1955 Oldsmobile 98 Holiday Transmission Problems
#1
1955 Oldsmobile 98 Holiday Transmission Problems
I’m new to automatic transmissions and this old girl has a problem. She will not shift out of 1st gear at all. She goes into all gears like drive, reverse etc. but will not up shift. Recently, after the car has been running for a moment or two, I can hear a hissing sound coming form the transmission. Is there anyone out there that I can turn to for some really stupid questions regarding this car? I would like to get it a bit more mobile than it is now. Any help at all would be appreciated. I really know nothing about automatics. I have a service manual for the car but I need some help to get started. Thanks!
-Kevin
-Kevin
#5
I'm no expert either, but to me the hissing sounds like its a vacuum leak. Alot of Auto's use vacuum to change so I would start looking in your manual to see what hookup there is for shifting up a gear? I would also get under the car and start looking for rubber hoses that aren't where their suppose to be. And or, a barb coming off the Auto without a hose attached.
That being, that you havent already done this?
what exactly have you done? that might help sort out where your up to.
That being, that you havent already done this?
what exactly have you done? that might help sort out where your up to.
#6
The hissing noise is probably coming from a vacuum leak - there are no rubber lines attached to the Hydramatic at all..You may have rot holes off your vacuum canister which to me seems common ( but i live in a rust belt state anyways ) Start off simple - is the transmission fluid up to the fill line?? I had a Hyramatic that was working fine until it busted a rubber transmission cooler hose... it wouldnt shift out of first at all due to the pressure lost, but you would notice that since the fluid would be peeing all over the exhaust pipe and there would be a cloud of smoke you can see from outer space. You could also have a defective front pump that you may be confusing for a hissing vacuum leak
#8
I checked the fluid first thing and it was full. Might be a bit over full but not much. There are no leaks that I can see. The only strange thing I know of is the fuel pump has been replaced with an electric pump thus bypassing the vacuum of the pump. But since someone mentioned no vacuum lines to the trans then that cant be it. How does this thing know when to shift? Is there a sensor of some sort? Thanks for all the help.
#9
59-later that I know for sure, and I think radiator cooling might have started with 56 Jetaway. 55-57 shop books have been kind of elusive for me and not many of those year cars around here either.
Always thought it strange having rubber sections in the trans cooler lines, but when I pulled them off one of my Starfires and found swaged ends on the metal lines, I said, Hmm. Somebody meant to do this. Then there it was in the shop book.
HydraMatics rely on a throttle valve rod integrated with the carb linkage to tell them when to shift. The rod moves a valve inside the transmission and changes hydraulic pressures inside it to make the transmission work. That's oversimplified, but that's the principle it works on. PowerGlides and Mopar Torqueflites too, and GM itself came back to TV cables for their OD TurboHydraMatics.
Your man on HydraMatics is Tom Kasper in IL. I'll try to find a number when I get home.
BTW, the vacuum chamber on the fuel pump works the windshield wipers and deluxe heater controls. Guess back then, they didn't fully understand orificing vacuum to reduce it to a workable level for those applications.
Always thought it strange having rubber sections in the trans cooler lines, but when I pulled them off one of my Starfires and found swaged ends on the metal lines, I said, Hmm. Somebody meant to do this. Then there it was in the shop book.
How does this thing know when to shift?
Your man on HydraMatics is Tom Kasper in IL. I'll try to find a number when I get home.
BTW, the vacuum chamber on the fuel pump works the windshield wipers and deluxe heater controls. Guess back then, they didn't fully understand orificing vacuum to reduce it to a workable level for those applications.
#11
I replaced the high pressure 'rubber' lines on both my '57 and '59 Olds. It is a short section that comes out of the transmission thats about 7 inches long that connects to steel lines into the radiator. Actually Fusick sells them new
#13
The auxiliary booster provided temporary vacuum to the wiper motor during low/no supply (WOT for instance) from the intake manifold.
Norm
#14
Kevin, a good place to start would be to double check your fluid level and use the instructions in your service manual to set the Throttle Valve linkage. This is a very important adjustment! It might take a couple of tries to get it right. Let us know if this changes anything.
BTW, don't bother with ordering the high pressure transmission cooler hose from Kanter. You can usually get it at your local auto parts store.
BTW, don't bother with ordering the high pressure transmission cooler hose from Kanter. You can usually get it at your local auto parts store.
#16
The part does not exist.
Norm
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