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Bolens Tube Frame Mower Deck With Worn Pulley And Shaft In Gearbox

3K views 28 replies 7 participants last post by  29 Chev 
#1 · (Edited by Moderator)
It appears spring has finally arrived in Southwestern Ontario so I decided I had better start working on the lawn mower deck for my 1050. Last year we had a wetter than normal summer which resulted in the deck getting a good work out and last fall the drive pulley on the lower shaft of the gearbox came loose and damaged the keyway in the pulley and the key seat in the shaft. I had noticed when I overhauled in about 2005 that there was a bit of wear in the keyway but it had worked until last year although every few years the roll pin for the gear on the vertical shaft would break and I would have to take the gear box apart and replace it. Last fall I did a quick fix by drilling another hole in the side of the pulley and adding a third set screw with the intentions of repairing it over the winter but that didn't quite happen. About a month ago I checked with Rick Show and he had a new pulley and vertical shaft at a reasonable price so I purchased them from him along with a new key, roll pin and a new spring for the belt. I compared the shaft and pulley today with mine and I think I can repair mine but I have the new pulley and shaft as a back up plan. The one thing I did notice is the hole for the roll pin in the vertical shaft is worn compared with the new one (you can just put a 1/4" drill bit through the new one by hand - whereas the hole in my shaft is 1/64" larger) which is probably why the roll pin in mine has been breaking every few years. The gears and the bearing in my gear box look to be in good shape so I will probably just leave them and replace the seals with new ones. The case has a piece broken out of it where the input shaft seal goes so I think I will try and repair that with JB weld. I had to use a puller to remove the PTO yoke on the horizontal shaft but the yoke came off fairly easy once the roll pin was removed - here are some pictures. I think I will try and sleeve my old pulley and try to build up the shaft where the key seat is and recut a new key seat.
 

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#3 ·
Started to repair the shaft today. The first step was to drill the roll pin hole out so that it was a uniform size all the way through - it cleaned up nice with a 19/64" drill bit. Next I took a 5/16" grade 5 bolt and turned the head off it and then turned the outside so it was a nice press fit in the enlarged roll pin hole. Then I cut the bolt 7/8" long and drilled a 1/8" centre hole in the centre of it - once I had that done I ground the worn key seat area of the shaft and the edge around the hole and pressed the bolt piece into the hole in the shaft.
 

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#4 ·
I slid a worn out gear with a 3/4" hub over the area of the shaft where the bearing and seal run so that no weld splatter would end up on the shaft there and filled the key seat area back in with the mig welder and then built up the area where the pulley and the gear sit and let things cool down while I greased the 1050 and did some other tasks. Once it was cool I stuck it in the lathe and realized that I would have to turn one of the welded area before I could check the bearing area for run out from the heat of the welding (one of these days I will learn to think ahead). I decided I would check the shaft for run out where I had not welded it and it showed about .006" runout so I decided to turn the weld at the pulley end so that I could remove the gear hub. I turned the pulley area to .750" and then removed the gear hub figuring that if worst came to worst I could always build that area back up again and turn it back down if there was too much runout at that end. I checked the bearing area and it showed about .006" runout as well so I turned the rear area down a bit so that I would have an even surface in the centre to press on and stuck it in my small press with the 2 ton jack and gave it a bit of pressure in the centre while I supported the ends and got the runout down to about .002" at the bearing areas and the pulley area which I thought was tolerable. So I turned the gear area down to .750" and polished the shaft.
 

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#5 ·
Once the shaft was the correct size again I used the 1/8" hole to index the shaft to drill the roll pin hole back to 1/4" in the drill press. One it was indexed and clamped in the drill press vise I drilled it out to 3/16" and then took it up to 1/4" 1/64" at a time. Then I decided to try and recut the keyway. Since I do not have a 3/16" keyseat cutter I mounted the 1/8" one I do have in the lathe and using the new shaft figured out where the left side of the key seat should be in relation to the shaft mounted in the milling attachment by turning the cutter by hand to see when it came up against the left side of the key seat in the new shaft (I also determined the finished depth of the key seat by turning the cutter by hand and raising the shaft up until the cutter started to touch the bottom of the key seat). I then removed the new shaft and mounted the old one in the milling attachment and cut a 1/8" key seat down to within .010" of the bottom of the cut and then withdrew the cutter from the key seat by lowering the shaft. I mounted the dial gauge and zerod the dial and then unlocked the bed carriage and used the dial guage to determine how far to move the lathe carriage over to the left to get a 3/16" wide key seat and then relocked the carriage again and then cut the right side of the key seat down to the bottom. Once I had that done I unlocked the carriage and moved it back and finished cutting the left side of the key seat to the finished depth. When I was done I compared it with the new shaft - the key 3/16" woodruff key is a nice snug fit in the key seats in both shafts.
 

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#9 ·
Great Work!

Its the guys like you that help keep these machines going for the future, so many would have scrapped what you are fixing!
Thanks for the kind words. One of the main reasons I post repairs like this is to show that if something is broken or worn there is another option rather than just throwing up ones hands and saying time to scrap it and go and buy a new mower or tractor and lose a piece of history. It is my hope that people will discover that what seems like a major obstacle can be repaired by the average person with some mechanical ability (I am not a machinist), a little bit of resourcefulness and a few machine shop services (if they do not have the equipment) - forums like this are what makes the internet so valuable as information like this can be shared so easily with people all over the world and be available long after I am gone. Bolens products such as this were designed and built to have a long life if looked after properly and also to be repaired if and when the time came in my opinion unlike todays "sell it cheap and often" products. While some of the parts are becoming harder to find they can still be had thanks to people like you and Rick Show taking the time to source new suppliers and find NOS from old dealers. I know most people dislike the use of the word "rare" but in my opinion what is "Rare in the Bolens world" are some of the "hard" parts that are no longer being made (such as the three gear cluster for a 6 speed tubeframe) and that eventually will cause people to park machines and equipment in the corner for the scrap man to collect and destroy forever - it is my hope that posts like this will prevent that from happening as long as possible. And who knows what the future will bring in 10 to 20 years - maybe by then I can take my old TRA10D Wisconsin down to the local computer store and for $200.00 they can take detailed pictures and feed the information into a computer and a machine will spit out a brand new replica complete with metallic brown paint and matching carb.
 
#10 ·
Started to work on repairing the pulley today. I thought about just broaching another keyway in the pulley but since the pulley had been loose I figured the bore was probably out of round and a quick check in the lathe confirmed this so I took the easy way (I think) out to fix it. I had an extra 3/4" weld on V hub that I use for the small gears on the snow blower and since it already was the correct bore and had they keyway already in it I turned the step off of the hub to make it a uniform size. I bored the inside of the pulley to .002" smaller than the outside of the hub for a press fit. I then machined a recess in the bottom of the pulley so that I could weld the hub at the bottom - the hub was a little shorter than the pulley but where the set screw holes were located it was almost flush at the bottom when they lined up. I lined the keyway up with the set screw hole in the hub (I thought) and then I started to press the hub into the pulley using the bench vise and got it within 1/4" of where I wanted it but I was afraid of breaking the vise and the pulley so I used the press the rest of the way and supported the recess at the top of the pulley with a socket so that when I pressed the hub in I was not applying any pressure to the outer (V belt) part of the pulley - did not want to end up with a broken pulley. When I got the hub where I wanted it I found out I was a little off on the set screw hole location so I had to press things back apart and rotate the hub a little bit so the hole in the hub was centred with the hole in the pulley. As you can see in picture 11 the holes in the pulley are larger than the ones in the hub but it is close to being centred.
 

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#11 ·
Then I welded the bottom of the pulley and hub and did a couple of short welds at the top of the hub to the pulley bore as well as filling in the groove where the pulley had rubbed on the deck when it was loose. Then I ground the welds off with the die grinder and used a file to clean out the weld spatter at the edges of the hub bore so the shaft would fit inside. Hopefully tomorrow I can drill and tap the holes in the hub for the set screws,
 

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#12 ·
Thanks for the kind words. One of the main reasons I post repairs like this is to show that if something is broken or worn there is another option rather than just throwing up ones hands and saying time to scrap it and go and buy a new mower or tractor and lose a piece of history. It is my hope that people will discover that what seems like a major obstacle can be repaired by the average person with some mechanical ability (I am not a machinist), a little bit of resourcefulness and a few machine shop services (if they do not have the equipment) - forums like this are what makes the internet so valuable as information like this can be shared so easily with people all over the world and be available long after I am gone. Bolens products such as this were designed and built to have a long life if looked after properly and also to be repaired if and when the time came in my opinion unlike todays "sell it cheap and often" products. While some of the parts are becoming harder to find they can still be had thanks to people like you and Rick Show taking the time to source new suppliers and find NOS from old dealers. I know most people dislike the use of the word "rare" but in my opinion what is "Rare in the Bolens world" are some of the "hard" parts that are no longer being made (such as the three gear cluster for a 6 speed tubeframe) and that eventually will cause people to park machines and equipment in the corner for the scrap man to collect and destroy forever - it is my hope that posts like this will prevent that from happening as long as possible. And who knows what the future will bring in 10 to 20 years - maybe by then I can take my old TRA10D Wisconsin down to the local computer store and for $200.00 they can take detailed pictures and feed the information into a computer and a machine will spit out a brand new replica complete with metallic brown paint and matching carb.
Excellent work :thumbs: and this paragraph says it all, thanks for posting :worshippy1:
 
#14 ·
Nice fix!
Thanks for the kind words but I found out there was a slight hiccup in my repair plan for the shaft which I will explain in a couple of posts.
 
#15 ·
Started working on the pulley holes this morning. First I verified the threads in the pulley were 3/8" UNC and then took a 3/8" course thread bolt and drilled a 15/64" hole in the centre of it in the lathe. Then I threaded the bolt into one of the holes and clamped the pulley in the vise on the drill press using the hole to line up the drill bit - note the use of a wood wedge at the end of the pulley for support while the hole was drilled. This method used the hole in the bolt to centre the drill in the threaded hole of the pulley and I drilled a 15/64" hole through the hub part. The bolt was then removed and a 5/16" drill bit was used to enlarge the hole in the hub to the correct size for tapping the threads - since the 15/64" hole was already centred in the hub part the larger drill did not disturb the threads in the pulley as it was guided by the initial hole. When I did the temporary repair last fall I drilled and threaded a third hole in the pulley to add a third set screw to secure the pulley so I did the remaining two holes in the hub the same way which left me with three holes to tap threads in. I then used a 3/8" UNC tap and threaded the holes to finish the pulley.
 

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#16 ·
As I stated in the first post the case had a piece broken out of it where the input shaft seal goes so I had used a couple of pieces of cardboard, a socket, and some masking tape to make a form to shape the JB Weld after I filed and cleaned the area around the missing piece so the JB Weld had something to stick to (I had inserted a piece of towel inside the needle bearing to keep debris out of it). I took one piece of cardboard and shaped it to conform to the inner part of the seal hole using a socket and another piece of cardboard to wedge it in place. Then I taped another piece of cardboard to the outside of the case with masking tape. After mixing the JB Weld I use a small flat screwdriver to force it into the area between the two pieces of cardboard making sure there was no air bubbles trapped. Once the area was filled I set the case aside for a couple of days while I worked on the shaft and pulley. Once it had sat for two days and appeared to be cured I removed the socket and used a utility knife to scrape the cardboard away from the JB Weld on the inside and outside. Then I used a flat file to clean up the inside a bit and contour the outside to blend in with the case - after that it got a squirt of red paint. Today in preparation for the seal I used the socket with a piece of 120 grit emery cloth wrapped around it to finish contouring the inside of the hole.
 

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#17 ·
Then I pressed in two new seals for the input and output shaft, cut a new gasket for the case out of gasket material, cleaned and lubricated the thrust bearings and washers, lubricated the needle bearings and new seal lips with some 80W90 gear lube and inserted the input shaft and positioned the half moon key in the shaft. Once that was done I got things ready to install the output shaft and discovered the hiccup in my shaft repair - the hole in the shaft for the roll pin was not in the centre of the shaft like I thought it was when I repaired it. I double checked by trying to install the roll pin and found out it was off by about 1/16" and the roll pin bound at the edge of the gear when it was inserted through the shaft and trying to enter the hole in the gear. I double checked the gear with the new shaft using a 1/4" drill bit and I could insert the drill bit by hand through the gear holes when it was on the new shaft but I could not do the same with the old repaired shaft. At that point I consulted with my two associates who have been observing things at various stages of the repair as to what I should do to correct the problem with the hole alignment. Blackie said "let me think on it" and Tiger said "I'm outa here" so I decided they were not going to be much help and took a break to see if I could come up with a plan "B".
 

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#18 ·
I debated about just using the new shaft but I decided I would try and repair the roll pin hole again so I drilled the hole in the shaft back out to 19/64", ground the edges of the hole, turned a new insert, pressed it in, welded it, let it cool, checked it for run out, straightened the shaft again and turned the welded area back down in the lathe. Then I mounted the milling attachment on the lathe, mounted a 1/4" drill bit in the lathe chuck and using the new shaft clamped in the milling attachment positioned the shaft at the proper height for the drill bit to pass freely through the roll pin hole in it and locked the milling attachment at that height and tightened the screws on the cross slide to remove any play in it. I removed the new shaft and placed the old shaft in the milling attachment at the correct depth so the hole would be in the proper location in relation to the end of the shaft and removed the 1/4' drill bit and mounted a 3/16" drill bit in the lathe chuck and drilled a hole through the side of the shaft by moving the carriage by hand towards the drill bit - I made sure to lubricate and clean out the hole every few seconds so the drill bit was cutting easily and straight into the shaft. Once I had the 3/16" hole drilled I removed the shaft and placed the gear on it and using a 3/16" diameter punch checked to see how it looked as far as being centred for the holes in the gear. It looked promising so I put the shaft back in the milling attachment making sure the 3/16" drill bit would pass through the hole easily to verify I got it back in the same position. Then I removed the 3/16" drill bit and mounted the 1/4" bit in the lathe jaws and drilled the hole in the shaft out to 1/4". I removed the shaft and tried the gear on it to see if I could insert the 1/4" drill bit by hand through the holes in the gear and shaft and it went which made me happy. To verify that things were aligned I pressed the roll pin into the gear with it on the shaft and it went so I am hoping that I can now install the shaft back in the gear case tomorrow.
 

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#19 ·
Got the shaft back in the case, roll pin installed, case bolted back on the support bracket and the pulley back on the shaft and snugged up the set screws. Turned the input shaft by hand and everything feels good and the pulley is running very close to true again - has a very small wobble but not nearly as bad as it was before. When I removed the U joint from the input shaft yoke one of the caps slipped out of my hand and fell and about 10 needles fell out of the cap - getting older does have it fun moments. I have hunted for the past few days for them and have found all but one so I bit the bullet and purchased a new u joint today so I should be able to put the input shaft back together now. Before I went in to get the u joint I pulled two of the three spindles apart and inspected the bearings as they had a bit of play. Once I cleaned the old grease out the cups and cones looked good so I repacked them and put them back together - just have to do the third one now and sharpen the blades. My thanks to Classic Bolens for the information sheet on how to set up the shafts and torque specs for the spindle bolts. I also have to weld in a piece that is broken out of the belt guard at one of the bolt holes so I got some green paint mixed up in a spray bomb - will see how well it matches when I get that far.
 

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#20 ·
Got the third spindle bearings repacked, blades sharpened and back on, and checked the pulley height on the gear box. It look good so I used some blue thread locker on the set screws and tightened them down. Then I put the belt back on and put a new tensioner spring on.
 

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#21 ·
Then I moved on to repairing the piece that was broken out of the belt cover to the left of the gear box. I had tried to weld the piece back in that broke out last year but it was thin and the weld broke again so I cut a bit more of the cover back to get back to some thicker metal. Once the piece was cut back I cut a new piece out of some heavy sheet metal I had from the cover of an old electrical fuse panel, bent it and fit it to the area in the cover - I left it a little large on purpose. I ground the area with the die grinder so the new piece fit fairly well, clamped it in place and welded it with the MIG welder.
 

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#22 ·
Then the welds got ground down, cut off the excess material at the edges, marked and drilled the bolt hole. Cleaned up and scuffed the area with a scotch brite pad, gave it a light coat of self etching primer and then painted it with the green spray bomb I had mixed up.
 

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#23 · (Edited by Moderator)
Here is a video of the pulley turning on the gear box with me turning the centre blade by hand. There is very little wobble in the pulley and the tensioner spring is not flexing very much. Before I did the repair the pulley and the spring were moving about 5/16" when the pulley was rotated. I apologize for my shaky camera skills.
 

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#24 ·
Got the new u joint pressed in to the yoke and put the shaft back on the deck after I bolted the cover in place. If you remove the yoke from the input shaft the cover can be removed and installed without loosening the bolts for the gear box but I think it is easier to just loosen the bolts than pull the yoke off. Got the lift arms bolted back on, greased and changed the oil in the tractor and then put the deck back on - now I have to clean up the branches in the yard that fell off the trees this winter and I should be ready to cut some grass.
 

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#25 ·
Well I had used the deck for three and a half cuts (takes about 6 hours each time) of the lawn this year and was hoping for a trouble free summer cutting grass. The first cut about 3 weeks ago was interrupted about one third of the way through when the blades stopped turning. I thought the worst and figured I had put something together wrong or the roll pin in the vertical shaft had broken but when I got the cover off it turned out the belt had broken (it looked ok when I put the deck back together but it had seen a few seasons so I just replaced it and put things back together. It worked well till today when I took up from where I left off cutting on Friday - got about one round done and the blades stopped turning again - so I headed back to the shop to investigate. I found that the roll pin that holds the PTO yoke on to the input shaft had left home and the half moon key had apparently left as well so the PTO yoke was spinning on the input shaft to the gear box. I also found the seal on the input shaft had come out of the housing as well as about 3/16" of the input shaft needle bearing was now showing out past the end of the housing. I removed the deck from the tractor and took the belt cover off and removed the gear box. I then unbolted the gear box from the support and removed the vertical shaft so I could remove the input shaft and have a good look at things. Once I removed the input shaft I found that the inner needle bearing had also moved forward about 3/16" which surprised and puzzled me as I had not disturbed the needle bearing when I replaced the input seal and they had worked fine for about the last ten years. I checked the thrust bearing and the two washers that they run on and things looked good - there was no evidence of over heating or unusual wear. I pondered to myself as to why the bearings had walked ahead thinking to myself there is nothing to create side pressure as the needle bearing washer butts up against the inside of the housing against a machined recess. I discovered that the JB Weld had lost its bond and come off so I am fairly certain that is why the seal came out as it probably did not have enough pressure from the housing bore to maintain a press fit when things got warm. I found I could also push in the outer needle bearing about 1/3 of the way into the housing so that may be why it walked forward as well but I am still unsure why the rear bearing moved as the needles were in good shape in both bearings and the inner bearing was a nice tight fit all the way. I cleaned up the bearing bore and the outside of the bearings with a degreaser and pressed the two needle bearings back in to the housing. I then ran a little green Loctite around the outer ends of both bearings to lock them in position and let them set for a little while and then I pressed the seal back in and ran a little green Loctite around the outside of it as well. Unfortunately I had left the camera in the house so I did not take any pictures of things to this point but since I had to go into the house any how for a bite to eat I grabbed the camera.
 
#26 ·
I figured that JB Weld would not hold any better the second time so I opted to make a sleeve out of sheet metal to go around the outside of the gear box housing to keep it from expanding and put a little more pressure on the outer bearing and seal. I went around the outside of the housing with a flat file to remove any ridges from the casting process and then I cut a piece of sheet metal about 7/8" wide and formed it to go around the outside of the housing. Once it was rolled around and I found out where it would overlap I trimmed the excess off so that it would have about a 1/4" overlap. Then I used the chain vise grips to squeeze it tight and make it a very tight fit and then I used the mig welded and welded the overlap and removed the chain vise grips. Then I found another half moon key and roll pin and put the yoke back on the input shaft. To make sure the roll pin stays put I put a piece of wire through the roll pin and then I put the gear box back on the deck. I wondered if it might be the gear lube building up pressure on the input shaft bearings when hot but the vent hose and vent are working so it should vent the same way it has for years and the output shaft bearings and seal have not moved. The other thing I thought about was the roll pin coming out on its own as it had never moved for years so I decided to install the new output shaft and pulley in case there was a balance problem that may have created a vibration that caused the roll pin and the needle bearings to walk. I then put the belt guard back on, put the deck back on the tractor and cut grass for about an hour tonight. So far the seal is staying put and things look good - do not notice much difference as far as any vibrations go. I also checked the PTO U joints and both have no play and the snap rings are all in place on the caps. Will see what happens tomorrow as I still have about two hours cutting left.
 

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