58 hydramatic
June 13th, 2019, 06:43 PM
#1
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Join Date: Mar 2012
Location: Brisbane Australia
Posts: 75
58 hydramatic
Hello again from Australia. Hope everybody is well !!, In my last post i was looking at getting my 58 Hydramatic rebuilt, I picked the car up from the transmission guy yesterday. He rebuilt the trans with the kit i supplied from Fatsco. and i also managed to buy a NOS speedo gear assembly and he used this as well.John who did the work said he was very pleased with the rebuild and that the car drove and changed gear very well, No more leaks etc either :-) i have no reason to doubt him. I was just wondering, with these 4 speed hydamatics can there be a slight surge or delay changing from 2nd to 3rd ? When i drive around town with just normal revs etc she changes smooth as but if i give the car a good boot full on the gas pedal the change from 3rd to 4th seems to hang out and when it changes you Know about it as the car really lunges, Nothing dramatic or noisy etc , I was just wondering if this is just normal for these transmissions or could it maybe need a little adjustment? He charged me $2300.00 for the job which i thought was very reasonable. When i saw what was laid out on the bench it looked like a minefield , lol. Any thoughts about this transition from 3rd to 4th would be greatly appreciated, Cheers. Ray, 58 Super 88
Last edited by piperman60; June 14th, 2019 at 04:22 AM.
June 13th, 2019, 07:51 PM
#2
Phantom Phixer
Join Date: Dec 2011
Location: Apopka, FL
Posts: 4,661
Yes , It is normal for some slight delay when changing from 3rd to 4th .
The 3rd to 4th shift is accomplished by filling a fluid coupling in the front planetary unit .
This takes part of a second to fill the coupling , so the shift is not as instantaneous as it would be with the application of a clutch .
The use of a fluid coupling instead of a clutch is what made this transmission much smoother than the previous Hydra-Matic .
As long as it shifts , don't worry about it .
The 1958 Oldsmobile Service Manual has a detailed explanation of the operation of this transmission , and is a good read .
The 3rd to 4th shift is accomplished by filling a fluid coupling in the front planetary unit .
This takes part of a second to fill the coupling , so the shift is not as instantaneous as it would be with the application of a clutch .
The use of a fluid coupling instead of a clutch is what made this transmission much smoother than the previous Hydra-Matic .
As long as it shifts , don't worry about it .
The 1958 Oldsmobile Service Manual has a detailed explanation of the operation of this transmission , and is a good read .
Last edited by Charlie Jones; June 13th, 2019 at 07:58 PM.
June 14th, 2019, 04:20 AM
#4
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Join Date: Mar 2012
Location: Brisbane Australia
Posts: 75
Sorry about this Charlie but what i meant to say in my post was from 2nd to 3rd, not 3rd to 4th, i feel like a goose . I guess this is the same deal. My apologies for the miss information., Thanks again , Ray.
June 14th, 2019, 04:14 PM
#6
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Join Date: Oct 2004
Location: Forest Ranch Ca.
Posts: 7,714
Usually there is more of a chance that the shift between 2-3 will be more noticeable than the 3-4 shift or at least in the Jetway's I have been around. Unless you are getting a lot of slippage between shifts it is part of the nuances of that type of transmission.... Enjoy your ride...... Tedd
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