Just bought a 1999 Ranger yesterday, 2.5L 5Speed. 90K miles. Runs great. One small annoyance. When in neutral, with the A/C on, the transmission rattles. I thought the idle might be dropping too low, so I replaced the ICV with a brand new one, and bumped it up a hair with the lock screw, after a minute it seems to have set the idle itself again, and the rattle comes back.
If I tap the accelerator, it goes away, if I turn the A/C off, it goes away.
It goes away when the compressor cycles off.
And, it goes completely silent when you push in the clutch.
I checked the fluid in the transmission, and when removing the fill cap, it wept normal looking red atf out.

So, what do you guys think?

Oh, and good to meet you all. I am Jerry

 

Not sure i developed a similar rattle on my 3.0 a few days ago when i ran the a/c for the first time this season so ill have to do some digging and see if i can get any answers for you I'm hoping its just the clutch on the a/c compressor which is fairly cheap and easy but mine is similar symptoms to yours.

 

I did run across this. Not sure if this means there is a fix, or just saying it happens, and not to worry about it. It does cover a range I think 91-99 but not sure.

1991 FORD RANGER
NHTSA* TSB Technical Service Bulletin Number: 609688 Bulletin Date: 19-Oct-1999
POWER TRAIN:MANUAL TRANSMISSION

VEHICLES EQUIPPED WITH MANUAL TRANSMISSION MAY EXHIBIT NEUTRAL GEAR ROLLOVER NOISE WHICH OCCURS AT IDLE WITH TRANSMISSION IN NEUTRAL AND CLUTCH ENGAGED. *TT