The other day I was driving my 92 5.0 Camaro with the 3rd 700 R4 transmission in it so far. I was getting on it a little hard but not full on crazy driving when all of the sudden I lost all gears. It just would rev like it was in neutral. Ive searched and searched and think it might be the pump or TC. It holds park fine but nothing else. It also makes a whining noise. I hooked up a little pressure gauge I have and it said 0.

My questions are if theres anyway to be 100% sure what the problem is and also...... will the pump from one of the 2 30 spline 700s will work in the 27 spline trans I have in there now. If its the pump that is. I know the TC arent interchangeable..... Im mechanically inclined and work on aircraft mostly but never got to deep into the transmissions of cars. Im on a tight budget and want my car fixed. If its the pump can I put one of the others in there? Someone please tell me yes!!!! If not I guess Im going to have to save and get another used trans and not know how long thatll last. We have about a year left paying off our business expenses and I cant wait that long to have my baby back.

Thanks for any help.....I love this site and you guys always help me out when I think all hope is lost.

 

I guess I'll answer my own question..... I ended up taking the transmission out and taking one out of one of my other Camaros and putting it in. The car runs now. I took the pump out of the bad trans. I was told the 27 spline pumps wont work with the 30 or vise versa...... I didn't even try to put one in. I got lucky and a friend of my husband had some 700 r4 parts in his garage and it was a 27 also I put the pump in the bad trans and put it back in my other Camaro and now it runs fine.....So it was the pump all along. I guess that whining noise means the pump is shot.....although I think from my understanding that a bad TC could also cause the same noise??? I dont know???? Anyways, all fixed now. I'm surprised nobody even took an educated guess. Oh well. Hopefully no more problems for awhile.

 

Ya bummer no one responded. So what was the culprit for the previous two trannies goin bad?

 

The input shaft that turns is the one you want to see if it is a 27 or 30 spline. All mid 1984 and later 700R4's are 30 spline. The stator support (holds the input shaft) that holds the stator in place in the torque converter is 27 spline and has never changed spline count. The 30 spline measures apx. .990" +/- .005" in diameter. The 27 spline measures apx. .890" +/- .005" in diameter. Measuring te shaft diameter is a lot easier than trying to count the splines. For you to lose all pressure at once is almost always a breaking of the rotor in the front pump.

 

Thanks for the reply. I still haven't messed with it besides checking the splines. I found out the hard way that it dont fit. lol Oh well....the trans had to come out anyways. I'm not sure exactly what happened with the other 2. They just wouldn't go worth a $8!#....... I was just told by someone it was shot and listened to them but kept them as practice dummies..... Glad I did.....I learned alot with the GM trans manual and tearing the pump apart in one of them....soon I'll got to the one that recently failed if it ever stops raining everyday. Thanks again guys