854 gear box

[pats854 6]

I have a 854 that we use to pull an aerator. Last year the gearbox locked up to the point that I had to use a Dolly  to get it back in the shed. 

 My brother gave me another gearbox to replace the locked one.  He doesn't have the brake drum. The  rub is that the brake shaft is flat on two sides and appears to be held on with a bolt and washer. The old box uses a snap ring and a key way Therefore , I cannot use the old drum. Any ideas would be appreciated. 

[stevasaurus 22,884]

Your 854 came with the Wheel Horse #5025 transmission.  Actually, I have not seen a brake shaft in a Wheel Horse transmission like you describe in your replacement.  That is not to say it does not exist.  Can you post a picture of your replacement transmission from different angles...it will help with options.

    Questions...

1. Do you have both transmissions off the horse?

2. Do they look like the same transmission case?

    Options...

1.  If the cases look the same, and the brake shafts are the same diameter...you could open up both transmissions and switch the shafts (mushroom gear).

2. Maybe someone has seen a brake drum like yours and has one to give/sell you.

3. Open up your old transmission and fix what is wrong.  It is very fixable.  Parts are available.

4. Switch out your old transmission for the right one.

 

If option (4)...I happen to have a #5025 rebuilt transmission.  I would be willing to trade...plus some money for your old transmission.  If you can get it to the Big Show in June, I could switch it out there with you (if you go to the Show)...or if you gave it to someone close to you to bring it.  We could work out details in PM's 

 

[Racinbob 11,260]

Some of the '4-speed' transmissions had that double D brake drum. I've had a couple over the years. The 5080 is one of them.

 

 

It's possible you're just stuck in two gears locking up the transmission. Pull the shifter and look down the hole. It should look like this when in neutral.

 

 

If it's not use a screwdriver and move them to this position and see if it frees up.

 

 

Edited March 17, 2016 by Racinbob

[pats854 6]

My brother doesn't know what model the gearbox came out of. I will try the screwdriver maneuver again, it didn't work before.That would be the best outcome if i could free it up. It begs the question - why is it locking up.

 

If this is from a 5080, will it work on a 854? Also, does anyone have a double D brake drum?

[Racinbob 11,260]

It will bolt right up but you'll have to fiddle with the clutch/brake linkage. The brake drum is mounted on the cluster shaft instead of the 11-44. It wouldn't be difficult but I can't say exactly what it would take. You might try posting in the wanted section here. I'm sure you'll be able to find one.

 

The design of the shifter rails and detent stops were such on the early Unidrives that the thing could try to go into two gears at once which locked up everything. Service bulletin #60, issued in 1965, addressed this with modified shift rails and stop pin. If this is your problem the rails are interchangeable. The 5080 will have the redesigned rails and longer stop pin.

 

 

 

Here's a couple of videos I did explaining the problem.

 

 

 

 

 

[Racinbob 11,260]

And one on another shift rail issue.

 

 

[stevasaurus 22,884]

I think if you check between the 2 transmissions, you will also find that the axles are longer in the #5080 then the #5025.  This would put your wheels out farther from under the fenders. 

   As to why is it locking up...watch bob's videos and see if it is the forks.  If it is not the forks, we have some things to try before you open it that will hint at the problem.  Is this trans still on the horse??    Can you post some pictures??

[pats854 6]

I haven't removed it yet. Several years ago it locked up but a diesel flush corrected it. I have a lot of other projects and would like the easiest solution. Going to drag it out of the shed over the weekend. If the screwdriver doesn't work what else can I try?

[AMC RULES 37,134]

While you're doing the screwdriver trick...

may be necessary to rock the tractor back & forth to remove tension on the forks...

to enable them to slip back into neutral position.   

 

[stevasaurus 22,884]

OK...this is to just give us an idea of what it could be.  To do what Bob is saying, I would remove the 2 bolts that hold on the seat and fenders.  Then you can lift up the rubber cover on the shifter to show the allen head set screw.  Loosen the lock nut and then back out the set screw (1/8") allen wrench by reaching from under the frame from the front...lift out the shifter.  See if the forks are aligned...if not, align them.  You are done and you can put it back together.  The "dog point set screw" point fits into the doughnut on the shifter.  Screw set screw in until snug and then back out 1/4 turn...tighten lock nut.

    If it is not the forks, take off your belt guard and drive belt.  Jack up the rear end so the wheels are off the ground.  With the shift forks lined up, which is neutral, turn one of the rear wheels in any direction...the other wheel should turn in the other direction.  It should be smooth with no clunking and consistent turning.  Now do the other wheel.  This tells me that your differential guts are OK...ie...axle gears, and pinions.  Now turn your input shaft pulley in a counter-clockwise rotation.  You are still in neutral.  It should turn very easily.

    Now put it in any one of the 4 gears and try turning the input shaft pulley...same direction.  Can you shift it into all the gears?  Is there one gear that locks up?  If you can shift it into a gear and turn the input pulley...the axles should both turn in the same direction and the brake shaft should be turning also.  Should be smooth and no jerkiness...which would indicate some broken gear teeth. 

    If it is the shifter, it is because of the suction of the rail shafts.  One thing that is important, if you are not going to switch them out, make sure you come to a complete stop when shifting and slowly shift between gears in a good "H" pattern...no speed shifting.  This will lessen your chances of having it happen again.

    There you have it...see what you got and let us know. 

 

In my 1st post above...option 1 is not an option.  If you look at your 2 transmissions, the brake shaft does not come out the same hole of the trans case.  The one on your tractor comes out the hole closer to the axle housing (11/44 toothed gear).  The one you have as a spare, the brake shaft comes out of the next hole towards the front...(cluster gear shaft).

[pats854 6]

Attached is a photo depicting what  I pulled out of the bottom of my gear box. I am correct in assuming that I cannot use the spare gearbox ? The weather is getting nice and I don't want to get involved in a gearbox rebuild. Is anyone aware of someone in ct or close by who  I can swap out my spare with for the right one?

[pats854 6]

I should a looked before I wrote. I see what stevasaurous is referring to. The measurements on the pulley and brake drum on the spare are at least three inches closer to engine. No need to answer the swap question. Need to swap the spare for the right one. 

[Racinbob 11,260]

It can be made to work just fine with some minor linkage modifications but you may not want to mess with that. It's a matter of flipping the brake band which is identical but the linkage mods I'm not sure of without seeing it. My grandson has a Commando 800 that I restored for him that has the double D drum. It's 1000 miles away but we'll be up there right after the big show. You can bet I'll be taking a closer look and get some pics.

 

You have the tranny opened up? That looks to be a shifter fork. I happen to have one I could send you.

I would suspect there could be other damage as well so I would check things out and ask questions if needed. 

[pats854 6]

I haven't opened it up. Right now I have too many projects to take on another one. At this point I think swapping out the gearboxes would be the quickest solution. I am not sure that I want to modify the original linkage, so I need to find a 854 gearbox. 

[stevasaurus 22,884]

Sure looks like a broken shift fork.  Can you tell which one it is?  Is it closer to the front of the tractor or toward the back?  This is a crap shoot, but you may be able to slide the offending fork gear a little, on the spline shaft, so you can at least roll the horse.  If it is the fork closer to the front of the horse that is missing, that is the 1st & reverse fork.  When you look down the shift hole, that fork gear will be on the left side of the transmission.  If it is the other fork, that is 2nd & 3rd gear fork and will be on the right.  Whichever, You may be able to take a long screwdriver and slide the offending fork on the spline shaft and out of gear.  I am going to send you a PM. 

[pats854 6]

With some coaching from stevasaurous, I cracked open the stuck gear box. I appears that the fork shafts are very hard to manipulate. I removed the gears and some concern about the condition of the gear at the bottom on the input shaft. The pictures are below. 

[Racinbob 11,260]

Did you stick the broken piece of the fork back to take those first two shots? They look OK is those. I'll take a look at the gears I have to see if they are better. Ignore the PM asking for a shot of the 3523. I didn't realize at the time you posted this.