Help Evaluating '74 Cat 951c

[JacobRussell]

Hey all -

I'm a landowner looking at potentially buying a machine to clear and level forested land, lay in a drive, drag timber around, etc. on a budget. Ideally I'd like to buy a machine, get good use out of it for a year or so without major work on the machine, and then make the call to sell it or keep long term.

http://dropshare.artisandm.com/531-front-quarter.jpg

I looked today at a 951c at a good price ($5k) that for the most part is in reasonable good shape. I had an equipment inspector run through everything with me, and we came up with a list of maintenance issues, larger issues, and potential dealbreakers. I'm looking for feedback on the issues we found to see if any are bigger warning signs, and most importantly any advice on the two larger dealbreakers to see if it'll still fit my needs. I'll work from bigger issues down the list -

Dealbreaker - There's a delay in movement when going into 2nd or 3rd gear in both forward and reverse. In 1st the machine moves immediately as expected, but when moving into 2nd or 3rd it sits for 3-5 seconds and then starts rolling. In 3rd it also seems sluggish once it starts moving. During that delay there's no sound, grinding, etc., it just sits. The movement of the shifter stick seems fine, as far as I can tell. I'm not sure how the transmission works on these machines, so I have no idea what could cause an issue like that. Is this a common issue? Is there some sort of relatively simple fix? If not, opening up the transmission to repair/replace larger parts will be a dealbreaker for me on this machine.

Potential Dealbreaker - The drive sprocket teeth on both sides are quite worn - this was pointed out to me both by the dealer and the inspector. The track pins are also worn. What I want to gauge is how much life this has left - can I get a year of moderate use out of what's left on this sprocket? At the end of that, what kind of cost / effort am I looking at to repair or replace the sprocket? From what I've seen, the more common choice is to re-weld a new sprocket rim on instead of replacing the whole sprocket due to ease of replacement. Photos here -

http://dropshare.artisandm.com/531-sprocket-teeth-right.jpg
http://dropshare.artisandm.com/531-track-pins-right.jpg
http://dropshare.artisandm.com/531-idler-left.jpg

Other concerns I'd like feedback on, but seem less severe given my needs -

• Blow-by described by my equipment inspector as moderate, not terrible.
• Mild leaks from 2 hydraulic cylinders.
• Moderate oil leak somewhere in the transmission area. Wasn't actively dripping but clearly there.
• Apparent diesel leak near the feed into the engine (hose or connector presumably).
• Lot's of side play in the upper bucket arms (not sure the correct name, but not the main lift arms), but according to my inspector they didn't have enough slop to worry about them snapping.
• Quite worn track plates - none worn through, but not a lot of ridging left on the plates.
• Loose plates / track bolts (every ~5th track piece on average).
• White smoke from exhaust after engine warmed up for ~10 minutes or so, along with an occasional miss from the engine correlating with this. Inspector thought maybe an injector issue.

Aside from those issues, the machine cranked up in the very cold (~15F) quite quickly. The dealer employee who jumped it (batteries nearly dead in the cold was no surprise, it's been sitting) used ether, but I don't think it was probably necessary. The engine looks clean, not a lot of oil/crud in the engine bay. The body is in remarkably good shape for the age. The bucket has some broken teeth but is otherwise solid. There was no moisture in the engine oil (black, so needs changed, but no moisture), and what appeared to be only moderate rust in the coolant. If not for that transmission concern, and feeling like the drive sprocket is right on the edge, I'd feel pretty comfortable moving forward with it.

So, hopefully that provides enough information! What I'm hoping to get is feedback on specifically the transmission / gear issue, and if this machine looks like it's in shape to be a performer for a year before needing any major maintenance. If I need to replace some track bolts, injectors, oil change, etc. that's no big deal. It's the big stuff that I'm trying to avoid as much as reasonably possible with a machine this age. I also have a video if it running here -

Edit - looks like image embeds don't work so I added links to the images.

 

[Cat977]

How big and what kind of trees do you have? How many acres and is it hilly? If its just your land and say 20-30 acres and fairly easy going' the undercarriage should have no problems. The track tensioners need to work. The sprockets will be fine if you don't run loose chains. The rails/chains look good, If you want to keep the machine for the long term or need the traction replace the plates. Triple grousers for dry and rocky. Double for soft and wet. The transmission sounds to be of the main concern. Hopefully its something like a transmission pump. Someone else can maybe able to help you out on pressure tests or whatever.
Best of luck

 

[JacobRussell]

How big and what kind of trees do you have? How many acres and is it hilly? If its just your land and say 20-30 acres and fairly easy going' the undercarriage should have no problems. The track tensioners need to work. The sprockets will be fine if you don't run loose chains. The rails/chains look good, If you want to keep the machine for the long term or need the traction replace the plates. Triple grousers for dry and rocky. Double for soft and wet. The transmission sounds to be of the main concern. Hopefully its something like a transmission pump. Someone else can maybe able to help you out on pressure tests or whatever.
Best of luck

Sandy hills, and a substantial piece of land (50+ acres) but I'm only clearing a 1-2 acre homesite of trees. Trees I'll want to push over include jack pine and sassafrass and other junk under ~10". Larger oaks and maples I've cut out already so this would be used for stump digging and dragging logs. I also need to flatten off the top of the hill where the home is going.

 

[Cat977]

In that case the 951 should do it. Double grousers. $5000 sounds good. But I don't know about parts availability on these. The trans problem could cost as much as the machine. I believe it has a 3304 95 hp motor, popular engine so no problem. Sounds clunky hopefully injectors. If it was a 955L then it would be a hot buy. I just haven't taken notice of the 951's. Read all the searches on this site and also https://www.yesterdaystractors.com/crawlers/wwwboard1.html

 

[Welder Dave]

For clearing tree's you need a ROPS at the very least. Tree's are very unpredictable and can fall backwards and crush you! What throttle were you at shifting gears and was the transmission oil fully warmed up? Is the oil full? If shifted at a low RPM there will be a delay until you give it more throttle, especially in 3rd gear. Does it spin the tracks in 1st gear when pushing up against something?

 

[JacobRussell]

For clearing tree's you need a ROPS at the very least. Tree's are very unpredictable and can fall backwards and crush you! What throttle were you at shifting gears and was the transmission oil fully warmed up? Is the oil full? If shifted at a low RPM there will be a delay until you give it more throttle, especially in 3rd gear. Does it spin the tracks in 1st gear when pushing up against something?

Oil is full, but I can't imagine it ever got fully warm - starting at 15*F and it only ran for 20 minutes. Delay was present both at full and mid throttle. Didn't try spinning the tracks in 1st.

 

[Welder Dave]

On my 931B it won't move when cold in 1st gear. Sometimes even after letting it warm up needs almost full throttle to get moving in 1st. After 1/2 hour or so of taking it easy till it fully warms up, it works properly. The oil in the final drives is cold and thick too. Not saying there couldn't be an issue with the trans. but it could have just still been cold. Has the machine been sitting for awhile?

 

[JacobRussell]

On my 931B it won't move when cold in 1st gear. Sometimes even after letting it warm up needs almost full throttle to get moving in 1st. After 1/2 hour or so of taking it easy till it fully warms up, it works properly. The oil in the final drives is cold and thick too. Not saying there couldn't be an issue with the trans. but it could have just still been cold. Has the machine been sitting for awhile?

It's been sitting for at least a year in this lot, not sure how often it's been run.

 

[Welder Dave]

I'd run it for at least an hour after fully warming up before condemning it.

 

[JacobRussell]

I'd run it for at least an hour after fully warming up before condemning it.

Can you offer any insight into how the transmissions on these work? I'm more familiar with tractors and cars/trucks, where if a gear is missing it probably means teeth are missing.

 

[Welder Dave]

It uses a torque converter drive kind of similar to an automatic transmission. More throttle makes it go faster but at idle won't move. If you tried to move from a dead stop in 3rd gear you'd probably just sit there. A direct drive transmission would still move at lower throttle and if tried in too high a gear could stall the engine. Pretty hard to stall the engine in a torque converter trans. but could stall the converter and potentially cause other damage like worn clutch packs. Someone more versed could explain it better.

 

[Cat977]

O'Yea since your new when I said "Read all the searches on this site". I meant you enter your own search up at the top right of the page. Maybe leave off the C and get more threads to read. You can also check this site out https://www.acmoc.org/. You'll have to register before searching.
Good Luck

 

[oldgold69]

Tracks look a little tight. The transmission should roll in first gear at moderate power But if not moving will tend to stall until the convertor pumps enough pressure to move it in higher gears. I have 951 c 86j trans does the same when cold Don't use third unless traveling a distance. 951 have a small trans cooler They tend to heat the convertor up when its running to hard in second But really more pushing in third. They like weld the sprockets on after they cut the old ones off. Pins are worn don't look like they were turned. Tracks are worn but not rounded on the edge or bent. The track is probably snapping that will snap the track bolts. I lost about 50 on mine. About the radiator can you see the core are the tubes plugged. Mine was. Had to take the radiator out and clean it 3/4 of the tubes were plugged with calcium and rust. Is that the belly pan in the bucket. If so why is it down. If it is down can they put the machine over a pit to look at the underside for the leak.

 

[JacobRussell]

Tracks look a little tight. The transmission should roll in first gear at moderate power But if not moving will tend to stall until the convertor pumps enough pressure to move it in higher gears. I have 951 c 86j trans does the same when cold Don't use third unless traveling a distance. 951 have a small trans cooler They tend to heat the convertor up when its running to hard in second But really more pushing in third. They like weld the sprockets on after they cut the old ones off. Pins are worn don't look like they were turned. Tracks are worn but not rounded on the edge or bent. The track is probably snapping that will snap the track bolts. I lost about 50 on mine. About the radiator can you see the core are the tubes plugged. Mine was. Had to take the radiator out and clean it 3/4 of the tubes were plugged with calcium and rust. Is that the belly pan in the bucket. If so why is it down. If it is down can they put the machine over a pit to look at the underside for the leak.

Is the converter building up pressure likely what I'm waiting for then when pushing it into 2nd or 3rd and having a ~5 second delay before the power kicks in?

 

[oldgold69]

With my machine the tracks are rusted. So they kink. Which puts tension on the final drives. So it takes more power to move the machine. Then when you try and start out in second or third gear it takes more power to make it move. and the tension on the finals takes that much more. It should shift from first to second with no hesitation but it may not move faster. third should do the same from second at full power When you downshift it should be instantaneous in the next gear. That what i worry about more. The old guy i learn from always used to work the throttle down when he shifted between forward and reverse. His kid would pull back the throttle and let her go forward or reverse. Check the trans oil stick I get a lot of condensation in the oil just from sitting outside. It has to evaporate it so you have to run a long time to get it hot. 5k is not a lot of money for it put if you have to fix anything it will add up fast. I repacked 4 rams, cleaned out the radiator put a new head gasket on it (thought head was cracked) I have 4 hundred bucks in just gaskets and packings . Did all the labor myself with kids. Might have to tackle the track tensioner yet. Now have to pay to repair it. BONG But it's a fun toy.

 

[Welder Dave]

Always good to decelerate for a second or 2 when changing direction.

 

[TomA]

Do not buy it. Undercarriage has no value. You won't be able to sell it. If transmission goes it might cost 10-20 thousand to fix. It might be in worth the money for the engine if you needed an engine.

 

[Cat977]

If you have no long term ownership desires. Haven't run these types of machines before. Would mostly need others to fix it. Are on a tight budget. It would probably be better to hire someone else to do do the work. Like others here have said many times. The learning curve means it will take you say 10-20-50 times longer then a experienced operator. But if it's the pride of doing it yourself maybe then its deferent. I believe this machine has grease adjustable track tensioners. If they need to be resealed its usually a difficult job to do. Probably have to break open the track. (Most people have a guy with a track press come out $). Possibly the Dealer has them pumped up, but if you use it for a couple days they can leak down. Then you start skipping teeth. That damages what's left of the teeth. If you want to put a new sprocket on. You need to take the track in to have the bushings turned $. A new sprocket needs a new surface. You will destroy the rails buy just butting on a new sprocket. These are heavy hard jobs.
A Compact Track/Multi Terrain Loader is a lot more expensive but easier to use and easier to sell. Maybe just rent one for 2-3 mounts. Get the biggest one. 3 buckets teeth, smooth, stump digger. They drop it off.
and pick it up. They fix it.
Best of Luck

 

[JacobRussell]

Per a lot of the feedback here, I'm going to go run the machine again tomorrow and see if warming it up more alleviates the shifting / transmission issue. I'm also going to do more thorough testing of the shifting at full throttle, from a stop, and from moving. I checked with the dealer again and they've had the machine on their lot for about 15 months, with no record of having done service on it. Given the time it's been sitting + the cold, seems worthwhile to see what happens once it's more warmed up. A few questions for my return visit -

• To warm up the transmission I'm assuming I should move around, run through the gears, etc. rather than just letting it sit to warm up?
• Are these machines meant to be moved into 1st, then shifted up to 2nd/3rd once moving, or should they be able to start moving immediately in 2nd/3rd from a full stop?
• What other in-seat testing should I do to test out the gearing & transmission?
• Any particular filters or places I should check to look for transmission issues / debris that are easily accessible in a dealer lot?

To those recommending against buying it - not ignoring those recommendations, just getting a full picture before making my decision. I appreciate all the input. To provide a little more context, I am comfortable wrenching on the machine, addressing leaks, replacing injectors, etc. I run a '48 Ford 8n on the property now that I rebuilt from the cylinder sleeves up, so old iron and the quirks that come with it aren't out of my wheelhouse. A machine like this is obviously an order of magnitude larger and has it's own potentially expensive problems, but I'm not ignorant to the challenge of old machines. What I'm trying to avoid is buying a machine that needs an immediate 6-month project to pull the transmission and rebuild it when I need to be pushing dirt around when the frost breaks.

 

[Welder Dave]

Get moving in 1st and then shift up (especially in 3rd) just don't do it when you're working it hard. Once warm should start in 2nd without too much lag. 3rd is basically for transport but a lot of operators use 3rd sparingly or not at all because of the increased undercarriage wear. Decelerating for a second when changing direction is best for the transmission but you can test it leaving it at about 3/4 throttle. There should be a noticeable jerk (not super abrupt) that pushes you back in the seat when changing direction (1st gear) if you don't come to a full stop. See if there's something solid to push up against to see if the tracks will spin in 1st gear or at least put a good load on the machine. Depending on the soil tracks may not spin a lot. Would be a really good idea if you could take someone experienced with you even if you had to pay them. Could save you from a potential money pit.