I have a Hydromatic (Jetaway) trans. from a 62 caddy but having problems with it some say these are a pain to rebuild and to get it done right. I have seen a kit to adapt a TH350, TH400 to any caddy engine 54-62. Has anyone ever done this and if so did you need to shorten/lengthen drive shaft or reposition the cross member??? I have a TH350 available collecting dust or would it be worth giving the Jetaway a shot???
If you are talking about the kit from Bendtsens, I can give you kinda some info. I did the same thing with a 64 Olds 394 engine. I didn't want to trust the Jetaway so I bought Bendtsens adapter to put a TH350 behind it. I am just in the process of building the car so I have no on the road experience yet, but I am very impressed with the quality of the components. Bob Bendtsen has been very helpful when I have called him for info and after seeing the kit I feel it is worth the $ 1000 because I will have a transmission any shop can fix if I break down far from home. Some others will have to give you more info about your particular swap, but I just wanted to give you a little info to get started. Here is a picture of my engine with the TH350 bolted up. And this is the cast iron pig I got rid of. Don
Thanks Don and by the way that set up looks good. I was actually looking at the kit speedway offers. Im not sure if youre using a different frame but with the jetaway you have the crossmember on there and with the 350 you dont, that is my main concern is if Ill have to make modifications to the frame Oh and good point about TH350 can get fixed anywhere if it breaks down out of town.
I have messed with a 63 Cadillac. The trans last forever. You just need to find who specializes in rebuilding the old stuff. Might be easier than all the unknown adaption. Those transmission just a rebuild problem for most shop but not all shops http://www.autotran.us/
The "Slim Jim" I had in my '63 Grand Prix supposedly had 3K miles on it when it went south. My trans guy tore it apart and the ears of the clutch pack had broken off. He said he could rebuild it if he could find the parts, but it would be cheaper to replace it with a 350th. I got my adaptor from Wilcap. The only difference I see from Bendsten is Wilcap makes their adaptor plate from aluminum and Bendsten is steel. Also, Wilcap doesn't stock them, but makes the kits when you order. It took weeks to get. I called Bendsten and they had them in stock. I ordered my 350th with a shift kit and a higher stall speed converter. The kit needed some tweeking to fit but works great.
Yeah, that old picture was in a different car and frame. We built a new frame for the new project, but in the picture the crossmember under the bellhousing hadn't been built yet. It is now in place. Don
Don: The swap looks good, but I can't resist asking how deep is the crankshaft to flex plate spacer is? That integral Olds bell housing is at least 3 inches deep, so I would think that the spacer would have to be 2.5" or more. The adapter does not provide a means of mounting on the bell like the Jetaway did, so new side mounts would need to be grafted onto the block, with the trans using the rear mount.
I wonder who many GM owners bought new B-O-P cars from '56 until the mid-60's but were afraid to drive them anywhere until a TH350 conversion kit was invented... Just wondering...
You are right on both counts. The kit comes with a huge round chunk of steel and a secondary spacer that moves a new triangular "flexplate" back to where the new TH350 torque convertor can bolt on. The two pieces I am talking about are the two below the adapter plate on the left side in this picture. And yes, we had to build new bellhousing mounts to support the engine as it had been originally. I wanted to use early Ford bisquits all the way around, so we made this mount.
So you wonder if all the hundreds of thousands of people thought their dual coupling 4 speed trans was junk and were afraid to go anywhere.......really? It's a damn strong trans....and not the same as the roto hydro which actually was a piece of crap from the git go. The dual coupling trans was brought in because the general population at the time did not like how hard shifting the old 4 speed hydro was.....you know the trans that became the B&M hydro, etc..........interesting how things change with time. I seriously doubt that any of these auto trans (by any mfr) were designed with gearheads in mind "down the road". I think it all had to do with mfrg costs, service, etc.......not necessarily high performance. JMHO
The problem is, back in those years you could find competent shops to repair those transmissions at a reasonable cost. Today it is not so easy. I called our local transmission shops and they were quoting $ 1700 to $2500 and said they hadn't done one before. I don't want to get 500 miles from home and have a transmission go out that I might have trouble getting fixed. You can find shops everywhere who know how to fix an ailing TH350. That was my logic. Don
I take it that the smaller spacer puts the flexplate with ring gear in the proper position for the Olds original starter. And the original lower bell housing is used too. Ross Racing chops off the integral bell housing on TH400 transmissions and puts a new shorter bell housing on the transmission via the front pump bolts. I believe it reduces the length of the crank to flexplate spacer significantly. Don't know if he does this with TH350s, but sure would think it wouldn't be difficult.
The DC hydro is a good, but not great transmission. The OP might have considered using a dual range slant pan from a 55-56 Olds, as this is what I plan on doing with my 59 Olds. Even though the DC hydro is leaps and bounds above the slim jim hydros, it will never compete with early hydros. The controlled coupling and sprags are not favorites of mine.
You are correct. The thin spacer puts the new flywheel in the same spot it went originally so the starter will engage it. The second spacer is about 3-4 inches thick and moves that triangular plate back to where the th350 convertor can mate up with it. Yes, you can use the stock lower bellhousing , but I had to use a switchover bellhousing as mine is in a hot rod and the steering box is in the way. As for the modified case thing, I had recently heard about the one Ross sells, and I did know of one other company advertising a modified 350 case where you send them your empty case and they machine it and send it back, then you have to load all your gears and stuff into that empty case. That seemed like a hassle to me, going through all those steps, so I just bought the adapter. Not sure if Ross does it the same way or if they sell the trans all ready to be installed. Don
It's one of my jobs to be a smart ass... But who would work on your Olds engine if it had problems? You sure wouldn't get most average 2012 technicians to even look at it... Carburetor? What's that? Points? Ditto... I'm not knocking the TH350 by any means... but so many are afraid of what we are not familiar with. I guess on of my favorite things about these old hot rods is driving something most would be scared to drive across the street. Looks like a cool project... have fun.
Don My trans kit for early Olds are delivered turn key ready to bolt on to the engine and use......you need nothing but the ph to place the order.....and It'll fit in any place a stock trans will without modifying the tunnel In your case ..... Your building around the drivetrain.... If car was already built.. You'd have to cut the floor out My deal is 5 inches shorter with the flywheel in place like the factory..... And no spacers Also I can use the factory side mounts when putting in a stock vehicle Just a little info since there where questions And I do these in 350/400 turbos as well as 700r4 and 4L60E Types Tony
Tony, I was hoping you would see this and chime in. That is some good info, and I bet the way you do it makes it a lot more simple. When I got my setup I didn't know yours existed, and the one I had seen that someone else sold seemed to be such a lot of work.....ie, I would have had to have the guts removed from my trans, ship it to them, get it back, and have the guts reinstalled. Don
well i gave it a shot i took the hydromatic to 3 different shops and same result. The trans. is shot and to find parts was going to be a pain it was going to take longer than normal and was looking at $1,200++. 2 of the shops said they would try but had never done it before on a hydromatic another said they wont even touch em....on the plus one of the shop owners saw my frustration and disapointment and actually gave me a TH350 for free...he said it was good if any minor issues to bring it back and he would fix it for free. Sooo i guess ill just buy the adapter and make the modifications.
Take that vintage ENGINE to any "modern" shop and you'll get the same answer. That's like John Force going to Wal-Mart looking for an oil change on his funny car... you have to go to the experts. I bet you can find someone to buy the remains of that old Hydro....
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