Ok so i topped off my fluid in my 72 Mach1 with an fmx. and car is shifting fine, the prob is that my shift points are funky, it shifts into 3rd at about 25-30 which i guess is fine but if i floor it at 50 or so it kicks down to 2cd causing my rpms to scream than wont upshift into 3rd until about 70mph and something tells me that a 3spd trans shouldnt be kickingdown at highspeeds when floored and really should be upshifting out of 2cd way before 70mph! my car does not have a stock carb it has a 750 holley double pumper. Is there anyplace i can take it in south jersey to have this problem fixxed? Im also willing to pay someone on here who can fix this problem for me, Its a linkage adjustment, i just dont feel like playing with it.
trans adjustment plz help!
- Thread starter oldskoool153
- Start date
woodsnake
15 Year Member
How does the car run other wise?
I don't think you have a linkage problem with the FMX. If the car has all it's gears, it isn't the linkage. And what I mean is, park is in park, reverse is in it's spot, etc....
It sounds like a vacuum problem. Either with the modulator, or with the line from the engine that feeds the modulator.
I don't think you have a linkage problem with the FMX. If the car has all it's gears, it isn't the linkage. And what I mean is, park is in park, reverse is in it's spot, etc....
It sounds like a vacuum problem. Either with the modulator, or with the line from the engine that feeds the modulator.
yea all gears are fine and where they should be..Vacume may verywell be the casue becasue when I got the car, vacume likes were cut and the car wouldnt upshift automatically, manually i could upshift into 2cd but the car WOULD NOT go into 3rd even manually it would not shift into 3rd. Than i put screws in the cut vacume lines and the car has since been shifting fine, but again the points are messed up. If i floor it at 50 and it kicks down to 2cd I can hear the trans at max rpm b4 it upshifts into 3rd at 70mph. I do most of the work to my cars myself but when it comes to transmissions i dont know alot. If I put a manual shift kit in, it should eliminate the prob right? I just dont wanna hurt my trans by spinning it too fast
woodsnake
15 Year Member
A manual shift kit will not cure your problem. Spend some time looking for vacuum leaks, and maybe make a few small adjustments to the modulator. There is a teeny tiny screw the modulator that you can make adjustments with.
Also, make sure the two hoses are in good condition. From the intake to the steel line, and from the steel line to the modulator.
Also, make sure the two hoses are in good condition. From the intake to the steel line, and from the steel line to the modulator.
woodsnake
15 Year Member
The modulator is the little can on the left rear corner of the case. Most likely the hose is disconnected or split, which would make the trans think your foot is on the floor all the time. A few cents worth of hose is a lot more sensible than ripping the trans apart and converting it to manual. Heck, even if the modulator is shot, it's only $60, still a whale of a lot less than converting the shift body.
Besides, manually shifting wouldn't be too groovy after a week or two it would be a real pain.
