TD6 Dozer Rebuild

[Pbach 32]

I recently acquired my second td6 crawler with an IH blade. I need to pull the engine to flip or replace the ring gear before I can try to start her up.  The manual talks about putting a wood beam across the front end and jacking it up to take tension off the springs and to give the engine clearance to come out. It then says I have to remove six bolts from underneath the bell housing. Can anyone explain where these bolts are? I don't want to get smacked in the head. Lastly, it says I need to remove two studs by turning a nut onto them? I only see one, maybe its underneath?  

 

Peter

[Pbach 32]

Some pics

[Pbach 32]

I removed the six bolts and u plate yesterday. It was tough to get the correct 1” socket on these as they were all smashed up from driving over rocks. I also found the second of the two dowels underneath. Are these reverse thread? The manual says they will come out by turning a nut onto them? 

[farmalldr 114]

Standard course thread but can't remember what size.  As you thread the nut on, it pulls the dowel out.  IH used this in several place on a machine.

You have quite a project going there.

Dennis

[crawlernut 14]

I usually don't pull the pivot housing. Jack up the frame so the pressure on the equalizer spring is off, pull the cap screws on pivot retainer and slide the spring forward enough so the engine adapter plate  and flywheel will clear the clutch housing and engine will slide forward and come out. Jim. 

[Pbach 32]

Ok so I didn't need to remove that u-plate thing that goes over the pin which you call the pivot housing? At least I can put some grease on it and clean up the bolts while its off. I guess I'm not sure what the "pivot retainer" is. I'll take a look next time I'm under there.

[crawlernut 14]

there is a round plate with 2 bolts on middle of spring which holds spring on pivot pin. Once removed, you can slide spring forward to gain the clearance to pull engine and adapter plate forward and up. Jim.

[sugarmaker 99]

Peter,

 Reminds me of some of my projects. I have not gone into my TD6 to this depth. But I am watching! Be careful. Your doing great! What is the plan for this machine? They are starting to multiply!:)

Regards,

 Chris

[Pbach 32]

Hey Chris, yes I ended up buying hanks machine haha. The goal is to get it running and working. I hope to actually restore both someday but we’ll see. If I do that right now I won’t want to use it in the dirt. I also have an Allis charmers WC that I would like to restore, maybe you can give me some pointers!

I noticed there are three smaller cap screws underneath the machine that go into the adapter plate of the engine. Do I need to remove these in order to get the engine out?

 

Pete

[sugarmaker 99]

Pete,

I see now. With Hanks machine you should be able to get one going. You sound like me I hate to see them not in working order.

Good luck with the WC. The Allis Forum is where I spend a lot of time. Good folks over there too.

Regards,

 Chris

[Pbach 32]

I got the engine out! Anyone know if I can just flip the ring gear or will there be problems with it seating right on the flywheel?

 

[sugarmaker 99]

Pete,

 You have been very busy! My tractor has so much loader frame stuff on it that I cant even think about pulling the engine. Looks like you have the right tools to get the job done. I don't know about the ring gear reversal? I know on my orange tractors it goes on just one way. But they can be marked and rotated (clocked) to put new teeth to engage the starter. I put a new one on the Allis engine I just completed.

Thanks for the update.

Regards,

 Chris

[trucker1 6]

I think the ring gear will go on the flywheel either way, but the service manual says " The chamfered edge of the gear teeth must be toward the edge of the flywheel." I think they mean toward the front of the engine, or toward the starter. I have read on here where other people have flipped the ring gear around but then had to bevel the new front edge of the gear teeth. Some people contend that every time the engine stops, it stops in the same spot, so that spot is where the ring gear teeth wear out, so if you take the ring gear off and then just rotate it 90 degrees or so, then the starter will engage in a good spot . I have never done this, but they insist it works.

 

George

[Ian Beale 872]

20 hours ago, trucker1 said:

so if you take the ring gear off and then just rotate it 90 degrees or so, then the starter will engage in a good spot .

What would be your chances of stretching it when removing?  IIRC isn't it a shrink fit?

[trucker1 6]

I have never done this job, so can't comment on the chances of stretching it. I can only quote what the service manual says.

"To remove the ring gear from the flywheel, either heat the ring gear with a torch (to expand it) then driving it from the flywheel, or drive the ring gear off the flywheel by using a hammer and punch around the outer edges of the gear."

"Install a new ring gear by first heating the gear to expand it and then placing it onto the flywheel while it is hot. The chamfered edge of the gear teeth must be toward the edge of the flywheel." 

George

[Pbach 32]

I was able to get the ring gear off with a hammer and punch. Initially I tried to take the ring gear off without taking the flywheel off but there’s no clearance to get a punch in there. 

I have been searching for a new ring gear but have had absolutely no luck. Anyone have any luck finding one in the past? Bates Corp shows 0 in stock and that’s the only place I’ve seen it.

Otherwise my options are to rotate the ring gear 90 degrees or flip the ring gear and grind the bevel into the teeth so it engages the bending gear properly. Is the grinding just a rough estimate of a 45 degree cut? How crucial is that to the function of the ring gear?

My plan is to put the flywheel in the freezer and heat up the ring gear in the oven when I reassemble. 

Pete

[farmalldr 114]

My opinion:  A four cylinder engine is going to stop at one of two places so I would rotate the gear somewhere around  90* after cleaning up the damage to the gear so the bendix doesn't get hung up there.  You cannot flip the gear on this application because of the chamfer.  I would not recommend trying to grind a new chamfer.  I think it would lead to more problems later if not done just right.  I don't think it is necessary to put the flywheel in  your wife's freezer but you can if she will let you,  The gear will expand plenty when heated with a torch or oven.  You might try here for a replacement.

http://www.fpsmitheq.com/

good luck, we are watching your progress

Dennis

Edited July 29, 2019 by farmalldr
info may have been wrong

[sugarmaker 99]

Pete,

I wold agree with Dennis, I dont think you need to do the freezer thing with the flywheel portion. I baked the ring in my shop oven for 45 minutes at 400 F. First try was not long enough  heating and I had to tap it back off. I have only done one of these (Allis) I chose to get a new ring gear. I didnt want to do this again!:) Mine was readily available. My luck would be that the tractor would stop at a bad spot on the rotated ring gear and not start!

Regards,

 Chris

 

[exSW 1,955]

I'd say do one or the other. Either heat the ring or freeze the flywheel. A frozen flywheel will suck the heat out of the ring faster than one that's room temperature. Gives you less time to work.

[Pbach 32]

All good advice, thanks. What temp should I get the ring gear to to avoid messing with the tempering?

[exSW 1,955]

13 hours ago, Pbach said:

All good advice, thanks. What temp should I get the ring gear to to avoid messing with the tempering?

I've never done a ring gear. But I've done smaller press fit stuff . 300* seemed to be the magic number. Put stuff in the stove on a pizza stone(!!!!) checked the temp with an infrared. As far as freezing I've had the best luck when it was well below zero outside. Just lay whatever on a old cut sidewalk stone and come back in twenty minutes.

[Pbach 32]

Thanks, got the ring gear on tonight. 425 F for about 45 min did the trick. Had to tap the ring gear down a little to get it to seat.

[sugarmaker 99]

Pete,

 I think you hit on the magic temp. I went to 450 for 30 minutes. Seemed to work well! Glad you got this done. You will like it and it will only take another 60 years to need a new one!:)

 Regards,

 Chris

[Pbach 32]

Good news: I was finally able to crank over the engine the other day with the new ring gear installed.

Bad news: when checking compression in each cylinder I found the following-

cylinder 1(rad) 35psi

cylinder 2: 45psi

cylinder 3 :65psi

cylinder 4(firewall) 100+psi

After doing a little research it would seem I have cylinder wear, valves not sealing, or a bad head gasket. Does this seem like a bad head gasket scenario since cylinder 4 has great compression? Anyone have any advice on what to do next?

Regards,

Peter

[mmi 387]

you could have rust, carbon,other obstructions

stuck bent starting valves

simply stuck or dry rings.

squirt some 3w oil in and try again  if 50 + gain  then fill them up with atf+acetone for 4-5 days  remove plugs and push out let sit 1 hour

 

try to start with known working plugs/electrics

then I would move on to stuck obstructed starting valve

main valves....

cranking speed and proper gauge.....valves set to gas.....?