I've got one that has "8611950 5" cast into the p***enger side of the housing, and the tag says "D51 18 371". Any ideas?
I will have to look the "D" up, but the year is 51 and should be a single range hydro (NDLR). Could be a Kaiser, Hudson (but I thought they used Z, maybe big car), Nash, Lincoln, definitely not Willys (late 53-55 and W), Olds, Pontiac, Cad. Not GMC or Chevy truck as they used it in 54-62. One other possibility is Muntz Jet, but I thought it would have C for Cad.
I have a 51 Caddy Hydro that was a complete rebuild 30+ years ago, never ran. It has been crated and stored all these years with the whale oil in it. I just picked it up a couple of weeks ago. My plan is to use it in my next project. Is it worth messing with or not? What should I expect from this ******?
The 4speed Hydro we're talking about here (if we're talking Olds) was the brainchild of Charles (The Boss) Kettering, a General Motors engineer) in 1938. It was first installed into Oldsmobiles and then subjected to severe duty in military vehicles like 6-wheel drive deuces, supply line semi's,etc.. No wonder they are so rugged! In '49 GM introduced the Kettering designed OHV Cadillac and Oldsmobile V-8s. Except for a few std 3 speed ******s, these engines were equipped with the Hydro. Both Cad and Olds used this Hydro up to 1955, not '56. The USA production Pontiac also used it to 1955. GMC and Chevrolet trucks continued to use the Hydro to 1959. Nash, Hudson, Kaiser and Lincoln were also users of the Hydro. In 1956, the Olds came equipped with the Jetaway transmission, a totally different design from the 4 speed Hydro.
Those of you who messed around with the race-modified Hydros might help me with this one. Did any of these modified Hydros run the TV rod? How was throttle pressure regulated? Or was it pre-set in the valve body?
All of the B & M Hydro still had TV's..............for street cars you needed to fab linkage and adjust like stock............for racing only, youcould get by with a cable that you could p;ull the TV wide open on the line before launching
The 4 speed hydro, designed by Luke Beach and his group of engineers was an amazing accomplishment. The valve body, which is no bigger than a large size index card, has so many features. Both Olds and Pontiac did use the hydro in 56 on 88's and Chieftains. The 2 coupling or "dump and fill" (as I put it) hydramatic was used in Super 88 and 98's. The star chief also used it. This newer transmission had less maintenance than the original hydro, but performance was not as good as the original.
Can't remember off the top of my head if the '51 ****** was single or dual range or if they still used the mechanical reverse or had gone to the cone clutch set-up. Generally, the later the Hydro the better, up to 56 or so (see post above for years of usage). But even a '51 ****** will be OK, it'll shift hard and be tough enough for most street usage. My roadster has been running a "mutt" hydro that's mostly 1950 vintage for the last 40+ years, works fine...
http://cgi.ebay.com/ebaymotors/1953...yZ140720QQssPageNameZWDVWQQrdZ1QQcmdZViewItem never heard of a hudra-matic before, but it could be a prize for you fellas freezing out there in the midwest. I know from firsthand expierience they are heavy as hell. I know the earlier than 56' 4spd dual-range are the most desirable. I'm shocked yorgatron has yet to educate us further in this thread
So, what about the Chevy/Gmc truck in the later 50s? I am trying to learn here. Someone said the truck used the 12 disc and the ability to stay in first gear? ..or is that trans not the same as the pre 56 hydramatic? I am just asking in case I can save some future transmissions that may get s****ped if I find any.
51 hydros should be single range, with hydraulic cone clutch reverse mechanism (1st year for that, last year of the single range) Dunno where the "tron" is?
Is the input shaft on the single range Hydros longer than on the dual ? Do the Olds and Pontiac use the same slip yokes (OD and spline) ?
Well, the one with all the detents you'll find as you move it through its arc is the gear selector and the other one is throttle valve... Seriously, the shorter, inner one is gear selector and the longer, outer lever is the throttle valve.
Well, which one has the course spline ? I have a course spline, I thought was a 1950 Olds ? and the distance from the front of the transmission to the tip end of the input shaft is about 1/2" longer the rest of them. But I was wandering how this distance was made up??????????deeper belhousing on some years or models??
Malk: I've got a bunch of dual-range Hydro exploded diagrams. The easiest to work with is from 55-59 GMC truck Master Parts Book as it is in loose leaf form. Post your e-mail address and I'll scan 7 pages covering the CA-177 model trans which was used in the GMC truck attached to a Pontiac V8 engine from 55-59. 95% of the parts are the same as the Pontiac transmission and the truck ****** had an externally adjustable front band which Olds/Pontiac did not have in 55-56.
bringing this one back to the top with a question-- I am in the info gathering stage of building two Hydros- one is supposedly a real B&M, from behind a Chevy, and will be going behind a built Enderle injected 327. The other is where the question lies-- I want to buy the Hi-Rank book, and build a full manual, full race unit, and have access to several cores- which would be the one to start with? 55-57 GMC 1.5 ton camper with v-8 55 or 56 Pontiac cars 63 or 64 Cadillac cars
\ 55-57 truck hydro should be as strong as you can get in stock form. Next would be the 55-56 Pontiac, Olds. 63-64 Cadillacs used the dual coupling type, which I would not recommend.
Dual coupling hydros are fine for most uses, but have the "slow" 1-2 and 3-4 shifts, because the coupling has to fill. Also I am not a big fan of sprag clutches for racing. (yeah I know modern day transmissions use sprags, but only are used in 1st gear planetary hold mode, all other shifts done by band or clutchpak. DC hydros use them for two of the ranges) I have one in my 59 Olds and can barely feel the 3-4 shift. Most hydro people would rather have the single coupling type because of crisp shifts and no sprags. They are almost bombproof, as they were used in tanks in WWII. One other thing, I would rather have DC hydro than any slim jim. Now that is a wierd and not so good transmission.
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