I am trying to track down a very strange problem with my 89 LB9 and TH700R with 120,000 miles. When the car is cold and put into gear, it sometimes makes a loud "metal scraping" sound in reverse or going forward cornering with some speed. After the car runs a couple minutes and warms up, this noise does not return. The noise comes in very quickly and ends quickly, maybe 1-2 seconds. It is loud enough to hear it clearly and get one's attention. It also feels like there is some "power loss" while the noise is happening.

I changed the oil in my trans with Mobil 1 ATF about 18 months ago and checked the level yesterday. The oil smelled fresh and was still a nice red but it appears that I may have overfilled it by a quart or two.

Could this have something to do with the noise?

 

Prolly not, but eeeeeezy and cheeeeeeeeeep enough to fix.

https://www.harborfreight.com/all-pu...gph-62783.html

 

Check the oil level when warmed up. Rear both sides of the dipstick, the low side is the true reading. Check when it is cold. If the level is much higher when cold, then you have torque converter drainback. Usually it does not make any noise, just acts sluggish (this happens in Mopar torqueflites) for a couple of miles till all the air is gone from the torque converter. Overfilling 700R4's does not hurt them, unless you go over a 1 1/2 quarts overfull, then you start aerating the oil and starts picking up air, and will start blowing out oil from the vent.

 

I can tell you the symptoms I had. I overfilled my 700r4 by almost 2 and a half quarts after a rebuild a few days ago. My symptoms were, late shifts, clunking into Drive. Mostly some weird shifts. I set my TV cable perfectly and it was shifting late and clunking into Drive. After I removed the excess oil It shifted great and was back to normal without touching my TV cable again. I feel like a 700r4 master after my rebuild LoL