1978 620 King Cab 4X4

[]2eDeYe]

This was free and lasted longer than I thought actually. :lol:

But ya, going to go divorced with this guy I think. Hopefully I won't have to move the t-case position too much to run it.

https://www.novak-adapt.com/catalog/adapters/transmission-to-transfer-case/kit-320/

 

 

 

[]2eDeYe]

So that idea will be expensive. I talked to a machinist that said he could make a new shaft happen with the appropriate components. 

 

After a trip to Oly4x4 to figure out what the parts were. I picked up a new T90 output shaft from them and order a new 280XZ slip yoke. 

I am going to see if the shop at work can do the machine work for me and save a couple bucks. 

[]2eDeYe]

New parts came in. Some part study pics of an original shaft.

 

 

 

[]2eDeYe]

Some of you may have notice the lack of updates in this thread.

 

Well, it's due to the metallurgical journey this broken shaft has taken me on.

 

 

I was able to source the original components used to make the shaft.

 

A Datsun 280ZX driveshaft yoke and a Dana T90 transmission mainshaft. The T90 was a 3-speed used by just about every 4x4 mfr at some point, so there was even one in stock at Oly4x4.

 

 

 

I took them to the machine shop I have used for other projects and they sent me to another local machinist that cut's gears.

 

Throughout this I have been discussing the best way to duplicate this shaft with the PE at my work. With his help and the help of the gear cutter a plan was formed to make this new shaft stronger.

The original shaft appears to be made by annealing the main shaft end that was machined to fit the ID of the spline root of the yoke. Then it was fully welded all the way around.

It broke right at the weld. I can probably push the little nub of the shaft out of the yoke. :lol:

 

 

 

So instead of that we can up with a way to retain the main shaft hardness and use the yoke, which is cheaper to have made into a fuse.

 

I had to get the main shaft annealed before work could start. The gear cutter sent me to his heat treat guy and he was able to soften the shaft for machining.

Both parts got left at the machinist at this point and some tulip viewing with my girls and some scouting happened. :D

 

 

 

 

 

 

 

Parts back from machining.

 

 

 

 

You can see the main shaft still has carbon buildup from the annealing process. Parts still fit like they should, time to get the main shaft re-hardened.

 

More scouting while we wait, this time we made to our chosen site. Same spot as last year and almost as clean as we left it. :)

 

 

 

 

CJ loves this game :lol:

 

 

 

Parts are complete, machined yoke and freshly re-hardened re-splined shaft.

 

 

 

 

 

The plan is to just take the yoke to the shaft to keep them together and the material properties stable.

Theoretically the super soft yoke will break first and should be easy enough to replace by grinding the tacks.

 

Tomorrow I start putting everything back together. :thumbup:

[Charlie69]

Nice approach to increase the strength of the part.  Sounds like you have some great people assisting in this project.  The out come should be breakage of the yoke instead of the shaf if I understand your process.

 

Beautiful pictures as always.  I wish my body could with stand the winters I would move in a heart beat.

[Boxcar]

I wish I had seen this thread before you went through all of the work . I have a divorced NW4WD short Dana 20 in the shop ready to go. It's even siting in a Datsun cradle. Oh  well.

 

 

This is the same unit that we used in the Sasquatch. The one I have left is just exactly the same.

[Donedreamin]

This truck is awesome! Very cool build

[]2eDeYe]

Nice approach to increase the strength of the part.  Sounds like you have some great people assisting in this project.  The out come should be breakage of the yoke instead of the shaf if I understand your process.

 

Beautiful pictures as always.  I wish my body could with stand the winters I would move in a heart beat.

 

 

That is the hope. Replace the cheap bit. 

 

Thanks, I love living here. Me and the lady have been discussing buying property in AZ for the winters though. :) 

 

 

 

I wish I had seen this thread before you went through all of the work . I have a divorced NW4WD short Dana 20 in the shop ready to go. It's even siting in a Datsun cradle. Oh  well.

 

 

This is the same unit that we used in the Sasquatch. The one I have left is just exactly the same.

 

 

I can hit you up after I break this stuff :lol: 

 

 

 

This truck is awesome! Very cool build

 

 

Thanks :)

[Charlie69]

That is the hope. Replace the cheap bit. 

 

Thanks, I love living here. Me and the lady have been discussing buying property in AZ for the winters though. :)

 

 

 

I can hit you up after I break this stuff :lol:

 

 

 

 

 

Thanks :)

Come on down the more the merrier!

[q-tip]

Smear some jb weld in it and put it together, it'll hold. :Lol:

[Charlie69]

q-tip are you saying "that'll buff out"! LOL

[q-tip]

Hell yeah, I'm a life long wheeler, I've spent a few nights on the trail in a broken rig, I've also had to tear a rig half apart to fix it to get it out. Jb weld, duct tape and zip ties are life savers. :Lol:

[]2eDeYe]

I've made parts from jb-weld and held junk together with duct tape and dreams, Trying to transcend a bit here. :rofl: 

[KoHeartsGPA]

Hell ya, JB weld, duct tape and zip ties are a must in the tool box :thumbup:

[]2eDeYe]

Our Memorial trip was a great time, no rain at all and enough clouds to keep it cool. :)

 

First I had to put the truck back together. While I was taking the adapter apart I notice that there was a small amount of end play. I measured it at .009 so I made a shim. This almost got rid of an annoying rattle when letting off the gas in 4th and 5th. Going to make a.010 shim when I tear it apart to check things. 

 

 

 

 

 

Bearing for the other end of the adapter shaft.I have a new one on the way.

 

 

Test run into Everett for an appt. Everything seems to be working well.

 

 

 

Packed to the gills :lol:

 

 

Made a friend on the first night :)

 

 

 

 

 

Hobo said he bought this for his daughter, but I only saw her riding it once. :rofl:

 

 

 

....some more camping pics.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

All packed up and ready to go home.

 

 

Now to put all the camping gear away :D

[hobospyder]

It is hers, I just didn't trust her on it. Back to flattish grass for her

[]2eDeYe]

Damage list from camping. :devil: 

1. Blown rear t-case seal. That explains the smell. :lol:

2. Sheared leaf spring center pin. That log should not have been there. :rofl:


Will be addressing his stuff after Canby. :)

[hobospyder]

What? Was this from repeated trips through the rocky area?

 

Found out yesterday the plastic towards the bottom of my daughters quad may be a bit scraped up

[]2eDeYe]

Well, the t-case seal is likely due to overheating. I thought I had enough gear oil in the but apparently not. I have not been able to find anything on Dana 20 gear oil capacity and my t-case is drastically clocked compared to where the fill hole was installed. 

 

The centering pin was because I got distracted by that giant cedar that was down. Ended up using that for firewood the last night. :lol:  

[Charlie69]

Is it possible to drill and tap a new hole in your transfer case for the fill hole.  Also if the vent on your transfer case is plugged up your will push oil past your seal/seals.

[]2eDeYe]

That is a possibility. Next time I have it out I plan to put a level gauge in it similar to this one. 

 

 

 

I should have just went with one of those t-cases to begin with, but I guess I didn't have to lay out all the $ at once. :lol: 

[q-tip]

Just looks like something else to get busted off by a wayward log or rock.

[]2eDeYe]

My t-case is tucked away, I'd feel a lot better knowing I have gear oil in there lol 

[q-tip]

Oil is overrated, the transmission in my Dodge had extra oil in it and it grenaded a bearing. :Lol:

[captain720]

Dodge is overrated, the transmission in my Dodge had extra oil in it and it grenaded a bearing because that's what Dodge's do. :Lol: