TJ D30/44 ARB Locker Rebuilding/Parts Sourcing

[53HiHood]

So I picked this ‘01 TJ up, it has a LP D30 front/D44 rear with ARB’s (I have to older gen RD30/RD06 lockers), and after the first trip out I realized the air lockers don’t engage and the compressor will run non-stop if I try engaging the lockers. I pulled the front diff cover to find a not-so-pleasant surprise, all 6 fasteners on the seal housing end of the unit  and 3 of the 4 shaft retainer pins were laying in the bottom of the diff housing. The air line was damaged, which will require a new seal housing, and the cross shafts have varying degrees of damage, mainly one of the short shafts. The fastener retainers were not present, so I’m assuming the locker was installed without them. Doing some digging online it appears the RD30 was notorious for having this failure due to the amount of flex in the D30 housing and/or lack of diff preload. The D44 rear didn’t have any surprises for me when I opened it up so I was able to start looking for the air leaks. It was leaking at the bulkhead fitting and from the locker unit so I removed it and found some gunk in the seal housing. The sealing surface in the seal housing is showing excessive wear from debris getting in there. It could possibly be cleaned up but replacing it would ideal for longevity.

I would like to rebuild the lockers but I’m having a hard time finding replacement parts due to these models being discontinued. Some parts are discontinued entirely, others can be found online but when I place an order I get a follow-up email stating the parts are back ordered. Am I wasting my time trying to rebuild these obsolete units since the manufacturer support isn’t there?

Jon

[Moses Ludel]

53HiHood...Great to see your posts...The volume of low pinion D30s would seem significant enough for ARB to continue producing these service parts.  AMC-era CJs, Jeepster/Commandos as well as TJs use the low-pinion Dana 30 with insignificant differences other than matching up the axle shaft spline count.  

I pored over the ARB U.S.A. site, as you likely did.  Your next move would be direct contact with ARB.  I found the link for a submission.  Ask whether service parts are available for your low-pinion D30 ARB Locker:

https://arbusahelp.zendesk.com/hc/en-us/requests/new

Beyond this, I would mention that many users have gone with an OEM style auto-locker (multi-plate friction type) at the front with an ARB at the rear.  I'm not a fan of auto-lockers and would do an Eaton ELocker before making that move.  (Over the years, I've done the ARB as rear only, an ARB front and rear (best overall), and a Trutrac rear with an open front.)  The Eaton catalog shows 1971-2006 D30 axle applications without a distinction between reverse rotation and low-pinion applications.  Here's the Eaton catalog link, see page 15:

https://www.eaton.com/content/dam/eaton/products/differentials-traction-control/eaton-performance-differential-application-guide-en.pdf

If there is a low-pinion D30 Elocker available, that's an option worth considering.  You can also live with an ARB rear only, though for mud extremes (your neighborhood), there is a distinct advantage with ARBs or ELockers at both the front and rear axles.  In any case, I prefer manual lockers, which includes the cable-actuated Ox, for the sake of vehicle control.  You can open up the differentials when on a slippery side slope or off-camber situation to maintain the vehicle's directional stability.

Let us know what works here...There are a lot of users in your situation.  Curious whether ARB has a solution.

Moses

[53HiHood]

I did shoot a message to ARB inquiring about the parts and I’m waiting to hear back from them. I might be out of luck with these units being discontinued so long ago.

I have been heavily considering switching to the Eaton e-locker, the Dana 30 model is OOS everywhere but I can find the D44 model readily. If I can’t get parts for the D44 arb I’ll start looking at other selectable locker options like the Eaton. Any experience with the Yukon zip lockers? I may have just scored great deal on a 30 spline zip locker and HP30 housing.

Jon

[Moses Ludel]

Jon...I checked out the Zip Locker (U.S.A. "assembled", which means offshore components, not necessarily a deal breaker).  It has a striking resemblance in concept and design elements to the ARB.  Model coverage looks good for your purposes; Yukon Gear offers most popular and marketable applications.

There is a caveat about 3/8" versus 7/16" ring gear bolts.  The unit for the D44 is drilled for 7/16" ring gear bolts and can be purchased with optional sleeves for a 3/8" bolt application:

"This unit is drilled for 7/16" ring gear bolts. If you are using it in an application which has 3/8" ring gear bolts, please purchase qty 10 of part number YSPBLT-027 to sleeve the ring gear bolts..."

Check out the Yukon Gear website.  They offer a number of automatic lockers plus the Zip Locker.  As you discovered, the Zip Locker is an option to the ARB unit.

Moses

 

 

[53HiHood]

I’m picking up the HP D30 housing and D30 zip locker on friday. I ordered most of the parts for the HP build from ECGS this morning; D30 reverse gears, install kit, chromoly axles (30-spline inners), and seals. I need to call them back in the morning to add a few things to the order like the artec truss and C gussets. ECGS also had the seal housing kit for my rear D44 ARB so I’ll be able to fix the air leak.

ARB contacted me today to confirm that all of the parts I need for the older model D30 ARB are in stock at their warehouse so I relayed that to my local shop that I placed an order with last week and they said they actually received some of my parts this week (better than the 3+ week back order they told me on Monday), so I should be able to get my front diff back together sooner than later I hope. At least I have the HP parts coming though, I should have that built by mid-November.

[Moses Ludel]

A couple of questions below in red...Confirming...

On 10/26/2022 at 7:51 PM, 53HiHood said:

I’m picking up the HP D30 housing and D30 zip locker on friday. I ordered most of the parts for the HP build from ECGS this morning; D30 reverse gears, install kit, chromoly axles (30-spline inners), and seals. I need to call them back in the morning to add a few things to the order like the artec truss and C gussets. ECGS also had the seal housing kit for my rear D44 ARB so I’ll be able to fix the air leak.

So, the HP (high pinion) D30 is going into this TJ to replace the OEM low pinion D30?  ARB parts, now available, will serve the D44 rear axle in the TJ?  You're getting an HP D30 housing and a reverse rotation, high pinion Zip Locker for the front of the TJ?  Is this a common changeover?  It obviously requires a chassis lift for driveline clearance and possible driveline length adjustment...You have enough engine and other clearance to fit a high pinion D30 at the front of this TJ?

ARB contacted me today to confirm that all of the parts I need for the older model D30 ARB are in stock at their warehouse so I relayed that to my local shop that I placed an order with last week and they said they actually received some of my parts this week (better than the 3+ week back order they told me on Monday), so I should be able to get my front diff back together sooner than later I hope. At least I have the HP parts coming though, I should have that built by mid-November.

 

[53HiHood]

The high pinion D30 should clear everything. The Jeep has a Rubicon Express long arm lift so I shouldn't have clearance issues. The swap is fairly common from what I gather and the question I see a lot is "why didn't Jeep use the high pinion in TJ's". This housing came out of a '97 XJ.

I picked the housing and zip locker up yesterday, and ended up with another RD30 ARB that the guy was going to scrap, it appeared to be in serviceable condition minus a missing bolt. I'll use it to get the front diff back together so that I'm able to drive the Jeep while building the HP diff.

The seal housing for the rear locker should be in late next week, I could be snow jeeping by the weekend.

[Moses Ludel]

53HiHood...I can see the advantages.  Curious whether the RD30's welded pads, shock brackets and link arm brackets match up with the TJ chassis and suspension.  Is the RD30 source an XJ Cherokee?  Grand Cherokee?  We'll follow your findings...

The ARB seal housing and clutch have always been a concern.  O-ring grooves must be smooth, no roughness.  The O-rings need to last a very long time despite the continual moving surfaces.  On my early ARB unit installations (the early nineties), I would polish the O-ring riding surfaces before installation to extend the O-ring service life.  Later units came with polished O-ring riding surfaces.  See how your clutch and seal housing look...

Moses 

[53HiHood]

On 10/30/2022 at 4:27 PM, Moses Ludel said:

53HiHood...I can see the advantages.  Curious whether the RD30's welded pads, shock brackets and link arm brackets match up with the TJ chassis and suspension.  Is the RD30 source an XJ Cherokee?  Grand Cherokee?  We'll follow your findings...

The ARB seal housing and clutch have always been a concern.  O-ring grooves must be smooth, no roughness.  The O-rings need to last a very long time despite the continual moving surfaces.  On my early ARB unit installations (the early nineties), I would polish the O-ring riding surfaces before installation to extend the O-ring service life.  Later units came with polished O-ring riding surfaces.  See how your clutch and seal housing look...

Moses 

The hp D30 came out of a 97 XJ so the control arm mounts are the same.  I have new seal housings coming for both ARB’s, hopefully I’ll see those this week so I can get the Jeep back on the road, it’s a cold ride to work on the Africa Twin this time of year.

[Moses Ludel]

53HiHood...I caught your earlier 1997 XJ reference after my 10/30 reply...So, the spring seats, track width, shock mounts, track bar mount, etc., are all dimensionally the same between the TJ and XJ?  The only difference is the high pinion versus low pinion? 

The transfer case clocking is different on the TJ (case is clocked higher for skid plate and ground clearance). The XJ transfer case is clocked to ride lower.  I did a new (Advance Adapters sourced) TJ-application AX15 install into a '98 XJ Cherokee recently.  See the article and video link below...The TJ transfer case position could have been the decision to go low pinion on the TJ, a high pinion might cause a driveline clearance issue with a stock TJ suspension height. 

For the TJ with a drivable chassis/frame (not a unibody like the XJ), Chrysler/Jeep may have wanted the transfer case as high up as possible for the shorter wheelbase and expected vehicle usage.  The stock TJ skid plate is already a rock hanger:

https://4wdmechanix.com/jeep-wrangler-ax15-transmission-to-xj-cherokee-swap/

So what do you think of the Africa Twin?  Getting much riding time when the weather permits?

Moses

[53HiHood]

7 hours ago, Moses Ludel said:

53HiHood...I caught your earlier 1997 XJ reference after my 10/30 reply...So, the spring seats, track width, shock mounts, track bar mount, etc., are all dimensionally the same between the TJ and XJ?  The only difference is the high pinion versus low pinion? 

The transfer case clocking is different on the TJ (case is clocked higher for skid plate and ground clearance). The XJ transfer case is clocked to ride lower.  I did a new (Advance Adapters sourced) TJ-application AX15 install into a '98 XJ Cherokee recently.  See the article and video link below...The TJ transfer case position could have been the decision to go low pinion on the TJ, a high pinion might cause a driveline clearance issue with a stock TJ suspension height. 

For the TJ with a drivable chassis/frame (not a unibody like the XJ), Chrysler/Jeep may have wanted the transfer case as high up as possible for the shorter wheelbase and expected vehicle usage.  The stock TJ skid plate is already a rock hanger:

https://4wdmechanix.com/jeep-wrangler-ax15-transmission-to-xj-cherokee-swap/

So what do you think of the Africa Twin?  Getting much riding time when the weather permits?

Moses

That's interesting information about the transfer case clocking differences between the two. I believe the XJ can be found with both LP and HP front diffs, but it could be that there are different models or years where they varied??

I'm still waiting on parts to trickle in to put my Jeep back together, East Coast Gear Supply is awesome and ships fast, same can't be said for the shop that's only 2 hours from me that has had me waiting 3 weeks now for parts they confirmed they have in stock. It's been a week since I last contacted them for an update and no response. Bummer.

I received the new D44 seal housing for my rear ARB and they have actually updated them with 3.5mm line (vs the old 3/16 that you can't get fittings for anymore) so the newer bulkhead kits can be used. I'm hoping I'll find the same when the front ARB seal housing arrives. I've already ordered the newer style bulkhead kits.

Jon

[Moses Ludel]

Jon...Sounds like progress in fits and starts...I like the 3.5mm line standardization.  You'll be setting that up as parts arrive.  The axles will be more than adequate when done. 

A D30 is plenty strong for the front axle, it only pulls half the torque in 4x4 ranges.  (An exception is CJs with a Dana 30 and twin-stick conversion than has a front wheel drive-only mode.)  As long as vehicle weight is within bounds, which yours is, this should work really well.  

The D44 is the smaller tube OEM optional axle, right?  This was a little known option at the release of the TJ in 1997.  They are out there...Small tube, larger tube, still plenty adequate for a TJ and much stouter than a D35.  We've gotten lucky on the family XJs (1998 and 1999), each has a factory Chrysler 8.25" rear axle, not bad.  

Moses

[53HiHood]

I’m still waiting for the new seal housing for the D30 arb, I talked to the shop twice and haven’t gotten anywhere with them. At this point I need to just cancel that order. I got tired of not being able to drive my Jeep so I spent some time last weekend reinstalling the rear locker and I put the front locker back together (it’s not hooked up to air) just so I could drive it. I didn’t replace the internal bonded seal in the rear locker because I didn’t have replacement locking tabs for the case bolts at the time, and I might be pulling it back out because the compressor turns on briefly even couple minutes if I engage the rear locker. No big deal though, ECGS had the locking tabs in stock and they should be here this week.

Jon

[Moses Ludel]

Keep us posted, 53HiHood...Sounds like the leak is at the bonded seal in the rear locker.  However, it pays to chase down the system with soapy dish liquid/water in a spray bottle with the compressor running...A leak can be anywhere in an ARB system but likely where you suspect.  Super 300 Permatex, used sparingly at the brass/copper and iron axle housing junctions, will help.  Plastic air tube compression fittings loosen a bit over time and require periodic tightening and testing for leaks.  The ARB compressors are not often a leak source. 

Moses

[53HiHood]

I did end up pulling the rear locker not long after my last post. I replaced the bonded seal and I had ordered some new carrier shims because there was no carrier preload, the locker would go in and out easily once the caps were removed. I got the preload set and backlash is perfect. We went snow jeeping the following day and the locker worked great. No compressor cycling once the gear oil is warmed up.

I recently picked up a used 30-spline ARB that I’ll be using for the HP30, I’m going to pass the yukon zip locker off to a buddy that’s running a non-selectable locker in the front of his CJ. I just got the housing back from the fab shop last week, trusses and c-gussets were installed, so I can start assembling it once I catch up on other projects.

[Moses Ludel]

53HiHood...Glad the parts for the locker came through...What trusses and C-gussets did you use?  Any pics of the trussed axle housing?   We just discussed trussing at this JK Wrangler exchange: 

Moses

[53HiHood]

I went with the Artec truss and C-gussets.

https://eastcoastgearsupply.com/i-15452070-dana-30-tj-artec-truss-system.html

 

[Moses Ludel]

Nice install and welds.  This kit does not "sandwich" the tubes with an upper and lower truss.  The strength of these upper trusses and C-gussets is tremendous.  They make up for the factory tube weaknesses.  These beam axles often came to the dealership with excessive negative camber, likely from factory jig welding, the inherent welding (heat) risks or even from being tied down too tightly on a car transport.  Off-road pounding on rocks with oversized tires will bend these axle tubes.  Yours won't.  Ever.

Welded right, in "stitch" fashion with thorough cooldown before welding adjacent sections, the camber should be on specification despite the extensive heat exposure.  Once together, a camber check will answer that question.

Moses