Looks like TM M14's don't like Sorbo pads
 

Just a heads up to others who may want to try this.

I have been using Sorbo pads (available at airsoftparts.ca) in my ver.2 and ver.3 guns for a little while now, seems to be working really well. Really made em more quiet. So I wanted the same effect in my TM M14, ver.7 mechbox. I ordered the Sorbo pad set for ver.6/7 mechboxes and installed one. Within 25rnds I had shredded a piston. I opened it up and noticed that the piston was stripped in the opposite direction they normally do, from the piston head end back. I did some thinking and testing and found that the Sorbo pad was almost exactly one piston tooth thick. As a result it offset the piston by one tooth.

What was going on was the first tooth on the sector gear was grabbing the second tooth on the piston (from the back.) As it worked its way up the second last tooth on the sector gear pulled the last piston tooth. The piston tried to go forward but the last tooth on the sector gear smacked it. I guess it took 2-3 shots to snap the first tooth on the piston (the metal one) and now there where 2 extra sector gear teeth hitting the second last piston tooth. Then three against the third last, etc. etc. After around 25 cycles I had broken half the teeth on the piston so it was only really half cycling. All this seems to have been caused by the offset from the Sorbo pad. I have never run into this problem with ver.2 or ver.3 mechboxes (including ICS split mechboxes) but for some reason it cost me a piston in a ver.7.

Just a heads up. Anyone out there know a way to avoid this and still use a Sorbo pad? Currently there is no Sorbo pad and its still damn quiet, also upgraded from the now fragged stock TM piston to a Prometheus hard type.

did you pull out the origenal pad or did you cut it flush with the plastic?
I just instaled one today and fired about 120rds (at 440FPS) and its still going strong. I will be doing more shouting tomorow. You have to remove the hole ruber pad and install the sorbo, Mine had the same overall length as the oridgenal Maruy head.

thats odd
I've had mine in my M14 for over 10 000 rounds with no problems what so ever

Except the Sorbo is starting to show a bit of wear to it from my 460fps spring

Im using a deepfire piston which seems to work wonders as that is showing no wear either
The problem with the V7 ones is that u need to cut the hole yourself which sucks. I usually just use a single hole punch as that works wonders :)

I also recently installed a sorbo into a buddy's TM m14 with no problems to date with probably a couple thousand rounds through his gun so far. I did swap out the piston head to a Prom. POM. His m14 is rediculously quiet with the sorbo and a silencer on it; I love it.

I took off the original rubber pad but the thing was its maybe 1/3 as thick as the Sorbo pad. Hmmm....

Did you completely remove the excess adhesive before replacing the sorbo pad?

Check your bushings and shims. Maybe you didn’t shim it well.

Here is my TM m14 cylinderhead
http://i290.photobucket.com/albums/l...r101/m14_4.jpg

In my measurement the outside thickness is 1.35mm almost same as the stock TM rubber damper.
http://i290.photobucket.com/albums/l...r101/m14_5.jpg

As of now I haven’t encountered any problem like yours.

Very true, cutting the sorbo pad is kinda hard. Nova316's cutting technique is same as mine ( cutting sorbo pad made easy by using a hole puncher)

I attached pictures for everybody to follow.

Tools - 7.5mm hole puncher, scissor and hammer.
http://i290.photobucket.com/albums/l...r101/m14_6.jpg

See image to follow
1. Punching the sorbo pad
http://i290.photobucket.com/albums/l...r101/m14-1.jpg
http://i290.photobucket.com/albums/l...r101/m14_1.jpg

2. Use a small and sharp scissor to trim the hole
http://i290.photobucket.com/albums/l...r101/m14_2.jpg

3. Install the sorbo pad
http://i290.photobucket.com/albums/l...r101/m14_3.jpg

Is Micheal Jackson your gun tech?

Sorbo in my recently sold m14. 400 rounds on a 410fps, no problems at all..