I'm in the process of setting up HP D30 to replace the disco D30 that is currently under my '99 XJ. I see that the donor HP D30 is missing one steering knuckle and the pinion yoke. I have read stories about checking drag on the pinion with an inch-lb torque wrench and then making sure the when you put it back together, you find the same torque.

What do I do when I don't have the yoke to do this?

Also what parts can I scavenge off my current disco and transfer to the HP D30? Knuckles I have heard are no Bueno. What about hubs, brakes? The pinion yoke? Thanks.

 

turn the pinion with torque wrench and socket on the pinion shaft nut.

I dont know why the knuckle cant be replaced, I have had mine on and off and back on. Id replace the ball joints at that time.

As for hubs, well the hub splines must match the axles, so if that is the same you should be fine I think.

I have a high pinion disconnect axle, with axle disconnect replaced with one piece axle. I went with over sized axles, so my hubs are not stock, i.e. manual hubs. but my steering knuckles are stock.

 

That works even though the yoke is already off?

 

You need to tighten the nut first, and that requires the yoke installed.

 

That's my issue. The donor D30 does not have the yoke attached. There is no yoke at all.

 

That's my issue. The donor D30 does not have the yoke attached. There is no yoke at all.

 

use the old yoke if still good, or buy a new one.

 

While I appreciate your help, I don't think we are on the same wavelength. I don't have the yoke. And without having a yoke on the diff, I am not able to check how many inch-lbs resistance I have, record the measurements and then match them when I put a new yoke on. I am starting with just a pinion sticking out of the diff.

I guess what I'd like to know is if there is a specification or range of inch-lb resistance that I could torque a new yoke and nut to. Do I really have to know what the previous resistance was? Because I have no way of determining that.

The knuckle issue is not that I can't replace them. Yes, they are replaceable. The question was whether the knuckle on the disco will fit the regular HP D30. I was told that they wouldn't.

Thanks again for your input. I'm sure if we were talking, it would be much easier to understand my confusing ramblings.

 

Per factory service book.... pinion nuts gets 200 ft lb torque minimum. then you turn the pinion via that nut to measure the turning torque, which should be 20 to 40 inch lb for new bearings, or 10 to 20 inch lbs for used.

Measure the torque while turning, not the break away torque to start it turning. A beam type wrench is what is needed here, not the clicker type.

as for the knuckle being different, I dont know. I dont know why it would have to be different however parts catalog lists one type for 1990 thru 2001, no mention of disco or solid axle variety.

For knuckle, inspect the surfaces that the brake pads ride on, if worn, then have a weld done to build it up, then grind down to restore original surface. deep notch in this area can cause brake pad to hang up and drag. I had to rebuild up mine, easy job if you got a mig welder and grinder, I did mine on car, if you go to a shop, just give them the knuckles as that should reduce the labor costs verses having the shop dissassemble stuff and work with it on the jeep.

 

Thanks! This makes sense. I'll have to find a beam type wrench somewhere.

The knuckle I will figure out. A couple sites did differentiate between the disco and not. I don't think the disco was used after 89 so I will leave the knuckles on the disco and buy a new one for the left side. Then I can sell a complete disco unit though I imagine I won't even get back the cost of the knuckle, lol.

The existing knuckle looks good as far as brake pad area. I'm probably going to end up putting new axle seals in and like you mentioned, ball joints since it will be easier to do all that while on the bench.

 

my 1990 came with high pinion D30 disco axle. I removed disco, and have one piece axle now on that side

Yes put new seals in for sure, might as well do it now while it is apart than risk a used unknown seal leaking. While you are at it, drill and tap a pipe thread in bottom of the pumpkin, then install a drain plug, add a magnet to the plug, besure pipe thread is tapped deep enough so the plug does not extend below the pumpkin. This makes fluid change a breeze, and the magnetic plug keeps the steel shavings from circulating in the oil.

Have fun!