Transmission Slipping: RPM vs MPH?

[tbryanh]

Can a comparison of RPM to MPH be used to tell if a transmission is slipping?

 

[turbo8]

If your rpms increase and your mph stays the the same I would say it's slipping excessively.

 

[csp]

Possibly. It depends if the torque convertor is locked up or not.

 

[alumarine]

Help yourself out.
Auto or manual?
What's it doing in particular?

 

[Gadgetguy]

If it's an auto its hydraulic, torque converter, or clutch related, if its manual its clutch or hydraulic related. If it's slipping it's slipping...... and that's not good on either

 

[TorqueOfTheDevil]

There are times however when RPM can increase slightly more than mph, its not fixed as it does rely on the trans fluids viscosity to transmit power.

The TC clutch is more for economy once up to speed, not hard acceleration as people tend to think.

Mine slips pretty badly when its hot under heavy load.

Lucas additive helped, the oil cooler I'll be fitting will help more, but its all just delaying the inevitable rebuild.