Every once in while somebody figures out a way to do something better than everyone else. You know that tiresome phrase about thinking outside the box? In the case of a replacement for the woefully inadequate factory GT500 shifter, George at MGW has done just that. I'd like to share what I've learned about the inner workings of his second generation Mustang TR6060 shifter that will hopefully allow for a better understanding as to why it really is that good.
I've documented just about everything possible with respect to the factory shifter and it's design faults in numerous threads here at SVTP. The bottom line is that it is a low cost unit, chock full of deflection and inefficiency. Many have suffered high rpm "lockout" or "grind" which makes for a really lousy driving experience on an otherwise good car. While the factory shifter can be improved, in the end you are still stuck with the "pendulum style swing" architecture. For those unfamiliar with any of what I just wrote, I suggest you watch the following video George did on the matter.
[video=youtube;DHXYSjOuWzw]https://www.youtube.com/watch?v=DHXYSjOuWzw[/video]
I installed a Gen2 last fall just before the weather took a turn. I wanted to tear it apart for a closer look but simply didn't have the time. So when I had the opportunity this spring, I pulled the unit back out of the car and completely disassembled it. I decided to dimension each and every part with hand sketches and then transfer all of it into Solidworks, a CAD program that allows you to analyze geometry, material properties, stresses, etc, as well as to assemble each and every individual part into a working assembly that would mirror the real thing. Every fillet, chamfer, radius, thread...everything, was dimensioned. It took me a couple of weeks and that included time on the weekends as well. I admit to struggling at certain times, for example, when trying to execute a variable chamfer on a curved surface. In the end, I figured it all out and learned quite a bit. So what I'd like to do here is provide a mix of CAD imagery along with the actual hardware to better illustrate what makes this shifter so good.
THE SHAFT
A 1" round hardened stainless steel shaft/joint are what connect the shifter linkage to the output shaft on the factory TR6060. Here are some sketches (some fully rendered) I did with the colors changed at times for better contrast. I did this because it can be difficult to see all the detail on black parts due to shadowing.
The shaft glides through a precision machined bronze bearing. The bearing is isolated from the body, or "box" of the shifter, by a layer of rubber which wraps around the circumference of the bearing such that the bearing doesn't actually touch the box. This is done for NVH, something George has addressed throughout on this unit. If I change the transparency of the upper box (or remove it), you can see exactly what I'm referring to.
The rubber shown above is fairly hard in durometer and allows for zero movement or deflection.
THE ARMS
As eager as I am to jump to the internals, I'd like to address the subcomponents that attach to the main box first. With the shaft out of the way I'd like to detail the arms and their supporting hardware. Constructed of CNC billet 6061-T6, these variable radius gems are what connect to shifter box to the TR6060 case (or rear housing anyway). While the factory uses tubular steel tied into a welded frame, the Gen2 arms (they are actually mirror images of each other so that you can install either one on either side) bolt to the box at the rear and use of the factory pins at the front.
George made quite an effort at the front of the arm to ensure NVH isolation as well as a deflection free joint. The factory failed miserably here with excessive deflection that allows the entire shifter to move anytime a shift is attempted. Instead of a single piece of rubber (or poly) such as factory, George engineered machined recesses in each arm that accept precision molded high durometer rubber bushings, each covered with a stainless cap and finished with a sleeve that slides through the entire assembly to allow the factory pins to glide through. Here's an exploded view of a relevant sketch of the arms/bushings.
The arms provide for a stiff and extremely stable connection to the transmission, with just the right durometer bushing.
THE REAR BUSHING/MOUNT
While the factory chose a buttery soft bushing "encapsulated in a sheetmetal bracket" methodology, George again took a different approach. He machines a beautiful housing that captures a proprietary diameter, large mass, rubber bushing which is then locked into place with a stainless steel cover plate. The bracket is bolted directly to the underside of the transmission tunnel (as factory) but uses two CNC machined pins which slide into the bushing and connect to the shifter box.
If I wasn't dimensioning anything I would have missed a lot here. To begin with, the rubber bushing is absolutely perfect. I have yet to see ANY OEM or aftermarket company produce a bushing like this to such exacting tolerances. The corners are sharp and voids simply don't exist (this goes for all of the rubber bushings George supplies). It fits perfectly into the machined housing.
Sketching this part was a joy. I could see into George's mind with every cut, extrusion, radius, etc. He designed the bushing to be symmetrical to ease in manufacturing and installation. Here's a quick render that came out pretty good.
So you have NVH isolation from the shaft coming in, the arms that connect to the box, as well as the rear mounting bracket. Carefully selected durometers and well executed designs that separate "metal from metal" while maintaining a firm overall structure.
THE BOX AND REMAINING HARDWARE
The box is actually two 6061-T6 CNC machined halves that are bolted together.
The halves lock in the bronze bearing, allowing the shaft to slide in and out as well as to rotate as necessary. At the end of the shaft resides a cup that bolts on and allows the poly ball to fit inside. This is where George's design really shines. Ditching the factory pendulum design and substituting one with a shaft that travels on a single axis makes for a far more accurate mechanism. Here's a cut section of the box which allows you to see inside.
The pivot ball cup.
The poly ball that fits inside the pivot cup is attached to stick portion of the assembly that rotates within a trunion. It consists of the ball and a CNC machined stainless stick, topped off with yet another isolation assembly.
An exploded view of the shift handle isolator. Again, George has separated any chain or path that NVH can follow, were it to make it this far. Precision molded rubber bushings make for a truly exacting assembly.
The above assembly fits through and rotates about the trunion (which is then attached to the upper half of the box). The trunion uses CNC bushings that serve to allow for the handle to move left and right as well as fore and aft. The bushings have grooves cut into them to allow for grease retention. The two rubber bushings you see serve to isolate the trunion from the box.
An aside, the trunion was one of those areas that proved to be a challenge with a number of complex contours. Solidworks wouldn't let me do a variable chamfer, so I had to section and do a variable radius, delete face/fill, etc. Head scratching at times, I ended up learning quite a bit and was thankful for the challenge.
Armed with a better understanding of certain parts and assemblies, here is another section/transparency that illustrates how the components integrate.
If I hide the box, arms, trunion, etc, you can note the amount of isolation that this entire mechanism embodies. The MGW has the best isolation I've ever seen in a shifter, factory or aftermarket. George has designed a lot of shifters over the years and took the best of each and figured out how to make it work within the GT500 framework. You can see the multiple isolation fronts pretty clearly below.
It really was a joy to draw and assemble the shifter in a virtual world as well as reassembling the actual unit out in my shop. The individual parts fit together into a complete shifter just as good in real life as they did on the computer. Pretty darn amazing.
In closing, a couple of things. I shared with George my intention to study his shifter in depth. We joked about my being on the payroll for an offshore "manufacturing" company (of which I am most definitely not) and I made it clear that I wouldn't share dimensions, etc. He was aware of the challenges I faced as he went through them on a larger scale when he took what he had in his head, put it into the computer, and started prototyping his Gen2 shifter. He offered to help me with the arms and their variable radius and I turned him down, wanting to be able to do it on my own regardless of how challenging it was. I ended up figuring out a way to sketch the arms with the utmost accuracy that was a bit easier than the method I used for everything else. In the end, I had a digitized assembly from which I could now converse with George from a much better perspective than I previously had.
George doesn't stand still and is constantly brainstorming, searching for a way to be more efficient in terms of manufacturing as well as to improve the shifters themselves. Hence why the last run of a certain shifter may deviate a little from the next. We talked about this at length and have had some great conversations about continual improvement. That is the nice thing about Solidworks, as I have been able to run the shifter through a few "studies" in search of any constructive suggestions - a rather daunting task considering how far George has taken this already.
I also wanted to thank V, my trusted friend. She's gone now but managed to sit with me while I painstakingly documented this entire effort, making it that much easier.
Tob
I've documented just about everything possible with respect to the factory shifter and it's design faults in numerous threads here at SVTP. The bottom line is that it is a low cost unit, chock full of deflection and inefficiency. Many have suffered high rpm "lockout" or "grind" which makes for a really lousy driving experience on an otherwise good car. While the factory shifter can be improved, in the end you are still stuck with the "pendulum style swing" architecture. For those unfamiliar with any of what I just wrote, I suggest you watch the following video George did on the matter.
[video=youtube;DHXYSjOuWzw]https://www.youtube.com/watch?v=DHXYSjOuWzw[/video]
I installed a Gen2 last fall just before the weather took a turn. I wanted to tear it apart for a closer look but simply didn't have the time. So when I had the opportunity this spring, I pulled the unit back out of the car and completely disassembled it. I decided to dimension each and every part with hand sketches and then transfer all of it into Solidworks, a CAD program that allows you to analyze geometry, material properties, stresses, etc, as well as to assemble each and every individual part into a working assembly that would mirror the real thing. Every fillet, chamfer, radius, thread...everything, was dimensioned. It took me a couple of weeks and that included time on the weekends as well. I admit to struggling at certain times, for example, when trying to execute a variable chamfer on a curved surface. In the end, I figured it all out and learned quite a bit. So what I'd like to do here is provide a mix of CAD imagery along with the actual hardware to better illustrate what makes this shifter so good.
THE SHAFT
A 1" round hardened stainless steel shaft/joint are what connect the shifter linkage to the output shaft on the factory TR6060. Here are some sketches (some fully rendered) I did with the colors changed at times for better contrast. I did this because it can be difficult to see all the detail on black parts due to shadowing.
The shaft glides through a precision machined bronze bearing. The bearing is isolated from the body, or "box" of the shifter, by a layer of rubber which wraps around the circumference of the bearing such that the bearing doesn't actually touch the box. This is done for NVH, something George has addressed throughout on this unit. If I change the transparency of the upper box (or remove it), you can see exactly what I'm referring to.
The rubber shown above is fairly hard in durometer and allows for zero movement or deflection.
THE ARMS
As eager as I am to jump to the internals, I'd like to address the subcomponents that attach to the main box first. With the shaft out of the way I'd like to detail the arms and their supporting hardware. Constructed of CNC billet 6061-T6, these variable radius gems are what connect to shifter box to the TR6060 case (or rear housing anyway). While the factory uses tubular steel tied into a welded frame, the Gen2 arms (they are actually mirror images of each other so that you can install either one on either side) bolt to the box at the rear and use of the factory pins at the front.
George made quite an effort at the front of the arm to ensure NVH isolation as well as a deflection free joint. The factory failed miserably here with excessive deflection that allows the entire shifter to move anytime a shift is attempted. Instead of a single piece of rubber (or poly) such as factory, George engineered machined recesses in each arm that accept precision molded high durometer rubber bushings, each covered with a stainless cap and finished with a sleeve that slides through the entire assembly to allow the factory pins to glide through. Here's an exploded view of a relevant sketch of the arms/bushings.
The arms provide for a stiff and extremely stable connection to the transmission, with just the right durometer bushing.
THE REAR BUSHING/MOUNT
While the factory chose a buttery soft bushing "encapsulated in a sheetmetal bracket" methodology, George again took a different approach. He machines a beautiful housing that captures a proprietary diameter, large mass, rubber bushing which is then locked into place with a stainless steel cover plate. The bracket is bolted directly to the underside of the transmission tunnel (as factory) but uses two CNC machined pins which slide into the bushing and connect to the shifter box.
If I wasn't dimensioning anything I would have missed a lot here. To begin with, the rubber bushing is absolutely perfect. I have yet to see ANY OEM or aftermarket company produce a bushing like this to such exacting tolerances. The corners are sharp and voids simply don't exist (this goes for all of the rubber bushings George supplies). It fits perfectly into the machined housing.
Sketching this part was a joy. I could see into George's mind with every cut, extrusion, radius, etc. He designed the bushing to be symmetrical to ease in manufacturing and installation. Here's a quick render that came out pretty good.
So you have NVH isolation from the shaft coming in, the arms that connect to the box, as well as the rear mounting bracket. Carefully selected durometers and well executed designs that separate "metal from metal" while maintaining a firm overall structure.
THE BOX AND REMAINING HARDWARE
The box is actually two 6061-T6 CNC machined halves that are bolted together.
The halves lock in the bronze bearing, allowing the shaft to slide in and out as well as to rotate as necessary. At the end of the shaft resides a cup that bolts on and allows the poly ball to fit inside. This is where George's design really shines. Ditching the factory pendulum design and substituting one with a shaft that travels on a single axis makes for a far more accurate mechanism. Here's a cut section of the box which allows you to see inside.
The pivot ball cup.
The poly ball that fits inside the pivot cup is attached to stick portion of the assembly that rotates within a trunion. It consists of the ball and a CNC machined stainless stick, topped off with yet another isolation assembly.
An exploded view of the shift handle isolator. Again, George has separated any chain or path that NVH can follow, were it to make it this far. Precision molded rubber bushings make for a truly exacting assembly.
The above assembly fits through and rotates about the trunion (which is then attached to the upper half of the box). The trunion uses CNC bushings that serve to allow for the handle to move left and right as well as fore and aft. The bushings have grooves cut into them to allow for grease retention. The two rubber bushings you see serve to isolate the trunion from the box.
An aside, the trunion was one of those areas that proved to be a challenge with a number of complex contours. Solidworks wouldn't let me do a variable chamfer, so I had to section and do a variable radius, delete face/fill, etc. Head scratching at times, I ended up learning quite a bit and was thankful for the challenge.
Armed with a better understanding of certain parts and assemblies, here is another section/transparency that illustrates how the components integrate.
If I hide the box, arms, trunion, etc, you can note the amount of isolation that this entire mechanism embodies. The MGW has the best isolation I've ever seen in a shifter, factory or aftermarket. George has designed a lot of shifters over the years and took the best of each and figured out how to make it work within the GT500 framework. You can see the multiple isolation fronts pretty clearly below.
It really was a joy to draw and assemble the shifter in a virtual world as well as reassembling the actual unit out in my shop. The individual parts fit together into a complete shifter just as good in real life as they did on the computer. Pretty darn amazing.
In closing, a couple of things. I shared with George my intention to study his shifter in depth. We joked about my being on the payroll for an offshore "manufacturing" company (of which I am most definitely not) and I made it clear that I wouldn't share dimensions, etc. He was aware of the challenges I faced as he went through them on a larger scale when he took what he had in his head, put it into the computer, and started prototyping his Gen2 shifter. He offered to help me with the arms and their variable radius and I turned him down, wanting to be able to do it on my own regardless of how challenging it was. I ended up figuring out a way to sketch the arms with the utmost accuracy that was a bit easier than the method I used for everything else. In the end, I had a digitized assembly from which I could now converse with George from a much better perspective than I previously had.
George doesn't stand still and is constantly brainstorming, searching for a way to be more efficient in terms of manufacturing as well as to improve the shifters themselves. Hence why the last run of a certain shifter may deviate a little from the next. We talked about this at length and have had some great conversations about continual improvement. That is the nice thing about Solidworks, as I have been able to run the shifter through a few "studies" in search of any constructive suggestions - a rather daunting task considering how far George has taken this already.
I also wanted to thank V, my trusted friend. She's gone now but managed to sit with me while I painstakingly documented this entire effort, making it that much easier.
Tob
... I hopefully recover this with some cheap deals on other parts I need...
