Hubs Locked = BAD Shaking

[lone-wolf]

I'm not very mechanically inclined, but I'll try and describe this the best I can.
I'm looking for other possibilities for my mechanic friend to take a look at.

With the hubs lock, while I'm driving(40kmph and up) the truck will start to violently(more speed = more violent) shake until I slow down to nearly stopped and then I'll be able to drive, at any speed, for 1min-5min and then it'll start shaking again.
Doesn't matter if it's in 4wd or 2wd and it's un-drivable when it shakes like that, I would have to slow down and pull over.
Hubs unlocked = nothing

My friend looked at it and we've got 2 possibilities so far.
-Wheel bearings need to be changed
-A couple U Joints need to be replaced

Now I did a search and some people had roughly the same problem and fixing the top two problems didn't always fix it.
So I'm wondering if fixing the top two things will solve the problem for sure or could there be some other causes?

 

[2ranger87]

That sounds like the same symptoms one of my trucks had. Ended up being one the axle u-joints was seizing up.

Bad bearings will usually give a humming noise that will change in pitch while turning, and will have play with the wheel(s) off the ground.

Does the truck have a suspension lift?

 

[LEVE]

I had that problem on my ol' '84 BII.

When the bind occurred the front driver's side fender would actually raise up 2 to 3 inches and then back down. It was downright scary. The driver's side axle shaft U-joint froze up. I couldn't remove the U-joint and took it to a shop. The shop took 2 hours to get it out using a hydraulic press and lots of lube. They handed me back the shaft with a new U-joint installed and a $25 bill. I got off easy.

 

[lone-wolf]

Does the truck have a suspension lift?

Suspension is stock. No lift.

Bad bearings will usually give a humming noise that will change in pitch while turning, and will have play with the wheel(s) off the ground.

It does have the humming and play with the wheels. Never notice any changes in pitch while turning though.

If the u-joint is seizing up, replacing the u-joint would fix it? What would cause this in the first place?

 

[WNY964x4]

yes the u joint is seizing , i has this same issue once , and the u joint seizing is caused usually by non-use , or from sitting for a while , and they are also a wear out item , how long have you had the truck ?

 

[lone-wolf]

Me and my friend spent the last three days replacing 2 u joints. Partly because of rust(stupid winters) and also because of our inexperience with rangers. He says if we did it again, it'd be less then a day.
The front differential(i beleive that's the name) had almost no lubricant in it, and crap load of water.

Anyways, the u joints were replaced and a couple bad wheel bearings were replaced too. So far the truck is working a lot better.

Had the truck since November, but it's been used. 286,000km on it.

 

[lone-wolf]

Just an update. Truck was working fine, but the shaking came back. Seems to be the same kind of shaking as last time. If I put the truck in 4hi with the hubs unlocked, it goes fine(friend said that could mean something, forget what). Hubs locked, shakes bad again in 2wd & 4wd.

 

[AKBroncoII]

All 4 of your tires the same size? Tons of things can cause this issue.

 

[AllanD]

Axle U-joint.

AD

 

[Hahnsb2]

Don't forget to check the front driveshaft u joints/dual cardan joint.

 

[lone-wolf]

Tires are all the same size, and most of the ujoints seem fine. The really bad ones were replaced. Could still be ujoints, my friend isn't sure.
Aside from ujoints, anything else it could be?

 

[wahlstrom1]

It would have to be a front driveline issue, but try pulling the front driveshaft out to eliminate the driveshaft and transfercase as a possibility.

 

[85_Ranger4x4]

Dunno if your truck is the same, but mine had these little strap deals that held the front driveshaft cross onto the pinion yoke on my front differential. Somehow the awesomness of my mighty 2.8 stretched them so they wouldn't tighten up... resulting a tremendous shake in the front end that was very speed related with the hubs locked in.

Easy to check, grab the driveshaft push/pull on it and check for movement, new straps and bolts are $7 at Napa.

They might have changed to a flange setup at some point like the rear axle that makes this post completely pointless though...

 

[buckshot]

front driveshaft out of phase?

 

[lone-wolf]

thanks, I'll run this stuff by my friend.