I have a 1992 LT1 Auto tranny that shifts really hard from 1st to second and when it gets up to between 60 and 70 it has a strong vibration to it. When I speed up or slow down out of this range it stops - what gives? Thanks ahead for any help.

 

lee,what do you mean by hard shifts.....explane?.................and the vibrating and shaking,sounds like your u joints' on your drive line are no good,when they are bad. they will cause the car to vibrate at high speeds',and when the car slowes down it will go away,the joint 's are worn out and loose, so when the drive shaft spins fast the joint are walking all over the place, making the driveshaft bounce around cousing a vibration,check all three shafts, ......driveshaft.....and the 2 rear axels wich are drive shafts to, and have joints allso,......lee put the car in drive and listen for a clink sound, if you heare it that is a signe that the joints are no good. and there are other things that can couse a vibration to at high speeds. a out of ballance converter or flex plate will vibrate the car,and a out of ballance harmonic damper will cause a bad vibration, CHECK THE TRANNY MOUNT TO, and the motor mounts.but i will put my money on the drive line.........universal joints.

 

[quote]ORIGINAL: corvette king

lee,what do you mean by hard shifts.....explane?.................



CK,
It will rev pretty high while in first, then act like it doesn't want to shift to second. Sometimes I let off the gas so it will shift into second easier becuase it doesn't seem like it wants to shift. This is the only time it does it - from first to second. When it does shift it jerks/jumps some.

 

sound like a couple of things, first check your tv cable hear is a site that will show you how to addjust cable, www.tciauto.com this is a good web site.i could tell you how to do it but pictures are better. the tv cable will efect your shif ,make it late.and will burn your cluches if not addjusted right,pull your dip stick in the tranny and smell the oil .if it has a burn smell your cluches are probley burnt,and the oil should be bright red,,not dark red.if it is dark and smells bad you might be looking at getting that tranny rebuilt.i also want to tell you to check and see if there is a modulator on the back side of transmission if ther is there should be a vacume line conected to it, check the line foe leaks,if it does have a moulator valve it mite be no good,that controles how smooth the sift comes in, hope this helps,

 

The hard shifting problem can be attributed to a couple of things. Since the car is a '92, It has a 700R4 transmission in it, I think. Either your detent cable is out of adjustment or not hooked up or you have problems in the valve body of the transmission, such as clutch material or brass making the valves stick or passage ways stop up. There is a procedure for adjusting the cable. On the side of the cable where it snaps in the bracket behind your throttle lever, there should be a metal half moon piece inside the plastic housing of the cable. If you can, depress the metal and take the end of the cable housing and push it in all the way til it stops, then release the metal. Now, sit in the car and depress the accelerator all the way to the floor, (you will hear a crunching noise from the cable, but pay it no mind) then the cable will be adjusted properly. If this doesn't fix your problem, you are probably looking at some serious transmission work, because if there is brass or clutch material in the valve body, thats not good. You can pull the transmission pan and see if there is any bad stuff in it (brass will make the fluid look like metal flake). If there is, then you are staring an overhaul in the face. Good Luck![8D]

 

Thanks very much King and Mech!

 

you are very welcome.

 

Thanks and hope the repair is not to much. [8D]