I hope it Ok to ask one non-Chev question a year. I have a 68 D@#$% 1 ton dump truck with a Dana 70 rear, a 4 speed with granny and a 318 engine. The truck is a beater that I use as a farm truck and to move dirt from one side of the road to the other or to get a little mulch now and then. There are a lot of things wrong but the one that bugs me the most is the vibration that I get between 35 and 45 MPH. It is fairly smooth up to 35 and then again after 45. I put new tires all around and had them balance the rims. That is, as much as a two piece rim can be balanced. The steering remains fairly smooth through the vibration so I don't think it is in the front end. Could it be the drive shaft? There are two on this truck, one from the tranny to the journal and another from the journal to the diff. Thanks, Gater
Absolutely could be your driveshaft is out of balance. Great friend of mine from high school days owned the biggest drive shaft shop in the land around here and the bass player in my band worked for him. that problem came up all the time. Find a shop that will balance it, probably not easy to do, and see if the problem goes away after that. The center joint could be bad also, but not likely as it would give trouble at all speeds. Andy
A couple things I would check first. If your wheels are in balance, make sure your rims are not bent. If you suspect the drive shaft, sometimes an easy cure is to rotate your drive shaft 90 degrees on your yolks. Thats worked for me a few times. BTW thats a tough old truck you have there. Chris
Thanks for the good advice. I think I will make it a winter project to get it in the garage (very tight fit) and drop the drive shafts and take them to the guy that fixed the one for my 3800. It sure is a tough old truck. I like it cause there is so much rust that women with small children run when they see me coming. At least, I think it is the truck. Gater
It's their ears. Long, sweeping ears. (Man this is hard to type without losing it!) You may be right. About it not being the truck that is scaring them. I'd rather not get into the goat jokes. It could get baaaaaaad. Gater
Vibrations It's almost certainly the driveshaft ~ grab it near the center support and see if the bushing is bad and allows up & down movement . then look at the yokes as it could have easily been re-assembled " out of phase " by the DPO , phasing means each yoke must be 90° out of alignment with the previous one or it's gauranteed to vibrate . Or , you can take it off and hand it to any driveline shop , balancing it is easy as pie and with all three new U-joints and perfect balance should co$t no more than $175.00 else they're cheating you . Good luck , this is a simple fix ! . Remember to check the total advance timing to 32° BTDC all in for good power when you're overloading it with dirt & rocks . When I first came to The City , we still had a whole fleet of 1970 Dodge D-600 dumpers with 413 V-ate engines and many had Allison Automatics with retarders , GREAT trucks if ugly as sin . Best of all , the entire fleet of them were painted...... Forester Green I may be a farm boy but I'm not touching any goat jokes with a ten foot pole
