sri Posted September 19, 2019 Share Posted September 19, 2019 We have a 12 speed with the air shifter. It is leaking air on the bottom of the air shifter.. This is on the top back of transmission. cant' really get in there to look but is there a plug on the bottom of the high range shifter .. Doesn't leak only till high range.. Appears to be a threaded hole there..Other wise from my understanding it's a big job to replace the shifter. Also looking for a parts breakdown of the same shifter.. Thank you Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/ Share on other sites More sharing options...
david wild Posted September 19, 2019 Share Posted September 19, 2019 another Mack trans problem ??? 1 Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-432438 Share on other sites More sharing options...
JoeH Posted September 19, 2019 Share Posted September 19, 2019 If your Mack dealer is as good as mine they can fax or email you the parts diagram, but you'll need to give them a little more info... Year? Transmission model? Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-432441 Share on other sites More sharing options...
sri Posted September 21, 2019 Author Share Posted September 21, 2019 Had a mack guy look at it.. said the top of transmission has to come off.. his guess O-rings or broken piston.. will keep you posted .. thanks.. this on 94 rb mack Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-432577 Share on other sites More sharing options...
Mack Technician Posted September 21, 2019 Share Posted September 21, 2019 You can get those off and on with the trans in chassis. It’s a real skill shot. May have to raise the cab a little, worse case scenario. Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-432588 Share on other sites More sharing options...
Mack Technician Posted September 21, 2019 Share Posted September 21, 2019 On 9/19/2019 at 2:49 PM, david wild said: another Mack trans problem ??? I did a search for BigEatonTrucks.com, nothing comes up, it’s weird? 2 Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-432589 Share on other sites More sharing options...
fjh Posted September 22, 2019 Share Posted September 22, 2019 18 hours ago, sri said: Had a mack guy look at it.. said the top of transmission has to come off.. his guess O-rings or broken piston.. will keep you posted .. thanks.. this on 94 rb mack Is IT a 12 OR Is it a 13 speed???? Big difference !!!! If its a 12 the air shifter has reverse on the knob as well if its a 12 the orings on the hi low split can be changed with out removing the lid! all orings can be changed except the shaft oring which rarely leaks! Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-432650 Share on other sites More sharing options...
sri Posted September 23, 2019 Author Share Posted September 23, 2019 On 9/22/2019 at 9:46 AM, fjh said: Is IT a 12 OR Is it a 13 speed???? Big difference !!!! If its a 12 the air shifter has reverse on the knob as well if its a 12 the orings on the hi low split can be changed with out removing the lid! all orings can be changed except the shaft oring which rarely leaks! tried to post a picture of shifter but failed.. it says it's a maxitorque extended range 12 speed with splitter . On shifter knob in cab has high ,direct, neutral and reverse Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-432724 Share on other sites More sharing options...
sri Posted September 23, 2019 Author Share Posted September 23, 2019 Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-432725 Share on other sites More sharing options...
fjh Posted September 23, 2019 Share Posted September 23, 2019 The bigger of the two cylinders ! get the orings and a snap ring before you disassemble the cylinder snap ring has been known to break and cause the symptom you describe at the rear it can be accessed at the rear of the trans Without removing the lid! Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-432728 Share on other sites More sharing options...
fjh Posted September 23, 2019 Share Posted September 23, 2019 KEY PAI REFERENCE EXCEL NO. OEM REFERENCE DESCRIPTION REFERENCE INFORMATION 1 GSI-0616 MAK136KC25BP1 INTERLOCK 1 Call MAK136KC312 INTERLOCK 2 Call MAK393KB420A COVER 3 GSC-0009 MAK6AX1308X SCREW(3/8in-16 x 1-1/4in) NAV 60001R91 4 BWA-0066 MAK37AX265 WASHER 5 GSP-1674 MAK107KD140 SPRING 6 GDB-1665 MAK48AX17 BALL MAK 48AX11 7 GSP-1672 MAK107KD116 SPRING 8 GSP-1676 MAK107KD157 SPRING MAK 107KD1177 9 Call MAK413KB13 COVER 10 ESC-0035 MAK6AX1359X SCREW(3/8in-16 x 1in) MAK 6AX1274X NAV 1670574C1 11 GGS-3970-007 MAK628KB124 GASKET 12 MSW-4396 MAK1MR2297 SWITCH,Reverse NAV 454925C1 MAK 1MR1320 13 Call MAK408KB217A COVER 14 EPP-3575 MAK49AX234Z PLUG NAV 444631 15 Call MAK136KC120 PLUNGER 16 Call MAK6AX1313 SCREW 17 BGA-3009 MAK56AX438 O-RING,Lo/Direct Shift(4 Req'd) 18 BGA-3004 MAK56AX436 O-RING,Lo/Direct Range Shift (2 Req'd) MAK 56AX546 19 GSH-1714 MAK591KC2283A RAIL,Reverse 20 BGA-3003 MAK56AX437 O-RING 21 BGA-3007 MAK56AX434 O-RING 22 Call MAK414KB262 COVER 23 Call MAK6AX1292X SCREW 24 GPA-2204 MAK336KC232 PISTON,Lo Range 25 BGA-3008 MAK56AX441 O-RING,Direct Shift(2 Req'd) 26 BGA-3006 MAK56AX439 O-RING(2 Req'd) 27 BGA-3005 MAK56AX440 O-RING(2 Req'd) 28 Call MAK6AX1314 SCREW 29 Call MAK414KB2127 COVER 30 GBF-6443 MAK541KB19 BREATHER 31 GAC-2206 MAK476KB316A CYLINDER,Airshift 32 GSH-1694 MAK591KC2322 RAIL,Direct(TRTXL-1070) 32 Call MAK591KC2294B RAIL,Direct(TRTXL-107) 33 GPA-2205 MAK336KC265 PISTON,Direct MAK 336KC238 34 GKP-3489 MAK79AX75Z PLUG NAV 1662500C1 MAK 79AX4 35 Call MAK502KB113 DOWEL 36 GSC-6116 EF61160 MAK7AX264X SCREW,Lock(Dog Point) MAK 7AX152 MAK 7AX255 37 GSL-0624 MAK170KC276 LEVER,Reverse 38 GSL-0625 MAK170KC292 LEVER,Direct 39 Call MAK79AX58 PLUG 40 Call MAK35AX1028 WASHER 41 Call MAK22AX40 NUT 42 GGS-3970-004 MAK616KB37 GASKET,Cover,Compound 43 GSF-0623 MAK699KC2132C SHIFTER,1st/Reverse MAK 699KC351 44 Call MAK591KC2266A RAIL,1st/Reverse(TRTXL-1070) 45 GSP-3103 MAK31KD1151 SPACER 46 GSF-0650 MAK575KB3128A FORK,1st 47 Call MAK575KB3153 FORK,Reverse 48 GKP-3496 MAK79AX35 PLUG(1in Welch) 49 GSF-0622 MAK699KC2126C SHIFTER,2nd/3rd MAK 699KC350 50 GSH-1685 MAK591KC2277B RAIL,2nd/3rd(TRTXL-107) 50 GSH-1687 MAK591KC2281A RAIL,2nd/3rd(TRTXL-1070) 51 GSF-0630 MAK575KB3130A FORK,2nd/3rd 52 GSF-0635 MAK575KB3170B FORK,Direct MAK 575KB3208 53 GSH-1695 MAK591KC2327A RAIL,Direct 54 Call MAK699KC2148 SHIFTER,4th/5th 55 GSH-1692 MAK591KC2214A RAIL,4th/5th(TRTXL-107) 55 Call MAK591KC2228A RAIL,4th/5th(TRTXL-1070) 56 Call MAK591KC2232P1 RAIL,Compound (TRTXL-1070) 56 Call MAK591KC325 RAIL,Compound(TRTXL-107) 57 Call MAK7AX265X SCREW 58 GSF-0621 MAK575KB394H FORK,4th/5th 59 GOS-6182 MAK88AX370P3 SEAL CHI 7414 NAT 1049 60 GSF-0657 MAK575KB42C FORK,Compound 61 GRI-2702 MAK97AX121 RING,Retaining 62 FKT-1148 MAK14RC1131 KIT,Valve,Major 63 GRI-2703 MAK97AX126 RING,Retaining 64 FKT-1147 MAK14RC1130 KIT,Valve,Minor 65 GBK-6562-100 MAK342SH594 KIT,Retaining Ring Includes Rings (1)GRI-2701 (1)GRI-2703 (1)GRI-2711 (1)GRI-2712 (1)GRI-2713 (3)GRI-2715 (3)GRI-2716 (1)GRI-2719 (1)GRI-2731 (1)GRI-2732 (3)GRI-2734 (9)GRI-2735 (1)ESR-2832 (1)GRI-2733 (3)GRI-2704 (1)GRI-2702 (6)GRI-2706 (12)GRI-2707 (1)GRI-2714 (2)GRI-2717 (4)GRI-2718 (1)GRI-2794 66 GBK-6562-200 MAK207SH32 KIT,O-Ring Includes O-Rings (2)BGA-3004 (1)BGA-3003 (4)BGA-3008 (2)BGA-3005 (4)BGA-3009 (2)BGA-3006 (1)GGA-2993 (1)BGA-3007 (1)ER64420 Lubricant (1)GSL-0383 Breather (1)ER64420 67 GSP-1679 MAK107KD1172 SPRING(TRTXL-1070) 68 LSV-3692-002 MAK9054-P58987 ROTOR Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-432730 Share on other sites More sharing options...
sri Posted September 24, 2019 Author Share Posted September 24, 2019 what part numbers would that be... you are talking to a novice here so give me some time. Don't think we want to tackle this job but can give the advice to who is going to do it.. Three experts said the top has to come off.. I don't have a clue.. Only use this for 500 miles a year for corn harvest. plan is to run it like it is,mostly in direct ,then this winter they can have at it... what would happen if the hole is plugged. Don't want to blow the top of transmission off Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-432746 Share on other sites More sharing options...
fjh Posted September 24, 2019 Share Posted September 24, 2019 (edited) If you are a Farmer you can do this job! That"s what farmers do fix shit to get on with things ! Or At least find some one who can and the the point is you use the truck once a year how much do you want to spend??? oring kit MAK207SH32 - 66 MAK97AX121 snap ring - 61 MAK97AX126 snap ring - 63 At the very least here! take the end cap off of the BIG cyl 4- 3/8 bolts see if the snap ring is broken and hanging things up! if not then reassemble and yes the lid will have to come off! Just sayin Edited September 24, 2019 by fjh 2 Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-432770 Share on other sites More sharing options...
Popular Post sri Posted September 30, 2019 Author Popular Post Share Posted September 30, 2019 put on our big farmer pants and took the back off,snap rings look good. So put it back together and going to run like it is till done... Thanks 2 1 Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-433056 Share on other sites More sharing options...
fjh Posted September 30, 2019 Share Posted September 30, 2019 Good Job Bro The easy fix check is done Best advice I have now is to get your work done don't use the split till ya got time to deal with removing the shift lid! There are two other semi common things that can happen ,The shift rail engagement knob has come loose on the piston rod you can deal with that when the lid is off! OR you have a broken shift rail , For this The trans has to come out PAI Is the place to by the parts ! And This is not the place to do a farmer patch the shift rail is a big project Trany out and into three pieces on the floor You need a nice warm barn to tackle this project in the winter! 😁 Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-433071 Share on other sites More sharing options...
sri Posted October 1, 2019 Author Share Posted October 1, 2019 got someone to do it this winter.. It does shift and stay in high ,just leaks a lot of air.. So think the linkage is not broken.. will keep you posted later.. What would happen if the vent hole is plugged???? Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-433159 Share on other sites More sharing options...
JoeH Posted October 1, 2019 Share Posted October 1, 2019 It would pressurize both sides and the fork would freely slide back and forth, destroying the gears? The air moves it and holds it too I expect. Quote Link to comment https://www.bigmacktrucks.com/topic/59082-owner/#findComment-433189 Share on other sites More sharing options...
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