: Early 70s turbo 400 transmission noise in 1st gear- need info

11-18-04, 01:07 AM
I am considering a 1973 General Motors car with a 400 turbo automatic- same transmission in the 71-74 Cadillacs (probably other years as well). When pulling away from a stop, when the car is in 1st gear, it (transmission) will make a "whine" or "hum" sound until the car shifts into 2nd gear. As soon as it goes into 2nd- it stops making the noise. When it shifts- the shifts are perfect, as it also is from 2nd to 3rd. No slippage, no hesitations. Also too, whether you put the car in drive or reverse, the transmission goes in instantly- which is great. I was told that the filter probably needs to be changed- which is why it is making that noise. I have no idea. I am thinking/hoping that since it shifts fine, that it is nothing major. Someone also told me this was typical of the GM 400 turbos, but I have owned a 1972 Buick Electra, 1971 Chevrolet Caprice and currently a 1969 Chevrolet Caprice- all with the turbo hydramatic 400 and they did not have this noise. Someone with a 71 Buick LeSabre (same transmission) told me that their car did this too- before and after a rebuild, and the shop said it was normal for these, but as mentioned- none of my 60s/70s GM cars ever did this. Any advice appreciated.

barge master
11-19-04, 06:31 AM
I'm no transmission expert, but my TH400s have made wierd hums also. They tend to hum in neutral or park when cold. I've found a fluid change helps it. You had an Electra too huh? Those things run a very close second to Caddys in my heart. I had a 75 and I loved it. BTW the tranny had a constant whine. :eek:

11-19-04, 06:37 PM
I'd like to know too. My 75 has the noise, and so did my 78. On the 78, I had the fluid and filter changed and it didn't make a differance.

11-20-04, 01:03 AM
Hello and thanks. The 75 Electras are nice. There is a local 74 Electra I have been thinking of checking on.

Yes, I had a 1972 Electra 225 Custom 4dr hardtop that I sold a couple of years ago. It was a true "found in a barn" car. It was a 1-owner car, with 90K actual. The original owner- a doctor had passed away and his son was selling it. It was like new and I drove it home. It had been setting in the barn for a few years, (covered in a thick layer of dust when I inspected) but still ran perfectly and still had ICE COLD AIR and had never been recharged. I sold it to a man in South Carolina- who bought it for his son. They still have the car- keeping it in beautiful condition. I miss that car. I paid only $1500 for it. I also had a 1972 Cadillac Sedan DeVille that I had back in the very early 1990s. I do not recall the transmission noise on that car either, nor on my old 1971 Chevrolet Caprice sedan- all with the 400 turbo.

Yes, that car did not have the transmission whine/hum, but as I research, it is not uncommon for these cars, nor does it seem to be a major concern. I will probably go ahead and buy this car I am referring to, if I can get it for less than $1200.

Here is a photo of my old 72' Electra. Photo was taken in 2001.

11-20-04, 01:08 AM
Here is another photo of my old Electra 225 Custom.

Top of rear seat. Interior was like new. Vinyl top was starting to get a little dry however.

11-20-04, 01:39 AM
I believe my Dad's 1972, Olds 98 had the 400 trans. and it was also whiney, but never had any problems.

11-21-04, 12:13 AM
Those 72 Olds Ninety-Eights were neat cars. They were the same basic car as my 72 Buick Electra that I have posted here. Oddly, my Buick did not have this "hum" in the transmission. However, some have reported it in some other GM cars of the same era- from Chevrolet, Pontiac, Oldsmobile, Buick and Cadillac with the TH400. Seems like not a cause for concerns.