Sounds like a rod knocking, but it's in the tranny

[Hugger-4641]

Thought I would get some opinions on this as I've never ran into it before. I know I've got to tear it down regardless and fix the leak, but my '85 Scottsdale 3/4ton 4x4 sounds like it has a rod knocking. It has set quite a bit between driving it and I keep it parked on a hill so the bed doesn't hold water. Consequently, it leaks tranny fluid while it is sitting, still has its original 700R4. It takes a few weeks for this to happen, but when it is a quart or more low of tranny fluid, you would swear it has a rod knocking, but it goes dead quiet when I fill it back up with tranny fluid. I'm thinking it may be the torque converter or the pump, or both, but it runs and drives fine after I top the fluid off. Anyone else ran into this before?

 

[Sad Sack]

Contact this member:
@NickTransmissions

 

[NickTransmissions]

Thought I would get some opinions on this as I've never ran into it before. I know I've got to tear it down regardless and fix the leak, but my '85 Scottsdale 3/4ton 4x4 sounds like it has a rod knocking. It has set quite a bit between driving it and I keep it parked on a hill so the bed doesn't hold water. Consequently, it leaks tranny fluid while it is sitting, still has its original 700R4. It takes a few weeks for this to happen, but when it is a quart or more low of tranny fluid, you would swear it has a rod knocking, but it goes dead quiet when I fill it back up with tranny fluid. I'm thinking it may be the torque converter or the pump, or both, but it runs and drives fine after I top the fluid off. Anyone else ran into this before?

Could be pump or converter, especially if the trans is low on fluid. That said, is the knocking present in all range positions? Or does it only happen when you put it in gear?

 

[Hugger-4641]

It's actually only knocking during start up and idle. If I fill the fluid up, it doesn't do it in any mode. If I actually drive it with it still being low, it quiets up until I go back to park and idle. Fluid is never actually low enough that it won't go into gear.