2004 Dually Launch Shutter

[Dukenrock]

I have a new Dually that has a shake between 3 and 4 mph when starting from a dead stop. At first I thought it was the nature af a dually. The more I drive it, the more irritating it is. I saw a post where someone spoke of launch shutter. Sounded like my problem so I took it to Dodge and they said they needed to order a drive shaft carrier bushing and another part. The part was on national backorder, however they did locate one. I dropped it off today to get it installed, (Along with a flash update for the fuel economy) and they called me and said they couldn't fix the shutter, that it was the nature of the truck. I told the service manager they needed to fix it. He agreed and is going to call me Monday to reschedule an appointment. (Afetr he calls Dodge) I pull a 16,000 lb boat, and when I pull the boat out of the water up the ramp, I swear the mirrors are going to fall off the truck!Any suggestions?

 

[lmills]

Have them check the u joints. Some guys have had problems with those and carrier bearings. When my u joint was going out, I crawled under the truck and after a long drive and felt the u joint caps. The bad u joint was hot the others were barely warm.

 

[Dukenrock]

I can check that. Thanks.

 

[TRLRTRSH]

Dukenrock: could also be the driveline angle. My 03 had the same shudder when pulling the 5er, didn't have time to dick around with the "5*" jerks, so installed air bags, solved the problem.

 

[DPKetchum]

Thought there was a new TSB on this. A bracket?

 

[FJfonda]

Yes there is a TSB. And it does work, I had the same situation and almost all of it is gone since the dealer installed the new bracket. The problem is drive line alignment and the TSB directs the dealer to measure the angles and use the correct spacer to optimize the angles. My dealer also noted that there is side to side "slop" in the carrier bearing mount and was carefull to tighten it in the best position to keep things in a straight line.



Dukenrock, what kind of boat are you hauling? What kind of hitch are you using for the 16,000 lb connection?

 

[DPKetchum]

Question. On wet grass with gooseneck trailer and "any" kind of wheel spin mine wheel hops(if correct term)badly. Is this something this TSB would affect?

 

[bbsmith]

Mine was the U Joint

 

[FJfonda]

DPKetchum,



I doubt the TSB would help the wheel hop. I believe what you are experiencing is axle wrap... which is where the leaf spring actually allows the axle to rotate due to drivetrain torque... when the wheel breaks loose, the axle snaps back and results in wheel hop.

 

[Dukenrock]

Launch Shutter cured!!!

I finally got it fixed! Dealership couldn't fix it so I took it to Dave's Diesel in Angola, Indiana. He lowered the rear angle of the drive shaft 1/2" by installing a new bracket. $70. 00 plus labor. What a difference! No more shutter and the truck has no vibration at high speeds. Dave said he has replaced so many rear universal joints on these trucks because of this incorrect angle.

 

[Cattletrkr]

I finally got it fixed! He lowered the rear angle of the drive shaft 1/2" by installing a new bracket.

Please try stating that again. You can't lower an angle 0. 5". Did he install a longer hanger bracket that decreased the angleS? I've had a shim put in mine that lowered the hanger bearing 0. 5" for about a month and the shake is still there. I was hoping you were having something else done. The different hanger/shim changes all the driveshaft angles not just the rear one. That's why I am hoping you can clear things up a little bit for me. My dealer is out of ideas and the shake is still there.



I even had the dealer install a shorter bracket just to try something different. OOPS! That was worse. Asked them about putting in ANOTHER shim to make it 3/4", mechanic said "bad idea".



Only option left if tearing the rear suspension apart and changing the pinion angle. Someone please correct my terminolpgy there as I'm not sure if that's correct. That's the only thing left to change.



I'm probably gonna add a few leaf springs to level the truck a little, but that won't cure my problem 'cause I've got the shake even when empty, just not nearly as noticeable.



Dodge has had this issue since '94. That's according to STAR. How the bleepitybleepbleepbleep can DC not know how to use a two piece driveshaft when EVERYONE else has got it figured out? I'm startin' to get a little frustrated. Oo. Oo. Oo.



Wheel hop/power hop is a traction issue.

 

[sag2]

Mopar makes a spacer to drop the center support. The TSB only gives the PN's for brackets that are shorter. I think I posted the PN of the spacer a few months ago. If not I can dig it up again. If you have launch shudder loaded, generally you will want a shorter bracket from the TSB. If you are trying to stop it unloaded, you need the spacer installed with the stock bracket.

 

[Cattletrkr]

Merry Christmas to ALL

Mopar makes a spacer to drop the center support. The TSB only gives the PN's for brackets that are shorter. I think I posted the PN of the spacer a few months ago. If not I can dig it up again. If you have launch shudder loaded, generally you will want a shorter bracket from the TSB. If you are trying to stop it unloaded, you need the spacer installed with the stock bracket.

I've got the shudder both loaded and empty. It's not too bad empty, but noticeable. Loaded is where the real problem exists. I tried the shorter bracket for about a week and that thing had to be replaced ASAP. The shudder was a lot worse empty, and somewhat worse loaded. By empty I mean with a 6k trailer in tow, putting about 1500lb in the box.



Sag2, since you are "fixing them and loving it", I'll ask your opinion. What would happen if I were to have an EXTRA shim/spacer installed? Thus lowering the hanger even further. Would this just cause more problems? The mechanic that's been working on this for me said it's not a good idea. I'm just looking for a second opinion.

 

[GerryDrake]

Related question

This seems to address a concern I have. Since I tow a 5'er, and the rear end of the truck is high enough I have to tow a bit nose up, for some time I have been contemplating the removal of the 2 5/8" spacers above the rear axle as some others have done. The main reason I haven't is that I have been concerned about the change, albeit minor, of the angle of the driveline. Might that initiate problems of the nature of the launch shudder being discussed here?... I suppose I could try it and see, and replace them if a problem arose, but am curious if you think it would cause such a problem...

 

[Dukenrock]

They TSB actaully has three different length spacers. The dealership said they tried all three and none worked.

 

[smokejunkie]

Dukenrock,

Manual or Auto trans?

 

[Dukenrock]

Automatic Transmission

 

[Cattletrkr]

Dukenrock,

What did Dave's do differently than the dealer. You said the dealer tried three different brackets and none of them worked, just wondering what anyone else would do different to change the angles. Thanks.

 

[strokerschmoker]

I know were talking about stock suspension but after lifting my truck i took a piece of 1" tubing and installed it as a spacer at the carrier bearing. This took away all vibrations. This was my first attempt to fix it and it worked. Its a thought and if it doesnt work your out 15 minutes and 5 bucks. Andy

 

[Dukenrock]

I think they had the wrong size brackets and tried what they had to work with. They never had to fix one befroe, whereas Dave's had many they fixed. It makes a world of difference. I still think that there is another problem lurking. At cruising speeds you get that "growl/vibration", nothing serious or anything to annoy me, but it's there. Now I have to work on the white smoke on cold startups. They already did a Flash once.