350C Power Issues

[Jason37756]

I’ve got a 350c that spins the tracks in 1st gear but won’t move more than 3 feet when placed into 2nd gear. The crawler moves better in 3rd & 4th but has no pushing power. I have the same results in forward or reverse.

What’s your thoughts on where the problem is?

I’m no expert with the wet clutch machines and have read so much that I can’t wrap my mind around what is going on inside the reverser as it relates to the transmission. I have the tech manual.

I don’t hear any abnormal noise or feel anything grinding.

New fluid and filter in the reverser. I am unable to check the pressure on the valve due to the plugs being wallowed out…the shift rate from forward to reverse is good.

Thanks

[LeonardL]

Sorry I didn't see your post on the wallowed out test port plugs. Unfortunately that is exactly where you need to start. Your issue could be one of a few different things or a combination of different component issues.

I have used heat to help get those plugs out. Then I replace them with a pipe plug that has the square head on it instead of the inverted Allen socket that comes from the factory.

Unfortunately you may need to drill these out and hope that you don't leave shavings inside the valve body after you're done. I have actually started the machine once I have the plugs out and let it flush oil out through the ports to flush anything out that may have gotten inside.

Your only other alternative is to pull the reverser and then break the valve body down so that you can get to the individual plugs better. I know it's deep but that may be your best bet.

I doubt your issue is transmission related. Usually on a 350 with a reverser the only thing that goes bad will be the spines on the input shaft. If it was that then you loose all power because the reverser and transmission are no longer connected.

You really need to know what your reverser is doing before you can proceed to another component. Sorry to be the bearer of bad news but that is what you need to do. Check the pressures, especially the engagement pressure and it should be a minimum of 125 PSI. Preferably on a 350C it should be up around 150 PSI.

[Jason37756]

Thanks for the reply.

I’ve already disassembled back to the transmission and repaired the plugs as you mentioned…I had a little problem with one of them on the repair so I’m gonna try to never unthread from the valve again by installing a short piece of pipe. We’ll see if I have enough clearance to leave it.

I am a bit confused with spinning the tracks in first gear and barely moving in second gear. Is it because the transmission is asking for more speed and the reverser simply can’t supply it?

I’m not a big fan of putting this thing back together for a test run. I would prefer to just rebuild the reverser if that’s where my issue rest at. I read where someone used a motor or drill to power the reverser for test purposes…I may try that before I reassemble anything.

I broke a oil tube in the process, so I’ll be needing one of those if anybody has one…My John Deere dealer says they can’t get it because it an obsolete item…I may have to machine one.

[LeonardL]

I have had these do what you're describing and in most of the cases it was a leaking seal in one or the other of the clutch packs. I have also seen the steel sealing rings on the manifold leak and cause your issue. And yes, they will sometimes go ahead and spin the tracks in first gear but not in any of the other gears. First gear of course requires less energy so the machine will still function in that gear.

So the line you broke?? Is it an oil line or one of the tubes that goes between the valve body and the manifold? If it is one of those tubes then you can find those select used at machine salvage yards. If it is one of the lines on the outside then you can replace those by either getting them used or I have replaced them with a good grade of hydraulic hose and the right fittings.

Your idea for the stand pipe is a good one by the way. If you run into clearance issues then try a pipe cap for the pipe. Then when you need to check pressures you can put your coupler on it to connect your gauge.

Personally... I would go ahead and rebuild that reverser while you have it out. Mostly because it is such a long way into them once you install it.

You can check your pressures while out of the machine. I have used a large gear reduction drill that will spin them fast enough to get pretty close to what your idling pressure would be while on the machine.

I would be careful if you hook an electric motor to check pressures. Just make sure the rated rpm of the motor is similar to what the engine would be. But then you are probably smarter than I am and know exactly what to do. I've just never tried hooking a motor up to one of these reversers. I know there are a couple of guys on here who have done this with great results.

You can also bench test the clutch packs by using compressed air. Just be mindful of where you apply your air. I always use the tubes that fit into the manifold. One is forward and the other is reverse.

[Jason37756]

Thanks for the reply…really good info.

So the oil tube that connects the valve body and the manifold is what I broke. I’ll have to figure that out. We really don’t have any good bones yards around here for these dozers.

Sounds like a reverser rebuild is in order…I’m not sure what the steel sealing rings on the manifold are but I’ll take a look at the parts catalog and go from there.

We’ll see how the bench testing goes. Might just hook the ol’ 3-179 to the reverser and see what happens if my drill doesn’t do it.

[Jason37756]

Here’s a sealing ring #30 in the accumulator. Would that be the steal ring you’re speaking of?

Thanks

[LeonardL]

No... there are two sealing rings on the manifold itself. Look in the parts breakdown for the reverser assembly and you will see the manifold and then a steel ring on either side. One for forward and the other is reverse.

Now that being said... the ring you referred to can cause issues with slippage. So you will need to take a look at it for sure. Usually however if it is a broken accumulator ring then it will slip in all four gears.

As for salvage yards, we have a good one here in Missouri. ( Zimmerman Tractor 573-378-7210 ) They will ship to just about anywhere I think. There is also out in New Hampshire, ( PB & H Equipment Parts 1-888-588-3005 or 603-588-3005 ) They will also ship all over.

You might even check with Lavoy who owns this site and see what he can do for you. He sells a lot of parts although a lot of what he does is older stuff. Still I would check with him. He's also a wealth of information as well.

[Jason37756]

Leonard,

Thanks for taking your time to reply with your wisdom.

I looked thru the parts catalog last night and saw those sealing rings after I had posted.

When I separated the transmission from the reverser I had a brown oil setting in rear of the reverser housing. I also had some clean fluid leaking from that area before disassembly…where the rear cotter pin #41 is setting designed to move and let fluid leak out if there is a leak. It appeared to be coming from the joint of the two housings…Had a reddish tint to it so I assumed reverser fluid. I can’t remember what those inputs and output areas looked like in terms of being wet with oil. In either instance it would suggest I have a leak there and could be losing pressure because of it.

I’ll follow up after I start the repair work. Thanks again!