JD 350C TRANNY QUESTION

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Pbrogdo
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JD 350C TRANNY QUESTION

Post by Pbrogdo » Mon Sep 17, 2018 7:48 pm

Hello all,
I am working on an old 350C dozer that had an issue with the tranny. The under carriage is pretty much worn out however was still running and performing. It was being used to pick rocks out of the ground for a final grade when all of a sudden it POPPED and quit motivating in either direction. Whenever the clutch is released it makes a whirring noise similar to what sounds like two broken ends of a shaft spinning against each other. I am assuming either the input shaft or the output shaft broke but I'm not sure. I have also been told it could be a coupler. I have been a mechanic for almost 40 years but none of those were on heavy equipment so I am at a loss here. I pulled the rear tank/seat as an assembly and am prepared to pull the engine but I read somewhere that to get the tranny out I have to go at it from the rear. I've also read from others that they pulled the engine and got at it from that direction. When I removed the rear assembly I noticed that the "bell housing" had a gap between itself and the tranny. I found NUMEROUS broken/missing bolts which have allowed the tractor to open up which in my mind caused the shaft to "flex" under operation which would also seem to greatly increase the chance for breaking a shaft. The tracks and slides are literally worn almost in half so I can only imagine how difficult it will be to separate the tracks not to mention I don't have ANY track tools to pull a pin with. I have been postponing this work for a year now but the time has come that it has to be done.
I am wide open for suggestions and will read every comment. I'm also working without a manual due to them costing $150. So far it seems pretty straight forward and I really haven't run into anything that I haven't been able to figure out other than which end to start at.
Perry/Twisted Grip
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gregjo1948
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Re: JD 350C TRANNY QUESTION

Post by gregjo1948 » Tue Sep 18, 2018 4:17 am

I'm going to assume there is a reverser on this machine. It sounds like the coupler between the reverser and the trans. has stripped it's spline. I'd start at the front of the machine and remove drive train until you get the reverser out. You'll be able to see the coupler and the damage to the reverser output shaft and the trans. input shaft. If you're lucky, the trans. shaft will be OK so you don't have to remove it also. Lavoy can fix you up with the coupler and shaft from the reverser. When these machines start separating between the housings, it miss aligns the shafts and the coupler causing it to strip the splines. BTW; you should post 350 and later model machines in the "late model" forum next time.
JD 350B diesel w/rops & 6way blade, Case 580B Loader/backhoe, Farmall 504 highcrop, International 404 utility, International 284 diesel w/belly mower, 1972 Ford F600 dump truck, Galion 3-5 roller

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Stan Disbrow
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Re: JD 350C TRANNY QUESTION

Post by Stan Disbrow » Tue Sep 18, 2018 4:39 am

Hi,

The output shaft of the reverser and the input shaft of the trans have external splines while the coupler has internal splines. The coupler is made from softer material as it is intended to strip out before the more costly shafts are damaged. But that theory doesn't always hold true when the bolts allow flexing.

You still have a coupler on a machine without a reverser. In that case you have a long shaft between the coupler and the master engine clutch (no master engine clutch with a reverser as that job is performed by two clutch packs inside the reverser). There were not many reverserless units made, and then only early in production. So, yours probably has a reverser.

These machines were built starting with the trans. Then, the reverser and engine were added forward and the final drives to each side. In this case, start at the front and remove everything heading rearward.

Stan
There's No Such Thing As A Cheap Crawler!

Have: '58 JD 420c 5-roller w/62 inside manual blade
Have: '78 JD350C w/6310 outside manual blade
Useta Have: '68 JD350, '51 Terratrac GT-25
Also Have: 1950 M, 2005 x495, 2008 5103 (now known as 5045D)

Jim B
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Re: JD 350C TRANNY QUESTION

Post by Jim B » Tue Sep 18, 2018 4:50 am

Good morning,

Your 350C questions should be in the Late Model Forum, perhaps Lavoy will move this over there. I am sure others will reply to you as well but from what you have described of the gap at the bellhousing; I would start by pulling the engine and see what the damage is inside before pulling other things apart. It may just be the isolator.

Do you use the free access John Deere Parts Catalog on line for your machine? Those you don't have to purchase. You can find the drawings of the torsional isolator there to get an idea of what connects the flywheel and transmission input.

The cost of a manual is a concern but it is really money well spent when you look at the time it can save and possible damage to other parts using it may prevent. There will be adjustments and things to check the manual will help you with, specific to your machine. You should check with Lavoy on a manual, he might have an option for you at a better cost. eBay often has some used manuals, or CDs. You likely have done this, but if not, check your serial number to confirm you actually have a C model. I mention this as there have been many cases of machines having the wrong decals installed. More than one person has found out after the fact the machine was not what the decals said. It can make a big difference in components of the machine. Good luck.
Jim

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Stan Disbrow
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Re: JD 350C TRANNY QUESTION

Post by Stan Disbrow » Tue Sep 18, 2018 6:27 am

Hi,

Good point. I should have said it myself because I was sitting here thinking that we can't trust the C designation. Which is why I tossed in the part where it might not have a reverser.

The older series of Deere crawlers, based on wheel tractors, used the letter C to denote a crawler. Beginning with the JD350 and 450, there was no letter used at first. Then, with updates, they went to B. As in JD350B. In 1976, another redesign from dry to wet steering clutches saw the letter bump to C. As in JD350C. Later, they dropped the JD from in front so now the decal was just 350C.

The problem comes in that older machines tend to get new paint and/or new decals. So there are many JD350 and JD350B machines out there sporting JD350C or 350C decals. On top of that, there are many machines missing their serial number tags.

The issue then becomes getting the correct parts. There were a lot of changes between the 350B and the 350C.

If it really is a C, then you will have a reverser. The wet steering clutches need the oil pump in the reverser to pressurize the steering clutch packs with wet clutches. And, if you have a reverser, then you have an Isolator on the back of the flywheel.

But, the description of hearing spinning shafts with no motion makes me think stripped coupler. If the isolator is gone, then no shafts spin. And, a busted isolator is usually one loud banging thing. Not that it really matters. You get to the isolator before the reverser and the reverser before the coupler.

You do need both the Technical Manual and the Parts Catalog at this point. It can be difficult to source the correct part from the current computer system at times. It always helps me to head in with the PC in hand and give them beginning part numbers to cross. And the TM tells you how to get things apart and put them back together. Yes, they cost. But, I get them even on brand new machines where I probably won't need them for years to come.

Stan
There's No Such Thing As A Cheap Crawler!

Have: '58 JD 420c 5-roller w/62 inside manual blade
Have: '78 JD350C w/6310 outside manual blade
Useta Have: '68 JD350, '51 Terratrac GT-25
Also Have: 1950 M, 2005 x495, 2008 5103 (now known as 5045D)

Pbrogdo
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Re: JD 350C TRANNY QUESTION

Post by Pbrogdo » Mon Sep 24, 2018 6:53 pm

Hello all,
Thanks for the replies. I will be buying a technical manual probably on cd before I go much further. I am ready to pull the engine now so that should come apart in the next week or so (I own a motorcycle shop and stay very busy). Also I am working by myself. Sorry about posting in the wrong section, it seemed like an old tractor for me but when I think about it I am dealing with a company that has been in business for just a year or two. I'll continue to check back and try to leave some post and maybe a picture or two if I can figure that part out. My "keyboard retaining nut" ain't real tight on this thing.
Thanks again
Perry Brogdon
Dover, Arkansas
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Re: JD 350C TRANNY QUESTION

Post by Pbrogdo » Wed Nov 07, 2018 9:59 pm

Good afternoon,

OK, I finally got around to taking the little dozer apart and found the coupler and the ends of both shafts to be in "poor condition". The tracks were basically what was holding the tractor together as all of the bolts holding the tranny and reverser together were either missing or extremely loose. Also, the bolts attaching the frame rails to the rear final drive case were in the same shape. Had almost a 1/4" gap at each connection which put a serious bow in the drive line. Looking at pics it seems relatively "easy" to replace the rear shaft in the reverser but the input shaft in the tranny may be another story. Can the tranny input shaft be replaced without pulling the whole tranny? It looks like a tapered roller bearing on the rear end of the shaft in the parts diagram pictures but I know looks can be deceiving.

I would very much appreciate a suggested list of parts that I'll be needing to get this done. I found the shafts for around $350-$400 each, the coupling is about $50 but I will be guessing at seals and gaskets needed to do this job. I would like to have as much as possible on hand before I actually tear into these components if possible.

I suppose my biggest question is whether or not I can pull the input shaft out of the tranny from the front or not.

Good night
PBrogdo
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jsal
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Re: JD 350C TRANNY QUESTION

Post by jsal » Thu Nov 08, 2018 7:58 am

had the same trouble on my 350 rather than dismantle both trans and reverser I opted to place hardened bolts in the splined coupling and through the shafts by using carbide
tipped drills used the ones for glass & stone from Home depot you have to cut hole in the top of trans case to install the bolt after you assembly It can be done !!

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Lavoy
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Re: JD 350C TRANNY QUESTION

Post by Lavoy » Thu Nov 08, 2018 9:54 am

While having the parts on hand is not a bad idea, usually you will find something else that needs to be replaced while you are in there.
I have some of the bearings on hand for the reverser, no problem to get the rest. I might have the reverser shaft on hand, input shaft is few day delay.
Yes, you will likely have to pull the tranny to get an input shaft in, but maybe if the other shafts will drop down enough get some clearance, it might come out.
I would replace all the trans to bellhousing studs, or at least be sure they are good.
Lavoy
Parts and restoration for antique and late model John Deere crawlers.
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Pbrogdo
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Re: JD 350C TRANNY QUESTION

Post by Pbrogdo » Thu Nov 08, 2018 5:27 pm

I'm going to HAVE to replace all of the studs/bolts due to most of them are missing or broken. This poor old tractor has been into before and by the looks of things whoever did it didn't have much of a mechanical background. Mismatched bolts, washers, etc, not to mention the condition of the tractor. I have it apart and gave everything a good steam cleaning today. Gotta let everything dry off good before I'm gonna get back at it if the weather will cooperate. I'm doing this under the apron on my shop which isn't heated. May have to build myself a plastic tent.

Sometimes I wish I didn't know how to do anything...

Perry
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Re: JD 350C TRANNY QUESTION

Post by Pbrogdo » Thu Nov 08, 2018 5:30 pm

Lavoy,
How much $ are you needing for the shaft/shafts? Looks like there is an abundance of used parts available so I'm gonna do my best not to buy new stuff unless I have to such as seals, bearings, etc
Perry
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Lavoy
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Re: JD 350C TRANNY QUESTION

Post by Lavoy » Fri Nov 09, 2018 9:45 am

Shoot me an e-mail at postmaster@jdcrawlers.com and I will see what I have on hand.
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