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2008 Pontiac Solstice GXP - Mysterious (with unkown origin blue sparkle in rear bumper cover paint)
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Just out of curiosity today i drive to work with my hand around the base of the shifter shaft (your joke goes here “_:)
I was surprised at the amount of vertical movement (up and down) when going over bumps etc.
Very unscientific but if i had to guess, the shifter would lean towards the passenger side 1/8-1/4” when stepping on the throttle and applying some torque. No opportunities for WOT on the morning commute so this would just be regular city driving.
For reference i have a 2008 GXP Manual with the torque bar.
Love to hear what other folks experiences are…
 

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That is 100% normal. the torque arm is what is actually lifting the transmission up. When you step on the accelerator the cars tires turn in the direction of the front of the vehicle. The resistance and reverse force of that makes the differential want to roll in the opposite direction. That movement causes the input shaft on the differential to pitch up, or at least try to. Since the torque arm couples the nose of the diff to the tail of the transmission that "lifting" from the diff gets realized by the transmission and since the shifter goes into the tail of the transmission and the transmission sits on rubber mounts it lifts up until it reaches the mechanical limits of the mounts. The movement to the right is the same thing that the diff is doin when it pitches except the left movement is being caused by the rotation of the engine.
 

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The torque arm is going to limit that movement to the right. so vehicles that do not have the torque arm are going to see more lateral movement then up and down movement and it's the lateral movement that would cause an issue with contact.
 
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" diff gets realized by the transmission and since the shifter goes into the tail of the transmission and the transmission sits on rubber mounts it lifts up until it reaches the mechanical limits of the mounts"
When i recently did my Ar5 (twice) there were no "rubber mounts". The transmission bolts directly to the rear of the engine block and the torque arm attaches on the side of the tranny behind the bell housing and the tail of the torque arm mounts to the side of the differential. Other than the motor mounts themselves and the differential mounts the transmission has no mount or support that I am aware of. Did I miss something? Egads!
 

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There is no bar that goes across the bottom of the car under the tail of the transmission that the transmission rests on?
 

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When i recently did my Ar5 (twice) there were no "rubber mounts". The transmission bolts directly to the rear of the engine block and the torque arm attaches on the side of the tranny behind the bell housing and the tail of the torque arm mounts to the side of the differential. Other than the motor mounts themselves and the differential mounts the transmission has no mount or support that I am aware of. Did I miss something? Egads!
depending on the vehicle and on how the motor is supported, the transmission may have no mounts at all, especially with no torque arm

Bill
 

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2008 Pontiac Solstice GXP - Mysterious (with unkown origin blue sparkle in rear bumper cover paint)
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There is no bar that goes across the bottom of the car under the tail of the transmission that the transmission rests on?
Not on my 08 GXP. The tunnel is wide open from the rear of the motor back to the dif. I believe that diagram is "pre-torque bar"
 

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No you can see the torque bar in that image.
 

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automatic transmissions have the mount manual trans does not.
 

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and that has me wondering if a mount can be added. I know the torque arm does break and the reason why it breaks is because of the lack of a transmission mount.
 

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automatic transmissions have the mount manual trans does not.
Well there ya go. "Floating" tranny so to speak.
 

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I know it cold be added I was wondering if it would be hard to do The 06 doesn't have the torque arm and it should have the mount and the transmission is the same so in theory it should bolt in.
 

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2008 Pontiac Solstice GXP - Mysterious (with unkown origin blue sparkle in rear bumper cover paint)
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A couple thoughts here.
I think that you would probably need a thinner shifter shaft to make usable "lanes" in a shift gate. (I have a DDM Short shift kit in mine but i believe they are the same "diameter")
The shifter boot and the weird white fabric doughnut underneath (assume this is a "heat" thing?) are helping reduce noise from the gearbox /tranny.
If one was to eliminate the shifter boot, i would think a newer more heat / acoustically viable "doughnut" be placed to eliminate noise / heat and dirt from entering the cabin via the open lanes in the Shift Gate.
 

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I know it cold be added I was wondering if it would be hard to do The 06 doesn't have the torque arm and it should have the mount and the transmission is the same so in theory it should bolt in.
Wouldnt these cause an odd geometry issue for torque? As it stands now, with the torque arm on my GXP, I imagine all torque streeses land at the motor mounts and the rubber mounts for the differential carrier arm... no?
One would imagine this was by design.. but why eliminate the rear tranny mount unless it was physically in the way of the torque arm. (which i believe it would be)
 

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10381819 - mount, top
11519184 - Bolt
15287646 - mount, bottom
15833877 - mount carrier

There is also another bolt and nuts that are needed just don't know the part number. This is for the manual transmission.

I don't know if it would get in the way of the torque arm. The mount is the same as what is used on the automatics and the automatics have the torque arm don't they?


The only purpose of the torque arm is to keep the nose of the diff from lifting. By using the torque arm they gain mechanical advantage when doing this but the elimination of the mount not puts a hell of a lot of stress onto the torque arm where it bolts to the transmission. That is the reason why the torque arm breaks and it breaks right where it bolts to the transmission.

If you taped 2 straws together and then tied a weight to the end then lifts the straws up from the other end what is going to happen? If there is enough weight on the end and the force pulling up is high enough the taped joint is going to fail. This is where the transmission mount comes into play because it reduces the amount of stress being placed on the torque arm by decreasing the length of the "lever" Right now the upward pressure on the diff when accelerating gets transferred down the torque arm and into the transmission and has to travel the length of the transmission into the engine and then part way down the engine to the motor mounts. That's a long span with nothing in the middle to stop it from deflecting at all. And deflecting is what it does do and it does it where the torque arm attaches to the transmission. Adding the transmission mount cuts that span in half which makes the amount of torque that can be handled exponentially higher and the deflection point gets moved into the middle of the torque arm where there are no bolts or mounting points which makes it stronger .
 

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what you are forgetting is the change in direction the torque has had to make to get to the tires which makes it perpendicular to the chassis not parallel. While it is still a twisting power it effects the vehicle differently because it is perpendicular to the chassis, it turns into lifting force instead of a twisting force.
 

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This is one of the reasons why top fuel drag cars have the engine behind the driver or the driver is sitting on top of the rear diff. This is to get the transmission in a place where it can be coupled directly to the differential and also lessens the weight at the front of the car and that translated into less stress that gets places on the chassis when the car takes off.

They still do snap in half because there does need to be some kind of weight in the front to keep it from flipping over but if the engine is the weight the car would snap in half almost 100% of the time because of the lifting force the diff has on the car.

Automotive tire Vehicle Wheel Asphalt Motor vehicle


Think of that being the diff, torque arm, transmission and engine and the kinked place is where the torque arm bolts to the transmission which is going to be the weakest point and there for the point of failure. Now imagine placing say a steel I-beam the whole length, that would be what the chassis of the car is and then where the kink is bolt it to that I-beam. not going to break any more and it accomplishes the same task.
 

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Just for the sake of seeing it. This is what happens with too much power and the engine in front of the driver and the driver is not sitting on top of the diff.

Tire Wheel Vehicle Automotive tire Motor vehicle
 
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