Jd350

[Monserandsons]

Hi folks, last year I did some work on a jd350 dozer. Thanks to all of you and Levoy it was a great success. Fast forward into winter and the engine is experiencing a locked up condition when ever temperatures are low. After lost of Trouble shooting, turns out that debris in the flywheel/ring gear compartment freezes and locks up the engine. Appears to be fibers/possible nesting,ect. So my question is can I drill a3” holi in the bottom of the bell housing? Clean it out and make an access cover. Would be much easier than removing engine from reverser. Cast iron is easy to drill, just not sure if there’s any bosses or other castings/anything that would deter me from drilling? Any thoughts are welcome, thanks john

[dtoots1]

Am not sure on the 350s, but usually most bell housings have some kind of weephole to let moisture out or maybe a rubber/metal plug to enable drainage...
However, before drilling, i would pull the starter and inspect visually use borescope to see what all in there....shop vac or air gun may well clean it out.
and yes critters get into darndest places

[Monserandsons]

Thanks, I did remove starter and used shop vac/compressed air to clean out as much as I could but still a lot in there. I does have a weep hole with cotter key in it. I guess bore scope is probably safest bet. Thanks again.

[LeonardL]

John,

There are a couple of problems I see with your idea. The fact that you would be taking a chance on the strength of the bell housing and its ability to hold the motor would be the first thing I see as being a problem. This is the only support for the engine. It is basically suspended out from the bell housing so there is a lot of strain associated with this. The bell housing on a 350 is the case for the reverser. So if it cracks or worse then you will be replacing the entire case for the reverser.

Another thing that comes to mind is you wouldn't really be gaining enough room to clean anything out. The flywheel on the back of the engine runs in a very close tolerance to the bell housing and even with a three inch hole you would still be limited in what you could do. To me it is not that hard to remove the engine. That way you can clean it out and then inspect the rest of the components while you're inside.

If you have debris inside then I would be wondering where it came from. The only access is the little drilled weep hole in the bottom of the hosing. So nothing could get in there to build a nest. Which makes me think your Isolator has lost its fiber wear ring. It could be just dirt that has found its way inside over the years. Coupled with the moisture it could freeze and stick the flywheel. As I said they run pretty close to the housing.

I know it sounds daunting and a lot of labor. But it really isn't that hard to pull the motor on a 350. Personally I think you would be better off in the long run. But... Just my opinion.

[LeonardL]

Another question I have is how you determined your motor was stuck due to freezing? The reason I ask is, assuming you still have the old Delco starter on your 350 it could be the solenoid not energizing the starter motor. If your solenoid is bad they will clunk or thump just like a motor is stuck. So I'm wondering if you are certain that the starter is functioning properly?

[Monserandsons]

We pulled the starter the first time it locked up to try and bar over the engine by the ring gear teeth. Wouldn’t turn over until it had been in heat for quite some time. And after it started turning over is when we took notice of the debris coming around with ring gear. Starter was rebuilt by a reputable shop. Cranks over fine whenever above freezing. I just did the work to the machine and am fine with pulling the engine, just means more money for the owner. What exactly does the isolater do?? Thanks again John

[LeonardL]

Sorry it took me a bit to get back to you. We have a winter storm going on here with snow, below zero temps and wind. I guess it knocked our internet out for a while so sorry for the late reply.

After I wrote the last post I realized I had "assumed" you have a reverser on this machine. There are a lot of 350's out there with a drive clutch and transmission and no reverser. So once again I apologize for assuming.

To answer your question, on machines with the reverser, the "Isolator" is the connector that connects the engine flywheel to the input shaft of the reverser. It also acts as a shock absorber or dampener to take some of the shock out of the engagement process. Depending on how old your machine is there are three possibilities of isolators for a given reverser. The very first 350's came out with an isolator that resembles a heavy truck clutch plate. It is a thin steel plate with a riveted fiber wear surface that is then connected to a center hub via several coil springs mounted inside the hub. There are only a very few of these first generation machines out there however and I have only ever encountered two in all my years of working on these machines.

The most common isolator is a central disc or hub made of cast steel and it also has a fiber disc bonded to it on the flywheel side. It is connected to the flywheel via five coil springs that hook to anchors on both the flywheel and the center hub. This style of isolator was used all the way from the later straight 350's to the 350C's.

The third and most popular isolator came out with the very last 350C's but were designated for the 350D. They are a steel dish filled with bonded rubber with a center hub that connects the flywheel to the input shaft. They have no fiber wear material at all.

Getting back to your machine, if you have a direct drive machine, aka no reverser then you may be getting clutch disc debris from the fiber on the clutch disc. If so then it will mean pulling the motor anyway. If you have a reverser then you could still be getting this fiber coming form the wear surface of your isolator.

My point to all of this is there is no way any rodents can get inside the bell housing if you have a reverser on your machine. The direct drives have an access plate on the right hand side of the center housing that sometimes gets lost or loose and rodents can then possibly get inside. Though this is rare.

[Monserandsons]

It’s a reverser model. Good explanation on the isolater. That must be what the material is. Also sounds like a risk to drill. We got a fair amount out with vacuum and air but there’s still enough to cause a problem. Thanks for all the advice

[FredJones]

Here’s some things to check regarding your motor not turning over in freezing weather.

If you watch a bunch of Youtube videos posted by Russian mechanics, you will see some of the problems they come up against due to the freakishly cold weather there…

Frozen water pumps. Not only do water pump housings break from freezing water expansion,
sometimes it’s so cold the impellers are locked up tight by the hard frozen ice, and the impeller or the
pulley twists off the shaft…

Frozen engine oil. One of the videos shows a fellow trying to pour 5w-40 oil ( says on the side of the container ) out of an upside down 1 gallon jug. The oil won’t pour out, or even glug out no matter how hard he shakes or squeezes the bottle…

Frozen water/oil emulsion in the engine oil pan. The customer complaint was that the engine wouldn’t turn over. The mechanic removed the oil pan to expose what looks like someone filled the bottom of the engine with dirt. It’s really a solid mass of frozen oil/water emulsion…

So, when your engine won’t turn over in freezing weather…
1. Loosen the fan belt to check if the water pump is frozen and preventing the engine from rotating.
2. Pull up the dipstick to see if there is emulsion “mud” or “glue” on it.
3. Try to drain the oil pan, maybe someone put 90wt oil or a gooey oil additive to tighten up some loose
bearing noise…
4. Iffn you’re really desperate, build a bonfire underneath the tractor to warm it up…

Search Youtube for “crazzy car” ( yes, 2 zz’s ) These fellows have good examples of this kind of thing
as well as some WTF 3-rd world repairs. Set the subtitles to auto-translate into English for a good laugh

[LeonardL]

There are some northern USA and Canadian videos on YouTube as well that have some pretty crazy cold weather issues. I remember as a kid watching a company under contract to the railroad back in the 60's actually warming D8 and D9 Cats by building fires to warm the engines and to thaw the tracks loose from the ground. That happened right here in Missouri. As a kid I thought they were nuts but it worked. I remember my Dad saying it was like -20 degrees on a few of those cold mornings when they did this.

[Monserandsons]

All good stuff and I love the positive feedback on this site( makes me wish I’d kept the 350 loader crawler), learned how to push dirt around on that thing lol. I alive starting engine’s when it’s brutally cold. Really gives you an idea of engine condition lol. I actually have a D69u and 2 D68u’s. Once a winter on the coldest day I pick one and fire up the pony. Now mind you most people call those pony’s mans worst nightmare... but believe it or not I have two that run just as good as any brand new Honda. Well, after those pony’s have run for 30-40 minutes those d-318 cats are warm to to the touch. Fire rate off and I NEVER use either. It’s a lot of fun pushing around snow piles for the kids, lol. (Probably more fun for me). Anyhow I dove into the parts manual and it looks like I can drill a hole in the bellhousing without fear. Maybe stay back from the front edge an 1” or 2 so as to not weaken it to much? I don’t see an isolator but I do see little spring’s in the drive plate. I’m assuming there for shock absortion. Definitely not nesting though. One thing I didn’t mention (assuming you didn’t see my thread about the steering clutches is that the machine was swamped badly. Pictures in that thread. So maybe that same go went up through the weep hole around the cotter pin. I replaced the antifreeze but it does have 15-40 in the engine. No emulsion. Thanks for the replies. John