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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: 87454westernhauler on May 03, 2013, 09:20:24 am
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just lost all forward gears except first and reverse in my 86 k10 chevy with a 350/ 700r4 4x4. i have changed the trans fluid and didnt change anything. is there any quick fixes that anyone knows of that i could check???
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was your old fluid burnt or low?
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If the transmission was fine before the fluid change.....you probably have a stuck throttle valve. You can place the rear end on jack stands, start the truck put it in gear and rev it up some. then "pop" the gas pedal quickly on and off and see if it frees it up. You may have to have some higher rpms when doing this, 3000 or so.
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the fluid was burnt when i changed it and i changed it after it went out. ill try putting it up on jack stand tomarrow and see what happens.
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well tryed putting it up on jack stands and revving and popping the gas, didn't change it. so i put a bottle of sea foam in the trans and have been driving it around. haven't gotten it to shift yet though... anyone else have any ideas as to where i should attack next?
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Here are some other possibilities:
- 1-2 shift valve sticking in the valve body
- 2-4 servo not applying and/or 2-4 band worn out or burned
- governor sticking or governor gear stripped (images)
Since the fluid you drained was burned, check the line pressure and second apply pressure per the 86 Service Manual (http://www.73-87chevytrucks.com/techinfo/7387CKMans//Service/X8632_1986_GMC_Light_Duty_Truck_CK_G_P_10_to_30_Service_Manual.pdf) (beginning with page 7A-51 (pg 1147)) in the Tech Section (http://forum.73-87chevytrucks.com/smforum/index.php/topic,25639.msg213706.html#msg213706)*. Pressures should measure virtually the same, per the included chart.
For additional detail on the transmission, reference the 87 Unit Repair Manual (http://www.73-87chevytrucks.com/techinfo/7387CKMans//Unit_Repair/ST_333_87_1987_Chevrolet_Light_Duty_Truck_Unit_Repair_Manual.pdf) (beginning with Section 7A, page 700-R4-1 (pg 599)).
*Tip: Once a manual downloads from the site (up to several minutes), save it to your hard drive with an appropriate file name for future access.
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Nice
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well i pulled the governor out and gear looked good, but the governor dint seem to move at all. but i have a couple of used 700r4 that need rebuilt, i pulled the governor out of one of them and gear is in good shape and it appeared that the governor was sliding. put it all back together and no difference still... i also put it on jack stands again and noticed that when i put it in neutral tires would spin even after i stopped completely they still were under power in neutral. would that be a sign of a stuck valve???
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... i also put it on jack stands again and noticed that when i put it in neutral tires would spin even after i stopped completely they still were under power in neutral. would that be a sign of a stuck valve???
That's not uncommon. It's probably just drag transferring through the transmission. It doesn't indicate a problem unless the vehicle moves in neutral with the tires on level ground.
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Another easy thing to try.......disconnect the TV cable at the carburetor, start the motor(leave in park) and pul on the cable with your hand....pop it in and out several times, 20-20. This will sometimes unstick the throttle valve, if its stuck.