In response to an earlier post Andrew sent me a MAF to test 'Ole smokey the Shark' Thanks to Andrew and others my car has kicked the habit.

After starting and running a mile or so my trans started shifting really hard. Under normal conditions it would leap/bang into gear. After about 2 miles or so i slowed and shifted manually into 2nd, it went into first and stuck there.

I made it home, waited 20 minutes checked shift cables, kickdown relay and switch, all seemed fine. I took it for a drive again and no change. Really hard shifts.

Any ideas???

This shark is an 86.5 auto.

Thanks

 

No vacuum signal to the trans will make it shift very hard.

With all that MAF swapping, you probably disconnected or broke one or more of the vacuum lines that go to the 7-way splitter under the MAF.

 

Thanks. Back to the garage...

 

Mine is shifting hard when backing off throttle in normal traffic conditions. I will watch this thread with interest. Would the vacuum lines affect downshifts? I also have that leaping feeling. I backed off the cable a bit but didn't notice a big difference.

 

Make sure you are getting vacuum to the modualtor. If you are then adjust the thing back a bit. Some people think they are smart tightening up the modulator to get hard shifts. Leave it that way and you will end up with a broken torque tube.

The modulator can be adjusted - the green or pink thing on the left side of the transmission with a rubber vacuum hose going to it. Remove the rubber cap. Pry out the 'T' handle and turn it counter clockwise for about 3 to 5 turns. If you get it too soft you can always adjust it back up. If it still shifts hard back the thing off some more.

The vacuum supply for the modulator is under the air cleaner and runs in a metal tube on the top of the torque tube.

Dan the pod guy.

 

Definitely check vacuum to the tranny - in my opinion and experience the 5 way splitter is the easiest to check, particularly the main connection that runs back to the transmission. My 87 had a similar issue - the vacuum line running to the tranny had become disconnected at the rubber coupling between the plastic vacuum line running from the 5 way splitter and the metal vacuum line that runs on top of the torque tube. PITA to fix - you have to drop the exhaust and the heat shield to get your hands up there. If your Mityvac doesn't hold vacuum at all 5 points inputs of the splitter you have your problem, then its just a matter of locating the leak.

Hope that helps.

 

Steve C said that a vacuum leak would cause all the shifts to be abrupt. Up shifts are fine, its just the downshifts when I let off the gas. Greg adjusted the modulator and also said the same as Steve. I am sure it is something inside, 15k on a rebuilt and I am dealing with this crap, just my luck. Thanks for the input and I will check the vacuum just for peace of mind.

 

Holy cow, you cant win... It has to do with your dealings with Andrew.. He diss'd the shrine you know.....

 

Yes...finally. The shark is back. Andrew's MAF and a repaired vacuum leak. The mouse that built the house under my intake ate through the 5 way coupler. Lucky i had another.

Thanks to all for the advice.

 

You lucky bastard!! :-) Hope mine is that easy, wish me luck!