OEM model retrofitted with new greasable U-joints, but I'm not exactly overflowing with extra cash. Is this something that I could buy and install myself relatively easy for a lot less money? I don't really want to go the rebuilt/re-balancing route. I've changed the oil, ignition wires, and spark plugs, but that's about all that I've done myself on this truck.

 

[jafir]

Is this something that I could buy and install myself relatively easy for a lot less money?

Yes. But you'd be better off buying something better than rebuilt OEM, installing it yourself, and you'll still be money ahead. 4 nuts and bolts at each end.

I rebuilt the one in my 2003... and I don't think I'd do it again. I'd probably buy something "heavy duty"

 

[pjkbrit]

Just buy the joints online and remove old shaft...take to shop and have them replace the joints and balance....$150 tops .......

 

[Plain2000DII]

I just spent a month or more chasing a driveline vibe on our 2000 D2, My $0.02 worth. call Justin at Lucky 8, buy a Tom woods front shaft, bolt it in and relax. I've rebuilt drive shafts and tried a "stock unit" for the little additional $ and eight bolts... TW shaft is the better mouse trap, cured my vibe problems.

 

[LRNationals]

proceedure here .... http://www.discovery2.co.uk/propshafts.html

 

[Jake1996D1]

http://www.4xshaft.com/

 

[drewhinkle]

Alright, on your advice I called Tom Woods for a front shaft. He wants $400 for a new one so I pulled off the old one for measurements. Then, I forgot to lock the diff and put it in gear for a few seconds before remembering that the drive shaft was out. It made a bit of a grinding noise briefly, then I locked the diff and all seems okay. Does this mean that I'm going to have a problem lining up the bolts for the new shaft, or can I just move on from here? thanks again for your help.

 

[mbrummal]

I think Will Tillery may have the Tom Wood's shafts for less than that. Give him a call.

 

[drewhinkle]

I ordered the Tom Woods shaft from Will Tillery on Friday; I hope I get the correct length. With the shaft removed it rides smooth as silk and quiet as a mouse again.

 

[drewhinkle]

vibration mystery solved?

So here are the facts so far...
Drivetrain vibration
After removal of front drive shaft, no vibration
Affix new conventional double-cardan drive shaft from Tom Woods, made to order
Vibration present again, but slightly different sound/feel
Checked yokes at both ends of both drive shafts
Yoke on transmission side of front drive shaft has very small amount of play, all other yokes tight as a drum

I know that Tom Woods shafts have had balancing problems in the past, but shouldn't this yoke be as tight as the others? If so, I think it's safe to say that this is the root of my problem. If my logic is correct, then I need to have the yoke replaced. The Shop already said that my T-Box needs to be resealed for $575. Is resealing the transfer case and replacement of the yoke interrelated? That is, will I save money by doing both at the same time, and is this something I can do myself? I have never done any type of tranny work. Thanks again in advance for your advice and expertise.

 

[Tugela]

Transfer case and transmission are two different systems. I can't think why the yoke on the driveshaft would cause problems. If there is play, it should be due to the universal joint. It seems unlikely (however not impossible) that this part would be faulty on a new shaft. Especially a Tom Woods.

If you are looking at re-sealing your transfer case, it might be worth digging a little deeper to learn if the output shaft bearing needs replacement. It's a common Disco wear area. This is also possible to do yourself, although it does require specialized tools that some auto parts stores will loan for free (with a deposit). There is an illustrated write-up on this repair in the tech section, I believe (see top of screen under the yellow Discovery).

 

[Blue]

What's your rotoflex on the rear shaft look like? I just ripped mine to shit while offroading this past weekend. I also just turned over 100K miles so I was going to throw my spare rotoflex on there anyway.

 

[drewhinkle]

I took my truck to LR today and they said that the minor amount of play at the T-Case is normal. I called Tom Woods and they first tried explaining that it was a heavy-duty shaft and not made for high speeds. When I reminded them of our conversation about replacing the stock shaft (still in perfect condition) for the sole reason of eliminating the minor vibe, they offered to do the right thing. They sent me a pre-paid UPS return shipping label so that they can "triple check" the balance of their shaft. I think we're all on the same page now.