99 4wd driveline vibration

[N0lan]

Hey guys,

New to the forum, if I'm posting in the wrong place my apologies.

99 ranger 4wd 4.0L

I'm getting a strange driveline vibration that I can not narrow down. My girlfriend drove my truck last week, when she got home she said your truck is vibrating bad, unless you hit a bump or come to a complete stop and start again, then it goes away.

I took the truck for a 5 mile drive or so and nothing, everything seemed normal. Next day about 3 miles up the road I hit a small bump in the road and the vibration started. Vibrating the entire truck but seemed to be coming from the front end. I pull over and discovered the dust cap and passenger side auto locking hub was missing. That's how bad the vibration is, enough to vibrate off the dust cap and lock out. I came home jacked up the passenger side wheel, no play side to side or up and down.

My next thought was maybe since the lock out on one side was missing somehow the other side was engaged for some reason. Removed drivers side lock out, still same issue. On that test drive I noticed that if I put it into 4wd hi, the vibration would go away until I hit another bump. Then i would just flip it back to 2wd and back to 4wd and vibration gone once again.

This led me to believe it had to be the u-joint in the front shaft. I pulled the front shaft and noticed the u-joint moved freely with no binding on anything. So I proceeded to pull the shaft on the t-case side. Never seen a driveshaft quite like this one. Had to beat on it pretty hard to get it to come off and when it did the bearings fell out. On a side note, what type grease do I need to repack the front shaft with?

So with the front shaft removed, I went for a test drive, again 2 miles up the road and vibration is back, but prolly only half as bad as It was with front shaft in.

I have yet to pull the rear shaft but just by looking at the u-joints everything looks ok. No excessive play at rear yoke or on t-case side when u grab and shake the rear shaft.

With the front shaft still removed, it is still hard to pin point exactly where the vibration is coming from. Kind of just feels the like its everywhere. Obviously with the front shaft removed switching between 2 hi and 4 hi does nothing. I plan on pulling rear shaft tomorrow and replacing u.joints but was just curious if anyone else had experienced the same issue. I can drive a while and everything seem normal, then hit the slightest little bump in road and the vibration begins. Now without the front shaft in, the only way to get rid of it is come to a complete stop and start again and the vibration leaves until I hit another bump.

Sorry for such a long winded post. I'm hoping someone out there has experienced the same issue and can point me in the right direction.

I appreciate any and all help/advice.

I love my ranger, other than the crap mileage you get with the 4.0. It only had 43k on it when I bought it 5 years ago. After buying it I came to the conclusion that the previous owners didnt drive it much bc of the mileage.

 

[dvdswan]

It almost sounds like death wobble.

Jack the front of the truck up and grab your tires top and bottom and see if your bearings and ball joints are tight. Next have someone turn the steering wheel back and for while you check your steering linkage for play or loose parts. Check the A-arms for play or looseness as well.

I'm sure there is something I missing. Others will chime in.

 

[N0lan]

It almost sounds like death wobble.

Jack the front of the truck up and grab your tires top and bottom and see if your bearings and ball joints are tight. Next have someone turn the steering wheel back and for while you check your steering linkage for play or loose parts. Check the A-arms for play or looseness as well.

I'm sure there is something I missing. Others will chime in.

I've already tried that. Everything seemed tight, no excessive play in any direction.

Wheel.hubs and Ball joints were replaced about a year ago.

So with the front driveshaft installed, I can get rid of the vibration by switching between 2wd and 4wh hi. As soon as 4wd kicks in, vibration is gone. I'm guessing it bc torque is applied to the front shaft and front axle. This is why I was so convinced it was the front driveshaft. But, as I stated above, once I removed the front driveshaft, the vibration reduced by atleast 50%. But, even with front shaft removed, it is still a significant vibration.

 

[Broosedamoose]

You may have a bad CV joint on the front axle.

 

[N0lan]

I haven't had a chance over the past week to work on the ranger. This afternoon I finally found the time to pull the rear shaft. I'm pretty sure that the rear shaft isn't phased correctly. Although I've had this truck for about 5 years and it's hard to believe that it has run for 5 years with the shaft not phased correctly and I haven't noticed any vibration.

There is no noticable slop in either u joint but since I have it out I'm going to replace them anyway. The shaft moves in and out on the splines just fine, no binding or sticking or anything.

I've included a picture of the shaft after I removed it. Can someone verify for me the phasing. All other rigs I have worked on with a slip style driveshaft had to be phased on each end. With the ear on the shaft on one end aligned with the ear on the opposing end.

Thanks in advance for the help!

 

[TheBassman]

I haven't had a chance over the past week to work on the ranger. This afternoon I finally found the time to pull the rear shaft. I'm pretty sure that the rear shaft isn't phased correctly. Although I've had this truck for about 5 years and it's hard to believe that it has run for 5 years with the shaft not phased correctly and I haven't noticed any vibration.

There is no noticable slop in either u joint but since I have it out I'm going to replace them anyway. The shaft moves in and out on the splines just fine, no binding or sticking or anything.

I've included a picture of the shaft after I removed it. Can someone verify for me the phasing. All other rigs I have worked on with a slip style driveshaft had to be phased on each end. With the ear on the shaft on one end aligned with the ear on the opposing end.


View attachment 57359

Thanks in advance for the help!

New owner of 2000 ranger 4.0 4wd===with the same problem as you (death wobble?) have you figured it out? Mine is the same a good bump and it's hold on tight . I can stop it by hard hitting the brakes .Like the truck but too many odd probs. Dome light always on ect.