"TRANSZILLA", side shift 914 - 901 build Options

[mrbubblehead]

after a couple of months of planning and parts collecting i have finally started my transzilla build. it will using a normal 914 side shift trans, with a few up grades, i will be dialing in the ring and pinion back to spec with this build also.

i laid all the parts out on my assembly table to give you guys an idea of all the parts installed.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i722.photobucket.com-12492-1362881754.1.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/i722.photobucket.com-12492-1362881754.2.jpg)

[mrbubblehead]

i think we left off at measuring the pinion depth. unfortunately, i didnt get alot of pictures but i will post what i have. first i install porsche tool p258, then the gear stack and take the measurement. i know i know more math. then subtract that number from the number in the book. that will give me my gasket(s) thickness between the case and the intermediate plate. pull the gear stack and put the proper thickness gaskets in. dont be fooled. the gasket "kit" comes with three gaskets, but they are all the same thickness. and close dosnt work. i believe they are 0.20mm but porsche offers them in 0.15 and .10mm. you will have to use an assortment of different thicknesses to hit the mark. if you have to use more than .50mm total in gasket thickness you will need to reshim the pinion shaft. and of course the shims are at the bottom of the shaft so the whole shmeer has to come apart to get at them. precision counts. so measure carefully.
(IMG:http://www.914world.com/bbs2/uploads_offsite/i722.photobucket.com-12492-1363290251.1.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/i722.photobucket.com-12492-1363290251.2.jpg)

after your gaskets are in place its time to measure again. in with p258 and gear stack. write the measurement down pull the stack and reinstall the stack again. its redundant i know but i like to make sure my measurements are repeatable and accurate. take your measurement and again subtract form your spec measurement. you only have a plus or minus of 0.03mm. mine came out pretty damn close. im satisfied.
(IMG:http://www.914world.com/bbs2/uploads_offsite/i722.photobucket.com-12492-1363290251.3.jpg)

the next measurement to take is bearing preload. again, its good to have a nice assortment of shims. porsche's price per shim? youl'll never guess.... $17.50 PER SHIM!! (IMG:style_emoticons/default/sheeplove.gif)

also since i am using skf differential bearings they have a different spec than the fag bearings. i think it is 22-30 inch lbs. after the break away. this measurement is taken with both bearings lubed with gear oil and no seals in the case or side cover. i am using a billit side cover which uses the bigger 930 bearing on the cover side and regular 901 on the ring gear side.
(IMG:http://www.914world.com/bbs2/uploads_offsite/i722.photobucket.com-12492-1363290251.4.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/i722.photobucket.com-12492-1363290252.5.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/i722.photobucket.com-12492-1363290252.6.jpg)
then is a matter of pressing on the bearings, install the dif and side cover, and measuring the preload. ONE WORD OF CAUTION! i never want to use too many shims to start with. to many shims will put the bearings in a bind, and you never want to put them in a bind. i start off thin and sneak up on it, untill im in spec. very very time consumeing.

sorry no pictures of the back lash adjustment, but there is one in the book. essentially what the backlash measurement is to mesh the ring gear to the pinion shaft. not to tight and not to loose (slop). this is a tedious job because you have your total shim thickness from both sides of the diff (preload). now you have to mix those shims to raise or lower the ring gear. it is alot of work pressing bearings off and on, swapping shims, assembling everything, measure, disassemble and do it as many times as necessary. one note. the manual says that the back lash spec is stamped on the side of the ring gear. i have yet to see this number stamped on a 914 ring gear. i have talk to 2 what i consider expert porsche gearbox builders and both told me the same spec. so thats the one i go with. it is a very minute amount of backlash with a very tight tolerance 0.03mm. again very very time consuming. and i make sure all my measurements are repeatable so i always have that extra step.

WHEW! questions so far?

next will be case prep.