Need help on 931b

[Long John]

I am needing someone that can tell me what the small 1/2 inch post on the left side fender behind the gear shift lever. It spins around so don’t know what it does. Also anyone that has a 931 do you like the way the throttle is done on the gear shift. I was thinking of putting a separate lever on the right side. Thanks for all the help.

 

[Simon C]

Post a picture, a serial number, year and maybe someone will attempt to help.
Simon C

 

[Nige]

Also anyone that has a 931 do you like the way the throttle is done on the gear shift.

Your machine is obviously fitted with the optional (rotational) engine governor control. The standard control is a pull-type lever to the right of the gear selector marked "1" in the illustration below.

I am needing someone that can tell me what the small 1/2 inch post on the left side fender behind the gear shift lever. It spins around so don’t know what it does.

Could it possibly be the location where the knob for the heater control is supposed to be fixed.? Which one of the two in the top left corner of the photo above are you talking about.?

Can I suggest that one of your best investments at this point would be an Operation & Maintenance Manual. You can download one for $52 from HERE by putting SEBU5650 and click the Search button. The image below should appear. The O&M would be very useful if you plan on maintaining the machine yourself.



You asked about year in another thread you posted. 25Y0801 was built on the 15th January 1980 but that date is irrelevant for the purpose of parts and service information. The machine Serial Number is key to everything.

P.S. I am going to ask the site admin to move this thread to the Track Loader section where it will get more exposure. The 931B falls into that category because the backhoe was only ever an optional attachment, the basic machine is a track loader.

 

[Welder Dave]

Could the post be the horn button is loose missing the button? Right beside #1 in Nige's pic.
I have the throttle on the gear shift. I've got used to it and prefer it for truck loading or lots of back and forth because it let's you slow the engine for a second when changing direction. Very similar to a decelerator pedal on a dozer. It's better for the transmission and faster than throttling down then having to shift the trans. and then throttle up again. I have to be aware because sometimes it sticks and you have react fast and pop into neutral. It also doesn't always hold when I want a constant speed for the backhoe. It detents at full throttle but I usually like to run about 3/4 throttle.

 

[Long John]

Thanks for all the info and will definitely be getting the manual. I cut the oil filter open and have a lot of what looks like aluminum . I also noticed that there was almost no oil in the filter and it had been moved about 7 days ago which bothers me. I have pics of the filter material. Maybe you can tell what to look for when I pull the pan.

 

[Nige]

Whatever it is that does NOT look good. Have you tried it with a magnet to confirm that it is non-metalic.?

I also think I see a few small particles of brass in there as well.

 

[Long John]

Will try magnet and I thought I saw some little specs of brass as well.

 

[Long John]

Tried a magnet and none of it sticks so it looks like it is aluminum. Hopefully it is just the wear off the main and rod bearings. I am going to pull the pan and check the bearings and the crankshaft. If crank is messed up I will have to pull engine.

 

[Welder Dave]

You will have a big problem. You can't pull the oil pan off without pulling the engine out because of the cross member connecting the track frames together. Actually the engine and transmission have to come out together. The trans. mounts have to be removed as well. I got a hole in the oil pan and in a round-a-bout way it caused a spun rod bearing. Apparently the pick up tube had a tiny crack as well. If I could have pulled the oil pan may have avoided expensive repairs. With the engine out I did a full rebuild with 3 ring pistons. Injection pump didn't require any work but a little later had a leaking throttle shaft. Fixed that using 2 seals as recommended by the Cat guru on these machines, the late Bob/Ont.

 

[Nige]

I’m not sure if you can even get the pan out with the engine in place.

 

[Welder Dave]

You can't. I think I read where somebody jacked or lifted the engine up and took out the cross member but that could be a nightmare too.

 

[Long John]

Thanks for heads up on that. On your engine does the oil filter stick out almost horizontal or vertical? Mine sticks out to the side and had almost no oil in it when I took it off.I found out from previous owner that the motor has been changed. The oil filter 1R0713 that it calls for will not fit but takes a 1R0734. The 713 has a 1&1/8 thread and the 0734 has a 1 inch.

 

[Long John]

Do these engines have sleeves in the cylinders. This is first time I have did any engine work on a Cat machine

 

[OzDozer]

The 3204 is a "parent block" engine, no sleeves. You can bore them up to .040", or install thin-wall sleeves.

They were a "cheap, throwaway, low-friction" engine design with only 2 rings, originally produced as the "V-636" V8 engine for Ford trucks, in 1967. The engine then became the "1100 series".

Then Cat redesigned the 1100 series V8 into the 3208 in the early 70's and produced the 3204, one half of a 3208.
The two engines share a large number of common components.

There are no replaceable valve guides either, you need to bore the guides and install "K-Line" bronze inserts. There are hardened valve seat inserts in the cylinder head.

Valves are cheap, replace the valves with good quality aftermarket U.S.-made valves.
IPD make complete engine kits for the 3204, use the 3 ring piston, it's more durable than the 2 ring design.

The wrist pin bushings are a weak area, try and acquire Cat wrist pin bushings, they are the most durable bushings of all the bushings available.

The 3204 oil filter design changed somewhere along the way, and the parts systems failed to keep up.
I had the same problem with my 3204 in my 931B, even the Cat parts system gave me the wrong filter initially.

 

[Long John]

Thanks OzDozer I had a mechanic come over today and going to have him do all the work for me. Going to put in new 3 ring pistons, new Cat wrist pins, oil pump, lower bearings, work head and front/rear seals. He said labor would be about $2000. I thought that sounded like a fair price for that amount of work.

 

[Welder Dave]

My 86 is somewhere around the time they changed oil filters where going by the serial number doesn't give a definitive answer. It is the newer number but I make sure to take the number off the old filter when getting a new one.

$2000 labour is a great price.

 

[Long John]

My 86 is somewhere around the time they changed oil filters where going by the serial number doesn't give a definitive answer. It is the newer number but I make sure to take the number off the old filter when getting a new one.

$2000 labour is a great price.

Do you use the 1R-0734 filter now. It calls for the 1R-0713 filter buy threads are larger.

 

[Welder Dave]

I can't remember off the top of my head. It's the filter a 931C uses.

 

[Imajica]

Years ago, I got a rock between the oil pan and belly pan that poked a small hole/crack in the oil pan of my 931b. For years, it would drain all of the oil in about 48 hours so the machine got little use…$100 in oil every time you started the machine. My solution was to drain and pump out every bit of the oil possible. Then remove the dip stick and tape the tube closed. Then hook up a large shop vac to the oil fill tube to create negative pressure in the pan. Then I repeatedly used alcohol to wipe the damaged area, some of which was sucked through the crack, removing the oil from the edges of the damage. Next, I applied West System (a liquid epoxy) to the area, some of which as pulled into the crack. Two application over two days and the area was sealed. light sanded and applied a coat of JB Weld to the whole area for additional protection. Flushed engine to remove any epoxy or residual alcohol. 4 years now and no leaks. PIA but much easier than removing motor and trans.

now, if I could just find some track for 29y2078!

 

[Welder Dave]

Years ago, I got a rock between the oil pan and belly pan that poked a small hole/crack in the oil pan of my 931b. For years, it would drain all of the oil in about 48 hours so the machine got little use…$100 in oil every time you started the machine. My solution was to drain and pump out every bit of the oil possible. Then remove the dip stick and tape the tube closed. Then hook up a large shop vac to the oil fill tube to create negative pressure in the pan. Then I repeatedly used alcohol to wipe the damaged area, some of which was sucked through the crack, removing the oil from the edges of the damage. Next, I applied West System (a liquid epoxy) to the area, some of which as pulled into the crack. Two application over two days and the area was sealed. light sanded and applied a coat of JB Weld to the whole area for additional protection. Flushed engine to remove any epoxy or residual alcohol. 4 years now and no leaks. PIA but much easier than removing motor and trans.

now, if I could just find some track for 29y2078!

You're lucky the pick up tube didn't crack. I had a root puncture the oil pan through the hole for the drain plug. It also cracked the pick up tube. Shop found a used cast iron oil pan for half the price of a new stamped one. Needed odd length bolts so they cut standard bolts shorter. I made a bolt on cover for the drain plug hole and welded short lengths of channel iron around it so it couldn't get snaged and ripped off. Any roots or branches would hit the channel iron instead.