Popular Post Freightrain Posted Monday at 07:07 PM Popular Post Share Posted Monday at 07:07 PM Well, my initial intent was to replace it with something newer. But, I thought I might just see what I had and make a decision later. After tearing into it, it was just one bearing on the mainshaft that was the big problem. I have it completely apart and washing it up now. Fresh out of the truck. Lids off, back box off. Compound gears. Good shape. Grimey parts Getting mainshaft out. Sleeve was stuck. Clean parts. Mainshaft out. Someone plugged the 1st oil galley, hence bushing worn and bearing junk. Trashed, why it had 1/4" slop in shaft. Dressed the ID of sleeve so it slips over shaft easily now. Main box going for cleaning this week. I have basic bearing list. Everything seems available. Even the dreaded "double taper cone" in the back box. I found a couple new Timken on eBay for under $100? I heard that was the whole deal with rebuilding these old transmissions. All the rest are off the shelf. Will update as I go along in the next few weeks. I had no clue as I dug into this thing but I figured why not? It is already in bad shape, and if I can vastly improve it I might as well before going through the work of replacing it with an Eaton. There is still a lot of work to be done but I think it will work out in the end. I want to thank Matt and Kevin for their assistance in getting it to this point. 9 2 1 Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/ Share on other sites More sharing options...
Popular Post mechohaulic Posted Monday at 07:57 PM Popular Post Share Posted Monday at 07:57 PM now there a memory maker. unlike todays iron (most of which are automatics) hardest part of rebuilding a tri/quad/duplex was picking the right color paint for the case outside. a self taught with mentors is knowledge never found in books. how lucky I consider myself to be involved back then. today it's parts changers not many rebuilders. units looking good! 4 Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565604 Share on other sites More sharing options...
mechohaulic Posted Monday at 08:20 PM Share Posted Monday at 08:20 PM seals for two back half input shafts ?? 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565609 Share on other sites More sharing options...
Freightrain Posted Monday at 10:41 PM Author Share Posted Monday at 10:41 PM 2 hours ago, mechohaulic said: seals for two back half input shafts ?? Not sure what you are referring to? The oil tubes between the shafts? Mine are likely worn but nothing I can do about those. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565628 Share on other sites More sharing options...
mowerman Posted Tuesday at 12:11 AM Share Posted Tuesday at 12:11 AM Nice going bud. Thanks for sharing. Looks like you’re well on your way. Good luck. Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565636 Share on other sites More sharing options...
mechohaulic Posted Wednesday at 01:51 AM Share Posted Wednesday at 01:51 AM On 1/6/2025 at 5:41 PM, Freightrain said: Not sure what you are referring to? The oil tubes between the shafts? Mine are likely worn but nothing I can do about those. two outside shafts from front case to rear;(for compound stick) do they not have seals ;; 1in od ? on rear half ??? front half is external /dry. recall shaft would be worn resulting in slight oil seepage. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565731 Share on other sites More sharing options...
Freightrain Posted Wednesday at 12:27 PM Author Share Posted Wednesday at 12:27 PM Yes, two seals for shift rods have leaked badly for years. On the list of needed parts. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565754 Share on other sites More sharing options...
Popular Post Freightrain Posted Wednesday at 07:03 PM Author Popular Post Share Posted Wednesday at 07:03 PM Well, I have the main box home from hot tank and mounted back on the stand ready for assembly. I spoke with local supplier and all bearings I need are $1500. This includes that double race in the back box. Everything is in stock, nothing special ordered. This is totally against all I have heard about working on these old boxes. Be a week before they are all in my hands from locations in Ohio and Indiana. Then I can start getting the countershaft preload set. Some may choke on the price, but see what it costs to go through an Eaton?? Or get one to put in my truck. I'll have a bunch more then $1500 in it. 4 Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565800 Share on other sites More sharing options...
Geoff Weeks Posted Wednesday at 07:16 PM Share Posted Wednesday at 07:16 PM Almost always cheaper to repair than replace, cheaper to replace like for like than to change to something new. Often it is the little stuff that keeps cropping up that drive the price up. I was surprised I didn't have much trouble when I was going through the British bus trans or rear axles getting bearings or seals. They used some odd bearings also. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565803 Share on other sites More sharing options...
Popular Post Freightrain Posted Wednesday at 07:52 PM Author Popular Post Share Posted Wednesday at 07:52 PM For 20 yrs all I have heard is "OMG"!! Been the complete opposite. Granted I could have gotten off much cheaper but I am not going this far and leave old stuff in there. I am going to make/repair the one gear bushing because it is so bad from lack of oiling. I have more pictures and some short videos just so I would have record of it. 3 1 Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565805 Share on other sites More sharing options...
Brocky Posted 15 hours ago Share Posted 15 hours ago Larry, Thanks for keeping us updated on this interesting project.. I will be looking forward to more pictures.. 1 Quote Brocky Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565875 Share on other sites More sharing options...
mowerman Posted 14 hours ago Share Posted 14 hours ago yeah 1500 sounds like a lotta dough,,,but thier available,and now you know what you got,,,and no more issues,,should outlast you,,,plus no unnecessary running around the country trying to find a decent replacement,,,,drive 300 miles to find another transmission,,and find out its in worse shape than yours,,,bob 2 Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565879 Share on other sites More sharing options...
terry Posted 14 hours ago Share Posted 14 hours ago 19 hours ago, Freightrain said: For 20 yrs all I have heard is "OMG"!! Been the complete opposite. Granted I could have gotten off much cheaper but I am not going this far and leave old stuff in there. I am going to make/repair the one gear bushing because it is so bad from lack of oiling. I have more pictures and some short videos just so I would have record of it. I know if a gear bushing is replaced they say it has to be broached, don't know exactly how important this is. terry Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565885 Share on other sites More sharing options...
Freightrain Posted 14 hours ago Author Share Posted 14 hours ago Broached how? My plan was remove old and shrink new brass in and bore to size. I was going to use my Dremel to put some oil dimples in it like original. A secondary thought was use my friends pin hone to finish the ID if my machining doesn't get a nice enough finish. Specs calls for .004-.005 clearance. First gear is currently .020-.025! 2 Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565888 Share on other sites More sharing options...
Geoff Weeks Posted 13 hours ago Share Posted 13 hours ago I suspect he means bore to finished size after install. Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565898 Share on other sites More sharing options...
mowerman Posted 7 hours ago Share Posted 7 hours ago it was probably very noisy mainly howling,,,bob Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565927 Share on other sites More sharing options...
terry Posted 7 hours ago Share Posted 7 hours ago 5 hours ago, Geoff Weeks said: I suspect he means bore to finished size after install. I’m not sure what the broaching procedure is, i think after new bushing is pressed in the broaching tool finishes the inside of the bushing some how. But sounds like freightrain’s procedure should work. Terry Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565932 Share on other sites More sharing options...
terry Posted 7 hours ago Share Posted 7 hours ago If you google broaching a gear bushing there are some explanations of it. Terry Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565933 Share on other sites More sharing options...
Geoff Weeks Posted 6 hours ago Share Posted 6 hours ago (edited) Broaching is typically cutting a slot, like for a keyway. Reaming is sizing after installation of a bushing. The bushing on mainshaft gears shouldn't need a keyway, just clearance for lube. There isn't load on the bushing when the gear isn't in use, it just has to let the gear slip on the shaft. Multi countershaft transmission the gears just "float" on the main shaft without any bushing. I haven't seeing anything of goggle that applies in this case. Here is what broaching can do Edited 6 hours ago by Geoff Weeks 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565937 Share on other sites More sharing options...
terry Posted 5 hours ago Share Posted 5 hours ago (edited) Maybe that broaching was a way to cut oil grooves or dimples like original gear bushings on the old 72 series transmissions.🤷♀️. Terry Edited 5 hours ago by terry 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565938 Share on other sites More sharing options...
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