Cat 627B

[Austin Strandlund]

Hey, we just bought a used 627B scraper, and engines and hydraulics run great, Newer tires so seemed like a good machine, But when you are going up a steep hill it seems to slip, and then engage into that gear, it may slip again and keeps shifting up, we took top cover of transmission cover off, and all the slides and valves look good no rust, and oil looks good just blacker then normal but no metal or sparkles, doesn’t smell burnt. So wondering if there is anything besides a bad tranny causing it to shift so weird. all answers helpfull, don’t know much about scrapers.

 

[Nige]

As always, please post a Serial Number. It takes the guesswork out of finding technical information. In fact post S/Ns for both the tractor and the scraper (they are separate).

Do you have an Maintenance Manual for it yet.? If not you really should get one ASAP. The publication reference is SEBU5765 and you can get one from HERE for around $50.

Next step would be to change the transsmission oil & filter (dark oil not good, dark/burnt oil even worse) plus remove and clean out the suction screen. What you find in the screen may give you a clue as to what might be going on.

It might be a silly question but is the transmission oil level correct.? Are you checking it with the engine stopped or running.?

 

[Austin Strandlund]

Ok I will get serial numbers, and ya have a service manual, the oil level is quite high, would that cause anything more then overheating ?

 

[Nige]

Ok I will get serial numbers, and ya have a service manual, the oil level is quite high, would that cause anything more then overheating ?

Is the “service manual” a thick binder or a book about a half inch thick.?

How are you checking the transmission oil level. Engine stopped or running.?

 

[Austin Strandlund]

I Got both the parts manual 1/2 book and then the big 3 ring manual, and have checked it with engine stopped.

 

[Nige]

I Got both the parts manual 1/2 book and then the big 3 ring manual, and have checked it with engine stopped.

So should I assume you haven't actually read any of them....?

The attached are the checks in the section titled "After starting the engine".

 

[Austin Strandlund]

I have read a lot of the book, mostly under troubleshooting of transmission, I checked oil in transmission while running and level is a little above Full, mostly wondering if anyone has ideas for anything besides replacing clutches. like the book suggests

Serial #68m967169m971

 

[Dave Neubert]

do a pressure test pull strainer and check for clutch materal

 

[Austin Strandlund]

do a pressure test pull strainer and check for clutch materal

Ok, where is strainer located on this ? or look like

 

[Nige]

Serial #68m967169m971

Thanks for that. So you have an early 627, not a 627B, even though it might have stickers on it saying it is a B model.

Look in your Parts Manual for 6D9000 - Transmission Tank & Lines.
The screen is Ref #19 on the illustration, just to the left of the transmission tank. The 9M8669 Screen is also illustrated separately.
The first thing I would suggest is to pull that screen and inspect. It has a magnet inside it. Look for both metal & non-metal particles. Post photos of what you find.

Also take a look at the front transmission 8S9010. There is a similar screen to the one next to the tank but mounted right into the back side of the case. It will have a square cover secured by 4 bolts.

Judging by the colour of the oil in your photo it looks burned. It should be clear and bright, not dark like that photo.

 

[Nige]

Below is an illustration of the back side of the front transmission. The magnetic suction screen #3 & 4 is behind cover "A". Look for 2S6472 in your Parts Manual.

 

[Nige]

Does the cover of the Maintenance Manual that you have look like the attachment.?
The reason I ask is that there is no online maintenance/servicing information available for the 68M/69M machine.

 

[Austin Strandlund]

Thanks for all the help found metal in the filter, does anyone know a place to get a manual to rebuild transmission or is the clutch job easy ?

 

[Nige]

found metal in the filter, does anyone know a place to get a manual to rebuild transmission or is the clutch job easy ?

Metal indicates what's known as a "hard" failure (as opposed to a "soft" failure which would be a clutch letting go). With a hard failure you can expect to find more than just a failed clutch or clutches in the transmission, there will also be damage to metal parts.

Can you post some photos of the metal particles.? In which filter/screen exactly did you find the metal, the one on the back side of the transmission or the one at the side of the tank.?

Regarding availability of a manual, I thought you said you had the big ring binder.? Doesn't that cover transmission disassembly.?

 

[Austin Strandlund]

Sorry for the late response, been busy time of year, but looked in the magnetic screen on the rear of the transmission, and found what seemed to be clutch material. When we could get it to shift the gears felt good, everyone think it’s just clutches? or a lot more ?

 

[OzDozer]

A lot depends on how long it's been since the screen and magnets have been cleaned - but I'd have to opine that transmission is on its way out, and very much in need of a rebuild.

Fine metal particles quite often come from failing bearings. Pressure tests are just one of the ways to acquire an idea of transmission condition.

Check that linkages are in good order and properly adjusted, and that the valve spools are not being held out of their detent positions, thus reducing oil flow or pressure to critical areas such as clutch pack pistons.

 

[R.D.G013]

Hey, we just bought a used 627B scraper, and engines and hydraulics run great, Newer tires so seemed like a good machine, But when you are going up a steep hill it seems to slip, and then engage into that gear, it may slip again and keeps shifting up, we took top cover of transmission cover off, and all the slides and valves look good no rust, and oil looks good just blacker then normal but no metal or sparkles, doesn’t smell burnt. So wondering if there is anything besides a bad tranny causing it to shift so weird. all answers helpfull, don’t know much about scrapers.

Are U sure it's slipping, and not just hunting for another gear, you say it keeps on shifting up. What happens if U stand on the trans hold pedal and keep it in one gear, does it still appear to slip then ????

 

[Tinkerer]

Check the engine rpm's when the transmission is doing what you described.
If it isn't running max rpm's the transmission will shift up and down ,rapidly depending on the how much load is on it.
Sometimes a simple thing like the throttle link adjustment will cause that.