I performed this mod. Like it a lot, but I installed a 1/8 inch washer and wondered what it would be like with another 1/8 inch washer. I installed and really don't notice that much difference, maybe a tad less notchy with my B&M.

Question: Is 1/4 inch too much???? Any issues with this?

 

I've heard that 1/4 is like removing the ball plunger completely. I have three 1/16-inch copper washers that I am going to install by next weekend. I also may play around with various thichnesses while the car is up in the air.

 

I did this mod last year and liked the results very much. I think 1/4" (.250) might be over kill. Nothing wrong with 1/4", I just think I got the same results (no contact) with my 3 NAPA copper drain plug gaskets. NAPA Balkamp part#704-1357 is a 20mm (hole diameter) copper oil drain plug gasket that is .051 thick. I bought the box of 10 ($6.90), used 3 (gave friends the rest) for a total thickness of .153 (just over 1/8") So there is no doubt that 1/4" will do the job. The archives posting in here on this modified Anti-Venom mod told of the target spacing to be at least 1/8" to realize the benefit. NOTE; a 3/4" washer requires work to get it to fit, a 20mm washer doesn't.

 

I've had my C5's plunger out about that far for about 1.5 years, no problems. On my C6, anything more than one 0.135 washer and the shifter didn't return to center as definitively as I thought it should (of course the C6 only has ~500 miles on it, so maybe after breaking I can use a thicker stack). The point is, it appears there is a bit of tranny-to-tranny variation, so I'd say give the next washer a try; if too much, you can try another 1/8" (3/8" total) to see if that's a happy medium.

 

what is this mod we speak of?!?!?!?!

 

This is a mod to lower the force required to shift between gears.

There is a spring-loaded plunger whose end rides along the shift rail in the tranny. The rail has three adjacent transverse grooves cut in it. As the shift rail is pulled/pushed fore/aft by your manipulation of the shifter, the ball on the end of the plunger follows the grooves. The center groove corresponds to neutral, and the two outer grooves correspond to gears 1/3/5 and to gears 2/4/6. You know that resistance you feel as you push the shifter from neutral into first? And after an initial threshold level of force is exceeded, the rest of the movement of the lever into first is notably lighter? That's the result of the plunger riding up out of the shift rail's neutral groove, over the top of the "hill" between the grooves, and into the 1/3/5 groove.

The plunger is mounted in a bolt that is accessible from outside the tranny. The "mod" is to remove the bolt, put a washer under the bolt head, and put the bolt back. The result is lower effort required to move the shifter between gears, because the plunger's engagement with the shift rail groove has been slightly decreased.

Pics here (it's on a C6, but it's identical to a C5): http://forums.corvetteforum.com/show...ight=antivenom

 

also give it some time. I installed 2 M20 copper drain plug washers I found at advance Auto and was disappointed with the results until I had driven the car for a couple of days, then I really started to appreciate the new shifting feel, I just need to shorten my shifter some and I'll be good.

 

The washers I bought are a tad big, so I put some teflon on the threads to make sure leaking wouldn't be an issue.....

 

It disappoints me to read here that members who have never searched the hundreds of posts (there are no negative posts on the Anti-Venom mod, just accolades) yet alone tried it themselves can prejudge the mod as a failure. Other than the shortened and threaded '07 Z06 shifter I bought from Gene Culley and installed the same day I did my modified Anti-Venom mod I credit the Anti-Venom mod for doing more to remove the notchiness of the stock shifter than the Z06 shifter (which did shorten the throws.) I've never either had or read of anyone's manual C5 popping out of gear because of this detent being disabled. What the final outcome is feels just like a Hurst Competition Plus on a Muncie. That's what I was trying to achieve and that's what I got. The original post I read stated that the target spacing should be at least 1/8" to gain benefit. I bought a box of 10 NAPA copper drain plug gaskets ($6.70), part#704-1357 that have a 20mm hole and are .051 thick. I used 3 for a total thickness of .153 or just over 1/8" To those who doubt this $2 mods value or think it will destroy their trans, don't do it. but take the time to search the folks that have done it and read what they have to say. Some owners won't change the lugnut covers on these cars others mod the heck out of them. Every mod that I've done to my bought new '02 vert with knowledge I've acquired mostly in here has been easy and improved a great car and made it greater. Some folks don't see anything wrong with the C5 stock shift mechanism, I did and was happy to get the successful tricks from some members that did the legwork for me to copy (they may not have got it right the first time). This was a long winded way of condoning this mod as being worth the effort (10 minutes and $2) in conjunction with the shifter of your choice (mine was GM).