GM Ring & Pinion gear failures 1980's

[Gary R.]

Calling on the old timers here to see if they recall service R&P sets having issue back in the 80's. I don't recall but I use either US Gear or USA Richmonds, as NOS gears were always hard to find. A couple of rebuilders told me to beware of NOS GM vette R&P with 80's date codes as they were soft. Anyone recall or experience that? Possibly it was the problem with a diff you had but you were not told of it for several reasons?
Thanks
Gary

[Edward J.]

Re: GM Ring & Pinion gear failures 1980's

Gary, I worked for a GM Chevrolet dealer as a line tech in the 1977 to 1987 for a high volume corvette dealer and never even ran into a rear end problem( very low horsepower engines in those days). At the time GM warrentys were not very long I believe they were only 12/12 . The only issue I recall was 1984? where they had some problems with the spider gear pin bolt breaking or backing out and you know what that means when it happens, I performed a few of these pin and bolt replacements along with loctite.

[Gary R.]

Re: GM Ring & Pinion gear failures 1980's

Thanks Ed. I do remember bad cam shafts in the early 80's and vette diff's failing from backed out RG Bolts but don't recall the soft gear sets. I don't doubt it though and will pass on using a set now.

[Clem Z.]

Re: GM Ring & Pinion gear failures 1980's

find a test lab with a rockwell tester and do a A/B test . i found that back in the 60s and 70s the GM gears were too hard and would break on the drag strip.

[George C.]

Re: GM Ring & Pinion gear failures 1980's

1975 Corvettes had a recall for noisy rear end gears back in the day. I can't recall the vin #'s. Maybe somebody can find the vin numbers of the recall. My 75 (1Z37J5S402602) 11/74 was an early car and was not included.

[Richard P.]

Re: GM Ring & Pinion gear failures 1980's

I am the original owner of a 1980 L-48. I still have the Car and most of its life it has had a High performance Engine and has been Club Raced. In Dave Mcleans book as the Cheif Engineer of the new C4 He said something interesting concerning the Late C3 Dana 44. As it was designed for the C4, and was ahead of Schdule it was addapted for the C3, at almost the late minute an Engineer came it to say that it was engineered for a Hyd Clutch where the torque load could be controlled and that the C3 had a manual clutch. Dave's responce was its to late now we will just see how many come back on waranty. When the C4 Dana 44 came along in 1985 it used a larger input shaft, larger bearings and suported the Main Caps with the Batwing. Although the Ring and Pinion is not interchangable it didn't change design much. Same with the Viper Dana 44. In my exsperiance with my own car I have broke Transmissions, U-Joints, Axel Flanges and 1/2 shafts. But never the Ring and Pinion. What I have found is that most of the Posi Clutchs are the biggest wear issue, and once worn the dump metal in the Oil wich takes out the Bearings. I for one have never herd of a soft metal issue with the R&P.