Super M transmission problem

[blue924.9]

Good morning gentlemen, I am working on a farmall super m for a gentleman that had it apart and put it back together, to put it politely things did not go well on reassembly and it has been long enough that he does not remember all of the details.

The problem I have is the front upper and front lower gears are pushing against each other and binding the transmission up tight. I was told by the owner he had the top shaft out to replace a worn 5th gear, I am not sure of he had the entire pinion shaft out or if he just slid a new 5th gear on

From what I can see the only adjustment is the shims on the pinion, nothing else moves. I believe I either need the top shaft to move towards the front of the tractor or the bottom shaft to move towards the rear of the tractor. Has anyone ran into anything like this before?

Everything is checking out according to the service manual the only thing I haven’t checked is the mating of the ring and pinion gear. I could see shims getting lost and I feel if the gears aren’t set up properly that would be one way to tell.

I have attached a picture of the two gears that are rubbing against each other

 

[Rodney51Cub]

The top gear circled is attached through a cover on the front side of the trans housing.
If you have a Super M with with out T/A use below diagram. If you have a Super M with T/A some one else will have to help, because I have no experience with the T/A tractors.

5 speed no T/A diagram

Items 39 through 50. Insure this is all assembled together and tight.

The other thing I would look at is the snap ring and bearing on the lower shaft, items 58, 59, and 60.

 

[John M]

Those 2 gears dont come into contact with each other, so if they are theres your problem. That lower gear rides on the gear with the cut teeth.

 

[Janicholson]

If the 4th gear countershaft gear 54Teeth were put on the countershaft backwards, it might be offset enough to bind. there is not much difference between the hub offsets at the hub Part # 65 in the diagram IH part number 356676 R1. Jim

 

[Jim Becker]

I'm not about to sift through the various Parts Catalogs for the M, Super M, Super WD6TAs etc. to see what variations may exist, but I would start doing some tooth counts on the problem gears and checking them against the proper catalog. If neither he nor you know what got put in, you could be dealing with a gear that is too big for what it is mating with.

 

[used red MN]

I'm not about to sift through the various Parts Catalogs for the M, Super M, Super WD6TAs etc. to see what variations may exist, but I would start doing some tooth counts on the problem gears and checking them against the proper catalog. If neither he nor you know what got put in, you could be dealing with a gear that is too big for what it is mating with.

Jim, I think your reply is very valid. When I first read his post I had the idea that the gear teeth were bottoming out as they mesh and were tight in that way. I think the real problem is they are rubbing against each other front to back. It would be nice if the OP would clarify if this is the problem. I am not sure if it will help or not but a slightly closer photo with light to see the actual areas that are contacting would be helpful. Also hopefully if the owner knows if he had actually had the counter shaft out would be helpful.

 

[Jim Becker]

Whichever way the interference is appearing, I think a wrong diameter gear could still be the problem, maybe along with some mis-assembly. It would also be helpful if the old parts that were removed were still on-hand to make comparisons. Unfortunately, one of the first steps most beginners make is to throw all the old parts away. I agree a picture that actually shows the point of interference would be a big help. If the two gears marked in yellow are really the ones he says, the upper gear must not be fully back to its normal position.

 

[blue924.9]

Jim, I think your reply is very valid. When I first read his post I had the idea that the gear teeth were bottoming out as they mesh and were tight in that way. I think the real problem is they are rubbing against each other front to back. It would be nice if the OP would clarify if this is the problem. I am not sure if it will help or not but a slightly closer photo with light to see the actual areas that are contacting would be helpful. Also hopefully if the owner knows if he had actually had the counter shaft out would be helpful.

That is correct, the gears are not meshing too deep and binding the gears are binding front of tractor to back of tractor. The gears that are contacting each other do not mesh

 

[used red MN]

That is correct, the gears are not meshing too deep and binding the gears are binding front of tractor to back of tractor. The gears that are contacting each other do not mesh

Do you think the owner would be able to tell you if he had the counter shaft out? That would be a lot of work compared to just pulling the input shaft and slipping in a new gear. Also, I suspect if this was a Super MTA I assume you would have called it that.

 

[John M]

The "top" pulley only runs the belt pulley assembly, it should not contact anything on the lower shaft. The other circled pulley contacts the input shaft on the geared area where it looks like the teeth have been shaved, which is for 5th gear. The entire bottom shaft should spin from the input shaft. Jim would be correct that the gear is the wrong gear

 

[blue924.9]

Do you think the owner would be able to tell you if he had the counter shaft out? That would be a lot of work compared to just pulling the input shaft and slipping in a new gear. Also, I suspect if this was a Super MTA I assume you would have called it that.

Yes this is just a super m

 

[blue924.9]

The "top" pulley only runs the belt pulley assembly, it should not contact anything on the lower shaft. The other circled pulley contacts the input shaft on the geared area where it looks like the teeth have been shaved, which is for 5th gear. The entire bottom shaft should spin from the input shaft. Jim would be correct that the gear is the wrong gear

After reading some old threads with more info yes it is the belt pulley drive gear. I was just calling it what he called it. It appears the correct terminology would be the belt pulley drive gear is rubbing the countershaft drive gear

 

[560Dennis]

Is the shaft bent or is the gear bore that far out true in phot , never seen that before .not close to being correct

 

[caterpillar guy]

I do know if the reverse gear in the bottom has been out and it gets put in backwards on an M you will not get 2nd gear and it will growl something fierce.

 

[used red MN]

I do know if the reverse gear in the bottom has been out and it gets put in backwards on an M you will not get 2nd gear and it will growl something fierce.

It is in correctly, the front gear (top in the photo) of the reverse idler(seen lower in the photo on the left) is always engaged with the counter shaft gear. If you look at it closely you’ll see the back edges of its front gear are square and not made to be slid to engage in another gear. The front of the teeth on the idler’s back gear are rounded for engagement to the sliding low/reverse gear. Which correlates with the changed direction of motion by the shift lever. Pushing it forward to shift to reverse pushes the shift fork back moving the gear back to engage into reverse.

 

[D Slater]

Good morning gentlemen, I am working on a farmall super m for a gentleman that had it apart and put it back together, to put it politely things did not go well on reassembly and it has been long enough that he does not remember all of the details.

The problem I have is the front upper and front lower gears are pushing against each other and binding the transmission up tight. I was told by the owner he had the top shaft out to replace a worn 5th gear, I am not sure of he had the entire pinion shaft out or if he just slid a new 5th gear on

From what I can see the only adjustment is the shims on the pinion, nothing else moves. I believe I either need the top shaft to move towards the front of the tractor or the bottom shaft to move towards the rear of the tractor. Has anyone ran into anything like this before?

Everything is checking out according to the service manual the only thing I haven’t checked is the mating of the ring and pinion gear. I could see shims getting lost and I feel if the gears aren’t set up properly that would be one way to tell.

I have attached a picture of the two gears that are rubbing against each other

Unless you cleaned stuff up looks like all parts maybe were removed. Looking at picture it doesn't look like the two gears circled are that close. Mybe just picture angle. Can't make out any shims at main shaft bearing housing but could be there. May not matter at least if the two gears circled are touching on facing sides. Input shaft distance inside housing is placed by a spacer between the two bearings with the front bearing having a retaining ring on the OD. Ring is clamped between the bearing and seal retainer. Rear bearing on input shaft just ends up in a smooth bore. Shaft retention also depends on front yoke contacting the inner race of front bearing and being tight. Counter shaft is placed by the front bearing retainer and hydraulic unit drive nut or nut if it came with engine driven hydraulic pump. Again, bearing has a ring on OD. Gasket thickness on input housing can affect a little the front to rear shaft positions. Two thick on seal retainers can let bearings move a little more. Constant mesh gear has spacer between hub of it and front bearing. Constant mesh hub is close to same on both sides. Most times number or front can be seen toward front. If gears were removed from bottom shaft they were pressed on. Maybe this will give you a idea where to check, unless parts are mixed. Other check for the two gears binding is front bearing on main shaft and correct retaining part and bolt used. On some a regular bolt head can be to thick. From picture it looks like the transmission drive gear and constant mess gear teeth engagement are normal.

 

[blue924.9]

Thanks to all for the ideas and suggestions I have it working properly again. It wound up being the front bearing on the front section of the upper transmission shaft was installed backwards. This put the snap ring on the wrong side and pushed the upper shaft back too far and caused the gears to contact each other. I pulled and flipped the bearing and everything is good to go now

 

[used red MN]

Okay, that makes sense. Thanks for comes back and telling us the outcome! It is probably a good feeling to help the guy out and get it working for him again! Looks like you joined YT about a month after I did.

 

[blue924.9]

Just to keep everyone updated I have turned my attention to the engine being locked up. I ended up finding main caps hammered on back wards as well as the cam hammered into the block messing up all 3 new cam bearings and new cam. I also found regular old red grease behind the main and rod bearings which took all the bearing clearance out. As a side note red grease also attacks the material in the new bearings so it is not a suitable assembly lube. I have the short block assembled and in working condition with a slug of new parts and am waiting to get the rest of the parts from him to finish. It will be nice to see this tractor going as he spent a considerable amount to restore this tractor. I am also planning on breaking it in on the dyno for him as well since he is planning on it being a parade tractor

 

[used red MN]

Thanks for the update! Okay, I realize that knowing how to assemble an engine correctly requires a great deal of knowledge. Trust me, I have every bit of sympathy for this guy. In all seriousness is he in acceptable condition both health and mentally to drive this tractor safely in a parade? If I was in your position I would assess the above and alert his family of any cautions or limitations they might consider.