2002 Ranger XLT 3.0 4x4 - It just snowed here and I was driving thru town in 4wd. Leaving town, I left it in 4wd. I wouldn't say the payment was dry, but I could have switch to 2wd. I was going around 55mph and suddenly it felt like I ran something over. It was dark, didn't see anything, but it was a sudden and brief (split second) feeling. I drove another mile at 55mph, not issues. I slowed, turned onto another county road, got up to around 55mph and I felt it again - so definitely a quick shutter - like when you run over something. Is this due to being in 4wd at a higher speed on payment that wasn't slippery? Also, while driving in 4wd, there is a "howl" - like a wind howl - that is louder at higher speeds. The "howl" is not noticeable in 2wd. Appreciate any ideas and feed back

 

Welcome to the forum

Yes, in 4WD there is a direct connection between front and rear drive lines, so much different than AWD, at speeds above say 40MPH on non-slippery roads shift back to 2WD as the transfer case will bind up and then release with a shudder you can feel
The front and rear tires are of course the same size but can have different air pressure so rotational speed of drive lines can be slightly off, over time/distance this difference builds up and is then released

Check the fluid level in transfer case to see if its low and causing the howl
2002 Ranger has Live Axles so the front differential and drive line is always turning even in 2WD, so howl wouldn't be from those if its only heard in 4WD