5600 - 2nd Gear Shudder

[Spooled-up]

My truck has a little over 1000 miles on it. Since new, it has had a little shudder in 2nd gear. If I start off in 1st, then shift to 2nd, it shudders, and if I start off in 2nd, it shudders. If I idle in 2nd, and give it the fuel, it still shudders.



It feels like maybe the clutch is slipping a little. Everything feels normal in all other gears.



Anyone heard of this before?



Thanks.

 

[Scrappy]

shudder

My truck does this also, mine does it @ 1600-1800 rpms. and only in second. I have 24k on the truck and the transmission was rebuilt at 18k. for the transmission mainshaft TSB. It doesn't seem to be a problem, but I am still curious what this could be.

 

[nickleinonen]

axle wrap maybe? 2nd is still a pretty deep gear [1st is deeper, but doesn't get the driveshaft spinning as fast] ladder bars might help, or swap out all the leaf spring stuff for a 4 link air suspension

 

[Spooled-up]

jvanwaardhuizen,

What was the reason for the rebuild at 18000?



Another oddity with this trans is that when compression braking down a hill in reverse, the trans makes a loud gear noise like it wants to spit the shift lever out of the case. It's hard to describe the noise, but it's loud enough for me to think there's something wrong. Is this common also?

 

[Briman]

My truck has the shudder as well. I think the rubber surround is too soft on the center bearing on the rear drive shaft and allows the shaft to rotate out of round on start up. The rubber should be stiffer for the amount of torque that is applied.



This may sound silly, but I was able to reduce the shudder on my truck by shifting the center bearing as far to the passenger side as possible by loosening all three sets of mounting bolts (top, middle, bottom) and pushing the bearing and two mounting pieces as far as the slop in the holes would allow toward the passenger side. Putting a string on the shaft to confirm straightness shows it's all in line now.



Dana makes a center bearing thats stiff at slow speeds and softens up at higher drive shaft RPMs. I think it is controlled by an electro magnetic field. It would be cool if we could retrofit this onto our trucks.

 

[Spooled-up]

Is there anyone out there that does not have the 2nd gear shudder?

 

[bighammer]

Why is there a center bearing? Why not a one-piece driveshaft?



I was looking at the center bearing as a source of it as well. It does seem sloppy loose. Does it need to loose at higher speeds? (I had thought about firming it up with some shims )

 

[Briman]

I think thats the theory, firm at low speeds and looser at high speeds. I have toyed with the idea of putting some wood dowls in the holes in the rubber, to "shim" it up. I thought that some butyl rubber window sealant might work as well. Just have not got to it yet.



I saw a long bed quad cab second gen in Salt Lake City the other day that had been converted to a one piece drive shaft. Kind of reminded me of the look the old ford high boys had. I did not get to ask the fellow how it worked out.

 

[nickleinonen]

why not replace the rubber on the carrier bearing with a solid aluminum block or solid poly block? too many vibes back in the cab?

 

[Scrappy]

shudder

Nick, my trans was rebuilt because of a TSB that dodge issued about gear clash while shifting into 3-4 while the truck was cold. There really wasn't anything wrong with it otherwise. another thing to look at, is the slipjoint aft of the carrier bearing seizing up and causing the carrier bearing to be pushed sideways enough to cause the housing to rub on the shaft during acceleration. Mine did any ways, I don't know if this is a contributing factor or not though.

 

[Prairie Dog]

Originally posted by DMKelley

Is there anyone out there that does not have the 2nd gear shudder?

I had a slight shutter when I let out the clutch but it quickly faded as the miles racked up. By the time I had about 4k, it didn't do it at all. It's perfectly smooth now unless the wheels slip in the rain, then axle wrap is clearly evident.

 

[Boonieman]

I haven't experienced any takeoff shudder at all. I have heard the transmission make a weird noise when coasting down a hill when I'm towing a load. It only does it for an instant, and sounds like some form of gear lash... . not gear grinding or anything. It's intermittent, so trying to figure out what it is has so far been next to impossible. Everything I own, except the wife's Honda, has manual transmissions. All of them have their own unique chirps, buzzes, whines, grinds, etc..... so I'm not going to get concerned about it unless I see little cogs rolling out from under the truck or something.

 

[CumminsPower98]

This is a very interesting topic to me as I have been through all kinds of hardships and a lot of money over this same thing. Back at the first of the year I installed 6-speed in my 98 12 valve. I got this trany with hardly any miles on but the mainshaft was way loose. I pulled the front bearing retainer and shimmed it up and installed it. I took it for a drive and it had a pretty bad shudder in 2nd and some in 3rd too. I thought that maybe it something was wrong with it or I had put too many shims in so I pulled it and removed some shim and tried it again. This time 2nd gear was pretty much the only place I felt it. The oil seemed to be getting pretty dirty after not many miles so I decided to send it off to Standard Transmission to have them check it over and set it up. After getting it back and installing it a third time I still had the exact same 2nd gear shudder. I decided to go ahead and drive it this way and see what happened. Finally I decided to get under there and check the driveline angles real closely. I started experimenting with different amounts of shim under the back of the trany and the carrier bearing. Right now I think I have 3/8" in both locations and the shudder is just Baily noticeable now. The thing that really threw me is that I did this same conversion in another '98 12 valve and had no trouble at all with no shims. My cousin also put one in his '97 and no problems. Why mine messed up I have no clue. I still may do more work on the angles some time but for now it's pretty good. I sure wish I had left that thing in there the first time because I feel I had about the right amount of shim on the mainshaft and it would have run just fine but instead I spent a pile of money on shipping and labor to have it checked out.



Sorry so long guys, I have a hard time not telling the whole story.



Mark

 

[DIESELMAN]

Here's something that tells me the Rear Drive Line front and rear U-Joints are not lined up with each other in the proper angles, I can 'tune' out all of the vibration that I get between 68 and 72 MPH using my Air Bags on the rear. This also tells me the rear spring pack blocks are the wrong angle, maybe a degree or more, and the center bearing is slightly (1/8") offset to the passenger side.



I just adjusted the ride height and it smoothed right out! Smooth as silk at any speed as long as I have a fair load in the back and can level the truck. Empty it sits up even with 5lbs of air and it vibrates, with fuel in the aux tank it squats a little and is perfect.



Then again I could be imagining it, but I think theres an error in the assembly specs with the new axles, and I think the vibration problems, however minor, will be solved by the '04's (opinion) and solveable on these '03's.

 

[Fred Swanson]

Bingo!!

DIESELMAN, you hit it right on the head. The change in driveline angle when loaded down, reduces or eliminates the slight shudder several people feel. Usually it is in 2nd between 6-12 MPH.

More than likely the rear pinion angle is offset too much, and the axle needs to rotate up, say about 2 degrees, and maybe as much as 4 degrees.

I know mine had no shudder until I put the 2 inch blocks in the rear. The blocks are straight cut for now, but I'll be pulling them out and cutting a 2 degree angle on one side and seeing if it goes away.

I

 

[Spooled-up]

I assume there is no TSB then.

I guess I'll take it to the dealer to see if they have heard of this at all.



I don't have high hopes though.



Can they check drive line angles and such to determine if everything is lined up or is that beyond their capability?



Thanks for all the good replies guys.

 

[Dean Upson]

Is there anyone out there that does not have the 2nd gear shudder?

Mine has always been very smooth shifting, no gear shudder. I do have the rattle and sure would like to see the mysterious tsb that even my dealer knows nothing about. Can anyone post this?



Dean

 

[DIESELMAN]

Fred - Thanks for the EZ swap, but I still have the problem, I'm checking further but not really sure what the issue is.



BTW, clean your yard!, looks like a construction zone out there , my brother lives 10 blocks west of you, no trouble finding your place, thanks again.

 

[krabman]

No shudder here at any time. Dont have any of the transmission noise that some people have posted about either. I did get the clutch rattle which I have had since about the 1000 mile mark.

 

[DIESELMAN]

Does anyone with a dually have the shudder or vibration at speed other than Fred who created it with the lift? I see most of the sigs that have it at all are SRW??