This may sound stupid but how can you tell if your torque converter is locking up? I don't think mine does.

 

At about 45mph does the truck jolt a little and then feel like it has more power?

 

I don't think so. How well can you feel it? Is it like it is going into another gear or just a slight movement.

 

If you've got a stock converter its like its going into another gear, and the RPM's will drop about 300-400. If you've got 3.54 rear gears the converter will lock at 30-32 mph in drive and 48-50 mph in OD.

 

A good test is when it would be locked in, like 35-40 mph with o/d off on steady throttle, tap the brakes a bit while keeping the steady throttle. If you hear the motor (or see the tach) go up a few hundred RPM, it's working.

 

If your asking, I bet your converter is slipping a bit.

 

take it up to like 55 mph then push the gas down about half way. If the rpms do not rev up say 600 then it is locked. In fact they should barely go up but rise gradually as speed increases. You will also hear the engine lugging somewhat or i guess i could say the engine is actually doing some work.

Hope this helps
Adam

 

These guys all gave you good advice.
When your TC engages in lockup you will be able to watch your RPMS and your MPH climb at the same rate. The needles should be equally climbing.
Is your check engine light on, what year truck?
And once in lockup if you tap the brake it will go out of lockup.


-Jared