Transmission Mods and Rants.
Results 1 to 8 of 8
  1. #1
    Senior Member sdunt's Avatar
    Join Date
    Apr 2017
    Location
    Central Illinois - Bloomington
    Posts
    1,520
    Thanks
    100
    Thanked 1,029 Times in 547 Posts

    Transmission Mods and Rants.

    I'm posting this in Workshop forum, because its part Modification and part RANT.. (Prepare for a Novel, this is NOT a short posting.)

    I picked up a 646 -73 (sn 9680512) a month ago in Michigan, and first problem right off was the flat tires. And, I Assumed…(always a BAD thing to Assume..) the tractor would not roll because the rear tires were flat.. WELL….

    Once I jacked it up and pulled the one tire off, I noticed that the rear axle on the other side is pulled part way out of the rear end.. JOY!! Guess we get to tear the rear end apart.

    Once I drained the water – then junk, then oil out of the transmission and pulled the transmission off the tractor I found that the clip for the left – drivers side axle is missing. I attempted to flush the gunk out of the tranny with Diesel fuel, pour it in slosh it around, drain.. Rinse and repeat. Never could get it 'clean' to my satisfaction and so far I had NOT found the missing clip. (turned out the clip had broken in half..)

    OK, suck it up and pull the differential out. I popped out the brake shaft, then pulled the remaining axle clip and pulled both axles all of the way out.

    Maybe it's a GOOD that I don't have pictures of what the inside axle bearing surfaces looked like, it would just depress me more.. There was close to an 1/8 of an inch of metal missing on both axles. Being that I basically run my own machine shop, I started the process of welding up the axles and turning the welding down to build up the missing axle sections.

    I have a Monarch Model A metal lathe (built in 1918) that will take about anything I have thrown at it so far: http://monarch14.blogspot.com/2014/01/this-is-my-antique-monarch-model-metal.html

    I am NOT a professional welder, nor do I like to push this antique lathe hard. Therefore, it took 5 hours to weld up (doing several passes) both axles and turn them down to size.

    When I have built up shafts in the past it has always been for Ball Bearings and if the shaft was a little rough that just gave the Red Loktite or Loktite 660 something to hang on to :-).. In this case the shaft IS the bearing surface and therefore needs a much smoother finish.. So I finally completed the Tool Post Grinder build that I have been putting off for YEARS. Once that was done I was able to grind the axles to a mirror finish to mate with the new bushings.



    Once I was over the hump of rebuilding the axles, I started looking at the transmission mounting, the gasket and the lid.

    WHO DESIGNED THIS MOUNTING SYSTEM??

    I'm not a Mechanical engineer, but this old farm kid knows that you can NOT tightened something down and keep bolts tight, especially the REAR AXLE MOUNT (which is relying totally on clamping pressure from the bolts to keep it in place.) when you pass the mounting bolts through a flimsy tin cover, then a FIBER gasket, then the frame you are attaching the casting to (Apparently there is or was a SECOND gasket) and FINALLY the casting?? Seriously?

    The gaskets and the cover will ALWAYS FLEX and the joint can never remain tight. The fiber gaskets alone cannot afford any clamping pressure on the frame and casting.. And the tin – flimsy lid also being part of the stack just compounds the problem.

    There are grooves worn in the underside of this tractor's frame, and oblong bolt holes in the frame caused by how much this transmission casting has moved around. That's not to mention the loose hydraulic lines on the hydro motor and loose CONNECTORS at the TCV, all of which tells me that this has been loose FOREVER.

    Ideally I should probably add steel dowel pins in the casting to frame joint, but I don't want to invest the time right now, in part because I think I can solve this with just the bolts. I going to assume that the 6 – ½ inch diameter bolts were intended to attach the transmission casting to the frame, so OK, lets have them do that.. (the ¼ inch bolts hold the cover - 'dust cap' on.. )
    IMAG1676.jpg

    Therefore my transmission has a light layer of “form a gasket” in between the casting and the frame and the 6 – ½ bolts go only through the frame into the casting. These are new grade 5's because they're only pennies more that new standard bolts (I had to replace ALL of the original bolts because the threads mashed and worn from movement of the transmission). These bolts have lock washers and thread locking compound on them in addition to being torqued down. Hopefully this stays tight for a while.

    The second part of my assumption about the transmission is that it is essentially a sump, there should not be any real splashing of oil around in there.. 90w gear oil does not spray around.. The cover on the transmission is more of a dust cover. Considering how loose the original cover was I can see how all of that crud got in there. Therefore just a dust cover over this should do the trick.


    So I made a new 'dust cover' for the transmission.

    IMAG1682.jpg

    Its just galvanized tin and its boxed up 3/4 of an inch to make room for the gears. I had to fold the corners together and pop riveted them. That SHOULD provide any venting needed. There is a layer of RTV that I let setup before I installed this as a gasket between my new cover and the frame. This is also notched so it is not under the 1/2 inch mounting bolts.

    I have a bench top 'arbor press' that I use for many things, I first bought it for cutting (broaching) keyways in pulley's and the like. But, outfitted as in the photo below its a really nice 'press brake' for forming sheet metal.. All I added were 2 small angle irons that are welded to a plate to form the V and another angle iron, that happens to have a long side on it. The upper angle iron has a bolt that sticks up into the center of the press's column. A piece of flat plate held vertically by a bolt welded to it, would do that same thing..

    IMAG0765.jpg

    I wanted to point that out because you could setup something very similar on a drill press. If make a way to lock the spindle so it does not turn you can use the spindle ram as a press and be able to form some of your own sheet metal items.

    One last RANT on this repair. When I looked up replacement bushings for this, ( IMO this is NOT the dealers, I have to believe the parts are priced this way from Case – Ingersoll). But this is an older non-bulged axle transmission case, therefore it uses 1 3/16 ID by 1 7/16 OD by 1 ¼ long flanged bearings for both the inner and the outer bearings.… BUT the outer bearings have a shorter flange than the inner bearings.

    For that 'less material' you get the privilege of paying about twice as much for the bearings.. Inner bearings. C12713 Are $14, the outer bearings are $23 each?? So I ordered 4 'inner bearings' and just cut down the height of the flange.

    IMAG1669.jpg
    Anyone can do this, it does not require a metal lathe because it does not have to be that accurate. What I did was put an old outer bearing on top of a new bearing on the axle to keep them aligned. (that shiny area above the bearings is what I welded up and ground down..) Then drew a line on the new bearing with a sharpie. Then I SANDED the flange down until the line was gone and now I have the correct dimension. 20 minutes with the belt – strip sander and saved $20..

    While I was checking the casting dimensions for the inner vs outer bearings I confirmed that left side inner bearing had SPUN in the casting and had worn about .020 off of the inner part of where the bearing sits. (when they built this in 1973 no one used loktite?).

    The most expedient repair for that right now was to bed the new bearings in JB Weld and let it go at that. JB specs say the compression strength is 4,000 PSI, so even if the entire tractor, plus 1000 pounds of counterweights were ALL sitting on the one bearing it would still not exceed the compression spec. Yes, Ideally I should mount the casting up on the big lathe and bore the inner bearing surfaces out to take oversized bushings.. I think the casting is thick enough at that point to handle it.. But for now, JB Weld..
    IMAG1679.jpg
    My question is how did the inner bearings get this bad? I read Lionel's posts on his 648 rebuild (https://casecoltingersoll.com/showth...xle#post488881) and his axles were worn at the OUTSIDE bearings but apparently Not much at the inner bearing?

    I have to assume that the oil level in the transmission was not maintained and the bearings were running dry – dryer than they should have, but WHY so much torque on the inner bearings? Is that kind of wear normal?

    As I bought it, this tractor has 2 factory wheel weights on each side, NO fluid in the tires and the weight box had some scrap ceramic tiles in it. NO cement, metal or lead. So approximately 200 pounds on the rear end? Not much weight by what I have been reading..

    This was owned by a gas and oil dealership.. The tractor came with the factory forks.. Based on the rear AG tires being very worn down as well, I am wondering if someone used this as some kind of tow truck for a trailer or something and in doing so they put lots of weight on the rear end?

    I can only postulate that there are 2 ways pressure gets applied to those inner bearings..

    1. Weight on the rear frame. LOTS of it. Which the loader in my mind would put weight on the front axle and tends to lift the rear end and not press down on it.

    2. when the tractor is moving forward, the drive gears will tend to pull down on the differential assembly. To go forward the drive motor has to rotate – pull the front side of the differential down and back.

    I recall a post on CCI where someone's differential gears where rubbing on the inside bottom of the casting.. That would seem to indicate that the wear in that situation was WORSE than what this tractor has because I find NO marks on the inside bottom of the casting.

    What is everyone else's mileage on bearing wear and causes?
    Last edited by sdunt; 05-23-2019 at 09:19 AM. Reason: Changed photos to large

  2. Remove Advertisements
    CaseColtIngersoll.com
    Advertisements
     

  3. #2
    Administrator
    Join Date
    Apr 2017
    Location
    Terrace BC
    Posts
    5,906
    Thanks
    1,183
    Thanked 1,892 Times in 998 Posts
    Hmm, being a pack rat, I did save the old bearings from my 648, plus the axles as well. Let me check the wear on the inner ones,, (I think they were bad as well, but won't confirm that till I look again.) (Don't ask why I save old worn out stuff,, I've no idea other then I like to hoard stuff.)

    Good idea on using the inners on the outer end of axles,, (wish I had thought of that as well, as everything adds up).

    The 646 that I restored last summer/fall. That transmission/bearing and axle wise was flawless. It had lots of oil in there though,, where as the 648,, no oil, just poured out water.

    The OEM calls for (don't quote me on this) a pint of oil in the rear case. Personally, I don't think much of that idea,, and because they have seals on the axles,, I pour in oil with the case open,, till I see it higher then the lower part of the axles themselves. Leaves lots of room for expansion, but more importantly,, (in my mind anyways) oil leaks passed the bearings/bushings and it lubes them up,, and the seals prevent it from leaking out.

  4. #3
    Administrator
    Join Date
    Apr 2017
    Location
    Terrace BC
    Posts
    5,906
    Thanks
    1,183
    Thanked 1,892 Times in 998 Posts
    So, I checked mine again,, and to answer this,

    My question is how did the inner bearings get this bad? I read Lionel's posts on his 648 rebuild (https://casecoltingersoll.com/showthr...xle#post488881) and his axles were worn at the OUTSIDE bearings but apparently Not much at the inner bearing?

    My inner bearings were grooved into the axle by at least .400" (Shaft diameter worn out) this was at the inner bearings. My outer bearings weren't as bad,, shaft was worn by .150". So, more then likely, very similar to yours,

  5. The Following User Says Thank You to Lionel For This Useful Post:

    sdunt (08-23-2017)

  6. Remove Advertisements
    CaseColtIngersoll.com
    Advertisements
     

  7. #4
    Banned
    Join Date
    Sep 2012
    Location
    Hemlock, Michigan
    Posts
    1,351
    Thanks
    71
    Thanked 298 Times in 203 Posts
    If the outer bearing is worn, the inner is as well. There is physically no way that this can not be true.

    Think about it some more. It is a 2 point bearing and there is NOT bearings that can swivel.

    I even wonder if the inner bearing wear is a factor in the carrier bolt issue. The inner bearing not only holds the axle but it positions the carrier is a space that should be shimmed to a small gap to where it could bind if not kept in perfect position.

    Sent from my XT1097 using Tapatalk

  8. #5
    Master Mechanic
    Join Date
    Dec 2010
    Location
    Ok
    Posts
    1,425
    Thanks
    0
    Thanked 640 Times in 424 Posts
    IMO, inner bearing wear is due primarily to poor or no lubrication. When in operation the gears are always trying to push apart, the more torque being applied, the more 'push'. Lack of lube would result in rapid wear, especially in a loader that is being worked hard. Pushing into a pile or digging with the bucket under high traction conditions, like lug tires and a weighted tractor, results in a lot of torque from the hyd motor. That torque applied to the gear teeth results in a large spreading force that is borne by the inner bushings.

    The outer wear is likely only due to load, weight and rotational wear.

  9. #6
    Senior Member sdunt's Avatar
    Join Date
    Apr 2017
    Location
    Central Illinois - Bloomington
    Posts
    1,520
    Thanks
    100
    Thanked 1,029 Times in 547 Posts
    Quote Originally Posted by Kenc View Post
    Pushing into a pile or digging with the bucket under high traction conditions, like lug tires and a weighted tractor, results in a lot of torque from the hyd motor. That torque applied to the gear teeth results in a large spreading force that is borne by the inner bushings.

    The outer wear is likely only due to load, weight and rotational wear.
    Ahh, guess I need to define my INNER vs OUTER.. I am NOT referring to the flanges on the bearings as far as wear is concerned. I am referring to the fact that the bearings on the inner end of the axles shafts as opposed to the bearings near the wheels were extensively worn.

    The wear I had was caused by downward pressure on the axles right at the differential, at the end of the shaft with the splines. The left side bronze bushing also spun in the casting and wore that area DOWN toward the bottom of the transmission case. When I cemented that bushing back in , I actually clamped it UP toward the top opening of the casting to put it as close to proper allignment as I could.

    This differential already has grade 8 bolts in it, which for a 1973 model as far as I know, someone had to have already been inside the transmission.

  10. #7
    Senior Member sdunt's Avatar
    Join Date
    Apr 2017
    Location
    Central Illinois - Bloomington
    Posts
    1,520
    Thanks
    100
    Thanked 1,029 Times in 547 Posts
    Quote Originally Posted by Lionel View Post
    The OEM calls for (don't quote me on this) a pint of oil in the rear case. Personally, I don't think much of that idea,, and because they have seals on the axles,, I pour in oil with the case open,, till I see it higher then the lower part of the axles themselves. Leaves lots of room for expansion, but more importantly,, (in my mind anyways) oil leaks passed the bearings/bushings and it lubes them up,, and the seals prevent it from leaking out.
    If I read the 646 owners manual, I see 3 quarts for the transmission - rear axle, which matches when I, like you, poured 90w into the transmission with the top off, and stopped when oil came out of the fill / check hole on the rear of the casting. That put the oil level part way up on the axles. The service manual says to put the oil groove that is cut in the bushings on the bottom, which SHOULD allow oil to flow into the axle space.

    BUT, once those bushing wear some and the axles 'bed' themselves, there won't be any oil grooves, it will be more like a honed surface. Then the oil needs to be over the top of the axles if it is expected to get the bearings at all.

  11. #8
    Master Mechanic
    Join Date
    Dec 2010
    Location
    Ok
    Posts
    1,425
    Thanks
    0
    Thanked 640 Times in 424 Posts
    Quote Originally Posted by sdunt View Post
    Ahh, guess I need to define my INNER vs OUTER.. I am NOT referring to the flanges on the bearings as far as wear is concerned. I am referring to the fact that the bearings on the inner end of the axles shafts as opposed to the bearings near the wheels were extensively worn.

    The wear I had was caused by downward pressure on the axles right at the differential, at the end of the shaft with the splines. The left side bronze bushing also spun in the casting and wore that area DOWN toward the bottom of the transmission case. When I cemented that bushing back in , I actually clamped it UP toward the top opening of the casting to put it as close to proper allignment as I could.

    This differential already has grade 8 bolts in it, which for a 1973 model as far as I know, someone had to have already been inside the transmission.
    I wasn't referring to the flanges either but the inner bushing that supports the axle's inner end.

    Study the direction or the forces, gears forcing the axle to the rear and the resistance to rotation from the tires forcing it to the rear. Since the driving gear is below the driven gear, that force is up and rearward.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •