RPM/Tranny Question

[DRock9]

My Dad and I just replaced the heater core in my '90 GT, it was a royal PITA but we got it done. Anyways, we went out for a drive after to make sure it was alright and i told him to listen for a knocking noise when you shift. Sometimes I hear one, but I noticed it was only when i shifted at like below 3,000 RPM. I told him this and he said that it is a "high performance car" and you need to wind out the gears when you shift so that it doesnt damage the transmission, and I told him the only time i shift at low RPM's is when i am going fast and i am trying to save fuel. He said i should still be in 3rd gear when i am going around 40MPH, I told him that I would rather be in 4th at around 1,300 than be in 3rd still at 3,000+. I know that i get a lot less power but it doesnt matter because im just crusing around in a straight line, but he was trying to claim that it is bad for the transmission.

Here is an almost exact quote from him, "The transmission wants to go fast, and if you go slow like if you were in 4th gear its bad for the transmission."

So what I am trying to ask is if there is anything wrong with going 1,200 RPM in 4th while im cruising at about 40+mph.

And is there anything bad with shifting at any low ammount of revs besides the fact that it can stall easier.

Thanks!

 

[DRock9]

ttt!

 

[jete]

I used to roll around town at about 45 in 4th or 5th sometimes. I didnt give it gas though. I pretty much just rolled. When I was in 5th it would be at about 600-900rpm? I dont really remember exactly but my tranny never slipped. I dont think it would be a problem unless you got a couple of fatasses in your car and the motor was strugglin. I drive in 4th in my pickup all the time at about 35mph. No acceleration and its at like 1000 rpm? It doesnt slip either and I dont push it but I did find out I had a bad tranny mount that way. As for saving gas I think its a great idea and ill continue to do it But if the motor struggles I always downshift a least a gear. Hope this helps