I noticed today while traveling down the interstate that the 1800 has developed a high speed vibration. I had the seals in the rear end replaced about four months ago and the rear end was topped up with 80W at that time. The vibration has more to do with speed than RPM's because at 6000 RPM's in 1st the vibration is not notiable, but at 3000 RPM in OD it is very noticable. The vibration seems to be constant whiether the clutch is engaged or not. I tested this by engaging the clutch while traveling about sixty five mile per hour and the vibration remained constant.

Hoping that someone on the board can offer suggested items to look at....
Is it possible that a universal joint is going out?

Thanks

Oliver
66 1800S

Well I found the problem last night during a quick inspection. Remember I said that I had the rear seal replaced a few months ago, well all four rear flange bolts had worked loose about an 1/8 to 1/4 of an inches. I guess the shop that did the work forgot to tighten them correctly. Everything is now tight and the car sounded much better coming to work this morning. Moral of the story "Always inspect any work done to your automobile".

BTW the bolts used in the flanges must be a special steel because not one of the four bolts had any distortion or abnormal wear. Considering that the car was driven for three or four days with loose flange bolts, I think that is pretty amazing.

Thanks to everyone that offered advice. Lucky for my wallet it was only something minor this time...

Thanks again posters.

Oliver
66 1800S

Oliver,
I agree with the other replies. These driveshaft parts are relatively cheap and easy to replace. Don't forget to mark the driveshaft halves before removing them from the car. All the u-joints must be on the same plane for the shaft to be even close to balanced. On that note, I would suggest having the shaft halves balanced at a shop that does this sort of thing. Shops that do alot of four wheeler work are a good bet.
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Roy Olson

center bearing as other poster said-probably due to at least 1 of 3 frozen u-joints.your time is worth than the parts cost-replace all or anything that does not freely.mark

u-joint, maybe, but...

Dollars to donuts it's the driveshaft center bearing.

Thanks for the pointer. I will get under the car this weekend and check out the center bearing. While the drive shaft is down, what else would be recommended to check????

Oliver
66 1800S