Steering gets heavy when engine is hot
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Joined: Oct 2014
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Steering gets heavy when engine is hot
Hi.
Im having issues with the steering getting heavy when the engine is hot. My headers are maybe 1 inch away from the copling (no idea what its called) on the steering column in the engine bay. This copling is filled with grease. Is this a weak link for heat?
Im having issues with the steering getting heavy when the engine is hot. My headers are maybe 1 inch away from the copling (no idea what its called) on the steering column in the engine bay. This copling is filled with grease. Is this a weak link for heat?
Le Mans Master
Joined: Jul 2000
Posts: 6,001
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From: Saginaw Michigan
Jim
Burning Brakes
Joined: Dec 2005
Posts: 992
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From: Baldwinsville, NY
What year and type of steering do you have?
Power steering on the factory supplied system consists of a steering column connected to the steering box via a flexibility coupling called the rage joint. The output of the steering box is connected to a control valve mounted on the steering relay rod which is connected to the wheels via the tie rods. The control valve sends power steering fluid to a cylinder that is also connected to the relay rod.
That's a quick statement of factory power steering.
1. Oil level
2. Clean new oil
3. Too much heat from engine or a failed control valve, cylinder or pump.
4. Steering box condition
I wish I could give you a quick fix like change the fluid, that is just not how things work.
You should start with oil level and use an ir temp gun to see what the temp is at the power steering pump tank.
Power steering on the factory supplied system consists of a steering column connected to the steering box via a flexibility coupling called the rage joint. The output of the steering box is connected to a control valve mounted on the steering relay rod which is connected to the wheels via the tie rods. The control valve sends power steering fluid to a cylinder that is also connected to the relay rod.
That's a quick statement of factory power steering.
1. Oil level
2. Clean new oil
3. Too much heat from engine or a failed control valve, cylinder or pump.
4. Steering box condition
I wish I could give you a quick fix like change the fluid, that is just not how things work.
You should start with oil level and use an ir temp gun to see what the temp is at the power steering pump tank.
Burning Brakes
Joined: Apr 2008
Posts: 1,222
Likes: 93
From: shelbyville West Michigan
couple things I would check would be something pinching the lines on the pump or valve when you are driving (maybe somebody re-engineered it with different hoses/routed weird).
do you know the history of the fluid? somebody put something in there that makes it thick when cold to cure a failing pump that thins out too much when hot? --try flushing and re-filling entire system with fresh PS fluid. may also have a sticky flow control valve, which may help clean out as well.
other easy thing is check your belts and pulley, make sure they are not slipping...
but probably time for a new pump!
do you know the history of the fluid? somebody put something in there that makes it thick when cold to cure a failing pump that thins out too much when hot? --try flushing and re-filling entire system with fresh PS fluid. may also have a sticky flow control valve, which may help clean out as well.
other easy thing is check your belts and pulley, make sure they are not slipping...
but probably time for a new pump!
Thread Starter
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Joined: Oct 2014
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Sorry for the missing details.
The car is a 68. And has no power steering.
Right next to the headers, right beneath the master break cylinder there is a "box" the steering column goes in to.
This is the part I think is getting hot and causing the steering to get heavy.
The car is a 68. And has no power steering.
Right next to the headers, right beneath the master break cylinder there is a "box" the steering column goes in to.
This is the part I think is getting hot and causing the steering to get heavy.
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
Le Mans Master
Joined: Jul 2000
Posts: 6,001
Likes: 112
From: Saginaw Michigan
One thought that comes to mind. There is a caution note with respect to the Corvette manual steering gear. It says to NOT overfill the gear with grease. There should be a pocket of air inside the gear that will allow the lubricating grease to expand with increasing underhood temperature.
If the gear box is overfilled with grease, the expansion of the grease with higher temperatures could cause excessive pressure against the grease seals that are located on the gear box input and output shafts. This excessive pressure could cause higher steering effort. (Note that higher pressure could also cause the grease seals to start backing out of their locating pockets in the gear box housing.)
The top view in the following picture has you looking straight down at the gear box as if you were leaning over the driver fender. Note that the words CHECK LUBE on either side of the top cover bolt nearest the driver fender. (Your gear box cover may not have these words but the gear boxes are the same.)
Now remove just that one bolt nearest the fender. Use a phillips screw driver whose size is just small enough to stick down into the gear box interior. There should be sufficient air space inside the gear to allow the screw driver to poke down into the interior without causing grease to extrude back out of the bolt hole.
If excessive grease is the problem, I just don't know if poking around inside the gear box will be sufficient to remove enough grease and create an air pocket in the gear box.
The best approach would be to remove the gear box from the car; then completely remove the top cover from the gear box and inspect the interior of the gear. NOTE, when you remove the top cover you will now have to go through a complete gear adjustment as described in the Chevrolet Chassis Service Manual for your Vette.
Jim
If the gear box is overfilled with grease, the expansion of the grease with higher temperatures could cause excessive pressure against the grease seals that are located on the gear box input and output shafts. This excessive pressure could cause higher steering effort. (Note that higher pressure could also cause the grease seals to start backing out of their locating pockets in the gear box housing.)
The top view in the following picture has you looking straight down at the gear box as if you were leaning over the driver fender. Note that the words CHECK LUBE on either side of the top cover bolt nearest the driver fender. (Your gear box cover may not have these words but the gear boxes are the same.)
Now remove just that one bolt nearest the fender. Use a phillips screw driver whose size is just small enough to stick down into the gear box interior. There should be sufficient air space inside the gear to allow the screw driver to poke down into the interior without causing grease to extrude back out of the bolt hole.
If excessive grease is the problem, I just don't know if poking around inside the gear box will be sufficient to remove enough grease and create an air pocket in the gear box.
The best approach would be to remove the gear box from the car; then completely remove the top cover from the gear box and inspect the interior of the gear. NOTE, when you remove the top cover you will now have to go through a complete gear adjustment as described in the Chevrolet Chassis Service Manual for your Vette.
Jim
Last edited by Jim Shea; Jul 24, 2015 at 10:01 AM.
Thread Starter
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Joined: Oct 2014
Posts: 73
Likes: 1
One thought that comes to mind. There is a caution note with respect to the Corvette manual steering gear. It says to NOT overfill the gear with grease. There should be a pocket of air inside the gear that will allow the lubricating grease to expand with increasing underhood temperature.
If the gear box is overfilled with grease, the expansion of the grease with higher temperatures could cause excessive pressure against the grease seals that are located on the gear box input and output shafts. This excessive pressure could cause higher steering effort. (Note that higher pressure could also cause the grease seals to start backing out of their locating pockets in the gear box housing.)
The top view in the following picture has you looking straight down at the gear box as if you were leaning over the driver fender. Note that the words CHECK LUBE on either side of the top cover bolt nearest the driver fender. (Your gear box cover may not have these words but the gear boxes are the same.)
Now remove just that one bolt nearest the fender. Use a phillips screw driver whose size is just small enough to stick down into the gear box interior. There should be sufficient air space inside the gear to allow the screw driver to poke down into the interior without causing grease to extrude back out of the bolt hole.
If excessive grease is the problem, I just don't know if poking around inside the gear box will be sufficient to remove enough grease and create an air pocket in the gear box.
The best approach would be to remove the gear box from the car; then completely remove the top cover from the gear box and inspect the interior of the gear. NOTE, when you remove the top cover you will now have to go through a complete gear adjustment as described in the Chevrolet Chassis Service Manual for your Vette.
Jim
If the gear box is overfilled with grease, the expansion of the grease with higher temperatures could cause excessive pressure against the grease seals that are located on the gear box input and output shafts. This excessive pressure could cause higher steering effort. (Note that higher pressure could also cause the grease seals to start backing out of their locating pockets in the gear box housing.)
The top view in the following picture has you looking straight down at the gear box as if you were leaning over the driver fender. Note that the words CHECK LUBE on either side of the top cover bolt nearest the driver fender. (Your gear box cover may not have these words but the gear boxes are the same.)
Now remove just that one bolt nearest the fender. Use a phillips screw driver whose size is just small enough to stick down into the gear box interior. There should be sufficient air space inside the gear to allow the screw driver to poke down into the interior without causing grease to extrude back out of the bolt hole.
If excessive grease is the problem, I just don't know if poking around inside the gear box will be sufficient to remove enough grease and create an air pocket in the gear box.
The best approach would be to remove the gear box from the car; then completely remove the top cover from the gear box and inspect the interior of the gear. NOTE, when you remove the top cover you will now have to go through a complete gear adjustment as described in the Chevrolet Chassis Service Manual for your Vette.
Jim
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