kt_Engineer

You need to turn 8LL input shaft 19.5 turns to see 1 turn on output shaft while T310MLR input shaft will need to be turned 27.31 turns to see 1 turn on output shaft. If you did put it in Lo-Lo gear obviously T310MLR would feel much harder to turn that doesn't mean rotational moment of inertia is higher than Eaton's. If you are putting a aux. box behind your trans that's another $5k-10k additional cost. Repair cost of range section of T300 should be around $4k. Isn't it cheaper in long run even if you had to repair it twice. T300 synchronizer has been beefed up but got a bad reputation by the time this was done. Even with bad synchronizer's they didn't go out until 350k-450k miles. To break-even with spec you are mentioning it would take over Million miles. Allison 4500 costs around $13k+ and add aux. box to it another $5k-$10k increased cost. Torque converter transmissions suck on fuel economy compared to manuals or Automated manual transmissions. Forget about breaking even or being less expensive option.

Most of T300's have a 0.71:1 Over-Drive. Only T310/T310M/T310MLR & T310ME21 have 0.73:1 over-drive. I do agree it might not make much of a difference when compared to 0.74:1. Eaton in a typical year in early 2000's made close 125,000-150,000 manual transmission per year. Mack T300 in best years made 16,000-19,000 trans/year. Obviously Eaton has economies of scale and parts/repair will be cheaper. RTO14908LL Forward 1st gear ratio: 19.58:1 ; Reverse Ratios: 15.22:1; 14.56:1; 9.85:1; 2.89:1; Mack T310MLR Forward 1st gear ratio: 27.31:1; Reverse Ratios: 23.96:1; 12.22:1; 6.54:1; 4.67:1; 3.37:1; 2.40:1 Fuller does not get better mileage compared to Mack. The triple counter-shaft allows the main-shaft gears to be freely floating supported by countershaft gear mesh. Fuller twin-counter-shafts require the main-shaft gears properly supported/pressed/splined onto the main-shaft. While Mack triple counter-shaft design allows narrower face-width gears as load is uniformly distributed between 3 counter-shafts, Fuller needs much wider gears. For this reason Eaton rotional moment of inertia will be higher than T300 and takes more power to turn compared to T300 transmission. Speaking in Fuel economy terms using Fuller will be $$ down the pipe.

I am assuming you are talking about the end play on the transmission output shaft? For manual transmissions with double taper bearing support or ballbearing and roller bearing support (on other end of output shaft/inside the the transmission) the end-play can be about 0.007"-0.008". For mDrive transmission when in neutral it can be as much as 0.040". It feels excessive but under drive the sun-gear in the planetary of range section is loaded and end-play will be much smaller. In unloaded condition there is only one ball-bearing supporting the entire planetary assembly hence the end-play is higher. The carriers should also have around 0.007"-0.008" as they have double taper bearing system that are pre-loaded.

Looks like a 2015 Pinaccle CHU? Meritor 14x Amboid 2.64 axle ratio.

Only S652 - CRD95/96 (65,000 LBS GAWR) has unique housing and carrier assembly. The rest of the carriers don't fit on S652 housing and CRD95/96 carrier doesn't fit on other top mount axle housings.

The spindles on S582 are different that S38R/S40/S442 (which have industry standard R-series spindles). If you have pre--2002 S38 etc axle housings then they will have different spindles too. Currently Mack uses R-series spindles for all housings upto 52,000 lbs GAWR (i.e S522R). You will need to swap out the axle shafts to match the housings (different lengths - couple of inches give/take).

CRD125/126,CRD150/151, CRD180/181, CRD92/93 & CRD112/113 will fit into any axle housing all the way from 38,000 to 58,000 lbs GAWR. So yes, you can take the differential from 58,000 lbs axle and put it in a 46,000 lb housing.

I think it could be your ABS sensor on driver side wheel on rear-rear axle is messed up. You might have a 4S4M ABS system with 2 sensors on steer wheels and 2 on rear-rear drive axle. If the ABS sensor sees the wheel spinning out it will apply brakes on both front-rear and rear-rear drive axle wheels on same side. Check the position of the sensor (close enough to tone wheel) along with wires going to sensor itself.

3.25 ratio is available in Meritor 14x as well as Mack axle CRD150/151 series. Generally, I would consider this a bit fast for something going into woods and recommend something closer to 3.79 or 3.98. The reason for this is the amount of input torque into axle (in loose sand, packed dirt etc) is much higher than when driving on freeway and faster ratio only makes in worse (hence my previous comment of 2.47 ratio). The increased torque stresses out internal components. If you are stuck in mud and wheels are slipping be careful about using Rockfree or powerlaunch feature. Improper use of these features along with wheel-hop with diff. lock engaged will cause tremendous torque spike to go through system and break axle-shafts, diff. halves, thru-shafts and worst case gears and bearings.

Yes, you can. Interwheel locks were not introduced with Mack rears until 2009. CRD150/151 (which replaced CRD92/93 which is what you might have on '95 RD688S) has interwheel lock and when you swap out the pumpkin and axle-shafts, you can hook it up to solenoids, airlines and in-cab switch and you have fully functional interwheel lock axles.

Wow...2.47 ratio for logging? Meritor 14x (2.47 is ratio available only in this series. Meritor 160 series tandem has 3.07 as fastest ratio) is a linehaul axle and recommended as an highway only axle typically pulling 80,000 lbs (and depending on grades upto 125,000 lbs in some cases). If you are using a really deep starting transmission gear ratio for off-highway use expect the axle to break soon (thru-shaft, diff. halves etc). Mack does NOT sell Gold Bulldog with Meritor diff's. Looks like someone swapped out Silver Bulldog ornament with Gold. Does it have T300 manual transmission or mDrive AMT?

Do you have Mack axles or Meritor/Dana axles? Changing out to diff. locks will need you to swap out carriers built with diff. lock function (diff. fork, clutch, splined diff. halves - not something you can drill and add to your current carriers) along with axle shafts. Then you will need to add solenoids and have air lines to diff. carriers to activate them. On other end you will need lines to in-cab switch to activate diff. locks. Not a easy job.

Do you have Mack CRD202-202-203 Tridem or a Meritor RZ166 Tridrive? Mack axle Power-Divider/Inter axle differential has automatic torque biasing and helpful for traction. In this case Inter-axle lock might suffice but Inter-Wheel diff lock will be helpful. The new Mack CRD180-180-181 Tri-Drive will have both Inter-axle and Inter-wheel lock.

TM308 has un-synchronized range and more robust if used properly.

44,000 is also a Mack fab. steel axle - 44k GAWR with camelback suspension gets 11mm wall thickness while with Air Suspension (HAS/AL) will get a 14mm housing.Recently Mack Engineering approved 11mm @ 46k GAWR for camelback and 14mm @ 46k GAWR for Air suspension. If you have newer version of the housings (post - 2006/2007) then you can use at higher rating. You have a Cast ductile axle housing @ 65K GAWR with CRD95/96 carrier. This has been in production since 1945.

"C" stands for Carrier The carrier P/N you are looking for with Power-Divider Lock-Out (CRDP202/PDLO/3.94 Ratio) is 21508361 (Mack alias 11KHA5479-P2 - Can't use this for ordering) The front Spiral bevel lapped set for 3.94 ratio is P/N: 25503211 Bull gear P/N: 25101491 (61kh436); Helical Pinion/Spur shaft P/N: 25101850 (56KH436) CRD92/93 has been out of production sine 2009 and will be hard to find. It has been replaced by CRD150/151 Mack axles are now assembled in Mack Powertrain plant in Hagerstown, MD. CRD202/203 might be replaced with a new carrier series before end of this year.

The spur shaft bolt issue was internal threads on the Spur shaft being over-size (during heat-treat process of gears) which doesn't properly allow bolt to reach clamp load. Unfortunately, it was supplier creates issue and not design related. But end of the day it didn't matter to customer who was at fault. Now a process has been put in place to not repeat the mistake. Single bolt design is unique to CRD150/151 carrier family series.

There will be a redesigned Mack Carrier launched end of 2018-early 2019. The new carrier will go away from single bolt threaded into the carrier housing concept to providing a flat surface on top able to mount the V-Stay with 4-studs. Is this other than M-Ride suspension (with V-Stay bolt stripping the carrier threads) you are talking about? What part of Mack carrier chunks are falling off?

M is multi-speed reverse transmission (not range shift speeds but speeds in reverse where you select the reverse switch and then shift the stick as you would do going forward and picking up vehicle speed). So T310M has 10 forward speeds and 6 Reverse speeds. T310MLR will have multiple reverse speeds with creeper gear in forward (27.31:1) and reverse is 23.96:1. T310ME is extended output shaft with more clearance for rear counter-shaft mounted PTO's. T310ME21 is extended range that can be matched with 2100lb-ft torque producing engines.

There used to be 20 models until 2-3 years back but now T306G, TM308, T308M, TM309 & TM309M are no longer available in production. Current models available T309, T309LR, T310, T310M, T310MLR, T310ME, T310ME21, T313, T313LR, T313 21, T313LR21, T318, T318LR, T318 21 & T318LR21.

You have either a T310, T310M, T310MLR or T310ME. The input shaft seal P/N is 88AX454/25632356. The seal can be installed without pulling the input shaft out.

It is a combination of suspension and axle housing that dictates the GAWR (Gross Axle Weight Rating). Different suspensions put different types of loads into the axle housing (Ex: Torque reactive Air suspension can twist load into axle housing especially with high C.G loads). Depending on the suspension the housings are tested under different load conditions (Ex: 2g to -0.5g vertical load while applying 1g lateral load for some spring suspensions as against a twist load ~ 150k in-lb for air suspension) for couple of 100,000 cycles. No cracks or failures are to be seen to allow high degree of reliability in the field. The max. rating is what axle housing (including spindles) are capable of withstanding. So a 11mm fabricated steel axle housing (tandem) can be rated to 46k lbs GAWR with a camelback suspension while it will be good only upto 40k GAWR with a AL401/HAS401 suspension.

This is a different type failure than earlier one. The thru-shaft failure occurs only when extreme amount of torque passes through it during shock loading/clutch dumping type scenario. Mack Power-Divider does a true 50:50 torque split due to unique CAM mechanism and thru-shaft can see more torque than a conventional inter-axle diff on Meritor or Dana axles (in wheel-slip and other scenarios).

The one bolt design to hold bevel gear onto spur/Helical shaft was introduced with CRD150/151 and is the only carrier series that has that design currently (CRD125/126, CRD202/203 or CRD95/96 have 3-bolt design). The issue you had coming loose is unfortunately not related to the design, it is the suppliers screwing up the heat-treatment and ending up with over-size threads. Bear in mind there are somewhere between 80,000-100,000 trucks in field with this design (Launched in 2009) and if it was a design issue we would have seen huge rash of failures in the field. The one's that have been analyzed show an over-size thread issue. More emphasis is being placed to control the thread size to avoid such issues in the future.

You will soon be able to order input shaft, range synchronizer kits. Changes are happening including updating components and design to last longer.