Advice Needed: Choosing a Manual Locking Hub Conversion Kit
- Thread starter Mr. Bills
- Start date
OP
Calls have been made. Its a question of logistics now - whether I need to (1) ship a hub, spindle and rotor from the Yukon kit to SoCal so @mrblaine 's machine shop can modify the rotor in the BBK kit to work with the Yukon parts, or (2) find a local machinist willing to call @mrblaine and follow his advice.
Based on @Chris 's experiences trying to get his fab shop to talk to @mrblaine, option #1 may be easier even though it will take longer and cost more to ship parts back and forth.
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Seems like people don't want to pick up the phone and call. Some people seem to think it's insulting that they could ever call someone else and ask for help / advice.
OP
Hopefully I can find a local machinist with time in his schedule who charges a fair price and who doesn't think he already knows everything about everything
OP
The center bore of the rotor needs to be modified slightly to fit the Yukon wheel hub and the holes for the wheel studs may need to be re-drilled. @mrblaine could explain it properly now if he has the time or inclination, but I should be able to offer a detailed explanation after the work is done and I have seen the actual modifications.
If I stuck with the 5-4.5" lug pattern then maybe I could get away with machining the inside rotor hat to fit. Didn't realize the Yukon hubs are bigger in diameter than a TJ unit bearing flange.
OP
The following information should be of assistance in determining what you might have to do to make the Centric rotor in the BBK kit work with the Yukon 5x4.5 kit. @mrblaine is the guy to ask for details.
This article in this link discusses the rotor specifications for the Yukon 5x4.5 manual hub kit: https://www.stu-offroad.com/axle/hubconv/hub-1.htm
This is how the wheel hub and rotor attach:
This article in this link discusses the rotor specifications for the Yukon 5x4.5 manual hub kit: https://www.stu-offroad.com/axle/hubconv/hub-1.htm
This is how the wheel hub and rotor attach:
To adapt it to the 15/16 and other kits, the rotor specific to the BBK has to have the center bore opened up to the diameter of the bearing hub on the back side of the flange. Then the holes for the lug studs need to be checked against the press in stud shoulder diameter to make sure the press fit is correct.
The rotor is held to the flange with the lug studs and the knurl is up higher on the stud so it registers in the hub flange. If the rotor holes are not correct, then they need to be opened up to the correct size or a new pattern has to be drilled if the current ones are too large.
Once that is done and the rotor is mounted up to the back side of the hub flange, then that is mounted to the spindle with the dust shield in place. Lightly torque the spindle nut, spin the rotor and check for run-out.
Once the rotor is running true, take the caliper saddle off the caliper and bolt it up to the knuckle. That is done to center the saddle on the rotor. If it is not centered on the rotor, shim it over with a washer and they have to be measured accurately to be the same thickness once the offset is determined. If they are not the same, the saddle won't sit true to the rotor and there will be a loss in brake performance and the pads will wear funny.
As I said on the phone, get in touch and I'll walk anyone through it that wants help. I used to have this stuff on the shelf but when Yukon took over the hub kits, they started changing offsets and dimensions so nothing fit.
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OP
Once the machining specifications are memorialized on paper I see no reason why the results cannot be duplicated and the rotors machined locally by any good machinist. I have also confirmed with @mrblaine that the first set of machined rotors can be used as a template for subsequent sets.
@mrblaine also suggested that one can save some time and money by purchasing a second set of rotors at the time the kit is first installed, having both sets of rotors machined at the same time, and keeping one set for "later." That may be what I do.
The other option for the 4x4.5 hub kit would be to use factory brakes with Black Magic pads and forego the Vanco big brake kit altogether.
As for my particular situation, I have detected the onset of analysis paralysis so to combat it I have forced myself to pull the trigger and have purchased the Vanco 16" Big Brake Kit from Black Magic Brakes. Hopefully the boxes will arrive before Christmas so I can gift wrap them and put them under the Christmas tree as gifts to me from "Santa."
Not really. Most won't drive their rigs long enough to wear out a set of rotors. I'd be comfortable saying they are good for 100,000 miles barring catastrophe or extreme rust.
That and one could always buy a spare set and have them modified at the same time as the first set and toss them on the shelf. Sorta like we do with our driveshafts, spare axle shafts, and other odd ball parts specific to our rigs that spares are not easily able to acquire in a hurry.
You should see the boxes mid week, maybe a little later but provided UPS does their job, in plenty of time for Santa to trip over them.
Mr Bills, I've been reading this thread with interest, and have one question. Is driveline vibration common after regearing, or is your issue the result of a combination of other modifications/upgrade?
The reason I ask is I have an LJ and plan on regearing soon.
The reason I ask is I have an LJ and plan on regearing soon.
OP
Re-gearing alone isn't the issue, its re-gearing to very low gear ratios. In some but not all TJ's and LJ's that have been re-geared to 4.88 or lower a harmonic/vibration develops at highway speeds. It seems to happen more often with the 42RLE transmission and NV241OR transfer case, but there have been similar reports from those with the 231 transfer case.
One working theory is that at such low gear ratios the front driveline is spinning substantially faster at highway speeds than with stock tires and gears such that a harmonic that wouldn't be apparent on a stock rig until 95+ mph is now evidencing at 65+ mph. Another theory is that the front driveshafts aren't being balanced at a high enough rpm to handle the increased spin rate with lower gears. Still another is that the front output bearing of the transfer case isn't designed to handle the increased spin rate.
"Fixes" include fiddling with the front pinion angle in an effort to reduce the harmonic as much as possible, or raising and lowering the transfer case, or re-balancing the driveshaft at high speed, or this, or that, or something else, etc. Sometimes experimentation works, sometimes not. Sometimes adjusting the pinion angle to where the vibrations diminish also takes away so much caster that handling suffers.
A more certain "fix" is to convert to manual hubs. Now the front axle shafts, ring and pinion, and front driveshaft aren't spinning at all when going down the highway so there is nothing to vibrate. Problem solved. Also, with manual hubs the caster can be restored to factory recommended settings. The only downside to this alternative is cost - it isn't inexpensive.
As noted in my first post in this thread, I don't have the patience for fiddling with pinion angles and transfer case angles and experiments that may or may not succeed so I am resolving the vibration/harmonic issue by converting to manual hubs. I have chosen the Yukon 5x5.5 kit which will require new wheels.
How do I know it will work? I won't know with 100% certainty until the hubs are installed, but since my harmonic/vibration goes away with the front driveshaft removed (i.e., there is nothing there to spin which is akin to it being there but not spinning) the odds are in my favor.
I'm taking the opportunity to upgrade my brakes to the Vanco Big Brake Kit with Black Magic pads at the same time.
And if someone will buy my old wheels and the tires then I can go to 35" tires on 17x9 wheels.
After all, its only money.
Link to FS ad for wheels: https://wranglertjforum.com/threads...y-wheels-w-bead-lock-rings.16474/#post-267764
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Mr Bills, thanks for the detailed explanation. Your solution makers sense. My LJ has the 42RLE auto and 32" tires.
I'm more or a trail cruiser, and not rock crawler. Based on your experience, I might regear to 4.56 instead of 4.88. Hopefully, this won't cause a vibration problem.
I'm more or a trail cruiser, and not rock crawler. Based on your experience, I might regear to 4.56 instead of 4.88. Hopefully, this won't cause a vibration problem.
OP
It is more important to gear for your engine, transmission and tire size than to choose a particular ratio hoping you won't get vibrations. My jeep has the 42RLE overdrive transmission and 35" tires. The previous owner had re-geared to 4.88 which was insufficient for the 0.69 overdrive ratio in the 42RLE transmission with 35" tires. I re-geared from 4.88 to 5.38, which is a much more appropriate ratio for that combination.
I misread ( or forgot) the details in your original post. I thought your vibration was when you regeared to 4.88. It sounds like 32" tires and 4.88 is less likely to cause a vibration issue.
jeepndogs
TJ Enthusiast
All depends on the Jeep. 4:88 is about where they start to get goofy. I have 4:88’s and 33’s and have the same vibration, I did the hub conversion last year and it solved my problem.