The Trailantula

[_Auzzy_]

Catchy thread title is catchy.

Exciting seeing a new build come to life on a table. You’re probably excited to roll out new ideas from past experience on a clean slate.

Oh I am! I've been wanting something thats both hardcore trail rider and comp rig forever and I'm gonna try for that with this

 

[_Auzzy_]

Slight update, brackets back on and looking gorgeous 👌



And got the alignment bar in the rear axle and Cory got the alignment pucks found and in 👌






Outter alignment pucks, one pushes into the wheel hubs axle bearing and the other fits inside the C's machined in making them all nice and tight




Then the inner 14b carrier pucks cory made way back when

 

[Hickey]

I’m naming my next dog Alignment Puck.

 

[_Auzzy_]

Started up some drivetrain shenanigans. Cory got the 14 bolt C's burned on in an extra fancy manner with his tig skills 👌👌








Then while.he was doing that I was giving my 205 some loving and getting her back together. With some new bearings and seals plus the awesome powder coating she's gonna be snazzy





Also grinder my rails for that front dig jazz and then drilled n tapped them for 3/8 heims 👌

 

[Ashcat]

I’m guessing the shift rails involved lathe magic? Once the ears are lopped off, must expose a softer core? I tried drilling stock ears to 3/8” without succes

 

[_Auzzy_]

I’m guessing the shift rails involved lathe magic? Once the ears are lopped off, must expose a softer core? I tried drilling stock ears to 3/8” without succes

These actually drilled and tapped really nicely. 👌 we were thinking they were gonna be some type of hardened material but nope, easy enough that it was almost like cold rolled

 

[_Auzzy_]

Yall wanna see something neat? How about a gorgeous np205??











Ooooh yeah, she's got some bling going and all back to being beautiful and fully functional with the front dig capable of high or low and all the tolerances, preloads, etc are back with in spec 🤘

Started today off with polishing the rails on the lathe so they glided a little more smooth



Then I hopped over to the mill for my aluminum pieces, first being the rear cover plate for the idler gear shaft. Added a little oil valley to it even though it may not be substantial or measurable improvmeent by any means but the peace of mind that I tried to help it where ever I could is there.




Next was the pto cover, big ol block of aluminum I took a 1/2 ball mill to and ribbed it for the chassis pleasure




Got all this done thanks to an army tm manual I found in an old pirate 4x4 thread and this guy's write up:

NP 205 Rebuild and Info - The 1947 - Present Chevrolet & GMC Truck Message Board Network

NP 205 Rebuild and Info All 4x4 Tech & Off Roading

67-72chevytrucks.com

Pictures and details n such 👌

And my bling bling 205 pieces came from Tom Gordon of bulletproof205 on Instagram

 

[_Auzzy_]

Allright yall got the under drive together and bolted up. Some of ya know how cool these are and the fun required to build/run one. For those who don't let me illustrate for ya

First off ya gotta gut the donor 241 case. The goal here is to retrieve the planetary set and the sun gear unharmed. Here's a reference photo of the breakdown of a 241 so you can visualize what I'm saying since I didn't photo every step




ok lets get started!
*pull out the tailhousing bolts
*remove the snap rings and speedo gear on the rear output then remove the bearing housing.
*Next undo the front output yoke nut.
*Now remove all the bolts along the outter edge of the case and separate the two halves. While doing this the rear output, front out put, chain etc will fall put, probably making a mess. Don't worry about it, it's going in the garbage.






Then from there you'll go to the front of the front half of the case, remove the big inner planetary gear snap ring then flip it over and remove the snap ring around the input shaft bearing. Now place something soft behind the gears to catch them and lightly tap on it with a mallet till it falls out.

Now on to the sun gear/annulus gear. This requires a steady hand and skilled eyes. There's a few ways to go about this but the easiest way we've found is to take a circular saw to the case and make cuts directly across from one another and through the trans mounting face side so we can free the gear.

*be sure to watch your depth you don't want to nick or cut the gear!*



Free at last! On to the next block of fun

 

[_Auzzy_]

Now for the better part of this. The behemoth strong box!!

First ya take the housing apart by undoing the 6 Allen head bolts and then take the blue half over to a monster of a press and get ready for a struggle. These gears have a cutter machined into them that helps lock the gear into the case and it takes some force to be set into place. So no you can't just tap it in. Sadly I forgot to get photos of this process so use your imagination.

*magic/straining 20ton press noises*

Poof. Gear is set and now for assembly!



First thing is to remove your input bearing off the input. Undo the snap ring on the input and it bearing slide off pretty easily. Next set your input shaft bearing into the blue housing half from the inside. Using a soft driver of some sort lightly tap it into place. From there you'll take the input shaft bearing snap ring and lightly modify it to fit the case. Using a grinder and a cut off wheel, slice off about 1/4" give or take a 16th and then make grooves into the ring incase ya ever have to remove it. Like so:









Next install your planetary gear set into the case and flip it over. You'll then use your snap ring off your input shaft and reinstall it back onto the input shaft like so



This keeps your planetary set where it needs to be. From there drive in your new provided seal



Now set that half aside and turn to the black side. put in the supplied gasket and bolts and then put the shift collar in the shift fork.



install the back half to your 205 case. Torque the bolts down to 25ftlbs should look like this now



Back to the front case! Now as you can see on the black half. There's two sets of mounting hole options. This effects clocking and may take some repetitions of assembly and disassemble of the strong box to get your clocking set where you want it. After all is said and done she should look similar to this:

 

[_Auzzy_]

From there I added my.own flare to the case. I used the drain hole as a spot for a 90* barb fitting so I can have a site tube for maintenance/inspection reasons.



Lil shop trick I learned from an old boy. How to properly cut zip ties flush. Get the zip tie good and tight then place your cutters at an angle so one blade is against the base of the tail and the other is against the back side of the head. Like so



Give it a quick squeeze and ya got a nice flush cut



Anywho back.to routing vent lines. Still not 100% sold on the setup but we'll see.



Also added a site tube here as well, made a block off plate for the speedo and added the upper barb for the tube. Also drilled and tapped the existing speedo hold down bolt hole to a 5/16. Also drilled and tapped the vent hole a 1/4npt barb fitting.



Ta da



So once I got the strong box on I realized I couldn't use my heim on the shift rail so I made a quick bracket and will be reusing the heim in the linkage now

 

[_Auzzy_]

Aaannnd waalaa.

May turn the case up flatter but for tonight it's together at least and setting a tone for this build





Cleared the table and moved the motor into position






Mmm yummy

 

[_Auzzy_]

More progress going down, got 2 out of the four knuckles burned in with arms and eliminators 🤘



only had one hiccup and that was we forgot to make sure the factory arms lined up with one another and they don't. There's about 3/8 difference in height and they're both cantered different.




So we originally made the arms for the driver side. With some grindage and slight adjustment the arm system still burned in



Here's the difference in the angles illustrated by the nut




Little post health action




Blam-o





Now to get them cleaned and to powder then ball joints and start assembly of axle trusses and steering etc

 

[_Auzzy_]

Forgot to mention this on rhe knuckles, vacuum port smoothed off and the nub for the brake line. Drop these bad boys off Friday, till then we're starting on chassis design

 

[_Auzzy_]

So sadly y’all do to some life changes I’m gonna back burner this for awhile, probably till next winter due to job change and an upcoming army vacation. I will be knocking out a bunch of little things on it though that can still be done without a chassis so here goes all that nonsense.

First up we got some axle fun. Finally finished up the 14 shave. Didn’t go for a huge cut cause I didn’t want to have to shave the ring gear and all that nonsense but still gained a bit even with adding back a 1/4” plate to cover the whole then 3/8” leaf spring material over that for sliding and dent proof etc.











Kind of an idea with some bald 42s on height wise, might be down another inch but dang close to fittin a 5gallon



Then came some bomb proof diff covers. 1/4” plate with leaf spring skids burned on

 

[_Auzzy_]

Next we got some aluminum work going on. Got my trans cooler fan shroud made. Just need to tack my spider on and send it to powder.





Next was my air filter housing. Using a Wix 10304 paper filter that’s meant for 14-18 ram promaster vans and random pieces of equipment. Housing will be 7.5” diameter with a nice bolt on face plate to squish the filter in and a 4inch tube for the motor inlet and for the filter to sit on / keep it centered.








Just need to sit down and burn that nonsense together. Got a sweet paint template out of the process. Bonus pic on the table corner of my filter housing cad design process.

 

[_Auzzy_]

Knocked out my steering cooler, 2.5”OD x 25”L x 1.5”ID 6061 aluminum. Fins are .100 thick with .125 gaps, took out 5/16” of material leaving a 3/16 wall. Also made sure to hit the edges with a nice triangle file and then built some end caps with some -10jic ends. And yes it took some time and made quite a mess.

 

[_Auzzy_]

Almost forgot to show these beauties off. Cory laid down some amazing welds as per norm, even with the material being thin and on edge, helping me bring this nonsense to life. The airfilter housing all buttoned up and filter fits perfectly in it with plenty of squish going on to keep it sealed. Then the trans cooler fan shroud got its spider on. Just need to grind the weld smooth then once we get the knuckles burned together I’ll be taking it all to our powder guy l.

 

[_Auzzy_]

Little update, been plugging away on the rear diff some more!

Random pieces, made little grease fittings for the wheel bearings and removed the axle shaft bearing to make room for the future stub shafts

 

[_Auzzy_]

Next I’ve been fiddling with the ram mounts and truss ideas and we finally came to these.

Got the ram up in place but realized off the bat it needed to move in and down other wise it was gonna stick way the hell out! So to conquer that I cut the cover open and recessed in a piece of tube







Mucho better!! Next we machined up some tubing to make end clamps on the ram





Then cory broke out his amazing tig welding skills and here’s what they look like



Then we cut out the rear plate of the truss to start formulating the next phase of the ram mounts and guard






Oh and I also made the bottom lip a little more smooth and got rid of the edges of the cover hanging past the edge.

 

[_Auzzy_]

Scored this little thing today, and on this note, I have officially decided that I’m going to be rebuilding the motor and throwing some goodies in it as well 😈 I’ll be digging into it after I get my axles out of the shop 🤘