Driving my 95 Chevy G20 van yesterday, made a left turn and noticed a whining noise. Thought the PS might be low on fluid, but it continued sitting still. Once stopped, I could tell the noise was coming from the tranny (sounded like the front). Figured it needed fluid, so stopped and put a quart in. Seemed to help,as things got quieter as I continued on. Everything was OK for next 60 or so miles. About 15 miles from home, made another left turn and started whining again. Got a burger, cranked up, now making a light metallic grinding sound. Stopped at stop sign and waiting for traffic to clear and noise suddenly stops. Has not made an unusual sound since. Everything else is normal. It goes into gear, shifts fine, downshifts, overdrive engages, fluid is clean, red and not burned smelling. This is a stock GM overdrive unit. Not sure of model, guess it is a T460L or whatever they came with. Any ideas???
I had a very similar noise in my 94 G20 van and while behind the steaing wheel driving I swore it was the trany, at idle no strange sound but after 20MPH it sounded like it was going to grenade. Fluid fine, shifted fine, and got me home but was loud enouph that other cars were looking at me. It sounded like metal grinding! Turned out my surpentine belt lost a cord and it had wrapped itself around the fan at the water pump. Take a look at yours, maybe it will be a eazy fix as mine was.
Did you bother to check the fluid to see if it was low, or did you just randomly add a quart? If it wasn't low, your trans is now overfull, which can also cause damage. Given your description, it sounds like the front pump is going and whatever was inside of it got ground up. Pull your pan and check for metal debris. Noises don't just cure themselves.....sooner or later you will pay the piper.
I know the extension housing seal leaks a little, so I felt it was safe to add some. I checked it after adding and it is a little overfull, but not enough to hurt anything. I am hoping it is later..........
Check where the tranny bolts to the bellhousing. If loose bolts remove the inspection cover and check torque converter bolts for tightness. Might be a good idea to check those anyway. If any of those bolts are lose you may have a cracked flex plate.
Interesting that it occurs on left turns, I cannot think of a correlation. Lower the pan and check for a loose filter, if it cavitates the trans will whine. If anything went blooey there ought to be some debris down there too. 4L60e trans probably, a pretty hearty unit. Good luck, hope I'm right about the loose filter.
Found the culprit. The belt idler pully bearing going bad. Cheap and easy fix. Thanks to all the contributors. :banana:
Rite on, I knew it had to be some thing simple...just from your description. Sure does freek ya out though when you hear strange wtf noises though, doesn't it!
I had a 1987 Chevy van that the idler pulley went out and made weird noises. Forgot that possibility. Also the AC compressor clutch froze up once and blew the AC system along with belts. Never had those problems with a Model T' Ford!