So on my 88 4runner, I have my rear brakes broken down for service and when I turn the axleshaft I hear/feel a rumbling type happening. There is no noticeable play in the bearings but is this noise normal? Is it the shaft turning on the gears? Or does it mean I should just change the bearings while I'm at it? And how about some feedback on the marlin crawler rear axle service kit and the heavy duty axle seal by ecoseal?

 

You should hear or feel no noise .

Is it one side only or both??

Being those are sealed bearings very seldom do you get play till they have failed. You will feel that it is rough when you turn it.

What ever it is making noise with no load is getting pretty bad.

You never heard any noise while driving??

Any of the seals leaking??

 

Our Eco seals are the best seals on the market Ive got them on my truck and it hasn't leaked drop.

On the sound that your hearing are your running a locker? If not its likely the bearing

 

I bought the Marlin rear axle service kit, perfectly happy with it. For me, being the original bearings at 27 years old and who knows how many miles, I'd change em just for the piece of mind.