Kraken Shimming

[Dusti69]

cool. i think thats the biggest and most important piece of info ive gotten out of this thread, and what i really wanted to know. thanks

[CDN_Stalker]

Each gear needs to be shimmed properly based upon it's freedom of movement vs. minimal side to shifting in the bushing/mechbox. Gear change, bushing change, or even mechbox shell change should have a check of each gear with a few screws in an empty mechbox (cylinder, piston, tappet out). Freely spinning is more important to have then a tiny bit of side to side movement of the gear. Proper shimming not only provides minimum side to side movement, but also maximizes area strength on the toothed areas of the gears, in their correct position to mate up with the proper part of the gear box (sector gear will be offset by a lot to mate up with the piston; bevel gear should have no shim under it for maximum mating with the motor's pinion gear) as well as proper clearance between gears to prevent rubbing and noise.

Simple answer, every shim job is done by learned feel, NOT by a diagram.

[m102404]

This is one of the best write ups on shimming that I've read. Lots of good pictures. As already said...shimming is learned and done by feel.

Devgru Shimming Guide

The purpose of shimming the gears, so far as I understand, is to setup maximum tooth to tooth bearing surface between the motor, bevel, spur, sector and piston teeth. There's shimming on either end to accomplish all of; spacing the gear faces apart for clearance (but maintaining max tooth contact), aligning the gear set to mesh appropriately with the piston teeth and lastly to ensure that the gears are not contacting the mechbox shell or bushings.

[Dusti69]

ok so i shimmed my gears. took a lot of trial and error to find out how many it took for each gear to not be going back and forth so much in the closed box. all the gears seem to be lined up evenly and it sounds better but they still make that dry RRRRRRAA!! noise when fired only its more high pitched and slightly less grindy sounding now. i dunno if i didnt do a good enough job shimming or maybe thats a normal kind of noise

[The Saint]

Less grindy is always good. High pitched noise could be a matter of your motor height adjustment, although that's even MORE of a trial and error than shimming. That one has to 'sound' good.

[Dusti69]

yea.... i just got done practically re-shimming my shim job. i stuck a thinner shim under the gear the motor hits and two more under the other two gears. there has to be like 12 to 14 shims in it now. probly coulda used less by using the thicker shims but i decided to use a bunch of the really thin ones instead. and i have to say it sounds more like it used to when i first got it now and i think i did a better job with the shims than i did yesterday. i completely forgot about my problem with the motor height. i should probly experiment with that a little next to see if it sounds any better with it lower or higher as its currently in the middle most position. the RRRRAA!! noise went to that more familiar RRRREOW!! noise so im hoping everything is alright in there now