700r4 pump noise

[Johnathan S]

Hello all, I have a 1987 R10 with a 700r4 out of 1986 C10. I had it rebuilt in 2018 and have had zero issues up until last week. The weekend before I drove the truck no issues, parked it for a week and went to take it out and all of a sudden it’s slipping bad right out of the driveway, barely wants to move. I got it around the block and back into the driveway and managed to get it back into the garage. If I shut the truck off and restart it’s good for about 30 seconds and then it slips again. Pump makes noise in park and neutral, fluid is good not burnt it’s a nice red color. I am getting debris on the dipstick though but I’m pretty sure that’s normal. It’s just weird the truck was driving fine and all I did was park it and now I have issues. The only thing recent I did was change the rear gears from a 3.08 to 3.73 but that was a little over a month ago and I’ve put some miles on it since then with no issues so I don’t think it’s a TV cable issue. Only thing I could think of was the filter so I changed it tonight haven’t refilled The transmission yet was going to do that tomorrow and try it out just wanted to get some opinions. When I dropped the pan I got a lot of gray paste around The magnet and in the filter assuming that’s just clutch material? What do you guys think?.

 

[NickTransmissions]

Hello all, I have a 1987 R10 with a 700r4 out of 1986 C10. I had it rebuilt in 2018 and have had zero issues up until last week. The weekend before I drove the truck no issues, parked it for a week and went to take it out and all of a sudden it’s slipping bad right out of the driveway, barely wants to move. I got it around the block and back into the driveway and managed to get it back into the garage. If I shut the truck off and restart it’s good for about 30 seconds and then it slips again. Pump makes noise in park and neutral, fluid is good not burnt it’s a nice red color. I am getting debris on the dipstick though but I’m pretty sure that’s normal. It’s just weird the truck was driving fine and all I did was park it and now I have issues. The only thing recent I did was change the rear gears from a 3.08 to 3.73 but that was a little over a month ago and I’ve put some miles on it since then with no issues so I don’t think it’s a TV cable issue. Only thing I could think of was the filter so I changed it tonight haven’t refilled The transmission yet was going to do that tomorrow and try it out just wanted to get some opinions. When I dropped the pan I got a lot of gray paste around The magnet and in the filter assuming that’s just clutch material? What do you guys think?.

Noise from the pump usually indicates problems. Debris on the dipstick is most definitely NOT normal. The gray paste is actually a bi-product of distillation of the transmission fluid itself.

Perform a line pressure test once you get it filled back up - you need to do this anyway if you disconnected the TV cable. You should see 50-70 PSI in Park, Neutral, Drive and Drive3...Reverse should have 90-110 PSI and manual 2nd and Low should have 130-175 PSI...

If your pressures are much lower and you have little to no line rise when testing at stall then time to yank it for overhaul as the pump rotor/slide are coming apart.

 

[Johnathan S]

Noise from the pump usually indicates problems. Debris on the dipstick is most definitely NOT normal. The gray paste is actually a bi-product of distillation of the transmission fluid itself.

Perform a line pressure test once you get it filled back up - you need to do this anyway if you disconnected the TV cable. You should see 50-70 PSI in Park, Neutral, Drive and Drive3...Reverse should have 90-110 PSI and manual 2nd and Low should have 130-175 PSI...

If your pressures are much lower and you have little to no line rise when testing at stall then time to yank it for overhaul as the pump rotor/slide are coming apart.

Any recommendations on where I can get a gauge? And I test all of this with the TV cable connected or disconnected?

 

[NickTransmissions]

Any recommendations on where I can get a gauge? And I test all of this with the TV cable connected or disconnected?

Amazon - search 'Transmission Pressure Gauge' ... Gearwrench and Matco have nice ones that are available on there. Test with the TV Cable connected and adjusted. You may or may not have to further adjust after the initial pressure test.

Read through these instructions to familiarize yourself with the process prior to doing the work so you'll know what to expect.