I'm new here, forums are great. I have a 95 Jimmy 4wd, 4.3 auto 4l60e. 120k. The trans blew and I had a shop bench rebuild it. As soon as I reinstalled it, there was a vibration and kind of a grinding noise from somewhere in the drivetrain. I took the trans back out and had the guy put in a new valve body plate. I got a new flexplate and heavy duty converter. Put it back in and the same vibration going on. Worse with accelleration. Trans shop insists it's not their mistake, that there's nothing in the trans that could vibrate. Two shops couldn't diagnose. I can't diagnose. Not vibration dampener, maybe motor mounts or injection or fuel pressure problem? I did drop the gas tank when the trans was out and there was a freaking dead mouse in it. I cleaned the mouse fur out of the filter screen and reinstalled the fuel pump. I hope to start really narrowing this down. 4.3 is a long block I put in with only around 15k on it. transfer case seemed ok on the bench. Thanks if anybody can take a shot at it. Trans does seem to shift OK. Front axle maybe?

 

Well..this may or may not be constructive[:-], but my padre's 2000 Explorer had the timing chain go out, dealer pretty much put in a new engine, and ever since theres a grind from 2200-2500 RPM. Same dealer couldn't track it, agreed it was there, independent shop said no symptoms, could just be result of the install and movement, but perfectly fine somehow. Havn't had a problem in 15,000 miles!

Hopefully it's the same deal for ya, but I don't blame ya for being worried...trannys scare me

 

Check your u-joints also. I had a vibration in a 94 bravada that got worse under acceleration and would smooth out at highway speeds. Ended up being a u-joint that when I crawled under the truck to check them they seemed ok but under acceleration one of the caps would shift and vibrate like hell.[/align][/align]