Popular Post Freightrain Posted January 6 Popular Post Share Posted January 6 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. 10 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 January 6 Popular Post Share Posted January 6 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! 5 Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565604 Share on other sites More sharing options...
mechohaulic Posted January 6 Share Posted January 6 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 January 6 Author Share Posted January 6 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 January 7 Share Posted January 7 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 January 8 Share Posted January 8 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 January 8 Author Share Posted January 8 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 January 8 Author Popular Post Share Posted January 8 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 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-565800 Share on other sites More sharing options...
Geoff Weeks Posted January 8 Share Posted January 8 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 January 8 Author Popular Post Share Posted January 8 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. 4 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 January 9 Share Posted January 9 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...
Popular Post mowerman Posted January 9 Popular Post Share Posted January 9 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 3 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565879 Share on other sites More sharing options...
terry Posted January 9 Share Posted January 9 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 January 9 Author Share Posted January 9 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 January 9 Share Posted January 9 I suspect he means bore to finished size after install. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565898 Share on other sites More sharing options...
mowerman Posted January 9 Share Posted January 9 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 January 9 Share Posted January 9 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 January 9 Share Posted January 9 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...
Popular Post Geoff Weeks Posted January 9 Popular Post Share Posted January 9 (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 January 9 by Geoff Weeks 3 Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565937 Share on other sites More sharing options...
terry Posted January 10 Share Posted January 10 (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 January 10 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...
Freightrain Posted January 10 Author Share Posted January 10 13 hours ago, mowerman said: it was probably very noisy mainly howling,,,bob This thing rattled and banged for the last 23 yrs. After a long trip, if I stopped I would have to leave the main in gear and the compound in neutral to keep it from sounding like it wants to come apart. 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-565988 Share on other sites More sharing options...
mowerman Posted January 10 Share Posted January 10 lol well i guess you see why now,,,looks like you got this,,,,,,nice going ,,,,,excellent...thanks for all the updates...bob Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565992 Share on other sites More sharing options...
mowerman Posted January 10 Share Posted January 10 11 hours ago, terry said: Maybe that broaching was a way to cut oil grooves or dimples like original gear bushings on the old 72 series transmissions.🤷♀️. Terry i think larry works in a machine shop,,,,im sure he has access to alotta hightech equipment,,,,which in this case is god sent,,,,,i didnt know what broaching was either 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-565994 Share on other sites More sharing options...
Popular Post Freightrain Posted January 10 Author Popular Post Share Posted January 10 I'm with Geoff, broaching is cutting a slot. Reaming is precisely finishing a bore. Does it have something to do with the dimples? I'm too young and never took machine shop training so if there was a term used long ago I am unaware. Don't worry about me having any high tech equipment at my work. Nothing but 80 yr old beat up, wore out, junk. Or "new" CNC equipment was bought 30 yrs ago. It's wore out now too. I'm glad I've had the opportunity to teach myself all this so that I can do this kind of work. Paying someone else would put it out of reach. 5 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-566029 Share on other sites More sharing options...
mowerman Posted January 10 Share Posted January 10 well alrighty then,,,atleast you have what you need,,,machine work can be a fortune,i paid 90 bucks for a sector bushing for my steering box they were spun by steering shop in san jose,,,,,,around here i dont even know where to have rotors turned,,,we used to have a huge independent auto parts store here,,,,they closed years ago,,,they had a huge machine shop Quote Link to comment https://www.bigmacktrucks.com/topic/74958-rebuilding-my-triplex/#findComment-566030 Share on other sites More sharing options...
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