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View Full Version : Cat T9B trencher issues


Scag48
05-11-2009, 05:31 PM
Hey all, thought I'd share an interesting story. Dad threw the trencher on the 216 a few weeks back to do some trenching which didn't work out very well. Trencher hadn't been used since last season, but as far as I know, it worked fine when he last used it. Turns out, the trencher, even in very favorable digging conditions would stall out and shut off flow when encountering any sort of load. I've ran in it the past, you can get into rocks and the thing will keep spinning no problem, it'll just hop around on the rocks if the going gets tough. Now, in sweet topsoil that should be easy digging, sink it about a foot deep and it straight up stops spinning.

Okay, so going by what I was told, I figured it would be a relief valve on the machine kicking out somewhere. The hydraulic system filter was due for a change, swapped it out with no change in performance. Dad decided instead of tearing into the machine, he'd rather send it down to Cat to have it looked at.

As it turns out, the trencher itself was the culprit. I would've bet $1,000 on this issue being machine related given the way it was acting. From what I'm being told, the techs slapped another trencher on the machine and it dug just fine. Who would've guessed? The trencher is my dad's only continuous flow attachment so testing it on another attachment at the shop wasn't doable. The time spent getting it down to Cat and having it looked at was worthwhile.

From here, I'm not sure what the best option is. I haven't yet had a chance to discuss options with my dad about what to do with the damn thing. Service dept. called my dad and told him it was going to be "expensive" to fix, I'm not really sure what that means exactly. I think he gave $4500 for it about 4 years ago when it was new, the unit has about 150 hours on it, it's in excellent shape as a whole. I'm also trying to figure out how a trencher just grenades, doesn't seem to me that there's a whole lot involved with spinning that sprocket to run the chain so I'm not really sure how it could work one day and not the next. The real issue is that it's worth nothing when it doesn't run worth a damn so it's not like my dad could part ways without losing his @$$ on the thing. That and I'm not sure if the service boys can give us an estimate to fix the thing, sounds like it'll be T&M deal to fix it which really makes it hard to decide which route to take; scrap it or keep it. For my dad, it's one of those attachments that doesn't get used all the time, but when you need it, you need it. He may look at renting a trencher from here on out and getting rid of this pig entirely, but we haven't completely hammered out the details.

What's more irritating is the fact that with only 150 hours on the unit, it does not run. Thanks for producing an excellent attachment, Cat. Without a doubt my dad will no longer purchase Cat attachments given this lack of acceptable service life.

Any opinions on a route to take? If a machine goes down, fix it, it makes you nothing while it's sitting. However, it's tough to want to spend a wad on an attachment that sees little use but is in good shape overall.

SiteSolutions
05-11-2009, 10:28 PM
That sucks! Sorry to hear about that.

I think if I was in that shape, I might try to tear into the attachment myself a little to see what might be done. I did a lot of fixin on my harley rake when I had to, rather than pay the dealer for it.

And you're right, how complex can it be? Seems like it should either work or not work. I don't guess there's much maintenance to do on it, is there?

Does it have any side-shifter or other auxiliary lines on it? Something where a check valve could be failing, or somehow the majority of the oil is getting around the motor? If it is a busted seal in the motor, I bet it would be expensive to fix, but maybe cheaper than a new trencher.

Best of luck to your dad and let us know what happens.

minimax
05-12-2009, 01:06 AM
Scag,I would look for a MPV(motor protecting valve),bad check valve or blow motor seal.On my brush cutter I was having a real power prob. and it was a bad MPV valve,Was opening at 800-1000 PSI Vs. 3500 PSI so US mower and I changed out to a check valve.Does it have a case drain line.I added one to my harley rake and that line is always warm from oil going though it so I know that it is working.You could always sent it to richies and sell it and buy a new one,Last auction they sold a old bobcat trencher for $3500 dollars.Did Cat build it or rebrand it?

minimax

ksss
05-12-2009, 01:23 AM
They are bring around 2K on IP if you wanted to just get what you can out of it. If CAT said it would be an expensive repair, I am sure it would be, I also find it odd that it would just take a sh!t. You might have an independent hyd. shop take a look at it before you send it down the road. 4500 dollars for a 150 hours doesn't pencil out very well.

Scag48
05-12-2009, 04:20 PM
Thanks for the opinions guys. Minimax, I don't believe it has a case drain, it's been a while since I've seen the unit itself and honestly cannot remember. Not sure if Cat makes it, although it is branded Cat that doesn't mean anything. I will look into that and see what I can find out.

At this point in time, Cat is pulling it apart, then will give an estimate for repair. We'll see how that goes, but I will wager that it could be an ankle grabbing experience. Once that number comes in, we'll see what the best route to take may be. I'm having a tough time trying to figure out where the cost is going to be, but I'm not a mechanic, either.

Sitesolutions, the trencher does have the side shift. Originally, that's what I thought. I told dad to check and make sure that selector valve is in the right position, either shift or flow to the chain. I was thinking if it was somewhere between the 2, flow would be interrupted. No dice there, he checked that.

CarterKraft
05-13-2009, 11:53 PM
I've ran in it the past, you can get into rocks and the thing will keep spinning no problem, it'll just hop around on the rocks if the going gets tough. Now, in sweet topsoil that should be easy digging, sink it about a foot deep and it straight up stops spinning.

I'm also trying to figure out how a trencher just grenades, doesn't seem to me that there's a whole lot involved with spinning that sprocket to run the chain so I'm not really sure how it could work one day and not the next.

What's more irritating is the fact that with only 150 hours on the unit, it does not run. Thanks for producing an excellent attachment, Cat. Without a doubt my dad will no longer purchase Cat attachments given this lack of acceptable service life.



That is something...

So was it properly greased as I replied in my PM?

Scag48
05-14-2009, 12:36 AM
Yeah I sent you a PM back but dad says he was keeping up on it. I'm starting to question the grease he's using if that's the case, I will have to look into that issue further.

minimax
05-14-2009, 01:05 AM
Scag, I was thinking about the trencher and was wondering about how tight the chain is on it.If the chain is to tight the motor could have a hard time turning it? And the idler turns freely?Are you out working big iron Yet?

minimax

Scag48
05-14-2009, 01:11 AM
Scag, I was thinking about the trencher and was wondering about how tight the chain is on it.If the chain is to tight the motor could have a hard time turning it? And the idler turns freely?Are you out working big iron Yet?

minimax

I know he watches the tension of the chain, if anything it runs a little slack at times. The idler has never given issues but will check that when it gets back to make sure we don't have some toasted bearings in there too due to crappy grease.

Naw I'm not working yet, just hanging out. Stimulus money takes forever to hit the ground. It's coming, but it's slow. I need a moderately decent season this year, 5-6 months of work would be nice, or I may have to reconsider what I'm doing, hopefully it doesn't come to that. I hear it's been slow up your way, how you holding out up there?

CarterKraft
05-14-2009, 01:56 AM
in "dirt deep" bearing locations sometimes too much grease is bad ass not enough.

The grease flushing out will open the seal up to contaminants coming in. I have a offset disk that we changed bearings on every weekend for a month, finally the guy at the bearing house told us to quit greasing the bearings, haven't replaced one since.

Scag48
05-14-2009, 01:59 AM
Interesting. I wouldn't say that he was over-greasing it, but probably somewhere around the recommended service interval and maybe 10 hours past it on an occasion or two. Like I said, the unit has less than 150 hours on it, no joke.

minimax
05-14-2009, 10:34 AM
I'm working my eyeballs out right now. I have a good month of work in front of me for now,But there are guys hurting petty bad too? There are a ton of repos comeing in to pape',As many as one per day:dizzy::cry:.

minimax

Scag48
05-14-2009, 01:47 PM
I'm working my eyeballs out right now. I have a good month of work in front of me for now,But there are guys hurting petty bad too? There are a ton of repos comeing in to pape',As many as one per day:dizzy::cry:.

minimax

Yeah I don't doubt it, I remember you telling me about the repo's earlier in the winter. Feeling like you need a newer 35 yet? :laugh:

minimax
05-14-2009, 11:50 PM
No new 35 yet,but have been eyeing the 50's abit.

minimax

Junior M
05-15-2009, 08:10 AM
No new 35 yet,but have been eyeing the 50's abit.

minimax
I was just thinking about saying that samething to you before I opened this thread.. :laugh: