Kk diff swap into kj

WhitbyKJ · **Posted:** Mon Mar 23, 2015 10:12 am

It fits!!!!

My kj cv's fit into the kk diff!!

As a matter of fact, the kj pass cv fits onto the kk intermediate shaft with NO play.

I am so pumped. Pics and vids to follow later this evening.

WhitbyKJ · **Posted:** Mon Mar 23, 2015 8:26 pm

Sorry boys, no pics tonight. Can't hardly see straight.

Gonna hit the sack early and get a head start tomorrow

JeepMorrison · **Joined:** Thu Jul 16, 2009 11:34 am **Posts:** 1236

Better be a update soon!!!

NAMoulton1 · **Joined:** Tue Aug 12, 2014 7:01 pm **Posts:** 1054

This was supposed to be my reading material all night! (Yay for night shifts...)

Gageraid · **Posted:** Tue Mar 24, 2015 12:13 am

Props for a good video.
Hope to see your KJ's progress in the near future.

WhitbyKJ · **Posted:** Wed Mar 25, 2015 12:24 am

Y computer is down, so I am workin off my iPhone. Here goes.

Two days ago (Monday):

I just couldn't resist sliding them in. I took them off the kj and slid them right into the kk diff. The kk retained its intermediate shaft. The end looked marginally better than my kj one. We know they round off... Nothing new. They fit tight with no wiggle at all. I had a problem with the inner cv boot wanting to keep walking down the shaft on the pass side. Figure I may use a length of rigid nylon tubing and epoxy it to the shaft (until the vibes drive me nuts lol) so that the boot stays tucked up where it's supposed to go. (It may not vibe at all actually.)

Another pic of the diff and steering shaft. Gonna be keeping my eyes open for possible upgrades to the steering assembly. I know I measured the kk cradle and re kj cradle today. Both measured 11 1/2 inches centre of bolts for the rack maybe I can find a better column?

Here's a teaser for ya. Not exactly sure what I am gonna do with that, but I got some pretty "bullet proof" ideas. I may not need it at all. But I know you recognize the shape

woot woot.
The offspring of me playing with cad for a day, water jet cut pieces

My lca put into the kk cradle. Nothing special here really. Other than... IT FITS!!

Tuesday:

So here you have it. Stock bolts. Both 5 iches long, with about an inch of space between the bottom of the cradle and the top of the bolt just before the threads catch.
Meaning a 1/4 to 1/2 inch cradle drop may be possible without getting different bolts. For you fellas that just wanna slide some plate under.

The rears are m12's I can't remember if it's 1.75 or 2 and the fronts are m14s. They are 135 mm long

So when you goto and call EVERY industrial supply place and fastener joint in a 50km radius and nobody has m12 or m14 (1.75 and 2.0) x 165 mm (6.5 inches long) you start to freakin panic. Then I thought whoa buddy. Chill. Got me some grade 8 threaded rod and nuts (so sue me it's not 10.9 stainless) Put them through the chop saw and bench grinder and of course then the mig welder.. And 2 hours later (including the hunt for bolts) and 65 dollars poorer (also grabbed other stuff I needed) 6.5 inch long cradle bolts were born.

K so you gotta understand. I live in a nice tame neighbourhood full of nice people and kids. Everybody has a new car and the grass is always green.. Or white. Lol. We see a police car maybe once every two years. Then there is this. An engine crane in your driveway. The looks I got today, confirmed it. Te neighbourhood knows, I got the jeep thing. And now it hurts when I pee. (They think I am nuts)

Kj and kk cradle side by side. I welded some 1.5 x 2.5 tubing to the kk cradle and capped the ends for strength. So I am dropping the cradle 1.5 inches.

Kk cradle in. There was ZERO screwing around required. The engine just dropped right, as it should. Considering they are 98 percent identical cradles. The actual changing of one cradle and putting the other on.. Took 10 minutes. Makes me wonder... Was I onto something whe.n said it is cheaper for car makers to modify or slightly alter existing assembly's when designing new vehicles than it is to retool a parts factory full on?? I think that's how we get parts interchangeability. (Brain fart)

Here is the semi final resting spot. I still have to drop the tcase. But that is fixing to be a super quick job.

Hope you guys enjoy. Sorry I am running behind with pics etc and vids... My comp is fried and I am getting a WILD head cold.

Stay tuned... Lots more exciting stuff to come. I promise.

Oh and... I have something extra extra special planned for the rear.

WhitbyKJ · **Posted:** Wed Mar 25, 2015 12:32 am

Sorry for the bad grammar and pokey jokes.

That took two hours to post using my iPhone.

Tomorrow I may just do a vid. It's faster.

TheBlueKJ · **Posted:** Wed Mar 25, 2015 12:49 pm

Most vehicles use the same chassis but different sheet metal. Lot's of Fords and Lincolns have the same chassis but different sheet metal. Crown Vic's used the same chassis all the way up until they stopped building them.

On another note looks like you're making some good progress!

WhitbyKJ · **Posted:** Wed Mar 25, 2015 6:19 pm

I hit a giant snag!!!

The pass side cv looks like it's too long.

An now I totally understand the longer knuckles deal. Lol.

Putting the brain into overdrive.

I think I screwed up by trying to add that daystar pos lift in the front to what I already had.

I am at 24 inches hub to flare. Sitting on a jack.

When suspension is fully extended the hub to flare is 26 inches, the suspension travels two inches then truck starts lifting off the blocks.

I don't get it. The ubj will fit into the socket but it mashes on the spring. I put the spacer in there and bobs your uncle. But why only 2 inches of travel??? I didn't try to jack it too far, as I am not interested in knocked the jeep off the blocks.

WhitbyKJ · **Posted:** Wed Mar 25, 2015 6:32 pm

Well it turns out the compressed length of a kj passenger cv is 22 and 29/32's and the "overall" length of the kk pass cv is 21.3 inches. That explains the cv issue. Now, what about this darn 2 inch travel anomaly?

NAMoulton1 · **Joined:** Tue Aug 12, 2014 7:01 pm **Posts:** 1054

That's more than the JBA struts at 4". I have 1" of down travel before the tire comes off the ground. There's not a lot down travel for the IFS...

WhitbyKJ · **Posted:** Wed Mar 25, 2015 7:28 pm

K, so I am in more hot water than I figured lol!!!

The kk diff is two inches longer than my kj one lol. Like the passenger side axle housing. How did I miss that lol???

WhitbyKJ · **Posted:** Wed Mar 25, 2015 7:29 pm

Gonna talk this over with the missus tonight and evaluate our position.

tommudd · **Posted:** Wed Mar 25, 2015 8:17 pm

WhitbyKJ wrote:

K, so I am in more hot water than I figured lol!!!

The kk diff is two inches longer than my kj one lol. Like the passenger side axle housing. How did I miss that lol???

I spent a lot of time under both, sitting side by side in my driveway measuring/ figuring etc when the KKs came out
I knew the frames were the same but when measuring I found the same things you are now running into

JeepMorrison · **Joined:** Thu Jul 16, 2009 11:34 am **Posts:** 1236

tommudd wrote:

WhitbyKJ wrote:

K, so I am in more hot water than I figured lol!!!

The kk diff is two inches longer than my kj one lol. Like the passenger side axle housing. How did I miss that lol???

I spent a lot of time under both, sitting side by side in my driveway measuring/ figuring etc when the KKs came out
I knew the frames were the same but when measuring I found the same things you are now running into

Can confirm with Tom, theres some things that are different for sure.

WhitbyKJ · **Posted:** Thu Mar 26, 2015 6:58 am

Well boys,

It's been fun.

I learned ALOT. I've never been that far into a vehicle before. Unfortunately, I don't have the funds to continue "experimenting" with this project.

I was going to loose the cradle drop, and see if I could take the outer passenger cv apart and plop it onto a kk cv shaft. Then I would be in business. Likewise I wonder if a kk hub bearing would fit the kk knuckle?? Then I could just use the entire kk cv shaft.

BUT. Right now, I am out of time and money to continue and it's against bylaw to have a 'derelict' vehicle on my property for too long. So I gotta slap the kj diff and cradle back in there.

Here's the spread:

The pros outweigh the cons from this project in that I now know every single nut bolt washer nutsert etc under that hood. And I was three quarters of the way to an engine swap when you think about it being as thought I had the darn thing on a chain.

I will return to this project and I will keep all the parts. In the future I will see about kk cv shafts and knuckles for both sides. In the future I will try not to get side tracked with "cradle drops" and delusions of grandure lol. The objective here was to put a kk dif into a kj, I sorta did it, but didn't have enough parts.

This will be revisited.

Sorry boys

In the mean time...

I wonder how long it's going to take my iro rear upper a arm to get here that I ordered last week??? (Stay tuned for more)

WhitbyKJ · **Posted:** Thu Mar 26, 2015 7:00 am

typo above: should read kj knuckle

Gageraid · **Posted:** Thu Mar 26, 2015 11:03 am

That's unfortunate.
Keep looking at the bright side.
You didn't get hurt, and no damage done to your Jeep.

Bmxer524 · **Posted:** Thu Mar 26, 2015 3:03 pm

NAMoulton1 wrote:

That's more than the JBA struts at 4". I have 1" of down travel before the tire comes off the ground. There's not a lot down travel for the IFS...

I think that's just our design. Basically you have the limits of travel when stock. Say 5" up and 5" down for a total of 10" of travel. When you lift it 4" you just change the travel numbers. 1" down, 6" up. I could be totally wrong though...

Anyways, keep us posted if you ever try to take another shot at this. It's interesting to see what people try and come up with.

tjkj2002 · **Posted:** Thu Mar 26, 2015 3:45 pm

You should never start a project like this with a budget or time restrictions,it never stay's in budget and always takes 2-3 times as long as you'd expect.

That's why I set no budget restrictions for my SFA build,heck I spent over $600 alone in hardware(Fastenal loved me).

Kk diff swap into kj

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