automatic transmission going bad?

[broken_line]

the transmission makes my uncles blazer shake like you are hitting big bumps in the road when in over drive and slightly shakes in reverse. gears 1-3 are fine and shift crisply.. fluid is red, smells like it came out of the bottle.. any ideas? shot? or sometihng plugged? it was all of a sudden thing happening

[jeffreyd]

sure it is not a drive line whip at high speed from bad ujoint or carrier bearing

[Phred52]

U-joint was 1st thing that sprang to mind for me too. Crawl underneath, grip the driveshaft near the u-joint and 'push, pull and twist' If you get any movement, it's a u-joint that's bad. Be sure to check both front and rear driveshafts if it's a 4x4. Phred52

[Jeremy airjer W]

what year is it?

Checking the simple things first, like the u-joints, is a good first step.

[broken_line]

it is a 1987, 2.8L engine. with i think 127000 miles. most of the miles were not spent pulling anything, sat in a shed for 4 years.. im stumped. it acellerates fine shifts fine but when in over drive going up a hill, it shakes also it does it a little bit in reverse. i will check the joints. how much would a rebuild cost if it was the tranny?

[Jeremy airjer W]

Sounds like you may be describing a missfire under load.

Wet down the wires with some soapy water and then power brake it. You will know immediately if there is an issue or not with the wires.

[broken_line]

that was the problem! bad spark plugs and a loose spark plug wire! thanks!!

[Jeremy airjer W]

Booo yah! Somtimes I amaze myself!

[Farley]

Holy Moses, nice job Airjer

[jwhjr]

Nice when it's a quick fix!