[Jimbird89]

My 1977 5269G needs help. It's pretty much worn out and in need of a rebuild, but I am trying to keep it going for now. There's a brass plug in the crankcase (about 3/16" in diameter)...toward the backside of the mower right by the cylinder head bolts. It looks like it's leaking oil around it. I know for sure that my D-481 did not have this, and I don't remember seeing this on any of my other D-series. What is/was it for and can it be sealed up without screwing up the crankcase? I think this is why the mower is so hard to start and runs like crap until it warms up. Crank seals look ok and everything in the carb is new.

 

[imaLawnBoyFreak]

Dont know too much about this model but could it be the brass nipple thats on the snow blower style blocks? You may have needle bearings for the main bearings which would be a plus...

 

[Jimbird89]

I sold my D-series snow blower, so I can't compare. This engine has needle bearing upper main, but not lower...at least that's what the diagram shows. Here's a couple pictures of this brass thing...

 

[Lawnboy77]

Yeah I think Freak is right, looks like the crankase has been changed from the original to the D-570 snowblower, I wouldn't think it would really matter though, should work just fine. I think Permatex makes some kind of sealant that would work for that application. It looks to me like you may have more leaks than just around that brass plug. I think I would just pull it all apart and put a new gasket set and while you have it apart put some new rings in and maybe a quick hone of the cylinder and you should be good for another 40 years. While you are in there take a look at the needle bearings and replace them if you don't like how they feel or look. If it is a D-570 it will have needles on the lower end. I know you said you didn't want to do a rebuild, but in my opinion it probably needs one and it's really not too expensive for rings and honing and bearings can be had fairly cheap to if you shop around. They used those engines on 1982 bricktops to, so it you need to look up parts for that I think you can punch in model number 5006 and that should breakdown the parts that you actually have installed.:trink40:

 

[Jimbird89]

Well, I am ok with the D-570 crankcase. That's a good thing. Now the problem is that I can't get the blade nut loose no matter what I do. Impact won't take it off. 2-foot long breaker bar and a piece of 2x4 wedged between the blade and deck won't get it. This thing hasn't been apart in a LONGGGG time, I guess. Maybe it's not worth pulling it apart yet. It's not ready to give in. The lower end of the crank has some side play, and it feels like the rings are pretty worn because the engine is very easy to turn over by hand. Maybe I'll keep using it until it expires completely. I have all the gaskets and bearings and rings already, but they may have to wait.

 

[Lawnboy77]

Well, I am ok with the D-570 crankcase. That's a good thing. Now the problem is that I can't get the blade nut loose no matter what I do. Impact won't take it off. 2-foot long breaker bar and a piece of 2x4 wedged between the blade and deck won't get it. This thing hasn't been apart in a LONGGGG time, I guess. Maybe it's not worth pulling it apart yet. It's not ready to give in. The lower end of the crank has some side play, and it feels like the rings are pretty worn because the engine is very easy to turn over by hand. Maybe I'll keep using it until it expires completely. I have all the gaskets and bearings and rings already, but they may have to wait.

Soak it with Liquid wrench or a similiar product and apply some torch heat and it should come loose.

 

[Wolfy]

Soak it with Liquid wrench or a similiar product and apply some torch heat and it should come loose.

Agreed. You may have to spray it for a week or so, but it will come loose. I have found that PB Blaster works great. I have a 52 GMC and some of those nuts and bolts looked to not been off ever. Several sprays over a week or so and they all came right off.

Then if you need some more, which is possible. Get a torch and heat up the nut. It will expand and it will come off.

 

[cityboy]

I've had some bad ones before and had to cut them off with a small air cut off wheel. IF your careful you wouldn't hurt the crank and be sure to put some anti-seize on it when you put it back together.

 

[Jimbird89]

I sprayed the nut with blaster and let it sit. I'll keep spraying it every day and try removing the nut in a few days. Now that I found out this engine is basically a D-570, I am a little more encouraged to rebuild it. It should be indestructible if properly cared for because of the lower bearing. Is it possible that this was a factory installed block? I know the 1982 bricktops had this block (after reading some other posts)..just wondering if some other models slipped through with the snow blower engine as well. It doesn't look like mine was EVER apart. The parts book says it's a D-409. The recoil says D-410..and a D-570 crankcase. I don't see a tag on the cylinder head like most D-570's, so it may be a D-400 head. Who knows what has been done to something that is almost 35 years old.

 

[Jimbird89]

Is it possible that if the engine (or at least part of it) came from a Snowblower, that it still has the 4000rpm governor spring in it? It sounds like it runs a lot faster than my other D's. The "light" speed sounds about like the rest of my D's on "normal" speed. Will it hurt it running that fast? Blade-tip speed too high? I know one thing...you can't stall it!

 

[Lawnboy77]

Is it possible that if the engine (or at least part of it) came from a Snowblower, that it still has the 4000rpm governor spring in it? It sounds like it runs a lot faster than my other D's. The "light" speed sounds about like the rest of my D's on "normal" speed. Will it hurt it running that fast? Blade-tip speed too high? I know one thing...you can't stall it!

I would think that 4000 rpm's is a bit too fast for mower applications. I would check it with a tach and adjust as needed, or if the wrong spring is installed I would install the correct governor spring so that you can get the recommended normal speed of around 3200 rpm's.

 

[Jimbird89]

At 4000 RPM's, the blade tip speed is 19,912 if I did the math right. That's only around 900fpm faster than the mandated limit. I imagine with a slight load while mowing, that drops the speed right down around the limit. I'll probably just use it in low speed until I tear it apart to avoid any injuries. I'm not concerned about hurting the engine because it's got all bearings, but if a blade decides to come apart at 4,000 RPM, it's not going to be pleasant.

 

[Jimbird89]

Well, I still can't get the blade nut off after a soaking it with PB Blaster and whatnot. I sealed up around the brass plug with some RTV. It runs very well now. Still a little rough when it's cold, but once it warms up, it's a beast. It needs a lower seal eventually. I leave it on low speed (about 3000-3200rpm) and it works great. I'll finish up the year mulching leaves with it and hopefully restore it over the winter. I like this mower so much I think I am going sell my 1999 Duraforce and keep this as my primary mower.

 

[Lawnboy77]

Did you try heating the nut with a torch?

 

[Jimbird89]

Did you try heating the nut with a torch?

That's the next step. I'm a little afraid to start a fire due to the fact that the lower seal leaks fuel right down onto the blade adapter and nut.

 

[Wolfy]

I have done this before and I have never caught anything on fire. All I get is some smoke off of the old oil. But you can always have someone behind you holding a fire extinguisher just in case. but it will come off, just get that nut red hot and it should come off.

 

[Indy452]

If your having this much trouble getting the nut off, what are you gonna do about removing the blade adapter? I can almost assure you its gonna be a real trick.

When and if you get to that point I can suggest pulling the adapter plate so it breaks and then cut the little collar off with a recipicating saw at an angle being careful to not nick the crank. I might even have some pictures somewhere in my collection if you need. Just let me know. Granted, you will have to get a new blade adapter but they are cheap and plentiful and avoiding the adapter struggle is sometimes worth it.

Good luck...

 

[Yard Nazi]

Yes, I agree with Indy. If you can pull the mounting flange until the welds break that will just leave the collar to be removed. I used a Dremel hand grinder with a small grinding wheel and worked carefully toward the crankshaft. Remember the shaft is tapered so be careful as you are grinding. When you get close, just tap the collar and the remaining area that hasn't been ground through will more than likely break and the collar will fall off. This whole removal process took less than 10 minutes so weigh the cost of a new mounting flange versus the time spent soaking and heating. You could also cut the nut the same way. Good luck with getting this apart. You can do it!!! Bill

 

[cityboy]

If I remember correctly I suggested just that a little while back. I've had to cut a few off before.

 

[Jimbird89]

I finally got it apart. Had to hammer on it with the impact wrench for a while, then the breaker bar popped it loose. I changed the lower oil seal while it was apart. Attached is a picture of the lower bearing that makes the D-570 so special in case anyone wanted to see. I also did a muffler conversion from the cheap, loud steel stock muffler to the D-600 dinner plate muffler. Has to chaned the deck plate as well. Should sound a lot better now that it's not rotted out. I also painted the deck while it was apart. Just a quick rattle can job with Valspar Garden Green. The steel ball bearing wheels are next to be painted...chevy orange.