Lockup issues

[_nickjoseph]

1997 K1500 5.7l with 280k on it. When I get to 45 mph cruising the truck jumps into lockup and stays that way until 55-60, which my transmission rebuilder said is normal. He drove it and told me it goes into lockup and that it’s normal. It shakes but also sounds terrible out the exhaust, it sounds like it is misfiring. Is this normal and has anyone experienced/ fixed this?

 

[indexcow]

1997 K1500 5.7l with 280k on it. When I get to 45 mph cruising the truck jumps into lockup and stays that way until 55-60, which my transmission rebuilder said is normal. He drove it and told me it goes into lockup and that it’s normal. It shakes but also sounds terrible out the exhaust, it sounds like it is misfiring. Is this normal and has anyone experienced/ fixed this?

Lockup should happen around 40mph and it will stay locked up while you are cruising. When the torque converter is locked up your engine is directly connected to your wheels so if your engine is missfiring or running rough you will feel it more when lockup has occurred.

 

[_nickjoseph]

Lockup should happen around 40mph and it will stay locked up while you are cruising. When the torque converter is locked up your engine is directly connected to your wheels so if your engine is missfiring or running rough you will feel it more when lockup has occurred.

I guess it’s a miss but only during this time, idk why

 

[indexcow]

I guess it’s a miss but only during this time, idk why

Do you have a check engine light? Have you checked your timing?

 

[_nickjoseph]

Do you have a check engine light? Have you checked your timing?

Yes I had it set at a mechanic shop