Droning hum in the Ranger

[dsmith41]

My 1995 Ranger (111, 000 miles) has developed a droning hum when driving. I was thinking maybe a wheel bearing at first because it only seems to do it when turning to the right but it seems to be coming from the rear of the vehicle rather than the front. I notice it worse when turning at low speeds so it's not like it gets louder as speed increases. I do notice the pitch goes lower as I slow to a stop though. I have rotated the tires-no change. Last summer I drained and refilled the differential and there is no signs of leaking fluid. After my 40 mile commute from work at highway speed I felt the differential cover and it was warm. I could only hold my hand on it for maybe 4-5 seconds before feeling burnt. That may be a normal and acceptable amount of heat though, I'm not sure.

Any ideas what to check to see about fixing this annoyance?

 

[05LGTLtd]

The plug seals on the ranger transmission can dry out and let the level get low. Hopefully that's not the case in your situation.

 

[SuperDave456]

Yep,
Check all other fluids.

If that doesn't work, then wait till it gets worse and you can better identify it.

 

[andyd]

Yah, when it is cool, open the fill plug and check for lube.. Also, if you smell gear oil out by the wheels. It may be a bad axle bearing. Having an axle break and losing a wheel is a very exciting few seconds as the car slides to a stop. The Rat has an open 8.8 diff. I fill diffs until the gear oil runs out. After a time, the level will settle to a slightly lower level.

 

[eagle23]

^^^ This is most likely.

The symptom, that it really shows up when turning in one direction, is the key, i.e., loading the outside wheel (whether front or back).

Definitely get it checked. You won't want the axle walking out of the housing.

Some might disagree but if the rear wheel bearing is confirmed, I'd do both and be done. But that's me.

 

[Lyman]

Carrier bearing will do what you describe. As will rear wheel bearings. I had to do Carrier bearings on my Mustang with an 8.8 rear end. I ended up having a 4x4 shop do the work for $300 + parts. Axle bearings will sometimes chew up the axle and will add to the cost of repair. Either way get it checked out soon.