350C Clutch Control Valve Adjustment

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Tjgerow
40C crawler
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Location: Central Virginia

350C Clutch Control Valve Adjustment

Post by Tjgerow » Fri Nov 20, 2020 1:04 pm

The service manual documents a procedure to adjust the steering valve rods and levers. It seems straight forward if you have done it before. However, this is the first time I'll be making these adjustments and I have a few questions for those that have done it before.

The manual states to start the engine (what RPM?), place in 1st gear, place reverser in gear (forward, reverse, doesn't matter?), set the foot brake and lock it down. So now I have a crawler running, in gear, with the brake applied, and the seat off...and trying to figure out when the clutch engages and when it disengages.

Question 1: where the heck do you stand to do this procedure? Or are you getting on and off the crawler a lot testing linkage adjustments?

Question 2: is this procedure bad for the clutches since its possible that the clutch you are not working on is already engaged but the brake is holding the clutch in place? I don't want to tear anything up during this process.

Question 3: the procedure says the Steering Levers should be 1.5" from the stop position when the clutch engages. I assume the stop position is the at rest position when the levers are resting on the steel peg on the floor board. Where is this measurement taken from?

Question 4: related to #3, is the clutch not engaged between the "stop position" and the Steering Levers being moved 1.5"? So with the levers setting on the stop position pegs and hands off the levers, the steering clutches are not engaged? Which means to start moving the Steering Levers need to be pulled back at least 1.5"? I don't have an operator manual yet and this might be answered in that book.

Question 5: With the brake set, how do you know when the clutch engages and disengages? Listen for engine RPM drop, crawler starts to move?

Question 6: This is more of a gripe, why does the manual not specify the distance the Steering Valve Rod should be protruding from the Steering Valve Housing for the clutch to be engaged and disengaged? It seems the Steering Valve Rods would engage the clutch based on a given distance of travel. For example, adjust the Eyebolts so that the Valve Rods are protruding 2.25" from the face of the Valve Housing when the Steering Arms are at rest. Then verify the clutch engages at 1.5" of Steering Lever travel and disengages at 2.5". This seems like it would give a better starting point. The Steering Valve Rods are pretty long and can be pushed in until almost flush with the Valve Housing but there's not a specification around where in the travel the rods should operate, only the Steering Lever travel.

Thanks for reading and any info you can provide.
1978 350CE Dozer, 6-way blade and winch.
Currently working with the owner to get it running before I buy it.
New clutches and brake bands. Just installed tracks.
Troubleshooting reverser and pressure issues (won't move)

Jim B
350 crawler
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Location: western Maine

Re: 350C Clutch Control Valve Adjustment

Post by Jim B » Fri Nov 20, 2020 2:16 pm

First, I will say I do not have a 350C manual, so I can’t see what you are reading for myself; therefore I may have something incorrect here. I’m sure LeonardL and some of the others will correct any errors I have made, and give you other pointers.

The manual states to start the engine (what RPM?), place in 1st gear, place reverser in gear (forward, reverse, doesn't matter?), set the foot brake and lock it down. So now I have a crawler running, in gear, with the brake applied, and the seat off...and trying to figure out when the clutch engages and when it disengages.

Answer: Another manual says “Start engine and run at a slow idle. Shift Transmission to 1st range forward.

Question 1: where the heck do you stand to do this procedure? Or are you getting on and off the crawler a lot testing linkage adjustments? Answer: You may want to have something in place of the seat you can place or remove as you need to check lever travel or make adjustments. You will likely want be in the seated position at times with the tools to measure within reach. Yes, you will find you have to get on and off multiple times. One of the things the writers leave to the person doing a task is how the person will position themselves. Different people do things differently because of their physical traits.

Question 2: is this procedure bad for the clutches since its possible that the clutch you are not working on is already engaged but the brake is holding the clutch in place? I don't want to tear anything up during this process.

Answer: My thought on this is, that the time you need the crawler running to do the checks is only a short duration each time, it would be shut off while making adjustments. You should not do any damage to the clutches for the short durations involved.

Question 3: the procedure says the Steering Levers should be 1.5" from the stop position when the clutch engages. I assume the stop position is the at rest position when the levers are resting on the steel peg on the floor board. Where is this measurement taken from?

Answer: Yes, stop position is with the lever on the peg at rest. The manual I am looking at references pulling the lever fully back into the brake just before this, so the clutch would be released then and engage at the 1.5” point as it is returned to the stop position. Measure from spots, you pick, on the dash to the top of the steering lever handles. These should be in line with the top of the handles so you have a straight-line measurement, mark the spots if needed so you go back to the same place each time.

Question 4: related to #3, is the clutch not engaged between the "stop position" and the Steering Levers being moved 1.5"? So with the levers setting on the stop position pegs and hands off the levers, the steering clutches are not engaged? Which means to start moving the Steering Levers need to be pulled back at least 1.5"? I don't have an operator manual yet and this might be answered in that book.

Answer: There should be a section of theory of operation in your service/technical manual that describes oil flows and how the steering and brake system works in detail. The short answer is the steering clutches are engaged (pressurized with oil) while the crawler is running unless you pull the lever back to the point the steering valve removes the oil pressure from the steering clutch. That point and when the brake applies are being set during this adjustment procedure.

Question 5: With the brake set, how do you know when the clutch engages and disengages? Listen for engine RPM drop, crawler starts to move?

Answer: There should be a noticeable change in the engine when the clutches release or apply.

Question 6: This is more of a gripe, why does the manual not specify the distance the Steering Valve Rod should be protruding from the Steering Valve Housing for the clutch to be engaged and disengaged? It seems the Steering Valve Rods would engage the clutch based on a given distance of travel. For example, adjust the Eyebolts so that the Valve Rods are protruding 2.25" from the face of the Valve Housing when the Steering Arms are at rest. Then verify the clutch engages at 1.5" of Steering Lever travel and disengages at 2.5". This seems like it would give a better starting point. The Steering Valve Rods are pretty long and can be pushed in until almost flush with the Valve Housing but there's not a specification around where in the travel the rods should operate, only the Steering Lever travel.

Answer: Yes, they could give a measurement as a starting point, but they don’t choose to. My thought on this is the valves have more travel than needed and the steering lever position and stroke is more critical for operating than focusing on the valve stroke. The adjustment procedure compensates for some of the wear in the linkages, which just setting the stroke of the valve would not address.
HTH Jim

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LeonardL
2010 crawler
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Re: 350C Clutch Control Valve Adjustment

Post by LeonardL » Fri Nov 20, 2020 7:34 pm

First of all... Jim you deserve an award for going through each of those questions and then giving a great answer to each of them. That took a while and it should be appreciated. So my hat at least is off to you. And... thank you for doing it.

I am going to have to dig a bit on this because it has been at least a hundred years since I last did this. I do agree with the initial observance of this procedure as it is written. Whoever authored it must have been on a really good hallucinogenic. I figure it must have been some really good stuff for them to come up with this crap!! It reads like a really good way to get someone hurt or worse. But... that's my opinion.

It is at the very least the absolute lamest excuse for a technical procedure of any I ever had to try to make work. I'm here to say that I never did get their procedure to perform as they described it. If a guy does what they say then you will most likely crash the crawler in its tracks! :shock: :lol: So... I set out to come up with a cheat that would do the same thing and not cause a crash in the process.

The only question I have is why are you wanting to adjust this in the first place? I mean it is not a routine adjustment that needs done every so often. Usually if nothing has broken or come undone you never have to adjust these plungers. Just curious why you're doing it.

Now... all of that being said, if you insist and really want to try what Deere has written then at least forget the locking of the brakes. Put your machine up on blocks that are secure enough to allow your machine to turn the tracks freely. Keep the machine at idle because you will still be in a difficult position to make any adjustments. At idle you will at least not go far enough to hurt much. Hopefully you and everyone around you will stay clear.

My cheat is pretty simple. And I didn't need drugs to figure it out. The steering valve is basically an on or off hydraulic control valve. It has a return spring behind each of the plungers that basically keep the valve where it should be to operate the clutches when the lever is at rest. If memory serves me, with the steering lever at rest, you can take the connecting rod loose at the eye bolt on the end of each plunger. Once you have it free, push the plunger in until you just begin to feel the spring. Don't push hard enough to start collapsing the spring, you only want to feel the end of it. Then screw the eye bolt in or out until the connecting rod will slip in and out of the hole freely. Then tighten the lock nut on the eye bolt and reconnect the rod with a washer and a cotter key. This should work. But check the operation of each track just to make sure. I always tell people that if nothing else, just make sure the clutch is releasing before the brake starts to engage.

As I recall your eye bolts should end up somewhere between 1-1/4" to 1-1/2" measured from the end of the plunger to the center of the eye on the eye bolt. This will be pretty close.

I have tried other things as well but this seemed to be the easiest to do. It sure doesn't need to be as complicated as Deere wrote it. Your clutch is either on or off. Engaged or disengaged. You want your steering lever to turn the valve off or disengaged in that first little bit of pull on the lever. In Deeres eyes that is the inch and a half they wrote for specs.

One thing to watch for is your steering lever connecting rods can be bent and cause problems with adjustment. If they are bent don't use heat to try and straighten them. They are heat treated in an attempt at keeping them from bending. But they will bend if given enough force. I have used a hydraulic press to straiten them but they usually break. If you try to heat them it takes the temper out and they will bend easily.

I hope I have remembered this correctly. If you have problems then let us... me know and I will go dig my notes out. Good Luck!!
40 years working on JD 350s and other equipment.

Tjgerow
40C crawler
40C crawler
Posts: 13
Joined: Wed Oct 14, 2020 9:27 pm
Location: Central Virginia

Re: 350C Clutch Control Valve Adjustment

Post by Tjgerow » Sat Nov 21, 2020 1:28 pm

Jim thanks for the detailed answers. Your information is very helpful and clears up a lot on this procedure. There should be an award emoji!

LeonardL, thanks for your information too. I think we both agree on the lack of clarity in the Deere manual. Your procedure will get me in the ballpark to start adjustments..

For the background, I was looking to buy a 350 dozer. A guy had a 350B but sold it the day before I called him. He told me he had a 350C that he was putting new clutches in and it would be ready in 2 weeks. I asked if I could come see it while it was torn apart as I have no experience with heavy equipment. I ended up driving 2 hours to see the dozer and stayed for 6 more hours to help him get the clutches installed, new brake bands and one final drive on. I've made 4 more trips back there to help him. Its been over 2 months now...not two weeks. But the guy is in his 80s and I'll give him some slack for his initial timeline :D . He gets around pretty good and is fun to talk with. I'm learning a lot from him and he lets me do most of the wrenching. I still have not decided if I'm buying the machine, mainly because it hasn't moved and pushed any dirt, so I have no idea what else might be wrong with it. Worst case I have a new friend and have learned a lot about a John Deere 350C dozer.

When he bought the dozer it would move forward and backwards but not push any load. He was not familiar with the C models and immediately tore it down to replace the clutches. From what I've read in the service manual there were a lot of tests that could have been done first. He's worked on a lot of straight 350's and B models, this is the first C model.

On the last trip up we got the tracks back on it. So it has new clutches and brake bands but it is doing exactly what it was doing when he got it. It will move forward a little, really doesn't want to move in reverse at all. You have to "pump" the levers and eventually it will start to move forward. In reverse you have to do the same thing and one side seems to go better than the other. We have only moved the dozer about 4 feet total.

I put the transmission in 1st gear and used the reverser in both forward and reverse. Nothing changed in how it behaved. I then put the transmission in reverse and the reverser in forward to see if maybe the reverse clutch was bad since the dozer seemed to move forward better than reverse, but the same issue was observed. So I think the reverser forward and reverse clutches are ok, or both bad :shock:

This leads to how to diagnose the problem. I started by loosening the brake linkage from the levers to make sure the brakes were not engaging before the clutch released. We also backed the brake adjusters off a lot to try and make sure a brake band was not dragging.

All fluids are full. The paper filter in the reverser looks ok. He sprayed some liquid on the outside of the filter and it dripped through to the middle pretty quick which seemed to be a quick way to tell if the filter was clogged. At least in that specific spot it was not clogged :)

He pulled the Clutch Regulating Valve plug out to check that prior to me getting there and then couldn't get the plug back in due to the spring pressure. I'm not sure what we achieved, in that we didn't take the plunger out or see it, only the spring and penny shim. So I don't know if the plunger might be stuck in a position that is letting pressure bleed off. The spring and plug were tough to get back in and it took some coordination between both of us to do it.

So after all this information, the short answer to your question is that the dozer has new brake bands and rebuilt clutches and I was trying to make sure everything was adjusted properly since the dozer wasn't working properly when the guy bought it. :D It's hard to tell what any previous owners have done to the machine or if anything was adjusted properly. I'm just hoping the rebuilt clutches were bench tested before we put them in.

I'm learning as I go and usually spend some time reading the service manual once I get home to get a better idea of what we were dealing with.

The next step when I go back in a couple weeks will be to do the pressure tests on the reverser and see if its making pressure. I'm thinking the reverser is not functioning correctly and hopefully its a stuck Regulating Valve or an accumulator issue that can be resolved without pulling the reverser out. If the reverser has to come out I may just have to pass on this dozer as winter is coming and I really don't have the time to drive 4 hours round trip every couple of weeks, plus we are working outside, so weather is an issue.

On the plus side, I have learned a ton about the final drive assembly and clutches. I feel confident I could work on this machine if I did buy it. He's offered the machine to me for under 9K delivered, once its running. He wants it to be right whether I buy it or not. If we do get it running correctly then it seems to be a pretty good deal and I'll know the machine inside an out.

I'll be making at least one more trip and then make a decision. I've even thought of offering him less to take it "as is" so I can work on it at home, I'm just not sure how much I would end up putting into it if it needs a reverser rebuilt or some other expensive item. I've been looking in the area (Virginia, Southern PA, NC, North East TN) for another 350B or C dozer but they aren't showing up on craigslist or facebook market place anymore. If I pass on this one then the next machine may look good but have some internal issues that could create an expensive repair. At least this machine I have some knowledge of the work done to date.


On a totally different subject...should I continue to post updates and ask questions in this thread regarding this dozer? Or create a new thread for each issue I'm trying to resolve if I don't find the answer in another thread? I was thinking that a new thread for each issue would make it easier for someone to find the posts if they had similar issues and they would not have to look through pages of chit chat to get to the answers.

Thanks again Jim and LeonardL for the information!
1978 350CE Dozer, 6-way blade and winch.
Currently working with the owner to get it running before I buy it.
New clutches and brake bands. Just installed tracks.
Troubleshooting reverser and pressure issues (won't move)

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CatD8RII
1010 crawler
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Location: PA

Re: 350C Clutch Control Valve Adjustment

Post by CatD8RII » Thu Nov 26, 2020 7:44 pm

Continuing on this thread will make it easier to follow IMO.

Get a gauge on your reverser clutch pressures, that will really dictate which direction to go afterwards.

You don't need the transmission in gear to check them.

Just remember, that oil is what feeds the steering clutches, so low pressure in one area can affect the other. Typically a leak in the clutch circuit will eventually transfer oil from the reverser into the transmission/clutch housing/final drives and end up overfilling them, while emptying the reverser.

If you suspect the steering clutches are a problem the manual illustrates a procedure to leak test the entire system (from the steering valves onward).
Just be sure to have your levers hooked to your spools, or they might pop out.

You can also cap off the feed line to the clutches and recheck reverser pressures to rule out the clutch circuit, it's either a -6 or -8 JIC fitting if my memory is worth anything.

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