Log Splitters and my DHT 25 Ton

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ColdNorCal

Feeling the Heat
Mar 6, 2018
331
Newcastle, Ca.
Finally have been able to put the splitter through its paces the past three mornings. Using it to split oak has left me with a less than enthusiastic feeling. Dont misunderstand me, I do "like" the splitter, it does work good and splits everything I put in front of it. However, it seems to split slower then the few vids I have watched, both the DHT 22 or 25 ton, at times. And it gets VERY hot which is my primary concern and issue.

Realizing that not all wood is the same and that even oak can be different makes it nearly impossible to make direct comparisons. But, the heat it generates is something that can be compared. The splitter gets so hot you can not place your hand on the ram. And even the tank is so hot that to place your hand on it for a full second is painful. The hydro fluid level is between min and max per the dips stick.

The past three morning working temps have been from 60 to 80 degrees with every morning having a slight calm breeze. The coolest morning was Weds and I stopped splitting by noon with a high temp of about 65 degrees. The tank and ram were just as hot that morning as today when I stopped when the temp was about 80 degrees. I did take breaks about every 60-90 minutes, working three or more hours each morning.

It seems that heat is not uncommon with these type of splitters due to the small tank size. None the less, does this seem normal? Should I drain the aw-46 and refill with aw-68? Splitting below 50 degrees most likely will never happen. Splitting above 80 degrees will.

Also, I emailed DHT a couple days ago asking what the engine rpm's should be set at. And what the hydraulic pump optimal rpm is for best performance. They have not responded yet. The thinking is maybe their is a little more power left if the engine rpm's are below the correct setting.

DHT 25 Ton Hydro Fluid.jpg
 
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Sawset

Minister of Fire
Feb 14, 2015
1,216
Palmyra, WI
I have a new county line 25ton, and have noticed the same thing.
A quick look up of operating temps for hydraulic fluids:
"Keeping the transmission temperature between 175 and 200 degrees will allow the fluid to last the longest. This is the normal operating temperature for a transmission. Remember the fluid is the life line or blood of the transmission. Damage to the transmission fluid begins at 225 degrees."
130deg is about what a hand can tolerate, and it's above that, no doubt.
I've also noticed that the second low stage going through hard knotted white oak seems to kick in only when the engine is about ready to quit, then it lets up and allows the engine to rev a little, albeit with a very slow ram speed. Does yours do that - they seem like similar models. Ive rented an iron oak 30t up to this point (>50cord), and notice quite a difference on how the iron oak can punch through tough stuff fast, and this one cannot, or does so very grudgingly.
 

ColdNorCal

Feeling the Heat
Mar 6, 2018
331
Newcastle, Ca.
I have a new county line 25ton, and have noticed the same thing.
A quick look up of operating temps for hydraulic fluids:
"Keeping the transmission temperature between 175 and 200 degrees will allow the fluid to last the longest. This is the normal operating temperature for a transmission. Remember the fluid is the life line or blood of the transmission. Damage to the transmission fluid begins at 225 degrees."
130deg is about what a hand can tolerate, and it's above that, no doubt.
I've also noticed that the second low stage going through hard knotted white oak seems to kick in only when the engine is about ready to quit, then it lets up and allows the engine to rev a little, albeit with a very slow ram speed. Does yours do that - they seem like similar models. Ive rented an iron oak 30t up to this point (>50cord), and notice quite a difference on how the iron oak can punch through tough stuff fast, and this one cannot, or does so very grudgingly.


This one has also almost stalled out like you said although not very often. It does cut very sloooow sometimes when I think it should not. And the engine hunts sometimes, change rpm's, when I think it should not. Part of all this could be due to my lack of experience. This is my first splitter so I have nothing to compare it to. Things I learned are to make sure the wedge is cutting in between grains and with the grain. Sometimes when the wedge tries to cut "into" the wood the splitter will be very strained causing it to go very slow, literally crawl, and sometimes almost stall out. Also, if their is a knot I always start the split on the opposite side of it. And large rounds are split in the vertical position and I start to split near the outside edge of the round, not start splitting in the middle of it. You probably already know all this. It sounds like the 30 ton you rented does not require all this special attention.

Thanks for the fluid temp information. Most likely the splitter is operating as designed. I mentioned the high temps in the email to DHT and will share what their response is.
 

SpaceBus

Minister of Fire
Nov 18, 2018
6,254
Downeast Maine
Do these symptoms only present when going after particularly dense wood? Even the toughest rounds haven't slowed down my Brave 20t splitter, unless I'm running it at a lower RPM. usually I run the engine as slow as I can and still split wood. The ram moves slower, but I don't mind since the engine noise is greatly reduced. On the occasion I get a gnarly round with loads of Knots or whatever, I turn the engine up. I've yet to come across something that has really given me pause, and I had to re-split some really well seasoned maple, like it's been sitting for a decade indoors.
 

ColdNorCal

Feeling the Heat
Mar 6, 2018
331
Newcastle, Ca.
As we both mentioned, oak. It would be fun to try your 20 ton on these rounds. The tougher ones are knotted, gnarly, twisty...
 

SpaceBus

Minister of Fire
Nov 18, 2018
6,254
Downeast Maine
As we both mentioned, oak. It would be fun to try your 20 ton on these rounds. The tougher ones are knotted, gnarly, twisty...
They must be pretty wild to slow down any 20+ ton splitter.
 

ColdNorCal

Feeling the Heat
Mar 6, 2018
331
Newcastle, Ca.
That is the question. Is the splitter not working at 100%. Or is the wood more difficult. Sawset says a 30 ton "punches" through the same oak that makes the 25 ton stumble and slow down quite a bit. Its pointing towards the splitters.

If it is the splitter, how do you verify a splitter is faulty when it does in fact split wood. I will probably call DHT next week to see what they think.
 

Sawset

Minister of Fire
Feb 14, 2015
1,216
Palmyra, WI
To be a little more clear - I think what I'm seeing has something to do with the two stage pump. It doesn't seem to matter what the wood is - cherry, oak, elm. When it comes time to bare down on it, like the first contact with the wedge, or going through a knot, or tougher grained stuff like the oak, the engine starts to loose rpm till it goes very low, then maybe the second stage will engage, maybe not. Either way, the 30t would go to stage two very easy, almost no rpm change, the 25t not easily, lot of rpm change. When that happens I'm having to work the control valve to relieve pressure manually. I've looked into a possible adjustment on the pump, but the owners manual says do not adjust the pressure relief setting, it's factory set. I'll need to get to the bottom of it, because it doesn't seem right.
 

maple1

Minister of Fire
Sep 15, 2011
10,809
Nova Scotia
On the oil temps comments, you can't really tell without actually measuring accurately with a thermometer. Feel by hand can be very misleading - holding your hand on for a second, without getting burned let alone just being painful, would still be within acceptable hydro temp range.

On the speed and other stuff, it may help to post a vid up, of it in action.

I would not put heavier oil in. Mine has simple ATF, year round, it left the factory that way. Chances are heavier would make more resistance & more heat. & maybe less speed.
 
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ColdNorCal

Feeling the Heat
Mar 6, 2018
331
Newcastle, Ca.
I thought about making a vid but it happens very seldom. And everything is split now.

It sounds like Sawset concerns are different. My primary concern are the ram and high tank temps but that seems to be normal.
 

Sawset

Minister of Fire
Feb 14, 2015
1,216
Palmyra, WI
concerns are different
I think they are too.
I came across some other threads for adjusting the pressure where the two stage pump switches between high and low. Otherwise, the ram slowing sounds normal under tougher conditions. Hot to the touch hydraulic temps also sound normal. Without a temp gauge it would be hard to tell if it is over any limit though.
 

maple1

Minister of Fire
Sep 15, 2011
10,809
Nova Scotia
I thought about making a vid but it happens very seldom. And everything is split now.

It sounds like Sawset concerns are different. My primary concern are the ram and high tank temps but that seems to be normal.

So the speed thing is an intermittent thing? I didn't read that in the OP.

That could just be the two-speed pump doing its thing, and if it isn't doing it quite right it could be gearing down before it should. Which should just be a simple adjustment to get right.
 

ColdNorCal

Feeling the Heat
Mar 6, 2018
331
Newcastle, Ca.
So the speed thing is an intermittent thing? I didn't read that in the OP.

That could just be the two-speed pump doing its thing, and if it isn't doing it quite right it could be gearing down before it should. Which should just be a simple adjustment to get right.

#3, and the OP was somewhat obscure in that I said "I do like the splitter", just not overly excited... "It does cut very sloooow sometimes when I think it should not. And the engine hunts sometimes, change rpm's, when I think it should not. Part of all this could be due to my lack of experience. This is my first splitter so I have nothing to compare it to."

If it was slow all the time I would not like it. In other words, I give it a 4 out of 5 when I thought it would be a solid 5. However, cant complain really since Lowes discounted it 60% with full warranty. It was a return that looked new with very little paint wear on the beam.


Are you running the aw46 or the 68.. if you have the 32 in it its going to get hot. I only split during the winter months so i have the 32 in it.. if i were to run the splitter right now.. it probably would self ignite

DHT told me, and it also says on the splitter, it comes with AW-46.
 

VirginiaIron

Minister of Fire
Dec 19, 2013
1,086
Central Virginia
I'd say at those outdoor temps you have the correct oil. But, with the heat you have on your tank and cylinder, your oil should be at max. Seems to me you are also low on oil (edit- due to expansion).
 

pjohnson

Burning Hunk
Oct 2, 2013
142
Doesn't sound good to me, the engine shouldn't bog down like that. Might be an issue with the two stage pump not kicking down. Could also be bypassing fluid causing it to heat up. Might be time to use that warranty.
 
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VirginiaIron

Minister of Fire
Dec 19, 2013
1,086
Central Virginia
Also, check under your slide for splinters and debris. If the slide is bound you might have substantially added heat. Take the nut out of the rod and see if you can move the slide by hand.
 

ColdNorCal

Feeling the Heat
Mar 6, 2018
331
Newcastle, Ca.
I'd say at those outdoor temps you have the correct oil. But, with the heat you have on your tank and cylinder, your oil should be at max. Seems to me you are also low on oil (edit- due to expansion).

Tank is 6.5 gals. Same size as the 27 and 30 ton splitters. Manual says to add 5 gals to 5 1/2 gals. Its currently between min and max.

I think its not a problem other then an inexperienced user not expecting such a hot tank and ram.

Doesn't sound good to me, the engine shouldn't bog down like that. Might be an issue with the two stage pump not kicking down. Could also be bypassing fluid causing it to heat up. Might be time to use that warranty.


Is this directed at me or sawset?
 

VirginiaIron

Minister of Fire
Dec 19, 2013
1,086
Central Virginia
Tank is 6.5 gals. Same size as the 27 and 30 ton splitters. Manual says to add 5 gals to 5 1/2 gals. Its currently between min and max. ...

Just a thought- Since oil expands when hot and you are between min/max at those high temperatures, I would think you should be closer to or at max when hot. This extra oil should help the system keep cooler.
What is your oil level when cold?
Is your wedge moving freely?
 

ColdNorCal

Feeling the Heat
Mar 6, 2018
331
Newcastle, Ca.
Wedge moves freely. Yes, more oil may help but by how many degrees. A temp gauge as previously mentioned would be a good first step. I may try that just out of curiosity. Read a couple threads that people just held a thermometer in the tank. Easy enough to do. But, all the splitting is done this year...
 

spudman99

Feeling the Heat
Jan 26, 2018
350
Yardley, PA
I also purchased the DHT 25T last July and now have about 6 cords thru it, residential use obviously. I had some 4 week old sugar maple 36" rounds that it would not split, the wedge bogged down and got stuck. Had to hammer a wedge in the opposite side to finish the split to continue.

Cant speak about the heat cause I never thought about it (my first splitter) and I am running the factory supplied fluid. Yes it was hot and I avoided touching it, never considered it a problem and figured that was all addressed at the design and testing phase.

My unit bogs down and the rpm slow when it needs all of the 25t power to push the ram. I always figured that was normal. Since I am not splitting commercially it didn't bother me. I always figured since this was a $900 unit I was not going to get top performance. It is on the low end of the splitter price range and that was acceptable to me.
 

Dobish

Minister of Fire
Oct 26, 2015
2,027
Golden CO
i noticed on my 22 that i had to run it at slightly higher RPM and also add a bit more oil to keep it from bogging down on some of the twistier elm stuff. That being said, I don't normally split when it is super hot out (although i have HUGE pile i need to get through in the next couple of weeks)
 

johneh

Minister of Fire
Dec 19, 2009
3,743
Eastern Ontario