We return to the Turbo-Hydramatic once more today, and our third installment sees us at a critical point in the timeline of the automatic transmission. Fuel economy pressure from the government and performance demands of the consumer increased considerably in the intervening years since the THM’s debut in 1964. That meant the creation of lighter, more compact, and cheaper versions of the Turbo-Hydramatic compared to its flagship shifter, the THM400. GM branched out into the likes of the THM350, THM250, and the very problematic THM200.
In 1987, GM stepped away from the traditional THM naming scheme and switched to a new combination of letters and numbers. Number of gears, layout, and strength combined to turn the THM400 into the 3L80. But the hefty gearbox was already limited by then to heavier truck applications; passenger cars moved on to four forward gears after the dawn of the Eighties.
TTAC commentator SavageATL writes:
I have a 1991 Cadillac Brougham, the old rear-wheel-drive model. The car was sitting for a long time, and it has a Chevy 305 with bad valve seals. Lesson: beware of low-low-mileage cars.
It smokes badly on startup after sitting and burns a good bit of oil — about one quart every 250 miles. I’ve driven it as-is for a while, but the day is coming when I’ll need to do something about it.
I was told that the heads would need to be replaced to the tune of about $800. I am thinking for that kind of money I can go ahead and swap out the 305 for an LS. I was quoted about $2,750 for a 5.3-liter junkyard LS swap and $3,750 for a 6.0-liter junkyard LS swap, start to finish.
Latest Car ReviewsRead more
Latest Product ReviewsRead more
- MrIcky Haven't these been out for a while? Is the news just that Japan gets them now too?
- JTiberius1701 Jaguar Contour....
- Analoggrotto How pathetic, as Telluride ATPs continue to soar with a model released in 2018, Toyota is living in the past, bringing back old heavy truck frame junk like this to sell a few hundred copies. They can't even remotely compete on reddit for the toast of society who enjoys the finest AVMs and ATPs by signing up for the finest SUV for under $100k and only #2 to the Purosangue beyond that. This is like the Miata of 3 Row SUVs, you can pay more but not get anything better.
- Dukeisduke The trans brake locks the transmission in both Drive and Reverse, holding the car while you get on the throttle to bring the torque converter up; when you release the button, you GO!
- Canam23 In the early 80's I was buying old American iron in Southern California, cleaning them up and selling them. Before the internet you could get some really good deals because no one knew what things were worth. I started with a 56 Lincoln Premiere that I bought for $400 and sold two days later for $2000. I had a Swedish buyer who told me he would take anything in good running order with lots of chrome and 30 years old because that's when they could be brought over without penalty. It was a lot of fun and some didn't sell as well as others. Then I had kids...;