Transmission Slipping
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Transmission Slipping
I have a 1978 Corvette with an automatic transmission that has about 22,000 miles on it. When I drive for about an hour cruising in traffic the transmission does not want to go into third gear or sometimes slips out of third and back into second. I have taken it to a transmission shop but when they drive it, it does not occur during their test drives. I can alleviate the slippage if I shift it back into second and push the shifter back into third, which it shifts into third. Any help will be appreciated. The transmission shop serviced the tranny.
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From: New Or-leens Loo-z-anna
It would help if you ran a temporary supply line from the transmission test port to a 300 psi gauge in the cabin where it could be seen easily.
There are charts for the amount of pressure your transmission should be putting out in different gears while idling and cruising.
It is possible the transmission filter SEAL is not seated properly or is missing completely or there are two seals stuck in the valve body where the filter plugs into which are causing the pump to suck air.
If your transmission has an electrical connector on the case, sometimes the terminals can get corroded or oil-soaked.
If it has a T.V.cable and valve, the cable can get out of adjustment or the valve can get "trash" in it.
The governor could have a bad spring/stripped gear/etc.
All the above problems can be corrected by you and are low-cost repairs/just time consuming though..
If the main valve body is worn/has debris in it.....that is a different story and a last resort because it involves removing the body.
Keep in mind I am only a rookie and have run into these problems......the elimination process was a learning experience!
There are charts for the amount of pressure your transmission should be putting out in different gears while idling and cruising.
It is possible the transmission filter SEAL is not seated properly or is missing completely or there are two seals stuck in the valve body where the filter plugs into which are causing the pump to suck air.
If your transmission has an electrical connector on the case, sometimes the terminals can get corroded or oil-soaked.
If it has a T.V.cable and valve, the cable can get out of adjustment or the valve can get "trash" in it.
The governor could have a bad spring/stripped gear/etc.
All the above problems can be corrected by you and are low-cost repairs/just time consuming though..
If the main valve body is worn/has debris in it.....that is a different story and a last resort because it involves removing the body.
Keep in mind I am only a rookie and have run into these problems......the elimination process was a learning experience!
Last edited by doorgunner; Mar 8, 2015 at 02:33 PM.
