Reverse slow to engage

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albjerryg
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Joined: Wed Dec 18, 2019 1:55 am

Reverse slow to engage

Post by albjerryg »

I have a 1966 Corvair 95HP with a power glide transmission. I have changed the transmission oil and checked the fluid level. When I shift into drive all is good when I shift into reverse it takes a few seconds before it engages. Also noticed when I back into my shop, which is on an incline it does not have the power to get up it unless I get a running start. Any suggestion. Thanks Jerry
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bbodie52
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Re: Reverse slow to engage

Post by bbodie52 »

It sounds like hardened, worn or leaky seals, or possibly the need for a shift cable adjustment. I would suggest looking over these troubleshooting charts and carefully comparing your symptoms to the possibilities on these charts...

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The second chart suggests the following additive...

K&W 402033X6 Trans-X Automatic Transmission Stop Leak & Tune-Up - 32 Fl Oz.
:link: https://www.amazon.com/dp/B000M8NZA2?ta ... f=aa_scomp
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  • Effectively repairs leaks in automatic transmissions.
  • Prevents leaks caused by aged seals & gaskets.
  • Powerful cleaning agents remove sludge, gums, & varnish to prevent premature failure and extends transmission life.
  • Ideal preventative maintenance tool when added to transmission fluid each time fluid and filter are changed
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
albjerryg
Posts: 63
Joined: Wed Dec 18, 2019 1:55 am

Re: Reverse slow to engage

Post by albjerryg »

I will go the step and see what I can come up with. I don't have any leaks under the car so I do not think that is it. Thanks
joelsplace
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Re: Revese slow to engage

Post by joelsplace »

Brad nailed it. 99% chance "hardened, worn or leaky seals" is the problem. It may have more issues since the bad seals will lead to burned clutches.
Unhook the vacuum modulator and plug the vacuum line to the engine and give the Trans-X a try. Disconnecting the modulator will increase the line pressure and compensate for the leaky seals. It might be enough to get you by while the Trans-X does its work.
An easy way to check the shift cable adjustment is slowly move the lever toward drive and note where it engages. Move it slowly toward reverse. It should engage a the same distance from neutral. If it doesn't the adjustment is off.
157 Corvairs, 5 Ultravans and counting
Northlake, TX
albjerryg
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Re: Reverse slow to engage

Post by albjerryg »

I will give it a try. Don't you think I would see some fluid if the seals were leaking? Thanks
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bbodie52
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Re: Reverse slow to engage

Post by bbodie52 »

albjerryg wrote: » Mon May 18, 2020 2:46 pm

I will give it a try. Don't you think I would see some fluid if the seals were leaking? Thanks
It is not necessarily the external gaskets and seals that are of concern. Even if the transmission fluid is not leaking out of the transmission, internal leaks and seals that are stiff with age and chemical deposits may not be controlling the fluid internally. An automatic transmission like the Powerglide is like a fluid-based computer (as opposed to electronic) that controls shifting by rerouting fluid through internal passages to perform work by engaging various friction clutches and bands to cause different gear sets to engage and release. Some of these can be seen in the illustrations below.

Hardened or leaking internal seals can interfere with the intended actions in the transmission design. The hope in using transmission fluid seal conditioner is to soften and increase the pliability and effectiveness of the internal seals, so that the "fluid shifting" can function as originally intended. If this fails it may be necessary to overhaul and rebuild the transmission, basically replacing worn seals and clutches and cleaning all of the internal passageways.

The Basic Parts of an Automatic Transmission (Part 2) does a good job of explaining why changing old, dirty, contaminated fluid and replacing it with fresh, clean fluid can actually cause other problems with the internal aging seals to become more pronounced and noticeable. If you are willing to invest some time in watching the videos below, the basic concepts of automatic transmission operation will become easier for you to imagine and visualize.

:pray: :dontknow: The hope is that the TRANSX seal conditioner may recondition the internal seals enough to restore some of the functions needed for proper operation. It may or may not work — but if the effort is successful you may gain some years of operation out of your transmission without having to rebuild or replace it.

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:woo:
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
albjerryg
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Joined: Wed Dec 18, 2019 1:55 am

Re: Reverse slow to engage

Post by albjerryg »

Thanks for the information.
albjerryg
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Re: Reverse slow to engage

Post by albjerryg »

OK I did what you said and right now it look like it is working. Thanks
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bbodie52
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Re: Reverse slow to engage

Post by bbodie52 »

:goodpost:

:dontknow: Did you disconnect the vacuum modulator, add TransX, or both?

I appreciate your update. I don't have a great deal of experience with Powerglide-based Corvairs. My first Corvair (in 1969) was a 1963 Corvair 500 2-door coupe with an automatic Powerglide transmission. I learned to overhaul and rebuild my first Corvair engine with that car, and after discovering an inoperable Powerglide with burned-odor brown-colored transmission fluid, I taught myself to overhaul that transmission as well. But all of the nine Corvairs I have owned since then have had manual 4-speed transmissions, so most of first-hand experience with attempting to correct problems like yours has only been theoretical (until now). Some others have expressed uncertainty and doubt about the effectiveness of using an additive like TransX in a faulty Powerglide. So if draining aging fluid and installing fresh transmission fluid appeared to expose new problems (like slow shifting into REVERSE), and if adding TransX afterward seems to make an improvement, and if that approach proves to be effective, your feedback can be a valuable "lesson learned" that can be helpful to other Corvair/Powerglide owners. Please let us know of your experiences, if TransX was used, of the effect and improvement and if it was immediate, and if performance continued to improve over time. Thank you.
:tu: :clap:
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
albjerryg
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Re: Reverse slow to engage

Post by albjerryg »

Yes I did disconnect the vacuum modulator. and added the trans X.
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bbodie52
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Re: Reverse slow to engage

Post by bbodie52 »

:goodpost: :ty:

I hope it continues to work for you and transmission operation continues to improve. Your continuing feedback may help others who are experiencing similar problems.

Incidentally, I noticed the TransX bottle comes in a 1-qt size. If the instructions required you to add the entire bottle, you may want to check the resulting overall transmission fluid level. A high fluid level can cause problems if the resulting level causes the rotating planetary gear assembly to spin in a bath of transmission fluid. This can result in air bubble entrainment (foam or bubbles mixed into the transmission fluid, which can wreck havoc with the transmission's hydraulic control systems.
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
albjerryg
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Joined: Wed Dec 18, 2019 1:55 am

Re: Reverse slow to engage

Post by albjerryg »

Yes I took out 1 qt before I added a quart. Thanks
David Payton
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Re: Reverse slow to engage

Post by David Payton »

I gotta tell ya, I'm really impressed just adding 6oz of the Trans Seal. I carefully measured out just 6oz. and added it to the Trans. filler tube. This was four days ago and then I'd get the car out each day since and give it a gentle exercise putting it in reverse and then down the street a few times and it has vastly improved the car's shifting into reverse. Thanks so much folks.
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