db4690, I had the vibration before I took the DS to shop for balancing. That’s why I took it in. I never had the vibration until I changed the u-joints and the carrier bearing, even though the u-joints were shot and the rubber bushing in the carrier bearing was shot. I changed the u-joints and the driveline shop pressed the carrier bearing on for me. The vibration started after I put the driveshaft with the new u-joints and carrier bearing back on the truck. The shop had nothing to do with the vibration.
One variable is the oblong slots in the carrier bearing where the blots fasten it to the truck frame. Slide the CB to one end - vibration. Slide it to the other end - no vibration.
Yeah, and every time I have a beer or eat salami, I shorten my own lifespan, but not by much. The vibration only started right after I changed the U-joints and carrier bearing and I haven’t been driving it at those speeds since I noticed it, only to test.
If you follow that up with a big slice of pizza the next day, that counteracts the negative effects of the prior beer and salami. According to George’s Health Clinic … lol …
UPDATE: Moving the carrier bearing to one extreme of the allowable range eliminated the most severe vibration, further driving at highway speeds revealed that subtle vibration still existed above 55mph. I reasoned that if moving the carrier bearing side to side increased and decreased vibration perhaps moving it up and down might also have that effect. Since the carrier bearing on a Dakota hangs down, I could only shim it down. I started with 1/2 inch, did some test driving, and increased the shim to 3/4 inch. After about 15 miles of driving over 60 mph I could sense no vibration. I will post another update after more highway driving.
I don’t know about the other First Gen Daks, but the Holley 6280 with the mixture control solenoid that was not available as a replacement when the originals went south is what done in many of the 87s. 88s and after had throttle body fuel injection. Don’t know what done them in. Old age, maybe.
I replaced the 6280 with a 2280. 2280 is an old school carb, no mixture control solenoid. No problems, passes smog, the truck rides like new, I swear. I even managed to resurrect the air conditioning. It has a ton and a quarter suspension. It’s been a great work horse and a smooth ride.
Shift, semicolon. Couldn’t resist.
