700r4 Transmission?

Question

I have a 1984 Chevrolet Suburban w/ the GM 6.2 Diesel Engine. This truck has the 700r4 Transmission, and here is my problem.

I don't know much about Automatic Transmissions, but I am fairly mechanicly inclined in reguards to the rest of a vehicle.

I was driving along, all fine and dandy, and then I stoped at a stop sign, took off, and the transmission sounded like it didn't want to shift out of first gear, so I eased off the accelerator a bit to let it shift, and it just fell out of gear. After this, it never went back in gear, not reverse, not 1st, 2nd, 3rd, or 4th. It will still go into park and lock into park like it should, but it won't even shift into any other gears. I can pull the shifter into any position, and there is no shifting into any gear.

I'd love to get this old beast moving again, so if anyone has any idea what may have happened, please enlighten me. I will answer any specifc question you may need for clarification.

Thank you all in advance for your help.

Trans Fluid level is OK, was the first thing I checked.

Answer 1

Since you have no gears , it points to a pump(pressure),valve body and/or a seal or component that is a common factor in all gears. If you can obtain a power flow chart, you will be able to pinpoint or eliminate certain components.

Answer 2

The converter may have puked, more likely the rings in the pump shattered and you lost all working pressure. Don't keep running it, if the pump let go you will chew the aluminum pump body up. Tear it down and you may be able to save it. To get the pump out you will need to have the trans out and pull the converter, then remove the pan and filter and lock up solenoid. Take the pump bolts out and use a slide hammer to pop the pump out of the case, don't try prying it out or you can damage the pump body. Remove the bolts holding the pump together and inspect the vanes and rotor. The rings hold the vanes out against the pump slide and are known to shatter. There are replacement rings on the market to prevent this. You may be better off taking the pump to a shop and having them assemble it for you, get a new gasket and o ring for it from them also and a filter and pan gasket. There is also the possibilty that the pump stator stripped, you know as soon as you try to pull the converter out. There won't be any splines left on the stator. In either case you will want a new converter.

Answer 3

The 700R4 has a .70 overdrive, so take your tire size and final drive ratio and multiply that by 70%. If you are talking about durability it depends on how the trans is built and what it's behind. A 540 could break a stock unit at 2,000 rpm or a well built one could live for years behind a 8,500 rpm small block.

Answer 4

that transmission is well known to have issues. you problem could be caused by many different things, just take it to a shop and have it checked out. it could be a fluid level problem, a filter issue, a vacuum modulator (although on a diesel not likely) it could be a shattered flexplate for that matter...

Answer 5

If its 4-wheel drive check to make sure that it is not in neutral. If not then rebuild the tranny, its toast. If you shelled the torque converter it damaged the tranny with the metal shavings. Drop the pan and check out the fluid and for metal shavings, if the fluid on the dip stick smells burnt and looks deep red then the tranny is gone

Answer 6

Transmission fluid level?

Answer 7

Maybe a torque converter