Things that you've replaced that made a world of differance?

[454cid]

What do I mean by that? Over the last 6 months, I've replaced my fuel pump and my starter, and didn't realize how tired they had become until I installed the new one.

I thought I had injectors that leaked terribly, as the truck was often hard to start. The fuel pump started to become intermittent, but the truck had been hard to start for several years. The fuel pump took care of the hard starting issue. I thought the fuel pump was fine until it started to not come on at all.

Starter motor... I just replaced this, and have an active thread on it. It became intermittent. When it worked, it seemed to work fine. I was only replacing it because it sometimes did not want to work at all. Now that I have the new one in, the truck starts better, or at least sounds faster/better. The old one sounded "fine" to me, but it's obvious to me now that it was getting tired.

What have you replaced, that had you known it had slowly degraded over time, you would have replaced much sooner?

 

[PlayingWithTBI]

The 700r4 in my truck was rebuilt just before I bought my '88 C1500 (in 2002) it always shifted fast and firm but, after I added a few ponies and changed the governor weights to shift @ 5,000 it was hitting harder. I really didn't think much about it until it wouldn't hardly shift at all. After replacing the stuck TV spool and a missing check ball, it now shifts fast and firm but smoother than I remember in recent history.

 

[Urambo Tauro]

To my embarrassment, I made the rookie mistake of neglecting to check the inner brake pads, assuming that they would more or less mirror the outer side that I could see. Boy was I wrong. Fresh brakes making full pad-to-rotor contact made a world of difference.

Oh, and motor mounts! Mine were SHOT. (pics here) Not only did it *clunk* into gear, but there was a loud SQUEAK as well. It wasn't the belt; it was the mount brackets rubbing against the clamshells. Replacing the mounts dampened the clunk, eliminated the squeak, and made an overall difference in reducing vibration.

 

[skylark]

I replaced a girlfriend with a wife! Much better performance and I'm much happier.

 

[studigggs]

Going from 5-blade to 11-blade fan and a new fan clutch...I no longer drive a fanboat and can actually hear the engine noises.

 

[Knuckle Dragger]

Replaced the 4.3 and put in a 5.3

 

[letitsnow]

Rear leaf springs. One was broken on the bottom of the eye that the mounting bolt goes through. When I bought the truck, I assumed that the front end was a bit loose, making it handle weird. The rear axle must have been moving around a bit, because it handled much better after putting new leaf springs in. The front end ended up being in good shape.

Assuming things...

 

[honkon]

Fan clutch

 

[Supercharged111]

Shocks

 

[Schurkey]

What have you replaced, that had you known it had slowly degraded over time, you would have replaced much sooner?

1. Foam seal between plastic HVAC fan box, and the steel cowl. I suffered for two or three winters--had the heater core replaced (no change) stuffed in a 205-degree thermostat (no change) and then finally figured out that the heater worked fine, it was just overwhelmed by the blast of cold air coming past the foam seal that had turned to jelly.

Huge labor, about $5 in materials. (And I could remove the 205 thermostat. I get roasted out of the cab unless I turn the heater down, now.)

2. SES light comes on at highway speed. Everything seemed fine at lower speed, but the engine set a code for "lean fuel mixture" at 65 or so mph. As this dragged on, the code would set at progressively lower speed. O2 crosscounts seemed fine at low speed. I checked the AIR system for pumping air into the exhaust manifold, I checked and increased fuel pressure, I looked for vacuum leaks...nothing. I spent months on-and-off trying to diagnose the lean fuel mix.

In frustration, I ripped out the O2 sensor and found that it was broken internally. A $13 sensor took care of the entire problem.