d30 unit bearing compatibility

alright i believe i am going to have problems with my axle build/swap and i have found information regarding unit bearing and knuckle revisions threw out the years but need someone who actually knows what they are talking about to help me out

my truck
-88 cherokee with a 94 motor, ax15, 231
-currently has a LP30 out of a 00 or 01 cherokee

the goal
-HP30
-4.88's
-lunchbox locker
-LCA skids

the plan i jumped in to
-bought a vac disco hp30 out of a 86 v6 5speed with 4.10's
-stripped it painted it
-brand new balljoints installed
--planned on vacuum disco block off kit
--already have 4.88's ready to install

the problem im looking at is this, will my LP30 unit bearings and axleshafts that are in my jeep currently, bolt right into my 86 knuckles? i read something about different revisions of unit bearings and knuckles. i do not have the 86 axleshafts or unit bearings, i know the axleshafts should fit but im really just worried about the unit bearings. and if they will not will my LP30 knuckles bolt up to my 86 housing and balljoints just fine? then allowing me to use the LP30 unit bearings?

i also have a complete 94 non vac housing (which i would like to use the 94 unit bearings with the 86 housing the most because they are new) if the 86 housing will be to complicated to make work i will just use the 94 housing but i already installed new balljoints in the 86 vacdisco housing haha.

tried to explain that with the least amount of confusion possible!
thanks for any help ::

Just check out the FAQ's - http://www.naxja.org/forum/showthread.php?t=1058413

Two types of steering knuckle designs were used: 1984 to 1989 and 1990 to 2001. The brakes follow the same year range and do not interchange across the 89/90 divide. Your knuckles and brakes have to share the same design/year range.

only helpful info i can offer...

https://sites.google.com/a/jeepinwv.com/tech/Home/new-d30---change

84-01 should be 3 bolts to the knuckle, not sure about any variances... hub inspection/removal/installation is ~6/8ths down the page in the ^link^

Mitchen said:

the plan i jumped in to
-bought a vac disco hp30 out of a 86 v6 5speed with 4.10's
-stripped it painted it
-brand new balljoints installed
--planned on vacuum disco block off kit
--already have 4.88's ready to install

the problem im looking at is this, will my LP30 unit bearings and axleshafts that are in my jeep currently, bolt right into my 86 knuckles? i read something about different revisions of unit bearings and knuckles. i do not have the 86 axleshafts or unit bearings, i know the axleshafts should fit but im really just worried about the unit bearings. and if they will not will my LP30 knuckles bolt up to my 86 housing and balljoints just fine? then allowing me to use the LP30 unit bearings?

Click to expand...

Not sure if this will be of any help or not. First off, you wouldn't want the 86 shafts because the long side would be a 2 part shaft. I also went with an HPD30 with 4.10s from a 1986 to put into my 2001 XJ. I kept the shafts, unitbearings, knuckles, everything from my 2001 and installed it on to the '86 with no issues. The things I ran into using the '86 axle is that there is no ramp on the inner axle seal to allow the long shaft to ride "upward" into the carrier. As well, I never got a great seal on that combo and I leaked diff fluid onto my pax side wheel all the time.

So, that said, the shafts and knuckles and whatnots should be compatible with 1 exception....some of the knuckles are not 1 piece knuckles. They have a bolt on part to hold the caliper and the pads. The bolt on version is about 1/4 inch smaller than the one piece. I tried to use a 2 piece knuckle and my caliper/pad piece was too large to fit so I had to use the one piece. Your '88 very well may have the 2 piece knuckles. Just take the knuckles off the '88, take the shafts from the '88 and attach them to the '86.

Expect some leaking and just keep your differential full. Make sure you have a backing plate when you remove the vaccum motor and the guts of the disconnect.

I believe you will be fine.

Yeah the link MT Mike posted is helpful. I asked this question a month or so ago. What I gathered was:

Hubs and rotors must match
calipers and knuckles must match (and pads too I guess, not sure how different they are)

so from what you posted, you should be ok.

Renix (87-90) calipers and pads are different than HO (91+), so my guess would be most likely 86 and down are different.

OP, if they are decent, what are you planning to do with the HP 4.10 gears? I would be interested in taking them off your hands.

Johnnie Walker said:

Renix (87-90) calipers and pads are different than HO (91+), so my guess would be most likely 86 and down are different.

OP, if they are decent, what are you planning to do with the HP 4.10 gears? I would be interested in taking them off your hands.

Click to expand...

was planning on selling them.

as for the knuckle and caliper issue i think i will just use the knuckles hubs and all from my LP and put it all on the HP

one last question! are all balljoints for d30 the same? i just put in new balljoints in the 86 axle and need to know if they will work with my current knuckles on the jeep which are 00 or 01 knuckles on a lp

Mitchen said:

one last question! are all balljoints for d30 the same? i just put in new balljoints in the 86 axle and need to know if they will work with my current knuckles on the jeep which are 00 or 01 knuckles on a lp

Click to expand...

You should be fine.

Mitchen said:

was planning on selling them.

as for the knuckle and caliper issue i think i will just use the knuckles hubs and all from my LP and put it all on the HP

one last question! are all balljoints for d30 the same? i just put in new balljoints in the 86 axle and need to know if they will work with my current knuckles on the jeep which are 00 or 01 knuckles on a lp

Click to expand...

you have it correct. Just swap the knuckles, hubs, rotors, and calipers onto the older housing. Balljoints are the same.

kastein said:

you have it correct. Just swap the knuckles, hubs, rotors, and calipers onto the older housing. Balljoints are the same.

Click to expand...

alright great pretty confident i will be able to get this all to work now, thanks! if i run into any trouble when i start installing the new axle i will come back to this thread. thanks ::

one question. why dont you use the 94 housing? it should be hp and non disco?

stroked88 said:

one question. why dont you use the 94 housing? it should be hp and non disco?

Click to expand...

If I'm reading the OP right, only the motor is a '94. The rest of the truck is an '88.

no, he says at the bottom he has a complete '94 non vac housing :dunno:

stroked88 said:

one question. why dont you use the 94 housing? it should be hp and non disco?

Click to expand...

He said that he has new Ball joints in the vac-disco axle and would like to use that. If he is using one-piece shaft and block off plate it will be fine.

stroked88 said:

no, he says at the bottom he has a complete '94 non vac housing :dunno:

Click to expand...

Yep, you are right...missed that.

Johnnie Walker said:

He said that he has new Ball joints in the vac-disco axle and would like to use that. If he is using one-piece shaft and block off plate it will be fine.

Click to expand...

what he said.

Will also need to adapt for the inner seal - but it's possible. Personally I'd probably press the balljoints out of the old axle and install them in the new axle :gee:

You can just swap the knuckles and you wouldn't have to worry about the unit bearing being right.

Also you don't need to buy anything for the block off you can do it yourself just open it up and jam something so the fork cannot move weld, hose clamp just about anything will work. I've done a few like that.