I recently picked up a '97 XLT on the cheap to replace my old '76 GMC rust bucket for hauling things around town. The truck looks great and has definitely been taken care of, but as expected for the price, it has a couple issues that I'm looking to sort out to have it be a truly nice reliable vehicle.

Issue #1 is that it has a slight clunk that you can hear and feel in the steering wheel when accelerating and braking. It only happens when starting off from a stop or braking while cruising. If you brake, let off, then brake again, it won't do it. If you accelerate, coast, then accelerate again, it doesn't do it. It feels like something is shifting a little bit back and forth depending on if it's pulling or stopping. The steering wheel also shifts a tiny, tiny bit up/down when it clunks depending on if you're accelerating or braking. The truck is a 4x4, but I've only driven it in 2H so far. I'll probably wind up taking it in to the shop for this one, but I'm curious what I may be in for.

Issue #2 is that something in the electrical system doesn't like rain. If the truck sits out overnight in the rain, it won't start in the morning. You can crank forever and it won't do anything. Now, if I pop the hood and jiggle all the spark plug wires at the distributer, it'll fire up, idle high and rough for a few seconds, then smooth out and act like normal. This song and dance works every time. I'm considering filling up the plug wire connections with electrolytic paste to prevent water from getting in there, but I don't really see how water could get in there in the first place. Any other ideas? Worst case scenario, I figure replacing the distributer and plug wires should sort this one out.

Thanks in advance!

 

last time i had a nice clunk in my truck it was the front U joint. i know a guy with a jeep and the same thing happens anytime it rains it wont start. he figured out any moisture at all in the air gets into the distributor and wont let it start. but he sealed his with silicon just to keep the water out and that worked

 

500 miles later, the fixit fairies have decided not to bless me with magical solutions, so I've begun to attack the issues. First off, I replaced the coil pack (nee "distributor" from the prior post). The truck now happily starts and runs in the rain. However, it does still have a bit of an intermittent miss at idle and when lugging so I'm going to try some dielectric grease (nee "electrolytic paste") and if that doesn't take care of it, I'll dump in another $100 worth of new plugs and wires.

As for the clunk, I crawled under the beast today to check things out. The front drive U-joint feels solid and the front drive shaft turns freely by hand (2H) as expected, so I don't think it's got anything to do with it. The rear drive shaft has maybe 5 deg of rotational slack and has no noticeable play up/down or left/right. However, when I pushed up on the driveshaft to check the U-joint play, I noticed that the whole trans moved a little bit. If I really shove on it, I can move the back up the trans about 1/4" up/down. I couldn't get any side-to-side play, but that could just be a lack of leverage. Being that the tranny mount is only $20, I think the next step will be replacing that and seeing if it solves the problem. If anyone else has any good ideas, I'm all ears.