KyleF

Hopefully this helps someone. I found there was some helpful but limited information out there about installing a shifter in a C4 with the ZF. Really couldn't find much on the B&M and what it did find was for the Hurst. A lot was still the same but I took some notes on mine to share if someone searches for this in the future.

First let me say that this is the most involved shifter install I have done. I have changed most of my cars to a short throw sport shifter over the years. They were all relatively easy, mostly done from the top. Not this car and it is a bit of work. It’s not that the shifter itself is complicated or any step is too difficult in itself, there is just a lot to do to get this job done and some frustrations. However, if you are like me and really enjoy a short, crisp, tight shift like I do, it is well worth it. I went with the B&M as it was in the “box of stuff” form the previous owner. I hear the ZFDoc shifter is a happy medium between the Hurst that doesn’t do much and the B&M that is really short and tight.

Tools Used:

Bench Vise Small Flat blade Screwdriver

Long Needle nose pliers Brake Drum Adjuster

3/8” Drive 7/16” Socket ½” Drive 13mm Socket

½” Drive 15mm Socket 3/8”-Drive 10mm Socket

3/8”-Drive 7mm Socket Side Cutters

Side Post Terminal Wrench Cordless 3/8” Drive Impact Driver

Cordless Drill ½” Drive ratchet

13mm ratcheting box end 3/8” Drive to ½” Drive Adapter

Punch/Drift set (Brass) 6” ½” – Drive Extension

Large Ball peen Hammer ½” – Drive U-Joint Extension

1/8” Drill Bit 3/16” Drill Bit

9/32” Drill Bit ½” Combination Wrench

6” piece of ¼” Drill Rod A Helper

Possibly Shim Material is factory shims are not enough 2X Mini Bungee Cords

Quickjack (Jack and Stands/Lift)



Let me give you some specs/measurements that I took between the two shifters




The measurements may not be spot on as I took them with a tape measure, but close enough for the purpose. As far as shift effort goes, the factory has a ratio of 7.85:1 while the B&M has a ratio of 3:1. What this means is summing the moment around the pivot point, 1 pound of force on the shifter produces 7.85lbs on the factory unit. To produce this same level of shift effort with the B&M you would have to put 2.6lbs of force. I am not sure what the shift force is on the ZF, but whatever the required thrust is, you will be putting 2.6X more effort into the B&M to produce the shift.




One more formality to get out of the way; I can’t promise your experience will be exactly the same. As these cars are getting older, many have had items modified or replaced, and all parts may not be the same. Also, these are my experiences and I am not guaranteeing this is an all inclusive instruction, more of an addendum or diary. You should consult the Factory Service Manual and the instructions that come with your shifter of choice. Additionally, working on your car can be a dangerous activity. Safety is your responsibility and you should consult the owner’s manual of your tools or equipment for all pertinent safety , lifting instructions, operating instructions, and ensure your tools and equipment are in safe working order. I suggest a complete read through of all instructions before beginning.

Now we get to start the fun part; installing a new shifter. As I said at the beginning, this is a bit involved. I started out following the B&M instructions and then learned some items later that I will share at the right point here. I will number the steps out per their instructions until I get to the spot I deviated and will let you know when I went my own way.

To prepare for the job, I removed my top and rolled down the windows. I was using a Quickjack lift and made it very nice to keep the car level. However you go about this, you will eventually need the rear of the car up in the air to remove the exhaust and work on the mating of the shift rod and shifter.




Section 1: Removing Console Trim Plate (90-96)

1. Put on the parking brake and put the transmission in 4th gear. Disconnect the negative battery cable. I used a side post battery ratchet that is very nice for this task.

2. Remove the shift pattern with a small flat blade screw driver. I just pried around it a bit at different sides. The leather deformed a bit, but came right back. Popped out easily. To remove the T lock pin, I used a disc brake adjuster tool, but any small pry bar should work. Again, the **** deformed a bit, but nothing that didn’t come back. Just work it around, don’t pry too hard in one spot. Unscrew the **** from the shifter

3. I didn’t have a lockout because my car is a 1996

4. Remove the console lid; remove the 4X7mm screws along the hinge from the console. It has a wire running through it, so I just sat it in the hatch.

5. The trim plate comes off by removing the 7mm screw under the cup holder and the two at the rear of the trim plate. Mine were covered by the carpet, so I pulled the carpet up, and sat it in the hatch as well.

6. Remove the trim plate by just wiggling and slide back from the dash while lifting. This is finesse over force item. It can crack easily. Unplug the cigarette lighter and the hatch release button. Sit trim plate to the side in a safe location.

Section 2: Removal of Stock Shifter (89-96)

1. From inside the car, remove the 4 acorn nuts with a 7/16” socket… instructions mention a spring clip. I didn’t have any spring clips? The plate comes up pretty easily once the nuts are removed. Note orientation, it is not symmetrical.

2. To remove the boot I just tugged at the shift boot. The adhesive around mine was not attached very well and released easy. The entire perimeter of the boot has adhesive. Note orientation, it is not symmetrical.

3. Removed the 4 nuts holding the plate down with a 10mm socket

4. Cut the cable tie. I pulled it out a bit with the thin flat blade and cut it. Then used the small flat blade to work around rolling the boot down while lifting up on the shifter base plate to separate it. It has to come up close to equally all around as it is tight on the screws. Note orientation, it is not symmetrical.

5. Put the car up on the Quickjack. The exhaust has to be removed unless you have a custom exhaust that gives you room to access the shifter. Mine did not. Not going to cover this in detail because of all the options out there and mine wasn’t stock. So I am sure your experience will vary including removing a cross brace if you have a convertible. In my opinion, on a C4 it is not hard. I also removed the exhaust spring hanger bracket (13mm Socket) from the transmission, but put the bolts back in. I also unplugged the speed sensor for more room to work. You will need to unplug the driver 02sensor. Brackets were all 13mm bolts, my clamps and the bolts to the manifold were 15mm. Rear muffler brackets were 13mm

6. Remove the lower boot by using a small flat blade to pull the cable tie away from the round section and cut it free. Then start working the boot back. It’s a bit difficult to get it to release but once I had it back, I secured it with a small cable tie to the exhaust hanger bolt heads. If you don’t do this, you will have to keep moving and trying to hold it out of your way later.

7. To move the snap ring away from the drive pin, I found it easier to grab it with long nosed needle nose pliers, pull it, and move it back. I used a screw driver to tap in around as I kept working it back out of the groove. You need to move it out into the u-joint area as the second ring it will sit in still shrouds the hole the drive pin is in. Leave the opening of the ring facing the bottom as the rod is toward the front of the car to mark its orientation.

8. I hit my pin with a drift and beat on it for a while. It didn’t move much. I say give it a shot, but if it doesn’t move just drill it out. A new one is around $12 to your door from ZFDoc. To be honest, it was so cheap and easy it’s not worth the time I have seen people post about it taking to work the pin out. I even put Deep Creep on it and let it sit before giving it a second go the next evening. I decided to just drill it. I center punched it, drilled it first with a 1/8” drill, followed by a 3/16” drill. After this, a few taps with a drift and out it came. Moved with each tap. Took about 5 minutes. Note, the pin is a ground 7mm and will determine if there is play in the shifting action. You want to make sure you have a very tight fit if you opt to replace it with another source.

9. Move the shifter gently to 3rd gear position. You should hear it separate. Now just wiggle and tug up. There are shims and nylon bushings at the ends of the factory shifter. They may fall into the boot, no big deal. I did keep an eye on the shims and noted which were front and rear. Combined they measured about .037” per end. This isn’t as important later as you will shim as needed, but I wasn’t sure at this step. They were equally matched shim pairs on each end. Also, I marked the nylon bushings over the pivot pins to put them back in the same location later. I marked them F & R.

10. When removing the flange bolt that held the shift rod adapter, mine looked to be flared on the non headed end. So it wouldn’t just punch out with a drift. There is a new spring pin in the kit so; I used a 9/32” Drill bit to remove the flared lip. Once I had cleared the end, the pin came right out with a few taps with a hammer and drift. You will re-use the shift rod adapter so protect it. I held it in a soft jaw machining vise while I drilled the pin.

Section 3: Installing the B&M shifter

1. For assembling the new shifter, I took the time to lay out all the parts from the kit according to supplied diagram. I like doing this on a clean microfiber towel so parts aren’t free to roll away and I can confirm I have everything nedded. Put a little grease in the grooves of the lower bushing. Then install the 4-orings and coat with a bit more lithium grease. It inserted into the shifter bottom hole easily. Just let it rest in there for now.

2. When installing the new spring pin between the shifter bushing and the gear shift rod adapter, make sure you are looking at your orientation. I had marked the lower shift rod with the ring. The opening of the ring was down as it faced the front of the car. The slot in the threads of the shifter should face the rear of the car. I suggest holding the assembly in something as you pound the pin in. I put mine in the soft jaw vise, started the pin in the shift rod, the slipped the slot of the shift rod adapter over the lower bushing in the shifter, lined the pin up, and hit it with a hammer to pound it in. It was a bit of a pain to get it started, but then went in very easy. I used a drift to make sure it was recessed on both sides pretty equally.

3. Skipped - Since I had drilled my pin, and was waiting on the new one to arrive – making one would have been easy enough, but this was a COVID-19 Stay-At-Home Order project, so I didn’t have access to a lathe at work. So for the next steps, this is how I completed the job and B&M assumes you put the shifter in the car at this point. I kept my shifter on the bench and kept moving forward.

4. Skipped

5. To install the nylon washers, I put some grease in the recesses on the shifter and pressed them in. This helped to hold them in place during the next step.

6. Before installing the swing plate, measure the width tip to tip of the brass pins of the new assembly and compare it to the old one. I didn’t do this here and found mine to be too large and needing to have the brass pins pounded in. Mine was too wide to fit in the factory spot and you could visually see the brass pins were not seated. The B&M measured 4.467” while the factory unit measured 4.321”. They should be close as you can shim later for a better fit. After adjustment mine measured 4.392”. This was close to the measurement of the factory width plus shims (.074” total shims) and now showing a difference of .071” to the large side. So, I went with this planning on not needing shims. Now the spring plate is ready to go over the shifter. Orientation again is important, slot in shifter threads to the rear of the car, threads of the swing plate to driver’s side. Slip it down the shifter until it lines up with the openings in the nylon washers. Put some grease on the 3/8” pivot axle, insert the axle, install a 5/16” acorn nut with ½” wrench on the passenger side, now turn nut until pin bottoms and nut bottoms out. Then on the other side, secure with the regular 5/16” nut with the ½” wrench. Assembly should be snug, but not overly tight. Movement should be smooth and free, but tight.

7. Put some grease on the brass pins on the swing plate and install the nylon bushings from the factory shifter per your earlier markings.

8. Now I installed the shifter into the car from the top. Again checking the orientation with the groove in the shifter to the rear and your acorn nut in the swing plate to the passenger side. Slide the shifter with the bushings installed into the factory location. Nest is to get the shift rod adapter up on the shift rod. I went under the car and grabbed the shift rod adapter with a punch in the drive pin hole to guide it up on the shift rod of the transmission. I could not manipulate it in the way I needed to get it to slide up to rod. So, I had my son get in the car, wiggle it right to left while applying light pressure toward 4th gear position on the stick. The shift rod adapter went the rest of the way onto the shift rod easily. I then used progressively larger drifts to line the hole up. Finally used a piece of ¼” Drill Rod that I ground a radius on the lead of. It was tight enough to stay in while waiting on the drive pin.

9. Now that the shifter was tight on the rod I could grab the shifter and check for tightness of the swing plate in the mount. While moving it forward and reward, I found there was play. I was able to get a .020” shim from the factory shim packs on each side for a total of .040” of shim. I had to use the thin flat blade to push the last shim down. Checked again and there was no extra movement in the mount. All movement of the shifter was at the pivot to move the shift rod.

10. Now start putting the car back together. I started by re-installing the lower plate but check the orientation marked earlier. I kept constant pressure on the plate while working around the boot with the thin flat blade to roll it up over the edges of the plate. The plate popped in pretty easily. Secure with a large zip tie and trim the excess with the side cutters.

11. Put boot back on and work the edges back down with the handle of a screwdriver. The adhesive was still tacky on mine and started to grab. Just get it well tucked down. Put the thin plate back on, checking the orientation again, and install the 4X acorn nuts with the 7/16” socket.

12. Re-install the trim plate and install the 3 screws with the 7mm socket.

13. Put the carpet and cup holder sock back in and then install the console lid with 4X bolts using the 7mm socket.

14. I had a new shift ball for mine that used a jam nut. I installed it at this point. The factory one can also be used and you would just screw it back on, put the locking T back in, and snap the shift pattern indicator back into the ****. The interior portion is now complete.

15. New drive pin arrived from ZF Doc and I ground a good ball radius on it. This allowed me to insert it about 1/8” inch so it would retain itself. Then just hit it with a hammer and drift until it was seated. I measured it with micrometers and it was just a bit over 7mm.

16. Once the drive pin is back in, the ring needs to be moved back over it to prevent accidental separation. I used the long pliers again to grab the retaining ring and work it back onto the groove the drive pin splits. I had to rotate it around by tapping on the edges of the opening with a screwdriver to rotate it around while working different sides into the groove, but was easy enough to get back in the groove. Remove the bungee cords

17. Getting the boot back up over the lower section was a mix of using the pliers, drifts, screwdrivers and hands to work it back on. It puts up a fight, but once it’s back up there, secure it with a zip tie, and then trim the extra with the side cutters.

18. Re-install the exhaust. Mine went from front to back. Mid pipes and hangers, then the rears. Leave everything loose and get a helper to look from the rear to confirm alignment as you start to tighten things up. Mine had 15mm bolts at the catalytic converter flanges and on the clamps. 13mm for the hangers and hanger bolts. The rear muffler retaining brackets were also 13mm bolts but I had to use the ratcheting 13mm box end to reach them.
Double check everything, make sure you can get into each gear, put the car on the ground, and take it for a drive. Check that all gears, including reverse work. With the B&M all I could say at this point was Wow! So much difference in shifter play, feel, throw and effort. Came out just the way I like it.

inadequate

Hey Kyle! This is great! looks good! I'm doing the same job right now, but I don't see the snap ring from Step Number 7. I'm pulling the boot back and I just don't see it. I see in your picture of the two shifters side by side the snap ring is there. Maybe I'm insane, I don't know. The short throw I bought is from Core Shifters. It's basically the Hurst style short throw for our cars.
Any advice would be appreciated. I called it a night for now and will be back at it tomorrow to try and finish it.
Thank you!

Also my car is a 1996

KyleF

I tried to put in my post how I did each step. The ring is important. It ensures the drive pin can't come out. If it is not there, I would just make sure to get one when you re-install. The biggest one was screw knocking the factory drive pin out. Just order one or make one and drill the one in there out. So much easier.

inadequate

I gotcha. Ok thanks! In your opinion what would be the simplest way to make one?

inadequate

Referring to the drive pin I mean

KyleF

Lathe. It needs to be tight so it needs to be sized correctly.

inadequate

I must be the luckiest boy on Earth. The pin came out very easily! I was able to finish the job on Sunday. 2 of the exhaust flange bolts snapped when I tried to remove them so I had to deal with that. The job was a a pain in the ***, but it was definitely worth it like everyone says. Feels a lot better! Thanks for your help Kyle! I appreciate it.

Brett

djxib

Here's my write-up from 2009, has a few other pictures.

https://www.corvetteforum.com/forums...plus-pics.html

Loved the B&M shifter, felt simply awesome, but I found that rapid shifting from 2nd to 3rd would sometimes "stick" and I couldn't get 3rd. (usually got me at the drag strip). Likely poor skill on my part, maybe tranny problem, but I ended up sending my old original shifter to ZFDoc. The ZFDoc shifter is a revelation, smooth as silk.

dizwiz24

Ive been real happy with my Hurst shifter

the most interesting thing to me is the way it ‘centers’ the lever and ‘directs it’ to the next higher gear (making ‘money shifts difficult to do (ie. You are redlined in 2nd and want 3rd But get 1st by mistake)

With the Hurst, Throw is reduced, Shifter height is lower, but effort (to move the lever) is a little higher now (its not/never has been buttery like a honda or even as buttery as the c6 z06 i once drove) . Id say its a little notchier , but it makes me more confident Im getting the right gear and there wont be any surprise when I let the clutch out

i have to believe the b&m, with even further reduced throw, that effort/notchiness is going to be higher - but again rewards the user with faster shifting

KyleF

Yup, a handful of people get this. I was hopeful, hit mine for a while, then drilled it. After 5 or so good hits, if it hasn't moved, I say drill it. It is worth giving it a few hits just to see if it comes out.

CDN94C4

Hey Gents, really good thread and greatly appreciate the step by step breakdown. Could you please provide the part numbers for your respected shifter?

dizwiz24

Any comments on increased shift effort / notchiness

dizwiz24

if you were using castrol bmw 10w-60 engine oil in your transmission (like some people used to) , that could have been part of the problem. This was my experience when I tried using bmw engine oil in my zf6 which was the 'rage' at one point.

KyleF

It's quite increased, not horrible. You have to mean it when you shift. As I mentioned in my write up, I don't have a good way to get an actual force measurement, but whatever it is, it will be 2.6X more effort with the B&M due to the lever ratio. Less lever = shorter distance = higher force.

dizwiz24

Now we need to hear from someone who has installed a B&M megashifter - and how that worked out

(Back when I went to high school, it was popular to have a 4 cylinder mustang, a stereo system that rattled the car, a neon license plate frame and a B&M megashifter)

KyleF

Isn't that for automatics?

CDN94C4

Can you guys provide a where you got your shifters from? Holley does not list a C4 short shifter and called them; they do not make one.....

KyleF

Mine came in a "box of parts" that came with the car when I bought it.

ChumpVette

https://www.ebay.com/itm/281852776484

KyleF

If I read the description correctly, are they calming the Core is the same design as the Hurst?

IIRC it was Hurst, ZF Doc, B&M in that order for shift throw reduction. B&M being the shortest.