shuddering/vibration

[hmickelson]

recently acquired 93 D250 ex cab, USgear exhaust brake, Banks Stinger,pyro,boost and tan temp,aux fuel tank over spare tire, 75,900 miles. Getting 20. 3 MPG running empty, Don't know towng MPG yet. After running freeway( 70 MPH) and local driving for 20 or more minutes then approach driveway or go into reverse experience A SHUDDERING/ VIBRATIONS clear back through the exhaust . the exhaust also is hitting against something. this thing is severe.



Have any of you out there experienced this and have had it diagnosed and cured? Help

 

[LarryB]

Auto transmission or 5sp??

 

[nascar mark]

Could be a motor mount? or bad u joint ? or center bearing loose or needing to be shimed.



I had a shudder in my drive line from the day i drove the truck off the lot and found the problem in the center bearing. Shimed the bearing by 1/4" increments until shudder was gone. It took 3/8" to fix problem.



If its a motor mount, it might also explain why the exhaust is touching something.



U joints can be funny also. Had one that would be fine until backing up and it would bind up and cause a shudder too. Looked fine, had no play,when trying to move it around by hand etc.



Hope it helps.

 

[Bob Beauchaine]

There is a TSP regarding driveline alignment. It includes shimming the carrier bearing (1/2 inch) and using angled shims on the rear springs to change driveline geometery. When I had it done it helped but it's much better since I installed the NV4500HD coupled through a Southbend Clutch. With the extended cab and 8' box the front section of the driveline has to be shortened 6. 5" to except the NV4500HD - I suspect that this has helped.

Hope this helps

Happy trails

Bob

 

[hmickelson]

Thanks Mark and Bob You have confirmed my suspiscions I think. this only happens when the truck has been runn on the freeway 20 minutes or so and the come to a parking or reverse situation.

I forgot to mention Auto transmission,ps, 3. 54 rear end. I do not do my own work as I once did but have a good reliable mech. I may mention the TSB after our conversation is along the way. At least it seems fixable.