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Thread: Talk me out of this...

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    Default Talk me out of this...



    The rear axle of the jeep has what some call "84 Cadillac Eldorado" brake calipers. These calipers are used in Drum to Disc conversions as the parking brake system is built into the service brake piston. It's a nice idea but there's a reason they are not in common use. Two detractors are the multitude of parts in the service piston and the fact that the customer needs to routinely use the parking brake to keep the service brake (pads) in adjustment (the parking brake system ratchets the service brake to account for pad wear - the service brake system - unlike all typical disk brake systems - do not self adjust for pad wear).

    So - the big question - talk me out of getting rid of these integrated parking/service brake calipers and going to a typical disc brake caliper - ditching the mechanical operated parking brake and move to a hydraulic line-lock parking brake.

    Pro/Con:
    Hydraulic line lock systems are not long term use items (hours/days/weeks) - as they bleed down and the brakes release. But - I basically never use a parking brake - especially long term. Why - because the mechanical parking brake system is quite unsatisfactory in performance. At its best it's a horizontal surface keep-from-rolling if there's no breeze pushing it type of brake.

    There have been a few times it would be nice to have SOLID parking brake performance and in those times it's turn the engine off and put the manual trans into gear. A few times it'd be nice to have solid parking brake performance while keeping the engine running - winching. The mechanical parking brake was never satisfactory to keep the jeep from moving under winching - thus I was in the cab with a foot on the brake pedal.

    In comes the idea of front and rear brake line electrically activated line locks. Push down the brake pedal, flip the switches (front axle / rear axle) to engage the line locks and I can remove my foot from the brake pedal (and be out of the jeep, while it's running in neutral, to tend some winching task).

    In this use - it's short term and I'm there in attendance - so hydraulic line bleed and brake release should be noticed and attended to.

    With conventional, self adjusting, rear brake calipers, my daily driving braking performance would be top notch (as best as possible). Larimer county / state of Colorado does not have vehicle inspection (which would likely require mechanical parking brake availability).

    Talk me out of making the switch...

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    Default Re: Talk me out of this...



    I had a similar kit on my first Jeep an 88 YJ with a swapped in Scout II Dana 44, it worked better with upgraded pads and rotors f/r. I'd probably do the swap to conventional, sounds like there is no downside except time and money, which your Jeep will take from you anyway.

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    Default Re: Talk me out of this...



    Regarding your two detracting points for the current setup:
    1. Wouldn't the hydraulic system be just as complex if not more than what you have? Maybe not the brakes themselves, but you are adding components that serve the hydraulics.
    2. I'm in the camp of always using my parking brake, so I don't really see that as an issue. What's the downside to using the parking brake every time you park?

    I'm a little confused about your current "conventional" setup. Is this the same as modern cars with disk brakes and a cable operated parking brake? Those are pretty straight forward and work well in my experience.

    Having said all that, I'm sure the hydraulic system will give the best benefit when wheeling, so if that's your main use for the Jeep, maybe its a worthwhile upgrade.

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    Default Re: Talk me out of this...



    Mountaineer01 previously posted:
    "What's the downside to using the parking brake every time you park?

    I'm a little confused about your current "conventional" setup. Is this the same as modern cars with disk brakes and a cable operated parking brake? Those are pretty straight forward and work well in my experience."

    Jim can give you details about his long running relationship with his eldo rear calipers, but here is the short of it...Most all conventional rear disc brakes set ups use two separate calipers for the service brake and the e-brake (and two separate sets of pads as well). When old school conversions from rear drums to discs are done, typically, a GM style front disc and caliper set-up is used on the rear that does not have provision for any type of parking brake. The original drum that was removed would normally have had an e-brake built into the backing plate or the system used something even older style, like a transfer case parking drum (functionally equivalent to having no parking brake). When going to a disc brake set-up, you basically give up a parking brake, or you have to use the GM Eldo calipers that fit on the GM style caliper bracket and have an integrated parking brake system. Basically, those calipers were 'finicky' to say the least - they were not produced and used by GM for all that long - but they are still commonly available as they are the only option for a simply bolted on cable actuated parking brake on most hot rod or other rear disc conversions. Even for those that try to use the parking brake consistently, the cable actuator have a tendency to freeze up with corrosion - especially in places like Colo with MgCl on the roads etc. If the e-brake cable clogs up or you don't use the parking brake, the auto-adjustment function of the service brake stops functioning, and as the brake pads wear, they stop making contact with the disc. The hydraulic caliper piston adjustment is tied to the mechanical parking brake cable. Going with a very high end, quality caliper can help (not typical auto part store), and consistently keeping the clean after use in mud or snow or road salt.....not ideal for jeep use. For those with some fab skills, a traditional dual service and e-brake set-up is preferred, but the GM style caliper bracket must be modified with an the ebrake caliper bracket welded to it or bolted into the axle plate. This can create other challenges with proper alignment and clearance etc.....Some standard hot rod axles may have some aftermarket swap options available, but the D44 is pretty much a front GM caliper swap with out other options.
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    Default Re: Talk me out of this...



    Thanks for that explanation James. I have always just had drum brakes until my current truck, but I haven't done a brake job on it yet so I never really looked too closely at the setup. I'm surprised that they don't make a better conversion kit for the YJ or the D44. Now you have convinced me that Jim should go ahead with the upgrade he wants us to talk him out of!

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    Default Re: Talk me out of this...



    James has it - corrosion.

    I dotted the i's and crossed the t's with my current setup. I bought the jeep modified as-is - with no working parking brake (with the eldo calipers). I learned the intricacies of these calipers and know how to properly adjust them (some come, out of the box at the parts store, improperly assembled and thus will be a pain to install and will never pad-adjust for wear).

    I purchased proper parking brake cables (stock cables were not long enough with the lifted setup - something the person who modded'd the jeep didn't tend). I replaced both calipers and had both properly working. I even changed my ways and used the parking brake frequently (not every time - but frequently enough to keep pads adjusted).

    Even though I used the parking brake frequently and had a new parts and properly installed setup - one of the calipers had the parking brake system freeze (as James mentioned). The lever was pulled "ON" but when I released the parking brake it only returned about 80% back to "OFF". It didn't cycle back to "ON" again and stayed frozen. This is not something that is evident when pushing/releasing the parking brake lever. The only way one would know of this issue is a physical inspection. Meanwhile, the pads on that disc slowly wore down and were not contacting the disc. I lost braking power on that wheel and never knew it (until I happened to be working near that caliper and noticed the issue).

    That's the major desire to switch to "conventional" (read - dead simple and reliable) calipers - to have consistent, reliable braking while driving. Parking brake doesn't directly factor into this part of the change.




    As for using line locks for temporary parking assist:

    A typical electric line lock is what I'll probably go with - but I'd like to see if a "manual" style lock that can be momentarily electrically activated could be found.

    My thought is to place a line lock at the output of each master cylinder port (one for rear axle, one for front).

    It seems there are two types of line locks:

    Manual push-button where the driver applies the service brakes (pushes the pedal), pushes the line lock button, then releases the brake pedal. The line lock keeps hydraulic fluid in the service brake system keeping the brakes applied. To release the line lock, the driver pushes the brake pedal to a value greater than originally applied and the line lock, via spring return-to-open, opens and typical service brake use returns.
    www.speedwaymotors.com - manual line lock

    Electric lock where the brake pedal is pushed, a switch is turned on that activates a solenoid that closes / locks brake fluid in the circuit. To release the lock the switch is turned off and the solenoid opens.
    Jegs - electric stage control lock
    .

    I like the manual style that requires brake pressure to unlock the system - but I'm not routing brake lines to the dashboard to have a manual push button on the dash. I'd like to find an electrically activated "manual" style where the locks would be at the output of the master brake cylinder. Anyone know of such a thing?

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    Default Re: Talk me out of this...



    Jim previously posted:
    "I'd like to find an electrically activated "manual" style where the locks would be at the output of the master brake cylinder."

    Are the traditional MICO line locks not just this? Well, I guess it wouldn't be at the exact output of the MC - say literally mounted into the MC port - but it would be in the line between the MC and the junction block? Of course, with a dual reservoir system, I guess you'd have to chose which or both circuits to put the MICO - I would guess its typically used only on the rear brake circuit (which is typically the forward reservoir at the MC).
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    Default Re: Talk me out of this...



    Mountaineer01 previously posted:
    "I'm surprised that they don't make a better conversion kit for the YJ or the D44."

    Not to derail Jim's thread, but first and foremost, YJs never came with D44, and the typical and easier swap for an upgraded rear axle is a Ford 8.8. There may very well be good disc brake conversion kits for the 8.8 with e-brake - I couldn't tell you as thats not something I've ever worked on.

    As for the D44 - the challenge here is that most rear D44s were used in vehicles in the 50-60s - before disc brakes were common. Into the later 70s and 80s, disc front/drum rear became common in GM applications, but D44s were mostly in the front (not strong enough for large v8 power for rear usage in full-size trucks), so the D44 disc swap kits are based on front disc set-ups which of course wouldn't have e-brake provision. Keep in mind that most aftermarket swap kits are really just companies that assemble all the parts needed from various existing applications to make it work - very little 'newly' engineered and fabricated pieces are actually produced (at least up until the most modern of times and specifically the JK and JL jeep aftermarket world etc). As GM parts were both the most common and continuously produced with minimal changes, they often are the basis for most swaps. Unfortunately, finding a rear D44 application with disc brakes is pretty much impossible although I believe late IH Scouts, some full size Jeep trucks, and even more recently Izuzu Troopers, Suzuki Samarai and even Geo Tracker and Sidekick used rear D44s with discs. But, quite a lot of those used a different bolt pattern and wheel hub (6-lug) and don't work well with common 5 lug jeep patterns. They can all be made to work, but it takes some mixing and matching of various hubs, bearings, races etc (Brennan metcalf is making some cool D44 disc swap kits from the Geo parts if anyone is interested - and is also working on an electric e-brake caliper to combine with the disc set-up)....So in the end, the Eldo caliper became the standard go to even though its not ideal. keep in mind that the eldo caliper works well in many hot rod and classic car applications that mostly street and strip rides that are not used in ugly weather, salt and snow, mud and other typical jeep conditions.

    As for me, living with two jeeps, both with D44 rears from the 50s and 70s, I've spent a lot of time considering disc brake swaps. Honestly, I've found upgrading to 11" drums is very reasonable, functional, cost effective etc. The axle Jim has under his YJ is kind of an unknown D44 - but most likely came with drum brakes. If it still had 11" drums with cable actuated parking brake, I would just keep it that way. of course, his has already had swap work done, so its hard to want to go 'backward' to drum brakes. For many of us in these old jeeps, just getting to 11" drums is a big upgrade, and if going with disc, just getting disc in the front with drum rear is awesome. And a rock makes a great parking brake!
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    Default Re: Talk me out of this...



    FINOCJ previously posted:
    "And a rock makes a great parking brake!"

    Cue the rock in front of the driver's front tire on the current Red Cone avatar pic!


    MICO
    www.mico.com

    That company never came up in my searching - THANKS!!!

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    Default Re: Talk me out of this...



    Maybe not helpful to the current problem at hand, but I always thought a t-case brake would be cool. A little cable activated caliper on a custom bracket and a laser cut rotor on the output flange of the t-case. If you had lockers and had the t-case in 4x4 you could have all four wheels locked up for winching. Without a locker I suppose if one tire of an axle slipped you would loose them both. Hard to implement on the NP/NV style cases.

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    Default Re: Talk me out of this...



    Here's a transfer case mounted disc brake at the rear drive line output.
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    Default Re: Talk me out of this...



    Here is some decent line lock reading:
    https://redlinelandcruisers.com/tech...parking-brake/
    ___________
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    Default Re: Talk me out of this...



    I've been poking through MICO's products - looking at the cable actuated item and wondering why I'm seeing wires. They have an integrated low pressure alarm switch! Now that'd be a nice item to have.

    Your Land Cruisers link does highlight a concern - solenoid duty cycle / heat.

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    Default Re: Talk me out of this...




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    Default Re: Talk me out of this...



    FINOCJ previously posted:
    "There may very well be good disc brake conversion kits for the 8.8 with e-brake - I couldn't tell you as thats not something I've ever worked on."

    My truck has the 8.8 with rear disks and a cable parking brake, so I'm sure there are millions of those around from the 90s and early 2000s.

    Jim - didn't you need to rebuild your differential also? Sounds like the perfect time to swap the whole thing to the 8.8 and fix both issues!

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    Default Re: Talk me out of this...



    Yes. Likely pinion bearing though a solid diagnosis has not happened.

    Swapping to an 8.8 is a consideration. What about width? Would the 8.8 be as strong or stronger than the 44?

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    Default Re: Talk me out of this...



    Just my thoughts.....Can't tell you about strength comparison, but for a 'small' YJ - even running 35s - a D44 is almost impossible to break. Not sure going stronger would gain you anything, and the 8.8 does have a large pumpkin that hangs a bit lower. Nothing against the 8.8 - it makes an excellent candidate for a swap from the OEM D35, but not sure going from the current, modified D44 to an 8.8 would justify the expense. With the current D44, rebuilding the axle, even going through the hassle of R&P set-up with new bearings is still really cheap compared to finding a replacement axle, that if used, still would need rebuilding, not to mention ARB compatibility. Basically, in addition to whatever cost of the 8.8 would have, add a locker purchase to it as well. The current ARB could probably be sold for some return, but a cut down, modified D44 may not bring much return to offset the cost of the swap....and not sure there is much benefit for that swap....maybe there is more benefit to the 8.8 than I recognize.
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    Default Re: Talk me out of this...



    I hadn't considered the ARB - a significant cost.

    I entertained it as I do have axle shafts that are twisting. When I had one out a couple years back I looked at the splines - there is a slight twist at the base of the splines - very slight. It's my assumption that the axles are upgrades and not stock - but if they are upgraded (stronger), going stronger yet is the consideration.

    Bottom line - if a re-gear would be needed for a swap, I'd probably re-gear to a higher ratio than the current 4.10 and that would mean a re-gear of the front axle as well - possibly requiring two ARB's. Fixing the pinion in the current axle (which has served me well for the past decade) would be the reasonable choice.

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    Good things to think about....Anyway, its -30F here, so I got nothing better to do than think about jeep stuff and type away....no obligation to further the discussion....

    Given that its a cut down D44, then either the old axle shafts were cut down and re-splined, or new ones were made. These days, I think its cheaper to just get new ones from Moser/Dutchman or whomever, but back in the day, it may have been cheaper and doable to get a local machine shop to respline. Most aftermarket axle makers put there name on the end of the axle by the hub - so I would think it would be somewhat determinable. Even OEM Dana axles should have the diamond Dana stamp on them somewhere I would think. Old Dana stuff is good, but age and abuse can be tough on it, and often, if it was resplined, it may not have the proper heat treatment and hardening as it would have originally. Certainly, new aftermarket axles would be pretty bomber in your set-up. I'd seriously consider replacing no matter what you decide to do with gearing.

    Regearing the axles shouldn't be a big problem for you....I believe the carrier break for the D44 is at 3.92.....so as you are already above that with 4.10, going to a numerically higher gear ratio would not require changing the internal carrier (case), just new ring and pinon gears. And I assume the ARB is the internal carrier now (it replaced the OEM), that would mean you can keep the ARB as is. If you by chance currently had 3.73 gearing (common for older D44s), and wanted to go to 4.10s or numerically higher, then a new internal carrier would be needed (and the ARB would probably not be usable). Ring gear spacers can be used in some situations to work around this, but its not ideal. Again, given your current 4.10s, you should have no issues going to numerically higher gearing - but worth checking the ARB specs to make sure.

    I had 3.31 (I think?) in my cj7 with the 4.2L and 33s - it was definitely not enough gearing. I always thought 4.10s would have been about right. You have 35s, but also a bit more power with a fuel injected 4.0, so not sure what is the sweet spot for your rig. 4.56 would probably be pretty sweet, but thats a lot of work to regear two axles for maybe not a huge gearing improvement. 4.88s would certainly give you a significant gearing change, but would it be too much gear? I run 4.88s in the cj5 with 33s, but of course my old jeep doesn't quite have the power of modern engines. You'd get a nice little bump in crawl ratio, get noticeably better throttle response when driving, and with your overdrive 5speed and 35s, you'd still be cruising the hwy with decent rpm. The 4.0 has a little lower power band than my v6 and the 35s would also reduce rpms a bit compared to my 33s.....IIRC, your 4.0 was carbureted originally, but now has later head and fuel injection, so its exact specs are a bit uncertain, but most 4.0s would be in the 170-190 hp range peaking over 4000 rpm, but with 220-235 ft-lbs of torque peaking around 3500rpm.
    I wanted to use an rpm to speed calculator to see what various gearing would produce, so I made a guess you have an ax15 with 1st gear of 3.83 and OD of 0.79 and 4:1 low range and 35 inch tires:

    with 4.10 gears:
    CR: 63
    60mph = 1865 rpm
    65mph = 2021 rpm
    70mph = 2176 rpm

    with 4.56 gears:
    CR: 70
    60mph = 2075 rpm
    65mph = 2247 rpm
    70mph = 2420 rpm

    with 4.88 gears:
    CR: 75
    60mph = 2220 rpm
    65mph = 2405 rpm
    70mph = 2590 rpm

    So, I like to look at the peak torque rpm and kind of use that to find the rpm sweet spot - its nice to be able to cruise in OD a good bit below peak rpm, and then be able to drop down a gear and jump the rpms up to near peak torque rpm. I am not 4.0 expert (my cj7 4.2 was its predecessor of course), but those numbers suggest you can definitely run the 4.88s and even if you cruise 70 - you'll still have some power in the engine. If cruising at 70 at 2590 rpm, and you needed to drop down a gear to pull up a hill - you'd jump to about 3280 rpm- right below peak torque rpm. I was thinking 4.88s would be a bit too low, but these numbers suggest its very doable. But the 4.56 looks really good to me - I have a tendency to cruise 60-65mph in my jeeps and being in the 2100-2200 rpm range for a straight six seems about right - and maybe a bit more fuel efficient and protects the engine life a bit over the long haul. In the higher revving v6 in the cj5 with a bit of cam - it likes to be a bit higher and around 2400 rpm it really comes in, so the 4.88s with 33s works. I am sure there is lots of discussion about gearing and tire size for the 4.0s out there - probably FR4x4 members with driver seat experiences. ou know how your jeep drives on the highway and how it pulls up the long hills and how much more rpm you want to get a bit more throttle response and go. I was thinking the straight wouldn't want to run too high an rpm, but the 4.0 (vs the 4.2) and fuel injection probably help it find a bit more rev as well as pull better at low rpm (carbs and low rpm don't go together), so running in the 2000-2500 rpm range for each gear shift might be sweet for the 35s.

    Whether its worth the increased work to get to 4.56/4.88 ....guess thats up to you. Assuming when you say you need to repair the current pinon, you mean the pinon bearing, and not the pinon gear. If just the bearing, you'll have some tedious work with checking backlash, but as you'd be re-using your ring and pinon gears and ARB carrier, and the basic set-up is there right now, and you just match the spacers of what you took out - then double check the measurements (check the used vs new bearing thicknesses as changes there would affect the amount of spacer shims). Doing a 'fresh' set-up of new ring and pinon gears has quite a bit more tedious set-up (especially with pinon depth) - if your pinon gear needs replacement, then you'd be looking at a fresh set-up, and at that point, you should certainly consider re-gearing. Of course, for a regear, you'd have to do it for both the front and rear.

    So after all this typing and thinking...how long you thinking about keeping this jeep? Regearing is a sort of long term investment. you ever think of either changing your 4wd vehicle, or possibly even moving on from wheeling that is fully locked on 35s? After years of being a bit budget conscious with my jeep investment (hmmm....is that even possible?), I am kind of thinking of going a bit 'all in' on some jeep projects so I can fully enjoy them on some specific trails and goals. I can also see one day moving away from trying to run 50 year old junk on hard trails trying to keep up with all the modern stuff....so the time is now to get this done, and then one day I can buy that luxury all electric jeep and do scenic dirt roads along the beach in mexico, far from the freezing temps of montana.
    ___________
    James Orofino
    1970 CJ5
    1958 Willys Wagon

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    Default Re: Talk me out of this...



    A couple, perhaps important, edits to your inputs:
    4.2 is the base motor with the Mopar MPFI kit (not 4.0)
    TerraLow 4:1 low range kit (not stock ?2.72?)

    The 4:1 low range is what is "allowing" the 4.10 stock gearing to be usable on the trails. I don't spend too much time in 1st gear - but it routinely does get used. On the road, heading up large hills (i-70 out of Georgetown and up near the tunnel), I'm dropping down two gears with the engine rolling as fast as I wish to push it with the jeep sitting about 50MPH.

    In many cases I find this a perfect match for me. Would I like to roll road speed up I-70, yes, but do I need to - no - and if I could - what other aspects would change that I might not find desirable (heavier vehicle / less room in the engine bay / harder to work on in the engine bay - more stuff to remove before getting to the part in question).

    For now, after Christmas, I'll get proper rear shocks on it. I'll probably warranty replace the "Eldorado" caliper - and then drive it to the shop to have the pinion work tended.

    When it comes back, I'll look into, first, putting line locks on both outputs of the master cylinder. Then, I'll look at swapping out the complex Eldorado calipers for direct fit conventional calipers - and run it. When the calipers get swapped, I'll look at axle shafts - or better yet - I might have the shop look at them during pinion work.

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