ms2125 showing clip after cap replacement!

Thumper88 · Post by **Thumper88** » Sun May 27, 2007 10:51 pm

if you know anything about engine rebuilding, it's basically like reaming the cylinders. A "ridge" forms around the top of the cylinder, caused by the piston rings moving up and down. So you use a ridge reamer to cut the ridge and smooth the top of the block.

marko · Post by **marko** » Sun May 27, 2007 11:06 pm

Thumper88 wrote:if you know anything about engine rebuilding, it's basically like reaming the cylinders. A "ridge" forms around the top of the cylinder, caused by the piston rings moving up and down. So you use a ridge reamer to cut the ridge and smooth the top of the block.

ahh, i see now! so is it the case of fet that gets reamed? i'm guessing the case although i havn't reallt noticed a problem with any ms amps i've taken apart yet....

Thumper88 · Post by **Thumper88** » Sun May 27, 2007 11:07 pm

I believe he's talking about the heatsink, not the transistors themselves.

1moreamp · Post by **1moreamp** » Mon May 28, 2007 2:26 am

Thumper88 wrote:I believe he's talking about the heatsink, not the transistors themselves.

Correct, the aluminum has a tendency to pull around the mounting screw treads. This causes the transistors not to set flat against the sink surface, Chamfering the hole face is the only way to repair this I know of.
Other then re-drilling and installing Keen-serts or Heli-coil thread repair inserts. Both of which I keep in stock from my PPI days gone by. I can't tell you how many PPI's I had to repair in the past, so the bottom case cover would reinstall properly.

The distortion is caused by tech's over tightening the mounting hardware. PG had a spec, and I am sure they used tools calibrated to that torque spec thats simply released or gave some visual or aural feedback that the install setpoint had been met. < usually in Inch-pounds >

This is another reason why Tenth editions have clamp bars, along with the fact they re-used all their old sink stock when possible. MW3's 2250 was a older 2125 sink that had been repainted. I had to chamfer Nico's new amp because PG did not and I also found plastic tape under his drivers mounted in the middle of the outputs < Yeah clear plastic tape> The threads had become distorted, and the builder just used a piece of plastic tape to prevent the driver from shorting to the case at the mounting hole.

Aluminum is very soft against those steel screws, and some tech with big iron wrists...