when i am driving, usually at freeway speeds, i sometimes notice what seems to be like the trans down shifts for a sec. than up shifts. But when the shifting occurs the rpms change only about 300rpm..so it doesnt seem like the trans is actually shifting. Could this be an engine miss? please help because it only occurs once in a while and usually at freeway speeds. is there any way to rule out the transmission so i know that it isnt going to blow up on me. thanks!!
engine miss? or trans?
- Thread starter nates92ty
- Start date
T/C
T/C
Sounds to me like a T/C solenoid goin bad. While you are driving down the Interstate in O/D, leave your foot on the gas and touch the brake with your left foot. You should feel the T/C unlock. If it doesn't change, your T/C isn't locking up. Sounds like the same thing mine was doing. Does this sound right to everybody?
T/C
Sounds to me like a T/C solenoid goin bad. While you are driving down the Interstate in O/D, leave your foot on the gas and touch the brake with your left foot. You should feel the T/C unlock. If it doesn't change, your T/C isn't locking up. Sounds like the same thing mine was doing. Does this sound right to everybody?
so when im driving down the road in OD, keep one foot on the gas and touch the brake and i should feel the TC unlock? i think i have done that and i did see the rpms change so i guess it unlocked? ill have to go do a test to make sure..what is the part # for the solinoid and where is it at?
turbodog
Donating Member
You might want to put 'torque converter shudder' into your favorite search engine and research a little. I used to have a link to a great site which described it (specific to THM trannys) in detail. Unfortunately, it was on my (ex-) work computer, and I can't find that particular site... but there are others. Bottom line: TCC shudder CAN be caused by an engine misfire, so make sure the engine is running well. True TCC shudder is usually NOT the solenoid, but (unfortunately) is in the converter itself, requiring rebuild/replacement. In some cases, the pump is a factor as well. Mild cases can be teated (usually temporarily) by transmission additives which modify the friction characteristics of the clutch surfaces, eliminating the oscillation.
Just now I saw a few sites describing valve body mods (in ford trannys) to fix TCC shudder, but have never heard of such a fix for 700R4s.
HTH
Just now I saw a few sites describing valve body mods (in ford trannys) to fix TCC shudder, but have never heard of such a fix for 700R4s.
HTH
turbodog
Donating Member
Trans lube additives is almost as dangerous a topic as politics. No matter what I recommend, someone is bound to say it's snake-oil (and they'd probably be right!). So, I will say that once I was in a similar fix with my Astro van. I had the tranny fluid changed out (using one of those fluid exchange machines at an oil change shop (~$90), filter pack replaced, and put in a bottle of (as I recall) Dura Lube. The shudder went away for about 20k miles. When it came back, I unplugged the TCC wire from the tranny and ran it unlocked for another 50k mi until the tranny finally gave up (at ~230k mi) and I had it rebuilt. Unplugging the TCC wire cost me maybe 2 MPG, and caused no ther problems (well, maybe it hastened the tranny failure, but I'm not gonna complain about 230k mi on a tranny that did a LOT of towing). The tranny fluid change alone might well have been the real (temporary) cure. HTH!