Hello,
I just got a 1998 disco 1 about a month ago and I’m hooked I love it. It has 98000 miles on it no rust super clean from the inside out, But there is something wrong with her and I’m not sure what it is?
It makes this whooping sound from the back end it starts at about 20-35 mph and gets faster as I go faster and stops when I stop moving. I’m going to be working on her Wednesday, I want to know where to start looking, I’m planning on changing all my fluids you know T-case, Difs and Trans also changing the rear rotors and pads wheel bearing. So far I have grist all the drive line points. O and I can’t get it to go in to 4lo. Please let me know what info is out there
Thanks

 

Could be low on gear lube in the rear diff, could be a bad wheel bearing.
Start by changing all the fluids, checking the level of them first so you have a idea of how well it was taken care of.
I use 75w-140 gear lube.
Dont worry about the 4-lo right now, first things first.
Report back if the noise is still there.
You can spin each tire by hand if it is off the ground and listen for the noise.