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73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: Supertrucker on September 20, 2006, 03:12:00 pm

Title: '86 K20 problems and questions
Post by: Supertrucker on September 20, 2006, 03:12:00 pm

Hey everyone...I've got a tired '86 K20 Chevy with a stock 350 and basically stock everything.  I had a body man put a '91 Suburban front clip in and ever since then I've had an electrical problem. I have fried the ground cable once (literally), and everytime I unhook the ground cable from the battery I get a big spark. The body man shouldn't have hacked up the wiring too bad to install it, but I can't seem to find the problem. I've also fried the big red wire from the back of the distributor. I don't know what this one is for but it runs from the distributor across the bellhousing and up to the friewall. Another issue is when the transmission is shifted to reverse (automatic), I get a major clunk from the rearend. Actually more like a bang. The transmission doesn't shift hard or slip and it's a stock 14 bolt rearend.  The entire pickup has 197,000 miles and is currently not running due to it jumping time.  I guess one of the timing gears broke because it's plastic? So I have a new set from Cloyes that I plan to install. Now my question is, once the set is installed with the timing marks lined up, how do I get the distributor back in time? Sorry for the long post but I have alot of issues that need further addressing as we go along.  Thanks for the help.

Title: Re: '86 K20 problems and questions
Post by: roundedline on September 20, 2006, 05:34:00 pm

I am assuming you are talking about the power wire to the distributor.  It provides 12V to the coil for spark.

For the clunking, have you checked the u-joints?  If they are ok, check the pinion yoke, and the transmission mount.

When you replace the timing gear, get the engine on TDC, pull the timing cover off and pull the gear, and put it back together.  With the engine still at TDC, verify that the rotor is pointing to #1 (move if not) and adjust timing from there.

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

Title: Re: '86 K20 problems and questions
Post by: Blazin on September 20, 2006, 08:43:00 pm

Get a Haynes or Chiltons manual.

Title: '86 k20 problems and questions
Post by: Supertrucker on September 20, 2006, 11:55:00 pm

All the u joints are tight. Most have been replaced recently.

Title: Re: '86 k20 problems and questions
Post by: Lt.Del on September 21, 2006, 11:11:00 am

You do have a lot of issues.,  As for the clunking noise, if the ujoints are fine (ie: no play when turning the driveshaft  both ways quickly) and not your trans mounts, it is from play from somewhere.  I would next check, as Chris said, pinion yoke.  See if there is any play in the yoke gear and pinion gear. By playing around and thinking about it, you should be able to diagnose it.

SgtDel
aka "Andy"

www.delbridge.net

1979 Big 10 383 stroker
1991 Blu 'Burb 3/4 ton 4x4