I find ALL comments on the 83, 84 and 85 Buick Riviera to be highly informative to a prospective buyer, here in the UK. It would seem that GM's 4 speed automatic transmission with electronic Overdrive is very unreliable, compared to its earlier 3 speed transmission.

From reading many of these excellent reviews, it would seem that US cars up to the late 1970's are much less complicated and more reliable than their 1980's counterparts.

Live Long and Prosper. So Say We All. Marty, England, UK.

How often should oil in the differential be changed in 1984 Buick Riviera with 307 gas V8 front wheel trans axle? It's shifting perfectly now.

Yes, I have owned 80 cars in my life ranging from the model year 1950 to 2001. I make it a point to avoid cars from 1975 through about 1993, and then again after about 2008.

I have a 1984 Riviera rag top which I have owned since 1991. The car now has about 215,000 miles on it, but many expensive repairs have been needed to keep it going. Rear air suspension has broken twice, engine rebuild at 165,000 miles, transmission rebuilt twice (yikes!!) really expensive replacement of convertible top material, various other annoying problems and now a leaking transmission line. BUT... they have all been taken care of and I still own the car because it looks great, is very comfortable and it is the last of the full size convertibles. Driving a full size convertible is an experience that cannot be topped by ANY other kind of car. I have not experienced any of the rust problems that others have talked about with my car. It is always garaged, but I live in the north east where salt and weather usually take a harsh toll on a car. Even the original paint is still pretty good 19 years later. I will probably keep this car until a new full size American convertible with great styling is produced - which might be never at this rate (unfortunately).