Posted by Kent on April 08, 02 at 09:36:30:
Greetings all,
I posted about a week ago with questions I had about a newly purchased 85 GMC 2500 sub. One of my Qs was about a "Druming" IE "RRRRRrrrrrRRRRRRRrrrrr...." from I thought was the driveshaft. I got some good advice on what to check. I greased the U-joints and the Slip Yoke. I also took it into the shop to get a look over from my mechanic. He said it appeared to be in good shape and my vibes were most likely coming from the tires not the driveshaft. Soooo, I headed out for a 800 mile trip through the mountains this weekend......now I have a few more questions.
1) What is normal operating Temp and Oil pressure? The oil pressure varied between 30-45 and the temp was between 160-210.
2) The vibes continued the whole trip....the faster and more load on the drivetrain......the faster and more severe the vibes. This leads me to believe that it not the tires. If it were the tires it would be consistent whether or not I was accelerating or decelerating.
Another new twist also happened. After cruising for about 3-4 hours I pulled off to get some gas. As I came to the end of the off ramp, there seemed to be some serious grinding. It didn't feel transmition related....it felt like the driveshaft was knuckling and binding. The same symptom occurred several times in similar situations. I am 90% convinced it is the driveshaft...either the slip yoke or the u-joints. The only thing that makes me reconsider is that it is seemed to be more severe and consistent when I was turning.....either as I was coming to a stop on the off ramp or turning from a stop. This makes me think that it might be the auburn posi in the rear end that is giving me the problems. Any ideas?
Thanks,
Kent