please help

[shomtx95]

ok here goes, 89 ford taurus sho, current tranny is from a junkyard, 130,000 miles. Yes i have yanked the crap out of the gears, but I have never done a burnout. Gears do not scrape at all. Well Something somewere has developed a knock It sounds like a rod bearing or a bad timing chain knock. Only does it under a load. With the car Idling, i can rev the crap out of it and there is no sound, so i am pretty sure it is not the engine. The more I drive it and the more I listen, I swear it only does it in 3rd and 4th gear. Is my tranny toast??. I am thinking about putting the car on jack stands and going through the gears. All replies will be very appreciated.
When driving the car, I can be in 3rd or 4th cruising. When i push the gas about half way, the knocking starts faint and gets louder the longer I hold the throttle, when i back off the gas, it quits.

 

[shomtx95]

nobody???.... I have now come to the conclusion that it makes the noise in 1st,2nd,3rd, and 4th. I put the car on jackstands and went threw all 5 gears up to 70mph and you cant hear the noise.

 

[sperold]

Do you feel anything on the shifter? It doesn't sound like the transmission to me. Think up some kind of listening device like a long flex tube, remove your hood, attach your tube to the engine pan area, and go for a spin. It should be nice and plain then if it is rod bearings.

 

[sperold]

.....Or, park at the bottom of a steep incline, open the hood and have a buddy stand beside the engine compartment. Let the clutch out and proceed up the incline. That will put the max load on your rod bearings and they will be singing a chorus for you if they are defective.
If you are near oil change time, perform the oil change and don't prefill the filter (which is hard to do anyways). If your rod bearings are bad, there will be more than faint noises in the time before the new oil hits your oil galleries and bearings. There is always some noise, so you may need a 2'nd opinion, or put a sound bite up here.