I replaced a bunch of shift bushings and adjusted the shifter the other night. But, I was suprised to see how the side shift works. (You must excuse me, I've only worked on taildraggers to this point) It twists the shaft by moving it side to side. I understand that the factory orientation of the shift coupler has the set screw pointing down. (This is a pic I stole from Mueller - ignore the extension for the V8)
Click to view attachment
This allows the motor/chassis to flex up/down but puts the shaft in a mild bind when in 1/R or 4/5 planes. Does anyone else notice this? It looks to me like the application is screaming for a helicopter/apex coupler:
Click to view attachment
Anyone ever done it? Since my car has the side shift conversion, I could just fab a straight rod, weld the coupler to it, and weld a boss to the other side of the coupler to tap for the cone screw - like Mueller did for the V8 adapter. On the tranny end, I could turn a rod to the right OD, and drill a hole to receive the set screw that goes back there.
Look to me like it would take up the misalignment in both planes and make the shifting more precise. Also looks easy to do. Anyone BTDT? I've installed a rennshift, but the side-to-side vaugeness could still be improved...
Tnx!
SMD
Full Version: Shift coupler orientation
you can buy those already machined from WEVO or SmartRacing, so yes it is a do-able project...
If you are running solid engine/tranny mounts this isn't a problem 
On a stock side shift car only the tranny mounts are flexible as the engine bar is bolted to the chassis.
On a six depends on the engine bar/mount if it flexes/bends. Again solid mounts with take care of it.
but on a street car you must have some flex/give on the noise and ride get too harsh so giving up a little shifting feel is a given. Brand new bushings/proper shift adjusting give you nice chrisp shifting or the problem lie deep inside the tranny with worn out parts $$$$. No amount of changes to the shifting mech. will fix that.
On a stock side shift car only the tranny mounts are flexible as the engine bar is bolted to the chassis.
On a six depends on the engine bar/mount if it flexes/bends. Again solid mounts with take care of it.
but on a street car you must have some flex/give on the noise and ride get too harsh so giving up a little shifting feel is a given. Brand new bushings/proper shift adjusting give you nice chrisp shifting or the problem lie deep inside the tranny with worn out parts $$$$. No amount of changes to the shifting mech. will fix that.
SMD,
shhh... thats a secret
(its being done on lots of race cars)
on ours, we've used the stock coupler (well, rebuilt with brass bushings) and cut it off of the bar.. Rotated it 90 degree's and then re-welded it onto our custom shift bar.
brant
shhh... thats a secret
(its being done on lots of race cars)
on ours, we've used the stock coupler (well, rebuilt with brass bushings) and cut it off of the bar.. Rotated it 90 degree's and then re-welded it onto our custom shift bar.
brant
"I replaced a bunch of shift bushings and adjusted the shifter the other night. But, I was suprised to see how the side shift works. (You must excuse me, I've only worked on taildraggers to this point) It twists the shaft by moving it side to side. I understand that the factory orientation of the shift coupler has the set screw pointing down. (This is a pic I stole from Mueller - ignore the extension for the V8)"
So what's the problem? Tail draggers work EXACTLY the same way. Same coupler, same shift lever setup, same same, with minor detail differences. (side shifters have one less leverage point.) In stock applications, the system is positive, long lived, and more than adequate. The Cap'n
So what's the problem? Tail draggers work EXACTLY the same way. Same coupler, same shift lever setup, same same, with minor detail differences. (side shifters have one less leverage point.) In stock applications, the system is positive, long lived, and more than adequate. The Cap'n
Mueller,
Tnx. I'm familiar w/ the wevo bits, but didn't know they had an application that fits the 914. I just checked their website, looks like I'd have to buy a bunch of their bits and weld them together anyway. How did you drill a tapered hole - or did you? I thought of drilling a straight hole, slightly larger than the OD @ the nose of the set screw, so that I catch the wall of the taper part way up. That or I make a tapered single flute drill out of tool steel.
Geoff,
Its a factory 6. I put the 911 sport mounts on the tranny, but dont know if a stiffer firewall mount is avail. I haven't really dug in there to see if I can machine some bushings for it either. Im not really interested in going to solid mounts.
Brant,
When they did my side shift conversion, they didn't "phase" the coupler correctly when it was rewelded, so its kinda like 60deg off. Brad caught it on the PPI, but it was making me wonder if a full 90deg would be better. Up/down chassis flex might still bind it a little on the front to back action, but it would be constant in every gear.
Tnx,
SMD
Tnx. I'm familiar w/ the wevo bits, but didn't know they had an application that fits the 914. I just checked their website, looks like I'd have to buy a bunch of their bits and weld them together anyway. How did you drill a tapered hole - or did you? I thought of drilling a straight hole, slightly larger than the OD @ the nose of the set screw, so that I catch the wall of the taper part way up. That or I make a tapered single flute drill out of tool steel.
Geoff,
Its a factory 6. I put the 911 sport mounts on the tranny, but dont know if a stiffer firewall mount is avail. I haven't really dug in there to see if I can machine some bushings for it either. Im not really interested in going to solid mounts.
Brant,
When they did my side shift conversion, they didn't "phase" the coupler correctly when it was rewelded, so its kinda like 60deg off. Brad caught it on the PPI, but it was making me wonder if a full 90deg would be better. Up/down chassis flex might still bind it a little on the front to back action, but it would be constant in every gear.
Tnx,
SMD
QUOTE(smdubovsky @ Aug 15 2006, 10:10 AM) 
Brant,
When they did my side shift conversion, they didn't "phase" the coupler correctly when it was rewelded, so its kinda like 60deg off. Brad caught it on the PPI, but it was making me wonder if a full 90deg would be better. Up/down chassis flex might still bind it a little on the front to back action, but it would be constant in every gear.
Tnx,
SMD
I know a half dozen 914 race cars doing it.
but they are all caged and probably have less chance to flex
I know with my AJRS shifter, linkage mods, and custom delrin/brass bushings throughout... I am amazed at how precise my shifting is now.
brant
Capn,
My 911 has a 915 tranny. The shift rod is supported in up front and it uses a ball cup at the bottom of the shift rod (the tranny locates the rear of the rod and keeps it from moving). It rotatates the rod along its axis but it doesn't move. Its been a while since I've had to adjust it, but thats what I remember. From pictures I've seen, it looks like thats how tail-shift 914s worked too.
The 914 (/6 thats been converted to side shift) moves the whole rod side to side to get the rotation. It simply has to bind the coupler to do this. What I find even weirder, is that if the 911 coupler bushings were used (w/ side to side slop) this wouldn't be the case.
I replaced all the bushings except the firewall (which was in good shape). WHich helped alot. Brad put a good coupler on earlier this year, and it still looks ok. Adding the rennshift (vs the weltmeister that was in there) helped more. The only thing I have left is to reengineer the coupler and/or firewall bushing (or go into the tranny and see how its gated). The tranny has been rebuilt w/ an LSD and had some gears changed. It seems healthy (no grinding or slow syncros) but Im not familiar w/ the 901 internal gating mechanism so something may still be sloppy in it.
Tnx,
SMD
My 911 has a 915 tranny. The shift rod is supported in up front and it uses a ball cup at the bottom of the shift rod (the tranny locates the rear of the rod and keeps it from moving). It rotatates the rod along its axis but it doesn't move. Its been a while since I've had to adjust it, but thats what I remember. From pictures I've seen, it looks like thats how tail-shift 914s worked too.
The 914 (/6 thats been converted to side shift) moves the whole rod side to side to get the rotation. It simply has to bind the coupler to do this. What I find even weirder, is that if the 911 coupler bushings were used (w/ side to side slop) this wouldn't be the case.
I replaced all the bushings except the firewall (which was in good shape). WHich helped alot. Brad put a good coupler on earlier this year, and it still looks ok. Adding the rennshift (vs the weltmeister that was in there) helped more. The only thing I have left is to reengineer the coupler and/or firewall bushing (or go into the tranny and see how its gated). The tranny has been rebuilt w/ an LSD and had some gears changed. It seems healthy (no grinding or slow syncros) but Im not familiar w/ the 901 internal gating mechanism so something may still be sloppy in it.
Tnx,
SMD
I cant type/reply fast enough... 
Brant, Thanks. Its good to know that some of my ideas aren't completely in left field. I might give that a try first (I have to fix what the PO did anyway). Though, when its all out I might take dimensions and built up a U-joint coupler too. Would be interesting to compare back-to-back.
SMD
Brant, Thanks. Its good to know that some of my ideas aren't completely in left field. I might give that a try first (I have to fix what the PO did anyway). Though, when its all out I might take dimensions and built up a U-joint coupler too. Would be interesting to compare back-to-back.
SMD
QUOTE(smdubovsky @ Aug 15 2006, 09:10 AM)
Mueller,
Tnx. I'm familiar w/ the wevo bits, but didn't know they had an application that fits the 914. I just checked their website, looks like I'd have to buy a bunch of their bits and weld them together anyway. How did you drill a tapered hole - or did you? I thought of drilling a straight hole, slightly larger than the OD @ the nose of the set screw, so that I catch the wall of the taper part way up. That or I make a tapered single flute drill out of tool steel.
I first drilled a hole that matches the smaller OD of the cone, then used a modified (please don't laugh
) spade drill bit. 
Worked quite well, I plan on making a better cutter in the near future, if this extension works I have a few people interested in one. Tnx,
SMD
Click to view attachment
I had some binding on my side shifter bar in my 6. I added the Wevo Coupler with some welding and its much nicer. The stock unit definately binds in certain situations.
John
John
Okay, I hate to be a real dummy, but sometimes you just have to go with it. 
What is required to fit the WEVO or Stromski coupler in lieu of the stock 914 coupler? In photos they seem to have a socket with set screw on one end and a solid shaft on the other. Does the set screw socket end fit on the forward shift rod coming through the firewall? Do you then cut the square coupler end of the rear shift rod and insert the solid shaft end of the coupler? Weld or set screw or through bolt? Is the overall length of the coupler close to the length of the stock item?
What is required to fit the WEVO or Stromski coupler in lieu of the stock 914 coupler? In photos they seem to have a socket with set screw on one end and a solid shaft on the other. Does the set screw socket end fit on the forward shift rod coming through the firewall? Do you then cut the square coupler end of the rear shift rod and insert the solid shaft end of the coupler? Weld or set screw or through bolt? Is the overall length of the coupler close to the length of the stock item?
Mike,
I don't see how using the wevo coupler is any easier than fabing your own. You need something to end up w/ something like:
Click to view attachment
Drill a coupler and weld a nut to it for the set screw. Weld coupler to shaft. Weld shaft to end of stock shift rod (or fab your own on a lathe and drill for the set screw).
The setscrew to setscrew length should be the same as stock. The phasing (angular orientation of the set screw holes) can be completely ignored since the coupler is universal. Now, it would be best if it was designed so that the setscrew near the firewall pointed a convienient direction.
The wevo coupler for 911s are usefull because the 911 uses splines near the tranny shaft and the coupler mounts right too it. They make one thats a perfect drop in replacement. Its hard to get a DIY solution to fit in there (plus splines are hard to DIY), but the 914 has no such limitations.
SMD
I don't see how using the wevo coupler is any easier than fabing your own. You need something to end up w/ something like:
Click to view attachment
Drill a coupler and weld a nut to it for the set screw. Weld coupler to shaft. Weld shaft to end of stock shift rod (or fab your own on a lathe and drill for the set screw).
The setscrew to setscrew length should be the same as stock. The phasing (angular orientation of the set screw holes) can be completely ignored since the coupler is universal. Now, it would be best if it was designed so that the setscrew near the firewall pointed a convienient direction.
The wevo coupler for 911s are usefull because the 911 uses splines near the tranny shaft and the coupler mounts right too it. They make one thats a perfect drop in replacement. Its hard to get a DIY solution to fit in there (plus splines are hard to DIY), but the 914 has no such limitations.
SMD
QUOTE(smdubovsky @ Aug 15 2006, 10:41 AM)
Mike,
I don't see how using the wevo coupler is any easier than fabing your own. You need something to end up w/ something like:
Click to view attachment
Drill a coupler and weld a nut to it for the set screw. Weld coupler to shaft. Weld shaft to end of stock shift rod (or fab your own on a lathe and drill for the set screw).
The setscrew to setscrew length should be the same as stock. The phasing (angular orientation of the set screw holes) can be completely ignored since the coupler is universal. Now, it would be best if it was designed so that the setscrew near the firewall pointed a convienient direction.
The wevo coupler for 911s are usefull because the 911 uses splines near the tranny shaft and the coupler mounts right too it. They make one thats a perfect drop in replacement. Its hard to get a DIY solution to fit in there (plus splines are hard to DIY), but the 914 has no such limitations.
SMD
I didn't realize that there was no off the shelf drop in replacement for the 914 using that joint, but looking at the shift rod again I now know why
I'm sure you could sell a few complete ready to go shift rods with this coupling in place if the price is right
QUOTE(Mueller @ Aug 15 2006, 12:38 PM)
I'm sure you could sell a few complete ready to go shift rods with this coupling in place if the price is right
i have to fab a custom shift rod for my /6 conversion (pretty soon i might add) and i for one would be buying one of those in a heartbeat!
Andy
i welded the sleeve side from another old shifter bar to my rear bar and in it went....
Just in case anyone was curious, the couplers from Pegasus Racing in Smdubovsky's first post cost about $100 each, which is about half the price of the couplers Wevo and Stromski advertise. This has me wondering...
maf914,
They can actually be had for slightly less that $100, but thats the ballpark. Since a few have expressed interest and I want to try one anyway, Im buying parts to build a prototype. It looks like I could fab them in stainless for ~50% more. The part that will take the most time will be fabbing the part that goes through the tranny bushing and takes the setscrew (right most part in pic).
Im not making any promises but if anyones interested, shoot me an email or PM with 1) your comments 2) mild steel vs stainless 3) ballpark price.
SMD
They can actually be had for slightly less that $100, but thats the ballpark. Since a few have expressed interest and I want to try one anyway, Im buying parts to build a prototype. It looks like I could fab them in stainless for ~50% more. The part that will take the most time will be fabbing the part that goes through the tranny bushing and takes the setscrew (right most part in pic).
Im not making any promises but if anyones interested, shoot me an email or PM with 1) your comments 2) mild steel vs stainless 3) ballpark price.
SMD
If this represents an improvement for ALL sideshift conversions (even the lowly 1.7s like me) there are surely quite a few more that are interested (like me) in knowing about this. However, for just street and AX, not sure if it is needed (?).
1) make the rod hollow and light
2) see above (chromoly tube?)
3) $200 or trade for 12 pack and steak dinner
I'm saving $$ for renshift. Just got rebuilt side shift, linkage, need motor mount with hole, throwout bearing, bushing kit for conversion (Pelican has the special firewall bushing)
1) make the rod hollow and light
2) see above (chromoly tube?)
3) $200 or trade for 12 pack and steak dinner
I'm saving $$ for renshift. Just got rebuilt side shift, linkage, need motor mount with hole, throwout bearing, bushing kit for conversion (Pelican has the special firewall bushing)
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