kt_Engineer

Triple countershaft transmissions are down because people don't know how to drive a manual transmission anymore. The fleets want mDrive as they can't retain or train drivers fast enough. Top mount double reduction axle is still significant portion of what Mack sells. It is standard option in Granite, MR and LE's. This is one component that is still "built like a Mack Truck". The L1 life for Mack axle is 500,000 miles for linehaul application (i.e 99% of axles will last that long without any failures). Some customer want watered down version of Mack axle b'cos it never breaks and expensive. Unfortunately, Mack axle does not have volume like Meritor or Dana axle. Mack axle is designed for worst case application and when it is advertised at 150,000 lbs (CRD150/151 carrier) it is for all ratios and does NOT come with conditions apply (unlike Meritor axle where only certain ratios are valid at high GCW and only if 100% load one way and 60% load return). There are some Mack carriers (CRD95/96) which were first designed in 1945 and still in production without any changes. Hub reduction expensive axles are no match to this Mack axle (this is coming straight out of a customer in Argentina who broke $40,000 Axletech axle in oilfield within couple of months while CRD95/96 did NOT have a single issue in 4 years. This is doing crazy stuff in oil field dragging 80,000 lb machinery literally on the ground).

Can you share some pictures. When you say wiring harness for locker device, did you get a REMACK with a inter-wheel differential lock when the original one did NOT have a inter-wheel lock? Did the original and REMACK have a inter-axle differential lock. When you say installing axles, I am assuming you are intending to say axle-shafts. The Left Hand side (Driver side) axle-shaft for diff. lock has longer spline but if your original version did not have a diff. lock and the REMACK version has a diff. lock (assuming it came with diff. fork and clutch), you will need to slide in axle shafts in a specific way to go across diff. clutch into the side gear of the differential. You should be able to use the REMACK carrier with the diff. lock on this truck.

it depends....if you are speaking about gradeability in OD gear, it matters how much HP and how your torque/HP curves look like. Most of the new diesel engines can produce constant power/HP over a wide band (~ 1000-1500RPM) and normal 3% grades will not cause to down-shift to maintain vehicle speed. When you encounter steeper grades is when it will be hard to drive in top gear. Being in Direct-Drive or under-drive will allow you more flexibility in terms of maintaining those gears for longer periods of time when compared to being in Over-Drive gear. If you are in a linehaul application, OD transmission definitely has advantage as of now but faster axle ratios being introduced will be a game changer going into future and Direct-Drive will be more beneficial (OD with faster axle ratios will push you into <1000 Engine RPM @ 65MPH and vibration issues will become predominant in this RPM Range).

Mack triple counter-shaft transmission and top mount double reduction axle are still designed, developed and built in USA. Reliable as always and built like a Mack truck.

The Mack super Econodyne (445SE) is spec'd with OverDrive mdrive (top gear ratio of 0.78:1) and rear axle ratio of 2.64:1 (Meritor 14x axle). This will be best fuel economy package with 22.5 tires. You will be cruising @ 65MPH at 1150 Engine RPM in OD gear and when you downshift the transmission will be in Direct Drive 11th gear (1:1) with no losses in transmission gear mesh even though engine will jump up to 1400 RPM to maintain ~ 65MPH. You will get double whammy fuel savings with this combination. If you want to stick with 24.5 tires and Direct drive transmission, I highly recommend you consider switching rear axle ratio to 2.28:1 Meritor 14x (or 2.26:1 Dana Advantek). You will be at 1150 Engine RPM @ 65MPH with this combination and get better fuel economy.

My best guess - One or two of the tooth on the pinion have been spalling (surface fatigue) for quite some time and the noise was ignored. Eventually the spall grew big enough that the tooth broke under load and got into the gear mesh. Once that happens that will take out bunch of tooth (in the mesh) in a jiffy. I have witnessed 10's of failures like these.

Did you compare the length of the axle-shafts? Both of them could be a 17 tooth splines BUT the axle-housings between '69 & 86 could be different and have different length shafts (the spindles could have changed and as a reason axle shafts could be different). Also there were some changes made in spider in the differential over years, not sure if this could be one of the reasons. Can you also tell me if you have regular differential on '86 CRD93 carrier and switched to a a'69 CRD93 carrier which had a Inter-Wheel Power Divider (limited slip differential?) (There could be a spacer in IWPD that might be causing your problem.)

I am NOT a official spokes person but all I can tell you is my knowledge on development/testing and manufacturing of MACK axle and Mack T300 transmission is extensive and I can provide technical details like no other. If you are adding lift axle and overloading rears only "onsite", you should be fine. The creep rating (i.e driving on grades no greater than 3% and at speeds no greater than 5 MPH) for SB38 is 50,000 lbs. You should be fine loading upto 50k lbs on-site.

With Variable Gated Turbos, it has been a problem running at higher HP and Yes, The 16 L's can withstand higher loads relatively easily but with Turbo-compounding the thrust bearing, connecting rods etc will be beefed up and should have about the same L10 life (in theory and to be proved through testing). TC 13L Engine with a DD transmission is also believed to offer ~5% improvement in Fuel Economy when compared to a similar 13L Engine. Were the pistons going bad with 13L when running at Higher HP and Higher GCW? I heard of problems with MP8's (505HP) in Mexico pulling 143,000 lbs.

Give a year or two, you will understand why D16/MP10 does NOT make sense. When you can generate 600HP & 2100 Lb-ft of torque with 13L - Turbo compound engine and save on weight as well as cost will you want to spend extra money on Titan? How about a pinnacle (CXU/CHU) with same power as Titan at a lot less cost?

SB38 is 11mm fab steel housing approved to 38 k GAWR (40K GAWR for low mileage Municipality applications) with HMX, HN type bar-pin suspensions. The axle housings are sturdy and tested at much heavier loads but the cracks will start at the bar pin bracket weld-seams when loaded excessively. When loaded appropriately, at rated capacity, the axle-housings will last 500,000 miles with 99% reliability and much longer at slightly reduced reliability. If you intend to load this at 46k GAWR (100% of the time) then expect a failure much faster. I also strongly recommend against doing this as it would be a safety hazard.

You have a synchronizer issue. The older versions have low range side of synchronizer with insufficient tooth engagement and improper shifting will cause the tooth to round off and eventually you will not be able to reengage lo side. The whole synchronizer will need to be replaced. The new kits that have been released in 2010 use higher grade steel (4320H) and also increased dove/taper that will decrease the possibility. of this happening

MP10 (2060 lb-ft torque) should specifically matched T310ME21, T313 21, T 318 21, T313LR21 or T318LR21. All 5 of these transmissions are rated to 2100 lb-ft. If you have a MP10 - 1860 lb-ft Engine you are good to match with any of the T300 or T200/T100 transmissions. I have to look at V8 specs but for transmissions HP is not a issue as much as torque is. Though HP= (Torque x RPM)/5252 , most of the time higher HP is achieved at higher RPM and not necessarily at higher torque.

Well....it is not a straight forward answer. Mack always offered S462 (cast ductile iron housing) which is good with 46,000 lbs GAWR and only compatible with Camelback, Walking beam, HMX, HN and some spring type suspensions. Mack also offers 11mm & 14mm wall thickness steel fabricated axle housing. The 11mm was sold with same spring suspensions upto 44k GAWR for general use and at 46k GAWR for Municipality applications. Recently this was changed after some testing and now 11mm is approved upto 46k GAWR (14mm is good upto 52k GAWR). If you have a air suspension then you will need a 14mm axle housing at 46k GAWR (Previously 14mm was approved upto 44k GAWR due to air suspensions putting more twist into housing). 14mm after improvements is approved upto 46 K GAWR with air suspensions.

Mack Axles come with standard Power-Divider where as the Power-Divider Lock-Out (PDLO) is an optional feature. This is the peanut lock-out as mentioned above and locks-out the differential action between front and rear-driven axles by flipping a switch in the cab. PDLO is available on CRD92/93, CRD125/126, CRD150/151, CRD202/203, CRD95/96 and older carrier series. The Inter-Wheel Diff Lock/IWDL (locking out left-side wheel to right-side wheel) is accomplished through a fork, clutch and diff half with extended spline. This is comparatively new feature and is only available with the newer series of carriers (i.e CRD150/151 introduced in 2009 & CRD125/126 introduced in 2012). IWDL is again an optional feature. Mack Axles also offers a Inter-Wheel Power-Divider (IWPD) which use a similar peanut mechanism as Inter-Axle Power-Divider and automatically transmits 3 times the torque to non-slipping wheel (when on slippery surfaces). IWPD is also an optional feature. The IWDL is purposely restricted to not work above 25MPH. The Vehicle ECU is pre-programmed to not exceed 25MPH with diff. locks are engaged. IWPD has no restrictions as such and works at any speeds. Only dis-advantage with IWPD is if one of the wheels has zero traction then the other wheel will see 3xzero torque (hence that axle will not move). IWPD in combination with PDLO and 6S6M (6 Sensors 6 Modulators) will offer superior drivability than any other options would offer.

You will need to look for a 11KH54xx or 11KH55xx number which would give more information on the carrier series. 64KH5104 is the carrier housing number and 19QF4414 is the axle/banjo housing P/N. The 4.17 ratio is a CRD92/93 ratio. If oil is thrown out of the Pinion seal then probably the carrier seal has gone bad (easily replaceable). If you are seeing 1/8" to 3/16" end-play most probably one of the front two bearings (#1 or #2) has gone bad or going bad. Remove the side Aluminum Bevel Compartment cover on the carrier and check the backlash on the gears. It should measure between 0.006"-0.018". Also look for metal at the big magnet in the Aluminum cover. Check the condition of the bevel gears.

The base T306G transmission weight (without lube and shifter) is around 464 lbs. Are you planning to replace outputshaft seal?

The 5.02 ratio is a CRD202/203 carrier. This can be converted to 3.63 by changing the Bevel gears in each carrier to 1.06 ratio (from current 1.46). The Helical gears can remain the same. The 3.63 can get you to 68MPH in top transmission gear ratio of 0.71:1 (@1500 Engine RPM & 512 Rev/mile tire). The 38k axle and 44k axle built after 2002 should be inter-changeable as far as carrier goes (that is the bowl size is same and spindle ends remain same, so the carriers can be swapped out). The axleshafts can remain the same as long as 38k axle also has a CRD202/203 carrier. If it has a CRD92/93 or a CRD150/151 carrier then axle shafts will also need to be changed as Helical bull gear offset position is different for CRD202/203 & CRD150/151 (CRD92/93) carrier. It you are going to swap-out the pre-2002 38k axle carrier onto your 2005 44k axle then the axle-shafts need to change even of the carriers are from the same series. Also other thing to watch out if you are swapping the CRD202/203 with a CRD150/151 (CRD92/93) carrier will be for drive-shafts will need to be lengthened or shortened due to different pinion gear positions.

The other possible reason for the leak could be the Helical Pinion retainer (on Mexican hat side) having a O-Ring over-sized (or bore under-size) which will cause the splashing oil from Helical gears to leak out through shim pack. The oil that leaks get accumulated around the carrier/axle-housing interface forcing you to believe that is where the leak is happening. One more leak area to check is the composite side(or Aluminum) cover on the bevel compartment cover side. It is the same O-Ring over-size/bore under-size issue on the cover that will cause O-Ring to pinch and oil to leak out accumulating around the carrier/axle housing interface. The best option in these cases will be to buy an O-Ring one size undersize and install them. The O-RING on helical pinion retainer and bevel compartment cover size are different and can be bought off-the-shelf. I am assuming you have a CRD92/93, CRD150/151 or CRD202/203 carrier.

You are looking for 25632356 - ( 88AX454) - OEM P/N.

T2180 is the 2nd generation triple countershaft transmission and has been out of production since 2002-2003 timeframe. T318 is the current production (3rd generation) 18 speed triple counter-shaft transmission. There are different versions of 18 speeds in both T200 & T300 series with slightly varying ratios (For example there is T318, T318LR, T318 21 and T318LR21; The LR's have creeper gears and 21's are capable of 2100lb-ft as against 1800 lb-ft torque engines).

The easiest thing for you to do is buy a brand new differential carrier from Dana (inherited the Eaton/Spicer axle when Roadranger partnership was dissolved). You should look at buying a DS404/405 or DST40 or DST41. All three axles have 3.70 & 4.11 ratio available. The question will be if the differentials fit in the axle housing you have. I think they might but I am not absolutely sure about it. Alternately you can buy Meritor 14x or 160 series axles. 14x has 3.70 & 4.11 ratios available.160 series has 3.73 & 4.10 ratio. You should be able to get used versions cheaper but swapping out the whole axle might not be easy. Also you will need to make sure the suspension brackets can properly bolt on with new axle housings. If they are welded brackets, the build will be much harder. Mack axles with CRD150/151 carrier has 3.79 & 4.19 ratio if you are interested in the swap. The have better pinion angles and you should not see any vibration issues.

Looks like you have a old TRL1076 or TRL1078 - 5 Speed transmission. Unfortunately, this 1st generation triple countershaft Mack transmission 5 speed (prior to T107 the T772 was a single countershaft design) had only provision for installing the PTO gear.

What 5 speed transmission model is this?

The Mack Transmissions in general do NOT have a separate PTO gear . The bottom countershaft gear (overdrive - on front box) is located to be SAE compliant and will mesh with 6-bolt and 8 Bolt PTO. This offers weight and and cost benefit when compared to an Eaton transmission. This is true with majority of Mack transmissions but there were some transmissions like TM308 which had unique PTO gear. This was due to gear mesh not being in appropriate positions to be SAE Compliant. The attachment shows PTO gear for a 5-speed transmission. In the picture below it will be the countershaft gear meshing with 2nd gear in the front box. T2050.pdf