So my friend has a question. He has a 1995 GMC 1500 4.3L V6 truck. Automatic transmission, 219,000 miles (that's 219k on that transmission and engine), and he has changed the transmission fluid on his truck every 60,000 miles. So the last change was at 180k. It's a 2wd truck btw, locking rear differential.

His question: Should he change the transmission fluid to synthetic? He says it shifts rough when taking off from a hard stop. His exact words: "taking off from a hard stop, it has a rough feeling to it"

So, any comments/suggestions?

10/14/2007 7:36:19 PM

he should go to a transmission shop and have the valvebody reamed and the updated solenoid installed.

10/14/2007 7:48:19 PM

use Dexron VI instead of III. they have it at pep boys. the specs should exceed that of a synthetic dexron III

10/14/2007 10:20:14 PM

you totally skipped over dexron V

10/14/2007 11:25:54 PM

Quote :

"he should go to a transmission shop and have the valvebody reamed and the updated solenoid installed."

10/15/2007 8:27:14 AM

Quote :

"His exact words: "taking off from a hard stop, it has a rough feeling to it""

tell him to grease the output shaft.

10/15/2007 9:47:10 PM

why dont you grease my output shaft.

10/15/2007 9:48:42 PM

i will while i'm plugging your exhaust.

10/15/2007 9:50:23 PM

"it has a rough feeling to it"

10/15/2007 9:53:38 PM

Oh god, this is going to make this thread sound even gayer.

OK, does the output shaft actually have grease (like grease fitting) or is it a fluid.

Duder says he didn't see an obvious way to grease it.

10/15/2007 10:02:20 PM

he needs to use GM grease made for this. its about $30 for a container of it. don't know what's so fucking special about it but it works. he needs to drop the driveshaft and grease the splines on the front of it. not a hard job at all. 4 bolts (13mm i think) hold the driveshaft in place at the rear u-joint. tell him to make sure the truck is being held by the parking brake and not the transmission so the driveshaft will come out easily.

10/15/2007 10:14:37 PM

Aha, the rough takeoffs were figured out. His muffler is corroding from the inside out, and as of right now it resonates at a certain RPM level, which happens to be the same as a hard takeoff.

Kthx, mystery solved.

10/17/2007 6:20:41 PM