727 Goes into reverse but

[BeepBeepRR]

My friends 727 Drops into reverse and goes backwards just fine. I checked the fluid level in neutral with the car running. The fluid level was fine. It will slightly pull forward if you give it a bunch of throttle. Dropped it all the way down to first nothing, second nothing drive barely pulls at all. Im not a transmission guy at all but if anyone has an idea as to what it could be let me know.

 

[dadsbee]

Sounds like my backhoe.. fawked...

 

[turbine68rt]

Check rear clutch. This can be air checked with the valve body removed using a rubber-tipped gun at about 30psi.
Port #5 is rear clutch apply.

 

[Rishi]

If the fluid levels are fine, you don't seem to have (very much) hydraulic pressure. You may have to pull the tranny at some point.

As a long shot, you can see if there is blockage in the cooling lines running up to the radiator and back. I'm not sure how to test this without an inline hydraulic gauge.

I might be tempted to disconnect the OUTPUT line from the tranny, and crank it over (no center distributor wire) to see if anything goes through. If not, I might then be tempted to reattach the coil wire and start the engine briefly (1-2 seconds running) with the OUTPUT line (from the radiator) placed into a container to contain transmission fluid if it sprays all over.

If it DOESN'T flow, pulling those lines off and blowing air through may, as a long shot, dislodge something. But unless you can figure out why you have no hydraulic pressure, the tranny may need to come out for service, teardown, and/or overhaul. Testing the function of some clutches by removing the valve body may not require pulling the tranny.

The starter motor turns the torque convertor, which is connected to the pump at the front of the transmission. So if the engine starts, we can presume it's all turning when the engine is running.

 

[pnora]

My friends 727 Drops into reverse and goes backwards just fine. I checked the fluid level in neutral with the car running. The fluid level was fine. It will slightly pull forward if you give it a bunch of throttle. Dropped it all the way down to first nothing, second nothing drive barely pulls at all. Im not a transmission guy at all but if anyone has an idea as to what it could be let me know.

Drop the pan and see whats in it. You can then drop the valve body and check the clutch packs with shop air. Sounds to me like the clutches are toast. Your friend should have a little more information. These things normally do not just happen.

 

[BeepBeepRR]

It does seem weird. I installed the 440 and transmission almost 2 years ago and it has been fine. The car went to an alignment shop and now it has no forward gears. I don't know how it was shifting prior to the alignment shop trip. But that was the last place it was before being parked in his cousins yard backed up to the garage. The 1st gear and reverse band are the same aren't they in a 727. My thoughts were that If I dropped it into 1st it would pull. But that was not the case. So maybe it just has some junk in it. Which line is output and which is input? I guess I can take them off at the radiator end to see if its pumping.

 

[R413]

Is this car something new or have you been driving it? Was it run without throttle pressure linkage?

You have fluid, it goes backwards and nothing all forward positions. Sounds like the rear clutch which is applied on all forward gears.

Might see if the filter is plugged and or pan full of clutch material.

Otherwise pull it and fix it.

Cooler lines plugged won't do this. I've seen guys plug the lines and use the trans. But it lubes the rear support where main shaft rides, better to loop them together.

 

[pnora]

It does seem weird. I installed the 440 and transmission almost 2 years ago and it has been fine. The car went to an alignment shop and now it has no forward gears. I don't know how it was shifting prior to the alignment shop trip. But that was the last place it was before being parked in his cousins yard backed up to the garage. The 1st gear and reverse band are the same aren't they in a 727. My thoughts were that If I dropped it into 1st it would pull. But that was not the case. So maybe it just has some junk in it. Which line is output and which is input? I guess I can take them off at the radiator end to see if its pumping.

Waste of time. If it backs up its pumping.

 

[kiwigtx]

Pull the dipstick and sniff the tranny fluid. That might be a clue.

 

[pnora]

Pull the dipstick and sniff the tranny fluid. That might be a clue.

Thats a bad image.

 

[dvw]

If it has no forward gears there would be 2 prime suspects. #1 Rear clutch failure, piston seals or frictions worn. #2 Stripped front planetary splines where they ride on the output shaft. Both will result in reverse working with no forward gears. I've seen both of these failures. You won't find either of them with a pressure check. Both require disassembly of the transmission.
Doug

 

[kiwigtx]

Thats a bad image.

I can tell you for a fact that when the tranny in my work van imploded....the fluid hard a nasty burnt smell....like burnt varnish.

 

[BeepBeepRR]

I pulled the dipstick and checked the level it smelled ok But he had just added fluid to it. So it may have masked another issue.

 

[BeepBeepRR]

If it has no forward gears there would be 2 prime suspects. #1 Rear clutch failure, piston seals or frictions worn. #2 Stripped front planetary splines where they ride on the output shaft. Both will result in reverse working with no forward gears. I've seen both of these failures. You won't find either of them with a pressure check. Both require disassembly of the transmission.
Doug

This seems pretty logical.

 

[turbine68rt]

The air check is to verify if the rear clutch is applying correctly. If the piston seals are damaged/worn you'll know it, which will require a teardown regardless of whether the seals or clutches are damaged.

 

[Rishi]

It does seem weird. I installed the 440 and transmission almost 2 years ago and it has been fine. The car went to an alignment shop and now it has no forward gears.

Maybe someone at the shop pulled a Ferris Bueller and took it for an extended 4-hour test drive and cooked the tranny.

 

[R413]

Pul it out, any checks won't tell you anything other than remove it and fix it.

 

[BeepBeepRR]

Maybe someone at the shop pulled a Ferris Bueller and took it for an extended 4-hour test drive and cooked the tranny.

My thoughts exactly... These morons around here I wouldn't put it past them. He does have a backup transmission that was on his 383 and its the original to his car but the condition of that one is unknown.

 

[Jerry Hall]

My thoughts exactly... These morons around here I wouldn't put it past them. He does have a backup transmission that was on his 383 and its the original to his car but the condition of that one is unknown.

A lot of work to test and unknown transmission.

 

[HEMIB]

Maybe someone at the shop pulled a Ferris Bueller and took it for an extended 4-hour test drive and cooked the tranny.

I took my new RAM in for a fault in the tailgate it had 1,000 mile on it when i got it back it had 1,200 so someone had been been joy riding