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formariz

Need advice on RJ tranny rebuild

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ground and unground bearings in your transmission

 

ground bearings are precision ground to a mirror finish for very tight size tolerance and fit

unground bearings have a larger size tolerance and fit they have a much wider range of misalignment they can handle over the ground bearings

you can feel this in your hand by the movement between the inner and outer bearing races

the wheel horse 3 piece trans cases are not pinned in alignment like the newer cast two piece trans cases when you look at a disassembled 3 piece trans

you can see where the different bearing types are used. The ground bearing are where they can be kept in truer alignment like the input shaft and the

unground style is used to take up any misalignment between the case pieces side to side

 

you can buy both bearing types from mcmaster-carr in the correct sizes

 

Brian

Thank you Brian . Now it makes a lot more sense to me and I notice the difference like you mentioned between the two different types.

Having then ground bearings installed on case sides would probably be an issue since sides are not keyed to each other using only center section for that. All three parts would have to be really precision built to each other which is not the case with this type transmission.

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So I took tranny apart again. This is how my bearings are placed. My issue is that I cannot move both axles at same time such as when pushing tractor. Aside from that it works perfectly. Also attached photo of differential with the two gears removed. Nothing seems to be hanging up in there.

The 3/4" bolt attaching spring bracket was in correct place. Nothing was interfering with any gear movement.

I think spider gears are also correct. Diagonally opposite gears are in same position.

"Closed" bearings are flush with keepers with one exception which protrudes 1/32". Could that one be the reason I needed a second gasket .

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Edited by formariz

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Those are the right bearings, but they are in the wrong places.  You have 3 "ground" bearings.  One should be on each end of the cluster gear shaft (incorrect in your pictures)., and the 3rd should be under the large gear of the mushroom gear (the mushroom gear ((large part of gear)) is correct).  You have 4 "un-ground" bearings...2 for the input shaft (correct)...one for the brake shaft (incorrect in your pictures)...and the 4th goes where the spline shaft goes (incorrect in your pictures).

 

Differential looks good...you should be able to grab the axles and when you turn them they should spin in opposite directions.

 

Yes, that little bit sticking up can cause the trans to be too tight...to where 1 more gasket would free it up.  I think if you move those bearings to the correct places you should be OK.  It is critical that the bearings be seated until flush, but not in far enough that you cannot turn the bearing with you finger.  :)

 

I see what appears to be a couple of chips on the bull gear...that is OK, but make sure there are no bits of metal stuck in the teeth.  It does not take much to jam the gears.

 

Here is the correct position of the bearings...

 

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Edited by stevasaurus

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I suspected they might be in wrong place. I just duplicated what was there. Obviously I was not the first.

Shaft does rotate freely in opposite directions. I still don't understand what could have prevented both axles from rotating together in neutral. Would the incorrect bearing location cause that?

Am I right to assume that in neutral the entire differential rotates as a unit?

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Yes, you are correct...the differential unit turns when pushing the horse in neutral...the pinion gears just let the outer wheel catch up to the inner wheel when turning. The only thing I can think of, is that you had or have a bit of something stuck in a tooth.  It could be in the axle gears and pinions, it could be the bull gear and the mushroom gear.  Just a little larger then a grain of sand can do it.  I use a small, flat blade screwdriver and a wire brush to clean between the teeth.  If your differential turns freely when turning the axles now...it is not in there anymore.  :)

 

You would be surprised how many of these transmissions, that I have opened, have bearings in the wrong positions.  I don't think the bearings in the wrong place would cause your issue...that kind of stuff would just cause pinching the trans when bolted together.

Edited by stevasaurus

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Ok thank you. I am going to assemble it again tonight (dry) and try to test everything prior to finalizing it.

Prior to assembly everything was totally clean since everything was washed with lacquer thinner but perhaps something got in there.

I should then once assembled perhaps with hubs on for leverage be able to turn both axles simultaneously by hand when in neutral?

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Sounds good...just remember, it will take a little work to turn the trans in neutral by the hubs.  You are not just turning the differential, you will be turning the mushroom gear, the cluster gear shaft and the spline shaft through the gearing working backwards...but it should do it.  :) 

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Both bearings going into PTO shaft should be the "open" type correct? One is not shown on photo since its hidden behind the other and having the seal next to it on PTO side .

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Yes,  2 of the "un-ground" bearings hold the input shaft...should be flush on the inside, and recessed enough on the outside to accept the seal.  You may have a collar to stop the out side bearing to make room for the seal.  :)  Like Vince said...pack the bearings with some grease first.  Don't need much, this is not like packing trailer bearings, but it helps in the break in process.  I like to use Lucus Oil Additive in the bearings and on the gears, but a little grease is OK.

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This thing is going to drive me nuts!

Changed bearings to correct locations. No bearings now protrude from keepers. Seems to have resolved clearance issues since I no longer need the third gasket.

Transmission works fine in all gears.

I now can turn both hubs simultaneously forward .

Cannot turn them simultaneously going backwards! By going forward and then backwards sometimes I am able to get a quarter turn backwards feeling sort of gear grinding and then it gets stuck. Going forward no problem.

Edited by formariz

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After relaxing for a bit I think I have figured what is going on here.

I now can turn both hubs simultaneously forward by hand. However not backwards. But if I turn them forward and then almost immediately turn them backwards I can turn them with a bit of difficulty while feeling a sort of " notchiness" as they turn. If I stop then I cannot turn them again unless I go foward and the backwards. I need that little bit of momentum in order to go backwards.

I then went and reviewed Stevasaurus videos and it dawned on me while watching the short video dealing with the two type of differentials,the replacement one with the more teeth and the older original one with the 31 teeth bull gear which I have.

My bull gear and the corresponding second gear which has I believe 8 teeth have very severe wear on them created from moving forward. Teeth on both have an odd concave shape worn on both gears. Shape on both gears compliment each other while moving foward but when moving backwards now contact between gears is on the convex part of that shape. There is the obstruction!!!. That is why if there is a little momentum from switching from foward to backwards it works, the "notchiness" being the gears climbing the convex part.

Geez, I am mentally exhausted now.

Edited by formariz
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I think you are saying your bull gear and your mushroom gear are not a matched set.  Can you post a picture of the mushroom gear??  :eusa-think:

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Even if a PO was in there before you, mixing and matching parts...

the binding now doesn't make sense...if it was working fine before.  :eusa-think:

Edited by AMC RULES

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If you look at the attached photos I think that the mushroom gear is getting hung up in the little square notch at the tip of screwdriver on the second photo. I think that is the "notchiness" I feel when I manage to turn both axles simultaneously backwards.

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Yep, you found the problem,,,50 + years of wear.  BTW, that is the right matched gears.  What you do now, depends on how you are going to use the horse.  You can probably find a new/used mushroom gear and a bull gear housing if you want...even the newer style if you can get both.  These early #5003 transmissions were built with a certain amount of "slop" in them...but once those brass bushings start to wear, in the axles and differential carriage, that slop increases a bunch and the wear shows up right where you have it.

 

Excellent work Mate.  :)

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Not a critical transmission usage wise. However if you know of any available differential old type or new I would like to make it right.

Brass bushings on it were worn down to absolutely nothing.

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If you think the mushroom gear is OK, then you just need the old style differential housing with 31 teeth.  If we find the newer style differential (I think I counted 48 teeth), then you will need the newer style mushroom gear (11/44 teeth).  I'll send you a PM.  :)

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Let me also thank you for the absolutely awesome videos you have regarding these transmissions. They are a valuable tool in understanding their inner workings . To be able while working on one to go and watch you doing it and explaining the process is not only a source of confidence boosting but a valuable education. I found your you tube page and bookmarked it so I can immediately have all videos on hand. They definitely should be placed all together somewhere in this forum for everyone to be able to access them on demand without much searching.

Thank you very much Stevasaurus .

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If you think the mushroom gear is OK, then you just need the old style differential housing with 31 teeth.  If we find the newer style differential (I think I counted 48 teeth), then you will need the newer style mushroom gear (11/44 teeth).  I'll send you a PM.  :)

Thank you . I am open to both of them if available.

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Thank you Mate.  I have had a lot of fun making those videos, and I am humbled at how many people have used them to fix their transmissions.  It was a pleasure working with you. :)

 

My favorite video is the one "Watching Paint Dry"...might even be my best effort.  :bow-blue:   :orcs-cheers:

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Come on Steve. You didn't post it but the chirping crickets video was right there with your Watching Paint Dry video. :ychain: I was glued to my seat for both of them. But then again, I'm easily amused.

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I think since it's still apart I am going to smooth or eliminate those notches and see if that makes things easier to operate.

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SUCCESS!
So I reshaped teeth on bull gear by grinding the little square notch that was causing transmission to get stuck when moving both axles simultaneously in neutral . Reassembled transmission with bearings in correct places. Tightened everything and tested it. Functions perfectly and now I can move both axles in neutral together in reverse without it hanging up.

So prior to rebuild this wasn't a problem since bronze bearings were virtually gone and there was so much play between bull gear and mushroom gear that bull gear was actually scraping center housing. All that play would allow mushroom gear to climb square notch . Once new bearings and bronze bearings were installed everything was snug and aligned properly making that square notch a real obstacle.post-484-0-41970700-1418526377_thumb.jpgpost-484-0-40863200-1418526395_thumb.jpg

 

Also been able to secure a complete set of the later type bull gear and mushroom gear with more teeth. I am however use this one this way saving those parts for another day. Second one to rebuild is already on the bench.

Edited by formariz
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One thing I had great difficulty doing in this rebuild was removing bearings from their keepers. I see from other posts that others also had difficulty. Seeing then Stevasaurus video using a plain chisel I tried it. It works. However he made a second too since his chisel would not remove bearing totally out.

Being a woodworker by trade and not exactly having a shortage of chisels around here, I found that a 1/4" wide chisel ground to a steeper angle removes the bearing entirely without any difficulty. Just go evenly around the inside of bearing using chisel bevel down and tap gently. Real easy.

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Edited by formariz
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