Jeep MJ Help "Knuckle",

[SlimShaney]

Okay guys & jeeps. 

 

Converting a 2wd MJ into A 4wd. 

 

Bought diffs from a 87 XJ dana 30/ dana 44. 

 

I noticed one of the knuckles was heavily damaged near the area the caliper bolts on too. Guess from removing or dragging when the guy removed?

 

Looking to replace it. But noticed part numbers online are different between 91+ - 87. Why so? 

 

Some guy i know in town has a pair of 92 knuckles forsale. Wanting to pick them up but if i do, will they still work? 

 

Are knuckles interchangeable? I can only find 91+in stock online. 

 

I'm in Canada not alot of spare parts around town, so I'm relying mostly on XJs. 

 

Whats the difference between older & newer XJ knuckles?

[Green Mesa XJ]

I believe it’s 84-90 on the front knuckles. You can use 91 up but have to change a few other parts. The Dana 30 front axel is pretty much the same except for vacuum disconnect the early models had and the late low clearance (?) 2000 or 2001 Cherokee axel

 

I don’t know if you can do anything but buy used 84-90, 91 up there are a few new sources

 

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[Pete M]

got a pic of the damage?

[SlimShaney]

5 minutes ago, Green Mesa XJ said:

I believe it’s 84-90 on the front knuckles. You can use 91 up but have to change a few other parts. The Dana 30 front axel is pretty much the same except for vacuum disconnect the early models had and the late low clearance (?) 2000 or 2001 Cherokee axel

 

I don’t know if you can do anything but buy used 84-90, 91 up there are a few new sources

 

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 Its strange, his 87 has a high pinion none vacuum dana 30. I think I'm gonna buy those knuckes, maybe install new ball joints & see what happens?

[Green Mesa XJ]

It was a option for a lot of early years but you’re better off without it.

The 91 knuckles if I remember right had bigger brake calipers and rotors, and beefier tie rod ends. The ball joints were the same part number but there was something different about the 84-90 joints, like a cylinder or something later models didn’t need. Sorry it’s been awhile since I looked at the parts, and I’ve never actually done the job on my old xj just the 91 up


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[SlimShaney]

7 minutes ago, Green Mesa XJ said:

It was a option for a lot of early years but you’re better off without it.

The 91 knuckles if I remember right had bigger brake calipers and rotors, and beefier tie rod ends. The ball joints were the same part number but there was something different about the 84-90 joints, like a cylinder or something later models didn’t need. Sorry it’s been awhile since I looked at the parts, and I’ve never actually done the job on my old xj just the 91 up


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Well if thats the case, I'm meeting the guy this Saturday or Sunday! I will keep you posted on how they mount up :) 

 

[Eagle]

From the manuscript of the book I started. Please note: This is copyrighted, and by posting it here I do NOT grant permission to copy it and distribute it anywhere, in any form. CC members can make a copy for their own reference, but not transfer or transmit it in any form to anyone. Please respect my intellectual property.

 

In general, the parts to be concerned with in keeping the front brakes compatible are the steering knuckles, the hub/bearing assemblies, the rotors, and the calipers. (There is a more complete enumeration of the interrelationship of these parts in Chapter 6, Axles.)

 

• Only two steering knuckle designs were used: 1984 through 1989, and 1990 through 2001. Left and right side knuckles are different part numbers within each group.

 

• Three different hub/bearing units were used. The hub/bearing units are the same for both sides of the vehicle. The different years for hub/bearing assemblies were: 1984 through 1989; 1990 through mid-1999 (composite rotors); and late-1999 through 2001 (cast rotors).

 

• Three rotor types were used: 1984 through 1989; 1990 through mid-1999 (composite); and late-1999 through 2001 (cast).

 

• Only two caliper types were used: 1984 through 1989, and 1990 through 2001. Left and right side calipers are different part numbers within each group.

[gogmorgo]

Easiest way to tell the knuckles apart is the old ones have bolt-on caliper brackets, but on the new ones the callipers bolt straight to the knuckle. You can't use the older callipers on the newer knuckles, so going from the old to new means also changing callipers, rotors, and hubs, like Eagle says.

Finding used parts has been a bit of an adventure here in Alberta. Seems you almost have to know someone for people to talk to you. Shopping on kijiji you almost have to buy complete vehicles. The fb groups have stuff, but if you try to talk to them when you're not in Edmonton or Calgary, it's like they don't want to have anything to do with you even if you say "I will drive to you and pull it myself if I have to". It took me like four months to track down a 2.5L for my MJ. 

 

19 hours ago, Green Mesa XJ said:

was something different about the 84-90 joints, like a cylinder or something later models didn’t need.

IIRC the early knuckles had a removable tapered sleeve for the ball joints that threaded in, so there was a replaceable wear surface if your taper got oversized. I don't know how likely it is your taper gets worn larger though, and I can imagine it being a right b*@ch to get that sleeve out if you have even a modicum of salt on your roads, so it likely wasn't worth the bother.