350B Brake Adjusting Bolt Seized

[Kaiverol]

Getting closer and closer to pulling the left side final drive to redo the steering clutch. Today I removed all bolts and tried to separate the drive from the machine. It did not want to move much but I did see some light (I.e. a couple sheets of paper width) at the bottom half of the drive. Was using a sledge hammer, but not hitting too hard. Wondered how others do it. Then thought I could put a hydraulic jack between the two drives. I put a small two ton jack and put some pressure ( again not aggressive) and it just didn’t seem right. That’s when I remembered that I need to back off the brake band. I went to do that and found the bolt to be seized. Tried the working side and it turned just fine. I decided that it was a good time to quit before I really mess things up.

Any advice on how hard I can turn the bolt or ways to loosen it? I have not sprayed any penetrating lube yet, worrying about the band itself. Is the final drive stuck for other reasons. Pretty sure I have not missed any bolts.

I am working with manuals and have read what I could so far.

Thanks Oli

[dtoots1]

definitely the brake band needs to be loosened!!! had to loosen it on my jd440ic before could get off... be sure and have some way to hold it when is loose...boogers are heavy
penetrating oil will certainly help...just not too much where it will get on brakes etch....

[gregjo1948]

I don't remember for sure but are there a couple bolts underneath from the inside out?

[LeonardL]

There are two bolts at the bottom inside that need to come out. If you haven't done this already you will need to drop the skid plate at the back to access these bolts. Make sure you have all of the bolts out before you continue and break something. There are four from the bottom front where the final bolts to the centering bar bracket. These are four large 3/4" bolts and two of them will be special bolts. Then the two from the bottom rear I just mentioned, then four 5/8" main bolts on the top face of the final and two smaller 1/2" bolts about midway down on the face of the final drive.

These final drives are also fitted with alignment studs that fit pretty tightly. They can be a bit tight and make it hard to get the final drive off of them. Once you get the final out past those then your brake band is usually the culprit trying to hold the final in place. That and rusted clutch packs, stuck axles and or a combination of all three.

You also need to be supporting the final drive with something to keep it from trying to fall. I use long grade eight 5/8" bolts, one to either side to slide the final drive out on and then support it with a hoist as well. I use the second set of 5/8" bolt holes on the face of the final to do this. Don't use the two 1/2" bolts as they aren't strong enough to hold the final from falling.

These final drives weigh a lot. I don't know how much because I never weighed one. They will crush your fingers if one falls on them. Been there and done that while young, inexperienced and just plain stupid!! Older mechanics warning me every inch of the way and I did it anyway!! And yes... to answer my Dad I did learn something!!

Your brake adjusting bolt will seize in a few different places. The first is the obvious threads getting rusted in place. The second is the shank of the bolt will rust and seize inside the pivot pin it fits through. The third place is the detent head on the bolt will get stuck between the brake anchor and where the detent turns against the pivot pin. Over the years they will wear from use and cause the detent to flare out at the bottom edge. When you try to turn them then they seize at the anchor.

Go ahead and use some penetrant and soak it good. At this point you're coming apart so it doesn't matter if you're getting the stuff on your band or not. Brake cleaner will take care of it after you get it apart. In my experience the band will most likely be junk anyway.

If it refuses to come loose then it will be time to get brutal and use what ever force it takes to get it loose. I've had to use heat and impact wrenches on some of these to get them loose. It's not fun because you will ultimately ruin something. But this is life as a mechanic on old rusty equipment. The absolute worst case I ran into was on a straight 350 and I literally had to use a torch to cut the linkage and the top of the band to get it to turn loose. Hopefully you won't need to go that far.

I hope this helps and as always >>> Good Luck!!

[Kaiverol]

Great info Leonard. Thanks. I have inexperienced and stupid in spades. Gave up young a while back.

Your advice on 5/8” supporting bolts is very valuable. I had already set up 1/2” threaded rod in preparation and was considering getting high strength rod because the existing support was so wimpy. Right now I have 7” long bolts, which are used for the sprocket with counterweight. Not sure how long you mean? Hoist is in place for support as well.

The belly pan has been removed and I have been under the machine so I am 99% sure I got all bolts. I bagged and marked everything so I will review one more time. Overall I have only found one special bolt, but one bolt was missing, so I am worried there are thread issues to deal with on reassembly. Was not too focused on that part yet.

Recently I met someone with a couple of machines in various states of disassembly. He showed me one of his final drive housings and the top section was snapped off. That’s one more reason why I’m wanting to be as cautious as possible when doing the removal. Since I did get movement on the bottom, I will ensure I get movement at the top now. There I no groove that I have seen to get a pry bar in so I haven’t figured out my approach yet beyond using a cold chisel.

I am now willing to force the brake adjusting bolt as need be, but will give it a few more chances.

Thanks again.

[LeonardL]

Yeah I gave up young a while back as well. Not sure I want to go back either!! Anyway... sounds like you have things well in hand. The seven inch bolts should be fine. The ones I use are nine inch but they are a bit too long. It was what I could find locally in grade eight strength so I have just stuck with them.

I also made special Eye bolts to use as lifting bolts. I use the very top holes in the final drive to lift from. These eye bolts are about six inches long and are 1/2" grade eight as well. I also have a 4' X 1/4" cable that I use to lift with. However you can use about anything to lift with as long as it is strong enough to handle the weight. I use the cable because on machines with the full track frame that has the sprocket guards you have to kind of roll / spin the final drive out from behind the frame. On machines that have the short frame you don't have to worry about it. The final will come straight out.

These final drives can give you the impression they are stuck when all they are is tight on those alignment dowels or studs. I use a thin flat blade screw driver to start them apart. You can also tap the flange the sprocket bolts to with your sledge and help loosen them a bit. Just tap straight down on top of the flange and it will help work the top of the final out. Once you get a little bit of a gap then you can pry them out with a good pry bar. I have an old tire tool that I found that works pretty good. It has a flat end on it with just enough bend to make it great for removing stuff like this.

Your lost bolt is hopefully just one that has come loose and fallen out. The special bolts that are used are meant as an alignment bolt to keep the cross bar bracket square with the final drives. The holes for them are diagonal from each other and no I don't remember from which corner. I think they are outside upper and inside lower. But that may be reversed.

Your two final drives are identical as well. So they will fit to either side of your machine. The holes where these special bolts go are all drilled the same. They counter bore the holes so the shoulder on the special bolt fits like an alignment pin. So bear that in mind if you have to do thread work on that hole. Some guys I know have done away with the special bolts and replaced them with standard bolts. They bore out the full depth of the hole and install Heli-Coils to thread the holes. Seems to work but I have never done it myself. I don't see any reason for it not to work because to be honest I'm not so sure the special bolts are a necessity. They don't need to be that square and the other two bolts are standard bolts anyway. So I fully understand the reasoning behind these guys going with a standard bolt. Some of these have been done for several years now and as far as I know they have never had any issues.

Maybe I have just been lucky but I never snapped a final drive hosing or ever ruined one in the process of removing or installing them. I can see however how it would be easy to do. So I feel for the guy who broke one. Once you do it is junk. That's when you go get behind something and mutter bad words. Or if you're like me you do it out in the open for God and everyone to hear!! I figure it is always easier to repent than to hold back.

[Kaiverol]

Gave the flange axle a few taps on the top today and low and behold the final drive opened right up. Was going to thread in the 7” sprocket bolts to continue the removal but they were pretty beat up. Didn’t have anything on hand to chase the threads, so didn’t proceed again. Also, put some good penetrant on the brake adjuster bolt and impatiently waited only an hour. Started working the bolt and thought it was moving. However, it ultimately snapped, but that’s okay. Was pretty rusty and so the threads were seized.

Hopefully I get back to it in the next few days.

[Kaiverol]

Pulled the final drive yesterday and found one side of the brake band friction band broken off. I did not measure anything yet, but the clutch was obviously not releasing. My first thought is that the brake would bind up well before the clutch had a chance to disengage. There was no oil or grease on the clutch plates and they were not stuck or seized so they came out real easy. Pilot bearing is in good shape and throw out bearing seems decent ( although I didn’t spend much time inspecting).

Also I am sure that the final drive bearings etc are in great shape, because I’ve never seen something spin so smooth and easily.

I have no problem replacing any or all parts. Just wonder what approach someone would take from this point on?

Decided to try photobucket to add some pictures. Hope it works, since I’ve never tried it.
Not sure if the URL below will work automatically.

https://app.photobucket.com/u/Kaiverol/ ... 1c19cde052

[Kaiverol]

Deleting incorrect info in this post.

[timmtnman]

Had the same thing happen on mine. Being a rookie owner and working on my first crawler 350B I learned a few things. First I ordered brake bands from Lavoy, got two of them. Replaced the broken one first and put it back together, clutch disc looked good from what I could tell and put it back together. Tore the other side down just to replace the brake band and it had a different clutch and pressure plate and had a bad hub also. Called Lavoy again and ordered clutch discs, steel plates, pressure plate, throw out bearing. Replaced everything on that side. Long story short, after operating it for awhile the new side works great and the other side doesn't steer near as good. So if it was me, I would replace everything new in it and you know what you have in it and will last a long time. Lavoy has good quality parts for these dozers and a good price also. Hope this helps you out with your decision you have to make.

[Kaiverol]

Thanks timmtnman. That’s what I’m looking for.

[Kaiverol]

I removed the throw out bearing carrier and throw out bearing the other day. The bearing ID is about 10 thou larger than the carrier OD. This is a very loose fit. On the carrier I found a crack and apparent wear. I’m pretty sure the carrier is not something readily available, but I’m sure it could be fixed up. Unfortunately I don’t have the machinery to do it myself. I assume repair would be to weld and machine the carrier. What to do?

https://app.photobucket.com/u/Kaiverol/ ... 9543c3c7ed
https://app.photobucket.com/u/Kaiverol/ ... 31efb98e37

As a point of interest, the parts diagram and my service manual show the bearing with the larger diameter facing toward the carrier. Is this shown like this just to allow the bearing shape to be seen more clearly?