930 shift pattern and cable shift question

[Mark]

I'm looking to use an inverted 930 transaxle for a GTM build and it seems that this forum has a alot more info on various transaxles. I picked up a '88 MR2 cable shifter for next to nothing but not sure if it will work. I need to know the shift pattern at the shift rod on the transmission, in otherwords, is clockwise and in- 1st gear, out 2nd- when facing the tail of the trans?

My concern is the MR2 shifter has the cable attachment above the pivot point of the shifter, not below like the Brandwood, corolla or tercel pictures I found in other threads. This would reverse the cable pull and I would like to keep that cable inline, on top of the trans, not through some bellcrank or other reversing apperatus. Here's a few pics of an MR2 shifter. Thanks for any help!

 

[Mark]

I had something like this picture in mind for the cables in the back. I guess the other info that might answer my question is if the original 911 shifter has the shift rod going to the trans attached above or below the fulcrum of the shifter, I found pics of 911 shifters in both configurations. Thanks.

 

[Dimi Terleckyj]

Hi Mark

IMHO you should dump the shifter you have even if it was cheap and get the shifter from the Tercel as it is a much stronger cast unit and it can be turned around to reverse the cable direction if you need it.

The only thing you will need to fabricate is a base plate to support the cable sheath/adjusting bracket.

Check out the enclosed photo of mine as set up in my car.

It is also a much smaller unit.

I only paid $20 for mine from my local wrecker.

It will save you a lot of headaches down the track.

Dimi

 

[Russ Noble]

I need to know the shift pattern at the shift rod on the transmission, in otherwords, is clockwise and in- 1st gear, out 2nd- when facing the tail of the trans?

No. Anticlockwise and in for 1st

 

[Mark]

Thanks Dimi. I've been looking for the tercel shifter online, no luck. I guess I will have to hit some junkyards. I do like the configuration of the shifter, thanks for the pic.

Russ, thanks for the info, I assume the pattern is an H with reverse left and up? So at the transaxle it would be anticlockwise-in = 1st, out=2nd, clockwise-in=3rd, out=4th. Reverse hard anticlockwise and in?

If this is correct I think my shifter would be appropriate, pulling on the cable for 1st, 3rd and rev. The MR2 unit seems to be a good quality compact mechanism, the baseplate is a little bulky and a bit flimsy not mounted but I would probably fabricate a new cable mount and ditch the the baseplate.

Thanks, Mark

 

[Julian]

I have a Renegade Hybrid shifter hooked to a G50/52, but I'm looking to change it as I seem to be able to set it up for Reverse or 5th, not both.

Anyone using a Porsche unit from the 996/Boxster? B&M make short shift kits for these Porsche units too and they come up pretty cheap on Ebay.

Thanks,

 

[Russ Noble]

Russ, thanks for the info, I assume the pattern is an H with reverse left and up? So at the transaxle it would be anticlockwise-in = 1st, out=2nd, clockwise-in=3rd, out=4th. Reverse hard anticlockwise and in?
Thanks, Mark

Yep, you've got it. Cheers

 

[Dimi Terleckyj]

Hi Julian
At the risk of repeating myself have a look at my build thread as my gearbox (G50) and sideshift assembly was supplied by Renegade but I did not use their shifter and used the Tercel shifter and have no problem getting all five speeds and reverse.

The Tercel shifter has more than enough gate movement to locate all gears and then some and the shifter is small and solid.

Dimi.

 

[GTPVette]

Mark,,,
I'm running one out of an Eclipse in my GTM. I did have to modify the cable mounts a bit,,, but seems to shift well.

 

[Mark]

Thanks Russ! GTPVette, do you have a picture of your cable mounts at the trans? Nice job on the shifter.
I really do like the Tercel shifter, compact and stout looking, I guess the fore/aft action is backwards though for a 930 according to Russ's info. If I end up getting a G50 I'll definitely hunt one of those down.

I'm looking for a rebuildable or take-out 930. I figure if purchased a rebuilt one, the warrantee would expire before it ever hit the road. I might as well get a used box and may just get a few miles out of it, maybe not. The build $'s will be better spent building the car instead of a bunch of expensive parts gathering dust.

Anyone know if the CV flanges are the same width and pattern as the G50?

Mark

 

[Bill Musarra]

Mark,
I am in the middle of fabing a shifter for my 930. I had originally envisioned a rod shift setup, but I have come to the realization that cable is really the only way to go. They use them in the Ford GT I believe.
I went to a "Pull A Part" junkyard and got an 89 Tercell for one hour of my time and $20. The 89 Corolla will work as well. I am sure there are other year models that will work. Placing the shifter frontwards or backwards will only depend on where you want the neutral gate to be. Mine is LHD, so the shifter sits in the middle console. The neutral gate arm sits on the driver’s side for me. It really doesn't matter that much. I’ll explain why in a minute. The main problem you will have is this. The shifter is what I call a central pivot action shifter. By that I mean when the shifter goes forward, the gear selector cable goes backward. With the shifter facing forward(neutral gate cable is on the left side), pull it to the left to select 1^st/2^nd/reverse and the lever goes forward. Remember I told you that it doesn’t matter which way you turn the shifter. Here is why. If you turn the shifter around and then pull the shifter to the left, the bracket still goes forward.
I think the only reason for turning it around is to get the neutral selector to go down the right side of the car. If you use the Brandwood transmission bracket or similar setup as shown above, then it won't matter which way you place the shifter for the neutral gate. You still have to attack the tail shaft from the left side of the trans(facing the trans from the rear). Irregardless of the direction of the shifter, the cable is in the pull mode and will have to be mounted on top of the selector shaft to go anti clockwise for 1st - 2nd gear. If it is turned around like Dimi's, pulling the shfter to the left will make the shift arm move in the forward direction also. If you decided to attack the selector shaft from the right, it will still be in the pull mode, but will have to be mounted on the bottom of the selector shaft to get the anti clock rotation. The real limiting factor here will be how close your exhaust is to the selector shaft itself. Too close, and you will have to come at it from the bottom. That will be determined by how low your bodywork opening is for the exhaust pipes. I have a license tag mounting there, so it drops mine down about an inch.
Now lets look at the gear selector cable. The logical way to mount the cables is toward the rear of the car. The trans is back there so why not. Regardless of the direction the shifter is mounted, the gear selector cable connection will move opposite to the movement of the shifter. This is also opposite the movement you want for the selector rod. The shifter goes forward, the cable goes backward, and you want the selector rod to go forward. You will need a Z link to change the direction of travel. If you run the neutral selector cable directly back you will need a bell crank to make the 90 degree turn to the tail shaft.
Let’s say you don’t like the Z link idea. Well there is a way to get around it. If you run the gear selector cable to the front of the shifter and loop it around to get to the tail shaft, you now have a direct relationship with the selector rod. If you do the same thing with the Neutral cable, you turn the pull motion to a push motion. If you come down the left side of the motor, the attachment to the tail shaft is on the bottom. The only thing you have to remember is that a cables strongest action is in the pull mode.
Here are some numbers to remember.

• The shifter gear selector motion is 4 inches maximum front to rear.
• The tail shaft movement is 1 ½” first to second gear.
• The neutral gate of the shifter is ¾” forward and ¾” backward
• For the neutral selector to get the full ¾” movement, the attachment is 1 1/2" above or below the tail shaft. The bell crank has to be a good distance away from the tail shaft so that the in and out motion doesnot pull it in and out. This will give the shfter in the cabin an arc with its shift pattern.
• The measurements of the bell crank(furnished by others on the forum) are in the pic below.
• You can shorten the throw of the Z link gearshift by decreasing the distance of the cable to the Z link centerline.
• You can shorten the throw of the Toyota gearshift in a direct action mode, by shortening the gearshift shaft.

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There is one more alternative to consider for the gear selection cable. That is to modify the shifter with a rod end mounted to the shifter above the central pivot. Then the shifter becomes a direct action shifter, and can be mounted directly to the gear selector rod
I hope this hasn't been too confusing. I have worked on this thing for some time now and it gave me a headache just thinking about it.
The thing you really don't want is the neutral selector cable making a loop unsupported near the axels. It needs to be supported.
I haven't finalized my own plan yet. What I have found is that it is hard to find cables (1) with bulkhead fittings on both ends, and (2) with 1/4 x 28 ends. TCIauto.com makes them(and sells them) and Summit sells TCI cables. I have found that in using the direct cables in my car requires a 7 ft. cable. For some reason, TCI TCI - SHIFTERS : Shifter Cables and Summit summitracing.com charge a lot more for the 7 ft. than any other length. Even more than a 10 ft. cable. Summit prices are less than TCI for the TCI cables(probably dealer discount). Summit however, charges almost double for the 7 ft. cable!?
A last note. I am using rear coolers and this limits the way a bell crank can be used. The coolers are next to the tail shaft and I would have to use a vertical arrangement rather than the horizontal because the crank hits the cooler mounts.
To get a better pic and explanation of the Brandwood setup, go to Big Foot(Randy) web page. It is for a G50-03 which is different from a 930, but it will give you some ideas.

Bill

 

[Mark]

Wow Bill, that was awesome reading that! I'm with you all the way, well stated. I extend a huge thanks for taking that amount of time to share that with me (and everyone else of course). The dimensional data is priceless.

If you look at the picture of the MR2 shifter i have in the first post you'll see I lucked out and purchased a direct acting shifter, no Z-link or bellcrank required. Maybe you could modify your shifter to this configuration (your idea), eliminate the bellcrank, solve your clearance issue with the coolers and maybe rid yourself of that headache as well....? The less moving parts the better.

I'll probably ditch the mounting plate on the MR2 shifter. The gate mechanism and pivot assembly, mounted to the bottom of the mounting plate are very simple and stout pieces. I'm sure I can fab up a sexier and stronger mount.

You mentioned that the cable is strongest in the pull mode, makes sense. I have worked with alot of Morse cables working as an engineer on tugboats for handfull of years after getting a marine engineering degree. We usually had cables routed for the most critical action or the most effort to be a pull on the cable. The prefered function that needs extra effort, i gather, must be the gate going to reverse.

I think I remember some thread on the GTM forum refering to 112" cables ordered from McMaster-Carr. I'll have to have components in place to measure up for cables anyways. Someone used garden hose for a yardstick and I think someone else used flexible conduit.

Anyways, I definitely received all the info I requested from the original post and more, thanks all! I think the only other info I need is the CV flange width and pattern compatability with the G50. The 930 is 249mm between flanges according to the gearbox comparison chart elsewhere on this forum, but blank for the G50. The GTM kit is designed for the G50 box and comes with axles designed to mate up with user-supplied inner CV joints for a G50. I would suppose the width of these flanges has to be at least close in dimension to work. Anyone have a G50 they could measure? CV flange patterns anyone? Thanks.

Mark

 

[Mark]

Here's another picture of an MR2 shifter on ebay right now, shows top and bottom. I found mine for $10 + shipping. It is an '85-'89 model. I just looked and there are four of these on ebay right now. Just search for 'MR2 shifter' - none will pop up though. Select "See additional Buy It Now Items" at the bottom and there you go.

Mark

 

[GTPVette]

Mark,,,,
Not the best picture but you'll get the idea.

http://www.lsspecialists.com/Shifter.avi

Good luck with it.....

Fred

 

[andys]

Bill,

That is a very nice write-up. It looks to me like it covers all the aspects necessary to consider when configuring a cable shifter both in the cabin and the transaxle. You stress some very good points

I would like to affirm one of your bullet points:

"For the neutral selector to get the full ¾” movement, the attachment is 1 1/2" above or below the tail shaft. The bell crank has to be a good distance away from the tail shaft so that the in and out motion doesnot pull it in and out. This will give the shfter in the cabin an arc with its shift pattern."

If you indeed do not provide some distance between the selector and the bell crank, you will notice an arc motion in your shifter which becomes more pronounced as this distance becomes shorter, so it is an important design consideration which would otherwise produce in an annoying result.

Keeping the cable normal to the direction of motion is preferable, IMO. If you look for example at the 5 speed Porsche Boxster transaxle linkage, you'll notice how they effectively use bell cranks to minimize the call for the cable to operate at odd angles (reducing the chance of both increased friction and failure). The Boxster 5 speed somewhat similar in that the selector shaft points toward the rear like the 930. Below is a photo of the Boxster set up (sorry for the file type), and another of how I configured my 01E linkage using a bell crank:

Mark, I personally prefer the Tuthhill cables as they are more flexible. Though they are available through McMaster-Carr and Summit, I would recommend you contact Control Cables, Inc (in SoCal). They will make any length, any bulkhead, any throw, any end, and can process your order by phone with a CC. Normally a much quicker process than using a third party (and a better price, if I'm not mistaken). Control Cables, Inc.

BTW, if you opt to use the Toyota Tercel/Celica shifter, here's a tip: To couple to the ball end of the shift lever, use a gas spring rod end, McMaster-Carr #9416K75 13 mm Steel Ball Socket For M8 Thread, W/clip (there's a stainless steel version if you prefer). You may need to make a metric to SAE thread adapter; I simply TIG welded a M8 bolt to a 1/4-28 rod coupling.

Cheers,
Andy

 

[CanAm Ken]

All,

Very good summary of the 930 transaxle shifting topic. I'm bulding a CanAm variant with an inverted Porsche 930, behind a twin-turbocharged small block Chev. I initially fabbed a shifter from a junkyard shifter (can't recall the make, right now) but was not overly happy with it. I had used a long looping Morse cable of the front of the unit to get the right movement for ths fore-aft shift motion, and was never happy with the "feel". Right now, I'm fabbing an alternative--I'm modifying a small universal joint, that I'm mounting to a steel plate base. Above the u-joint, I'm welding in my shifter (about 8" in length, and midway up that shifter, I'm welding tabs for a rod end--this rod is thereby mounted "above the pivot point of the shift" which will give me the proper fore-aft motion for the 930. All the geometry works out for relatively short movement of the shifter to properly operate the 930's shift rod for the 1-2, 3-4 and neutral-reverse movement. On the U-joints joke, I've welded an extension (about 2-3/4" long) that will traslate the left-right motion of the shifter to effectively an up and down movement; with a shore heim joint linkage, I route this movement to a bellcrank mounted about 3" behind the U-joint to get the up-down movement translated into another for-aft movement; I route this through a second Morse cable to move the 930 shift rod laterally. I rely upon the detents within the transaxle to locate my reverse, 1, 2, 3, and 4 locations on the shifter. Everything (the "u-joint" shift rod and the bellcrank) all move in needle bearings and is very positve and relatively low friction. I may add a gate plate over the shifter, but it doesn't seem necessary if my mock-up translates well to the final product. I haven't had the time to draw up a diagram, nor take pics, but I hope you get the idea. Again, I've been down the road with Brandwood, Renegade, AJ Speedshift, and CNC Performance alternatives, and yet I'm suspecting my approach will be pretty straightforward and direct (i.e., keep it simple). So far, I'm out a total of $00.00 on this one--I already have the U-Joint and Morse cables in my parts bin. The rest is TIG welding and some metal work.

 

[CanAm Ken]

I don't have a good close-up pic of my current shifter, but it reused a junkyard shifter and (probably too small) Morse cables. The car itself is styled after a McLaren CanAm, but with "more modern" locomotion--small block Chev, twin turbos at 18 lbs boost, intercooled and fuel injected. FYI......

Ken

 

[Randy V]

I got the Brandwood shifter with my car from RCR - but the shifter was designed for a G50/50? It would not work on the transmission side with the "shortened" G50/03 box I am using - so I spent the next little while modifying / fabricating brackets and arms to bring the assembly back into play.
I may still do a bit more work on the neutral gate cable bracket to put even less of an angle on the cable's sheath - but for now it seems to not be torquing the sheath so I decided to move on to more pressing tasks..

GT-FORTY.COM

Seems to work alright - although at this point my car has not been on the road.

Here's a few extra clips;

 

[Bill Musarra]

Just remember that Randy's adaptation is for the shortened 03. His web site takes you through what he did to alter the Brandwood tail shaft adapter. The best part is how he altered the tail shaft connector. Probably over engineered, but what is needed if you plan to do some relatively fast shifting. His 5th pic down is the comparison of the Brandwood unit and his own. The 930 tail shaft can be shortened a little, just have to leave enough for the adapter to clear. The only thing I don't like about Randy's is the angle that the neutral gate cable has to go through. When you come in from the side like that, it is something you have to put up with, and the further away it is the less angle it has to go through. My only suggestion is to make sure that when the tailshaft is in the neutral gate, that the cable is aimed straight at its connection on the tail shaft.
That is one reason that I like the bell crank. The rod end on the bell crank is designed for the misalignment angle. The rod end is also fictionless essentially.
Can Am Man what you describe is exactly what I was saying about attaching the fore and aft cable to the top part of the shifter. I think you would get a better action with the Toyota unit as it is lubricated and allows you good connections for the cables. It is a strong unit and a deal at about $20.
I am considering coming at the neutral gate from the bottom of the trans. I have designed a mounting piece that would hold both the neutral unit as well as the fore and aft cable. It needs to be cleaned up a little. It could have a Z link at the top or if the rod end is mounted to the top of the shifter, a direct mount to the tail shaft.

Bill

 

[CanAm Ken]

Bill (Musarra),,,,,, you referenced "the Toyota" unit in your last post. I'm not familiar with this shifter. Can you advise which model (and year, perhaps) Toyota you're refering to? Do you have any pics of the unit?