Project: PolarRAM

[xj_man_646]

Nice work!

[6DoF]

2 steps fwd n one step back ... never fails.

got the tunnel and floor sealed/cut last night, that went well. i decided there was no reason to go too crazy and throw sparks under the dash, so i made the tunnel patch semi-permanent and removable. could go back to the factory trans easier/ patch was easier / it's sealed in place and the new carpet will make it look pretty.

then the NP205. the single stick running 2 shift rails deal wasn't good when new, let alone after 30 years. if i'm making a custom shifter for the 5600, it's going to be a twin stick, if it's a twin stick it has to be capable of FWD. easy enough, just pop out the main shift rail and grind out for the interlocks. sure enough i now have FWD-high, and FWD-low!

i also now have rear-high and fwd-low at the same time ... and since it's the direction that a passenger could just kick one stick one notch and get there, i'm going to have to re-pull the stick and add some metal back. oh well.

[6DoF]

fixed it! no more NP205 cross ratio! mod all the 205's though, that only took me 35min to pull the rail, weld, re-grind, and totally reassemble/test.

twin stick kit should be here today, hoping the lateness wasn't cuz UPS destroyed the box and it's missing parts ...

[xj_man_646]

Twin sticks in the tow pig. That is sweet .

[6DoF]

twin sticks complete and functional! not only that, they fit thru the hole ever so nicely.

started with a GM shifter kit from JB Custom Fabrications and started cutting them up. crazy enough the offset was too much and i had to section 1-1/4" out (1-3/8" on the angle) to get the center of the sticks 7" from the center of the 5600 shifter. 1/4" plate and angle mount bolted to the trans was good spacing, but better with the little spacer that came in the kit. the fwd boss already had a thru-hole and i just tapped the angle for the bolt, while the rearward boss needed to be drilled and tapped. i drilled and tapped the center of that boss, and the shifter pivot is 2" up from that rear bolt, and 2-5/8" forward of it.

the shifter connectors aren't as nice as i wanted, but i can fix them later. instead of buying new heims or threaded sleeves and such, i welded a bolt to one end of a 5/16" rod for the female heims to adjust, while i just welded the male heims right to the rod. if i ever need to replace a heim I'll redo them better ... till then this was all i had laying around. i moved the mounting hole in the bottom of the shifters for better misalignment clearance and i didn't need the extra length like the GM kit required.

the adapters bolted to the 205 shift rails are swapped from what the GM application called for. the one on the fwd stick is unmodified while the other i had to cut the sleeve shorter and drill a new hole for the bolt thru the rail. real happy how those came out, and were easy.

i now have the transmission bolted into the truck for good! while still missing the crossmember, i had to see how the shifters felt. this is a short-throw shifter with a factory 3rd gen stick screwed to it and the EATON shift knob. pictured is 2nd gear, talk about an easier reach than the factory setup! depending on how you hold the shifter you can hit your hand on the steering wheel in the 1-2 shift, but I'm going to drive it before i start modifying that.

i think the t-case shifter hole is good to go, the new twin boot covers and seals it great. i MIGHT have gotten the 5600 shifter hole a little small

[6DoF]

wow, decent weekend of work! wife actually left me alone and i was productive.

finished getting a lot of little things like the trans adapter covers, starter bolted in, clutch master on, etc. shoot, i had already converted my g360 slave cyl to use a braided stainless -3an hose (very worth it) so i just tossed the 5600 slave on that line. low and behold it was too short had a 36" line in the truck, needed a 48". set about searching thru my "inventory" (the parts hord) and found a 48! hooked up, re-bled, much win.

cut down the rear DS and ended up with this stubby thing, not impressed but will function. the carrier is even basically trashed but together. i have about 68" yoke to yoke, so when i re-do the rear suspension later this spring I'll get a new 1pc shaft for back there.

you ever paint stuff and keep working hoping it'll be dry by the time you need them? doesn't always work ... almost as bad as forgetting to power wash the fluid film off before major work and cleaning eeeevvverything.

cross member came out nicer and easier than i ever thought it would. i was finishing up taking all my measurements to go CAD up a nice custom tube cross member, when i looked at the factory unit, had to at least see how it lined up. well after the g360 riser had been un-riveted, it slid in there against the frame without hitting anything, no other modification! even the clocked down np205 was still above it! in order to clear the front shaft, the crossmember is about 9.5" back while the t-case only moved just over 6" back. by moving the factory 5600 trans mount back by 1.25" on it's trans plate, i got the mount centered on the crossmember even. the new 4" c-channel riser is 1-1/8" tall.

my front drive shaft was 19deg different from the pinion before this, now it's only 9. should be WAY less chatter with the hubs locked now. hopefully i can make that a few deg better this spring when i mess with the front suspension too.

the twin stick feels AMAZING to shift in the truck. 10,000x more positive feel and smoother than the wallered out factory BS. highly recommended. no more trying to find what feels like half a detent move between 2wd and 4wd high.

[6DoF]

last night started out pretty satisfying, the shifters are all in and ready to drive!

the factory boot might not be the ideal, but i think it's going to work good. the square shifter of the 5600 doesn't fit as well in the round boot though. first thing was to cut out the inner boot since the shifter sticks up much further thru the floor. actually fixed most of my ripped boot issue. then since i got the short throw shifter it uses this 1" spacer for the longer stick below the pivot. to gain some clearance for shakin back n forth i had to round the corners more. 2 cut, 2 aren't in the pictures for demo, but i did all 4. shoved it on the tower, marked my hole locations, and made a template to mark out what i could cut and still seal. i actually forgot to grab a picture of the final clearance, but we should be ok.

might shorten or re-bend the shifter later after driving we'll see, but the twin sticks are just awesome to shift thru.

[6DoF]

after the shifters i started in on the exhaust. since it was apart i just can't leave well enough alone!

almost a complete re-do of the down pipe, then adding in a BD Diesel exhaust brake and FTE resonator before the t-case. still have some tweaks to make tonight before i burn it all home, but it's all guna fit!

[xj_man_646]

Exhaust brakes are sweet

[6DoF]

i drove it!! holy sh!t it's better!

got the exhaust welded, painted, and installed back to the t-case and couldn't wait any longer, i had to test drive it. worth it. even with it dumping right under the passenger seat up in the frame, it's quieter. that FTE muffler/resonator thing is really good. i'll finish out the exhaust tonight and be done with this conversion.

new clutch feels 1000x better, i just need to adjust my pedal down to make sure i don't over travel this thing. Chinese short throw shifter is a little sloppy but ok, i might take it apart some time to see if i can tighten it up. no vibrations at all, trans is way quieter, and every synchro works.

i guess i need basically a full tank of fuel city driving to break in the clutch before i start playing games or towing. debating if i do that now or start into something else on it first.

- front suspension recombobulation
- rear suspension re-do from scratch
- floor clean/seal/sound deadener + new carpet
- new seat mounts ... wire new seats
- 1000 other little things

[xj_man_646]

What are the details on what the suspension needs?

I do recall when I test drove a 1st gen Cummins, the thing rode like a damn hay wagon.

[6DoF]

yeah, factory they are known for being the worst riding of the era ... mine however has the stiffest aftermarket lift spring available and is basically a hard tail. if i jack it up by the hitch, the rear axle has maybe 1" of droop, and that includes bushing slop. it's just wrong. i'm pretty sure the PO wrapped up the rear springs doing torque stuff and thought these would help, then added traction bars anyways.

currently i have the 4" spring and the factory 4" block, the factory rear spring is 54". i bought 1998 GMC 1500 3" lift springs that are 64" long. while having to relocate both front and rear spring hangers, i'll do a shackle flip as well. the GMC lift spring should actually be more like a 6" lift for this truck, so with the shackle flip i will get to ditch the block. just lots more betterer. most of my miles are unloaded so this setup should ride/flex WAY better, then i have airride load bags for towing capacity. i'll also have to re-mount the traction bars well under the axle to keep my "link separation"

the front is just a whole lot of tweaking. front shackle is super short factory, so the 6" lift spring is longer to keep that from being inverted. under a good bump the spring eye actually hits the frame (infinite spring rate FTL). longer shackle, easy enough. however this points the pinion down and adds more lift. so i plan to remove the shortest leaf and add 2deg shims. with any luck i'll end up about 1/2deg up more on the pinon and about 1/2" lower ride in the front, all with a softer spring that won't bottom on the frame any more. all that would also help my front DS angles that already got way better with the trans swap.

i need to do the front first so i can set the rear height where i want to match it best. just in case i drop like 1-2" taking out a mid spring or something. TBD

while in the front i'll also re-do the steering stops to maximize turning. that might require some clearance on the shaft yokes, and maybe re-drilling the TRE hole in the high steer arm. you know, just little things ...

[6DoF]

holy crap on a cracker, it's not even the same truck any more. i didn't even have time to notice the ride cuz i already had to shift again seriously though, there is stuff i never expected to change that's just better. like it smokes way less daily driving it now, i just don't have to lug into turbo lag. i can even turn up the fuel more if i wanted.

less lag, sh!t is faster
more fuel for the smoke, sh!t is faster
better gear splits, sh!t is faster
smother faster shifting, sh!t is faster

no more front drive shaft rattle, t-case is quieter
new spline coupler on the 205 input, t-case is quieter
new twin sticks don't rattle, t-case is quieter
entire transmission is just quieter, there's basically no gear noise
FTE resonator made the exhaust HUGELY quieter inside, but still sounds great outside.

clutch mid-plate does make more noise when released ... i didn't get the quite one, should have paid the extra

new engine mounts with the new trans mount smoothed it out
new clutch that isn't coming apart smoothed it out
alignment in the rear DS apparently was needed to smooth it out
no more front shaft vibes

PLUS! i can get it into 2nd from a stop without putting it in 3rd first. i can put it into any gear i want without grinding. just don't miss 5th n hit reverse, that makes some noise.

it rev's smoother and better even while riding the governor, even more reason for less turbo lag, it's just smoother and quieter and more proper in every metric and every area. it's crazy, i still don't believe it, but i'm freakin thilled. i don't even have carpet or floor insulation in there yet, it's still bare steel! i just bought 2 gal of lizard skin to spray it all down with and new carpet with extra heavy bat.

motivation is HIGH to knock out more of the list to really keep dialing this truck in.

[Hoofmann]

I remember the getrag in my old first gen was a noisy, finicky bitch. The 5600 is much more refined.

[6DoF]

well fukk ...

below picture was a clean dry floor, truck driven 1hour on the highway and parked there. we'll call it excessive ...

1) the hand-ground seal surface for the np205 coupler is 100% not functional. i think i got it a tad small, probably not perfectly round, and i know the striations were going the wrong direction so probably pumping fluid out. i thought maybe worst case it would be a slow enough leak that it would just keep the truck from rusting, but no ... i'm going to have to pull the seal and glue the t-case on like most suggest. i might have a machinist buddy machine the opposite end of the coupler, but i might not be patient enough for that.

2) Rear Main Seal ... nothing more fun than doing preventative maintenance and replacing a non-leaking seal with a bad leaker. turns out, most likely installation error! i hadn't seen the specific Cummins instructions before and just installed it like a normal seal by making sure everything was well oiled. turns out the seal has some Teflon transfer or break-in period and requires a 100% oil free crank to work. oiled, will never seal, time to pull the transmission ... AGAIN

[xj_man_646]

I wonder if it is that (reason you mentioned) is why there are so many leaky rear main seals on Cummins engines. That sucks!

[6DoF]

driving the truck around til the new seals show up, and i love it. the 6spd was worth every cent and all the work. now i really want to get the interior finished up and the suspension smoothed out!

built a new WMO set up last week. hose is nice n secure on the barrel for wheeling it around, and the air-over pump is awesome. little meter on the handle to know how much i put in, and no more filling jugs! the pump and hose came from a local auction site too, so they were super cheap.

then started stripping the door panels to re-cover them with the headliner material. one piece was proper, but why was the carpet hot glued and stapled on!?!? both will be christmas tree installed.

[6DoF]

minor freak-out today ... i'm going nutz!

last night i got the 205 all glued up, even installed a housing drain plug for that void. new rear main installed DRY, but was a little bit notchy at the transition from the install tool to the crank surface and my automotive-ocd is pulling out my hair wondering if it is straight or has a folded under lip. clutch is all back on with the starter ... i just want to break it in before installing the transmission to find out

my exhaust was also kind of coming apart when i got under there to start, so i need to redo a bit while the trans is out of the way. while in there i also got a picture i forgot to take, how i beat the pinch seam up against the floor for bell clearance.

[6DoF]

it's all back together, new rear main seal in place! got it together Friday evening right after work and went to town to pick up dinner for the wife n i. about 15 miles, stop n go, plus idling 3 laps around the damn Chick-fil-a building ... after dinner was able to confirm that i made the seal worse! but further confirmed that i freaking love driving the 5600 in this truck. worth every penny and the extra work.

got to talking with a buddy and realized that the PO had put a crank wear sleeve on my engine. big question, is a wear sleeve seal different than standard for the extra dia!?! also, the standard installation tool doesn't quite reach the sleeve and i had to bump it past "the ditch" between. figure there's a decent chance it folded under at that. i've been pulling the crank housing to do this (i won't ever do that again once this is totally fixed) but there's a chance that the oil pan and gasket recombobulation biased the housing up as well. SO ... i have to pull the oil pan this time to be sure, and that requires lifting the freakin engine off the mounts.

[xj_man_646]

Hmmmm sounds very fun .

Sucks, but you'll sort it out and then you'll have a very desirable truck on your hands.