I have a 2003 Dodge Grand Caravan with ~170,000 miles. The transmission (we think) has started making a tambourine shaking sound when the RPM gauge is around 1800 and the engine is under load. Coasting while at 1800 - the sound is gone. A mechanic friend drove with me and he said he thinks its the torque converter going bad - and that the sound is happening when the torque convert is going into lockout. I am clueless - so I'm asking here. Is this a likely scenario - he's saying with parts and labor around $450 to replace the converter. I don't want to do it if its really something else inside the transmission. Another clue is that when we go into reverse - the transmission sounds really rough. Maybe that's a different issue?

Thanks,
-Chris

 

BTW, the mechanic friend suggested trying some LubeGard to see if that solved the problem. We added 10oz of that (took out 10oz of fluid first) and have driven 500 miles since then - with no change in the sound.

-Chris

 

Do you think the sound it coming from the bellhousing area or inside the transmission?

 

I honestly have no idea. The sound does not happen if we rev in idle ... the engine must be under load, so we have to be driving. We know the problem is not in the motor - as we had the motor replaced two months ago and the sound is still present. It always happens at the same RPM ... just a tiny bit at ~20MPH, more around 40MPH, and very consistently in the 60-65MPH range, as long as the RPMs drop down into ~1800RPM. The mechanic friend of mine said I should tap the brake slightly when the noise is happening to see if it goes away and it does. If I set the cruise on an incline to 60MPH and make sure RPMs are right, the sound will jingle all the way up the hill, but if I keep my foot on the gas and barely tap the brakes, not enough to change speed or anything, the sound disappears. He says this is proof that the problem is in the torque converter, as tapping the brake takes it out of lockout. Does the TC go into lockout at the top end of each gear?

Maybe I have two problems ... maybe the tambourine noise is my TC and the rough transmission sound in reverse is my clutch pads?

Another POI ... about 6 months ago, when having some other work done on the vehicle, the shop said we needed to consider having transmission solenoid replaced, as the gasket around it was leaking. Not leaking bad enough to be a dripping issue - but definitely they could tell that the seal was going bad. Could this be part of the problem?

Thanks for the input.

-Chris

 

FWIW - we located the source of the "jingle" sound. It turns out the flex joint between the catalytic converter and the engine was the culprit. Seems that at around 1800 RPM - the motor pulls away or something like that - and opens up the gap there at the flex joint - and enables a broken part of that joint to jingle like a tambourine.

-Chris

 

Thanks, Chris for the information.