Hey guys, I own a 1993 Pickup, 22RE 4x4. I recently had my truck shipped to me and while at first it ran fine, in the last few weeks its begun to develop a steady pulsing vibration in the higher end of third gear, most of fourth gear and the bottom of fifth gear. It runs fine in lower speeds around post, but once I get the speedometer needle on "40 mph" in fourth gear this rumbling starts instantly. If I let off the gas, it immediately stops. Once I reach fifth gear it goes away, until the needle reaches about 50 or 55 mph where the rumbing starts up again instantly. Again, If I let off of the gas at this point the rumbling immediately dies.

If I keep pressing on and get the needle up to 70mph or so, the rumbling goes away and the truck runs smoothly until I begin to slow back down to the 50-65 mph range (with the gas pedal depressed) where the rumbling starts again.

I changed my engine oil, oil filter and air filter recently and while doing so I pulled out my owner's manual and checked the proper transmission fluid level. I found the filler hole and pulled the plug bolt out only to have the fluid pouring out steadily, instead of the indicated level of no more than .2" below the fill hole. The fluid coming out was a clean yellowy-amber with no metal flakes or filings in it. I simply plugged the hole back up and took the truck for a spin. It shifts fine (a little rough on a cold morning) but other than that no trouble. Just that vibration in the previously mentioned speeds. any ideas what the problem is and how i can fix it?

 

Sounds like possibly front wheel bearings but probably a universal joint.

 

^ x2 on the universal joint(s). When under acceleration, the joint is under stress causing vibration, and when releasing the throttle, the stress is relieved on the joint.

 

First and foremost, Thank you for your service!

Lets start with the simple things. Do you feel this rumble in the chassis or in the engine. Could be as simple as a wheel weight knocked off in shipment, or a weight knocked off the drive line. Check for a shiny spot on the wheels and check for the same on the drive lines. While checking the drive line, you can also check for movement in the u-joints as previously suggested. Keep us posted.

John

 

the vibration feels like its mostly under my ass...not the engine or anywhere near the rear axle...it puts my legs to sleep and starts to numb my hands on the wheel....if i put my hand on the transmission hump under the stick i dont feel anything. it will vibrate through the pedals and steering wheel and driver seat....passengers say they feel it too. UV joints? I doubt there is any shiny spot left under my truck from all the mud and surface rust...