Help me diagnose a 700R4 problem? (BAD vibration).

[jdyates]

I have a VERY bad shudder at around 45mph. Apparently, this is when the TC is supposed to lock. I don't know when it started, or what might have caused it, but it was just kinda THERE one day a few months ago. When i tap the gas pedal a bit or let off a bit, the shudder stops. Someone suggested it was my tires, and i just replaced them with a brand-new set, and it fixed the vibration in the steering wheel, but the trans shudder is still there. It is a VERY bad vibration, and seems like it's coming from the trans, right under the seat. I read this:

"Torque converter shudder in 4th while lockup is engaged; problem goes away when the brake pedal is pressed slightly to unlock converter. Have a shop verify line pressure, and provided no valves in the TCC hydraulic circuit are worn, replace the torque converter. Also, Lubegard Shudder Fix will at least fix this for awhile. Or try a transmission flush by a shop that uses BG brand products."

But have no clue what it means, can someone help me out?

 

[jdyates]

BUMP. I really need some help or advice guys. It makes me legitimately scared to drive this thing.

 

[ChrisAU]

You have a miss, its an ignition problem. Whens the last time you did plugs, wires, cap, and rotor?

 

[JonZ71]

do a trans flush. it should clear it out. That's what i did. or you can do a couple of drain and fills if flushing isnt your cup o tea

 

[jdyates]

You have a miss, its an ignition problem. Whens the last time you did plugs, wires, cap, and rotor?

A miss could cause this problem? Plugs and wires are new. Guess I should do cap and rotor.

do a trans flush. it should clear it out. That's what i did. or you can do a couple of drain and fills if flushing isnt your cup o tea

I've heard that trans flushes can clog up the valves and do more damage than anything.

 

[ChrisAU]

A miss could cause this problem? Plugs and wires are new. Guess I should do cap and rotor.

Absolutely.

 

[bluex]

I've heard that trans flushes can clog up the valves and do more damage than anything.

Only on a high mileage never before serviced Trans. Hadn't yours been rebuilt already?

 

[jdyates]

Only on a high mileage never before serviced Trans. Hadn't yours been rebuilt already?

Once. Close to 100,000mi ago.

 

[jdyates]

Absolutely.

Cool, I'll try that. Thanks, Chris!

 

[bluex]

Once. Close to 100,000mi ago.

That's when they should be serviced anyway. Have it flushed an the filter changed then.