Vibration at highway speeds

[william lopoulos]

Now that I have my injector issue resolved, I am getting a vibration at highway speeds, 65-70. It feels a little like driving over the rumble strip, but not quite that bad. I dropped the rear driveshaft and both u-joints are OK. The front driveshaft was replaced a couple of years ago, and I have been keeping up with greasing it. Plus I haven't been driving that much lately.

In doing some reading, I am wondering about the transfer case. I have 350K miles and it has never been rebuilt. There is quite a bit of play on the output shaft, but in reading some other posts, that might be normal. Is that true?

Is it most likely the transfer case? Is this something that I can rebuild myself? I don't have a lift, can I remove it myself?

2006 Cummins 2500, 4WD, 350K

thanks

 

[Smoke Eater]

Do you have the 2 piece rear drive shaft? I'd look at the carrier support bearing first if you have the 2 piece shaft.

 

[william lopoulos]

It is a 1 piece. No carrier

 

[Jim W]

How old are your ball joints and tie rod ends? They maybe worn out or starting to wear out? When was the last time that the steering stabilizer was replaced? Have the tires been rotated and rebalance? Some other areas to consider that could be causing the vibration at speed. Just a suggestion.

 

[william lopoulos]

Ball joints and rod ends replaced and well greased. Will recheck ball joints. Tires are a possibility, will have to have them checked.

 

[william lopoulos]

feels like it is coming from the back half of the truck though

 

[Ozymandias]

Does it change with speed or with throttle position?

 

[william lopoulos]

Feels like it is only at highway speeds and only sometimes. Sometimes I think it is just the pavement, but I know that isn't the case. Need to characterize whether I am going uphill or down, adding power or coasting

 

[GCroyle]

This is from way out in left field a recent post so I can't substantiate it or dispute it. Jwade420's post and description.

https://www.turbodieselregister.com/threads/new-fuel-control-actuator.271327/

"In addition to solving the problems of the symptoms above the engine now runs much smoother at highway speed. It also no longer "bucks" while going downhill with the cruise on. A vibration that I was sure was the driveshaft carrier is no longer present as well. Power delivery is much improved at all RPM. Thanks again to the forum and Geno's for the good factual information"

What say you Guru's?

 

[william lopoulos]

Already installed a rebuilt fuel pump with a new actuator and new injectors

 

[AH64ID]

What pressure are you running in the tires?

I've felt vibrations from tires at 80 psi and no load.

 

[PLohr]

William,
Without experiencing the vibration, this is a guess. Have you looked at the tires? My rear tires were not properly balanced which caused slight high and low spots. Now I have a vibration at 60 MPH and up. If you can't see any tire issues, maybe have the balance of the wheel / tire assemblies checked. If the shop doesn't calibrate their balancer once per week, I won't ask them to do the work. Road force balancing is preferable but you should be able to find this with a basic electronic balancer. Brake rotors can cause an imbalance but it is more rare than tires being the cause.

 

[william lopoulos]

I will go have the tires rebalanced. Dropping the front driveshaft this weekend to check it and will check fluid level in the transfer case

 

[bcbender]

Check the CV (double cardan) in the front DS for slop / hard points..., that was my problem... dealer replaced all three u joints and carrier w/o solving... I pulled the front shaft and test drove... no more vib. Fleetpride here in Greensboro rebuilt the front DS with new parts and ujoints... balanced and never had another issue with VIB.

 

[william lopoulos]

going to do that next

 

[sag2]

I will go have the tires rebalanced. Dropping the front driveshaft this weekend to check it and will check fluid level in the transfer case

Make sure you mark both ends before removal. Then clock it 180 at each end one at a time going back in to see if makes any difference.

 

[william lopoulos]

OK, thanks