Flail Mower Flail mower bearings - Alamo

[tlj87]

I picked up an Alamo SHD88 yesterday. It's well used and needs work. Former NY state owned. I had previously purchased a Ford 907 also needing work, but decided I'd like a more robust, modern unit to sink some $ into rather than the Ford. If you're in western PA and are looking for a 6' Ford 907 for parts or project, let me know! Anyhow, some questions on how to proceed with the Alamo:

1. Gearbox bearings seem good as in there is no obvious play and it all spins, but it is leaking some at both the input and output shaft seals. Does it make sense to just replace the seals or should I really do the bearings too? Oil is and apparently has been traveling down the extension shaft tube.

2. The rotor bearing on the non-pulley side is bad. Is there any reason to buy the bearing housing and the bearing over just the bearing? There is enough bearing left that I'm assuming the housing is OK.

2a. The rotor bearing on the pulley side seems OK. Should I replace it as well since the other end will be replaced for sure, or just leave it alone for now?

3. Roller bearings need to be replaced. Like question above, any reason to replace the housing with the bearing if no obvious defects?

4. The idler pulley arm has a little slop in it, so I figured I'd get a new idler arm assembly to be easier on belts.

I've prepared a list of what I think I need so far and will try to reach out to Flailmaster.

 

[dieselscout80]

The rotor and roller bearings have to be rocked into place in the bearing housings exactly to line up the grease holes.

 

[tlj87]

The rotor and roller bearings have to be rocked into place in the bearing housings exactly to line up the grease holes.

Are you saying that that is difficult to do and I would be better off buying the housing and bearing kit rather than just the bearing?

 

[leonz]

I picked up an Alamo SHD88 yesterday. It's well used and needs work. Former NY state owned. I had previously purchased a Ford 907 also needing work, but decided I'd like a more robust, modern unit to sink some $ into rather than the Ford. If you're in western PA and are looking for a 6' Ford 907 for parts or project, let me know! Anyhow, some questions on how to proceed with the Alamo:

1. Gearbox bearings seem good as in there is no obvious play and it all spins, but it is leaking some at both the input and output shaft seals. Does it make sense to just replace the seals or should I really do the bearings too? Oil is and apparently has been traveling down the extension shaft tube.

2. The rotor bearing on the non-pulley side is bad. Is there any reason to buy the bearing housing and the bearing over just the bearing? There is enough bearing left that I'm assuming the housing is OK.

2a. The rotor bearing on the pulley side seems OK. Should I replace it as well since the other end will be replaced for sure, or just leave it alone for now?

3. Roller bearings need to be replaced. Like question above, any reason to replace the housing with the bearing if no obvious defects?

4. The idler pulley arm has a little slop in it, so I figured I'd get a new idler arm assembly to be easier on belts.

I've prepared a list of what I think I need so far and will try to reach out to Flailmaster.

About number one:

If the seals are leaking the input and output shafts are usually worn as well and may need to be replaced.
The thing is that it is going to take you a long time to dissassemble it and then get the gearbox in a vise to
begin the job of tearing down the gearbox.

You need a spanner sized for the seal retainer and a seal driver to drive the new one into place; if your lucky a
piece of pvc pipe the same size as the seal outside diameter will work buuuuuut a seal driver is easier to use and
usually you can rent them

Be prepared to replace the entire gearbox as the gears are probably very worn as well and a new gearbox will be less expensive
than the individual parts.

It is better to add oil occasionally or simply push grease in the gearbox later on if the weeping oil is spilling out faster.

About number 2 and 2a:

It is better to purchase the complete bearing housing for both bearings as it takes a bit of time to replace these roller bearings and the bearings can be damaged if installed wrong in the housings.

About number 3:

Replace them both making sure the bearing support mounts are not cracked and the rear roller stub shafts are not worn-this is easily seen when the rear roller is removed.

About number 4:

If the idler arm is sloppy the snubber pulley also needs to be replaced.

 

[toolslinger]

I'm on the back side of rebuilding a Mott 72. Obviously older than the Alamo you've got. It's been run hard, and abused.
All that said, the gearbox is immaculate. Yea, it needed seals, and I did the bearings just because I don't want to tear it apart again, but there was zero wear on the gears. I wouldn't get too stressed about that. Seals aren't all that hard to replace. All the parts are available for the gearboxes. There's the older style like I have, and then the newer version that is a little easier to set preload on. The two styles are interchangeable, so if you had to do a complete swap, it's possible.

If you want to see where you are, then it's bearings first, and spin it up. Mine was shaking so bad, I knew it was going to need the works. Last piece of the puzzle should be done in a week or so. The bearing seats on the rotor were trashed, so having them built up, and turned to size. All my bearing housings were fine, if dirty, and clogged. Can't say what the Alamo housings are like, but I can't imagine they're that difficult. Even if they're self aligning, they're just irritating to do, not all that hard.

By all means check with Montage, or Flailmaster for parts pricing unless you have an in with Alamo someplace. It might be virtually the same to get premounted bearings, but one never knows.

 

[tlj87]

I'm on the back side of rebuilding a Mott 72. Obviously older than the Alamo you've got. It's been run hard, and abused.
All that said, the gearbox is immaculate. Yea, it needed seals, and I did the bearings just because I don't want to tear it apart again, but there was zero wear on the gears. I wouldn't get too stressed about that. Seals aren't all that hard to replace. All the parts are available for the gearboxes. There's the older style like I have, and then the newer version that is a little easier to set preload on. The two styles are interchangeable, so if you had to do a complete swap, it's possible.

If you want to see where you are, then it's bearings first, and spin it up. Mine was shaking so bad, I knew it was going to need the works. Last piece of the puzzle should be done in a week or so. The bearing seats on the rotor were trashed, so having them built up, and turned to size. All my bearing housings were fine, if dirty, and clogged. Can't say what the Alamo housings are like, but I can't imagine they're that difficult. Even if they're self aligning, they're just irritating to do, not all that hard.

By all means check with Montage, or Flailmaster for parts pricing unless you have an in with Alamo someplace. It might be virtually the same to get premounted bearings, but one never knows.

Thank you. I may be in touch with some questions as I proceed and you're in the thick of it.

In terms of priorities, top would be replacing the rotor bearings. I haven't and won't run this thing until this is addressed. I think I'll just do both sides. The bad side has a visible gap between what's left of the bearing and the shaft. I suppose once I get it all apart/out of the machine, I can see if the end(s) of the shaft are going to need machine work or if it'll be usable. Next, the gearbox seals (maybe bearings) and transverse shaft bearing on pulley end. Then, I need to get the rear roller off to find out if it has round or hex ends so I can get the right bearings. Finally the idler pulley setup and maybe a new belt if I have any money left. It's probably going to be in the ballpark of $1000 based on the parts prices I have rec'd so far... :-(

 

[toolslinger]

I had to replace the roller on mine. That was painful. I got mine for next to nothing, but it'll be a $2000+ machine by the time I'm done sadly. At least it's almost done.. Still feel better than dropping the same money on some China machine. At least I know I can get parts as needed for the foreseeable future.

 

[dieselscout80]

Are you saying that that is difficult to do and I would be better off buying the housing and bearing kit rather than just the bearing?

Yes the alignment is difficult and it takes a lot of leverage to do per Fail Master and Montage.

 

[tlj87]

Here is the ugly old thing as it sits. Hope to make into something good over the next few months. Will try to update the thread as I go.

 

[dieselscout80]

TLJ87, when you go to order parts what have Alamo SD88 not a SHD88.

The roller attachment point (adjustment bolt mounting) is one way to tell.

Another is the gear box the small cover on the rear th held on with four bolts says it’s a SD88.

 

[tlj87]

TLJ87, when you go to order parts what have Alamo SD88 not a SHD88.

The roller attachment point (adjustment bolt mounting) is one way to tell.

Another is the gear box the small cover on the rear th held on with four bolts says it’s a SD88.

Great - Thank you! Looking through Flailmaster's catalog, I haven't seen any differentiation between parts for the the SD vs. SHD. They just use the widths of the units. So, I'm guessing that generally most of the parts are the same for the SD vs. SHD. That being said, they do show different roller mounting brackets, but don't say one is for the SD vs. SHD.

 

[toolslinger]

That little plate on the gearbox is also indicative of the older style gearbox. If/when you get in to it, be careful to keep track of the various shims. They are what set the preload on the tapered roller bearings, as well as setting the backlash between the gears. When I get home Tuesday I'll try to remember to post the gearbox rebuild paperwork and parts breakout I've got on it.

 

[tlj87]

What type of wrench/socket do I need to buy to remove these bolts on the extension shaft tube where connected to the gearbox?

 

[toolslinger]

Looks like a 12 point socket to me.
Mine were switched at some point to allen head bolts.

 

[dieselscout80]

I use a 3/8” 12 point swivel socket.

 

[tlj87]

Update: I ended up sending the unit to a welding/fab shop for some work. The non pulley end of the cutter shaft was out of round. They removed the shaft, built it up with weld and then turned it down. New bearings and housings from flailmaster were installed. They also fixed various cracks and deficiencies.

I got the unit back this week and installed all new extreme service blades. I’ve got the extension shaft apart to replace the bearing and spacers/retainers etc. I found that the gearbox input and output shaft seals that flaimaster sent were incorrect but after clarifying with Alamo exactly what model/version I have, flailmaster is sending correct seals today. The bearings look and feel good still in the gearbox.

The weld shop still has my roller brackets which they’re going to try to straighten up as one of the two is tweaked. I have new bearings with housings and dust boots ready to go when I get it back. I also have a new idler arm assembly to install.
Excited to get this thing together and try it out… then maybe clean up and paint?

 

[tlj87]

TLJ87, when you go to order parts what have Alamo SD88 not a SHD88.

The roller attachment point (adjustment bolt mounting) is one way to tell.

Another is the gear box the small cover on the rear th held on with four bolts says it’s a SD88.

So, I was able to get a full parts breakdown from Alamo. It seems based on the parts book that all of the 3pt Alamos are SHD, but there are changes over the years. The one I have appears to be manufactured between March 1972 and August 1990 based on the style of Gearbox and the roller mounting. It also seems the rear roller was replaced at one point because it has hex ends and those didn’t become available until 1994.

 

[dieselscout80]

Interesting

I think it was a guy at Alamo who told me that information.

You did a great job fixing your Alamo!

I’m going to be getting rid of my Alamo SHD96 due to it being too much for my tractor.

 

[tlj87]

I got everything more or less back together and ran it for a bit. It cuts great, but something isn’t right. I’m guessing a balance issue, but how do I identify where it is and how do I fix it? After running about an hour, The pulley side of the rotor is warm but not piping hot. The other side however is quite hot to the touch. I don't have an infrared thermometer to really know if there is a significant difference. The drive side is kind of cooled in part by the pulley itself, i would think.

EDIT: My new theory is that the issue might actually be, in part, the PTO shaft since the vibration at idle seems not as "fast" as the rotor is spinning? Here's a quick video at idle:

 

[dieselscout80]

An easy thing to check is if your u-joints on your PTO shaft are in phase.

If they are I think you might want to have your rotor checked for straightness and balance.

A machine shop that does drivelines should be able to do it.