1975 L-82

[donald yielding]

do all L-82's prior to 1976 have a th400 transmission? I looked in my Hayes manual and it does not show a th350 prior to 1976. just to clarify I am looking at auto only.

[Tom B.]

Re: 1975 L-82

Donald,

1976 was the first year for the THM350 but only on the L48. Same for '77 and in '78 the THM 350 was the only automatic. '76 and '77 L82 still got the THM400. The L82 was also available with a 4 speed in these years.

Tom

[Joe L.]

Re: 1975 L-82

Donald-----

From 1968 to 1975 all Corvettes equipped with automatic transmissions used the THM-400 regrdless of engine. Beginning in 1976, both THM-350 and THM-400 were used. Usually, the THM-350 was used for L-48s and the THM-400 for L-82s for 76-77. For 1978-81, the THM-350 was used for all Corvette automatic trans applications. Beginning in 1982 the THM-700R came into use. Although the nomenclature has changed (4L60) and electronic control added (4L60-E), the same basic transmission is used in Corvettes today.

[Craig S.]

Re: 1975 L-82

Tom - I once had a 77 L48 my wife ordered brand new and we were the first owners, it was a July 77 built 77 (1Z37L7S441367) and had a few 78 items on it, such as the new (problematic) anti-theft key build into the drivers door and the new 78 style crossed flags on the front fenders, and it had a THM400 for sure. So, the rule about L82's only getting the THM 400 at least for late 77 is not absolute...Craig

[donald yielding]

Re: 1975 L-82

I thought that was correct, tks for the info. Donald member# 39420

[Tom B.]

Re: 1975 L-82

That's interesting Craig. I wonder if it was due to a lack of inventory on the 350 trans or some other production problem.

Tom

[Craig S.]

Re: 1975 L-82

I'm not really sure, but, I suspect it was always OK to install a heavier duty as substitute...it seems the window sticker (tank sticker I am sure also) had the M40 listing as well...Craig

[Joe L.]

Re: 1975 L-82

Tom-----

For 76 and 77, GM did not specify that L-48s were to be fitted with THM-350s and L-82s were to be fitted with THM-400. For 1976, I believe that all L-82 were equipped with THM-400. L-48s could be equipped with either, although the THM-350 likely predominated.

For 1977, I think that it's possible that either transmission could have been used for either engine, although the THM-400 for L-82s and THM-350 for L-48s likely predominated.

[Tom B.]

Re: 1975 L-82

Joe,

That makes sense. I was going by the trans codes in the Pocket Spec Guide. 1976 code AM, XH 350w/L48 and code CZ 400 w/L82. 1977 code AM 350w/L48 and CB 400 w/L82. My book is a '97 so it may have been updated with new info.

Tom