We have been working my 972h pretty hard lately and I am getting a lot of heat in the axles and triggering the axle over temp light. Engine and transmission are handling it just fine. We are a Small just starting up quarry operation crushing down in the pit and having to pack the rock out to stock pile with loader pulling a fairly steep grade. Not enough room or funds to run conveyors yet. I spoke with local cat dealer and he said he remembered cat coming out with a optional external cooler lot but thought the cost was close to $10k. I am thinking about piecing together my own cooler setup using a heavy duty 12volt pump and a cooler with possibly a small fan. I'm just wondering if anyone else has fabbed up anything like this or if anyone has any advice in general. Thanks
Yeah, the one 980 I worked on had the axle cooler setup, worked good. The pump ran off a hydraulic motor I believe, powered off one of the circuits. I have seen this kind of kit sold somewhere, it was a generic thing, but basically a hydraulic oil cooler with fan, and some kind of electric pump that would handle hot oil. For truck transmissions I think? Anyway, the critical part would be the pump. Maybe one for each axle would be best? This might work, eh? http://www.summitracing.com/parts/til-40-524
Our 980g came with axle oil cooler kit its a duplex hyd pump that belt drives on the engine one pump for each axle there is a electric clutch like an ac compressor pumping the oil though a radiator Advice in general get a stacker before you go broke hauling with a loader
Or a rock truck if you can afford that.
Another thought is make sure your not using the brakes enough for them to add heat to your axle and maybe you can cut your grade down on the way up too
That's about what I was looking at lantraxco. Stackers are on my list as soon as possible. After this next shoot I should be able to lay the ramp down a little more to help. We thought about brakes adding to the heat also so have been using extra caution to downshift and not over use the brakes. I believe once this summer heat breaks we won't be having near the problem but heat index of 110 in the afternoon is taxing our equipment.
Just a thought. When you travel downhill which brake pedal do you use, the left or the right..? Secondly, when you apply the brakes how long in seconds (+/-) do you keep the pedal pressed for..?
Using the RH pedal. Not staying on them any longer than necessary. Maybe 3-4 seconds at the bottom of the hill. Was going to have cat mech check my pad thickness but they forgot to have him bring a depth mic last time they were out.
If I were to attempt that, the oil cooler and fan would be the easy part, and the pump would be a little harder. How about a pair of power steering pumps from the junkyard? old honda's had a nice little pump that had two hoses with a remote reservoir. You could run them off the engine or a small motor. Another option would be 4 or 6 fans mounted to blow air directly over the axles, maybe even simple shrouds to direct the flow around the bigger sections.
That sounds fine to me. The problem with the inboard multiple disc brakes on the 972H is that all the time you have your foot on the brake the axle oil is expelled from the brake pack and so everything heats up. The heating gets worse the longer you have your foot on the pedal. The only time oil is circulating within the brake pack to cool the discs is when the brakes are released. Is it feasible to descend your grade using 1 gear lower to see if you can do it all on engine braking without relying on the service brakes at all.?
Cut the grade down is my thought. Use the brakes as little as possible until you can get a truck or stacker.
But in reality. Just plumb in that 12volt pump that guy linked drop out of the drain plug and return to the fill plug. With a simple oil cooler mounted in the back with the other radiators act. I'd bet for 1k you could do it. Just watch busting the hoseoff the drain side. Could turn out to be a bad day fast
Yea I've had the drain plugs out of these axles twice now and both times I ended up wearing quit a bit of oil. Plus I just changed the oils in both axles about a week ago with $600 worth of cat tdto 30wt so when I plumb this up I'm going to try to either save the fluid or not loose much during the process
It's a shame that you changed the oil so recently. For your particular high-stress application I would have gone with TDTO SAE50. When you change axle oil you can reduce spillage to almost zero using a vacuum transducer. Hook it up to an air line and plumb it into the fill plug. The suction it creates will allow you to get the drain plug out and get whatever you are using to collect the oil under the drain without wearing the oil. Works for hydraulic tanks too and is good if you want to change an o-ring or something like that without draining a system.
If you don't have the vacuum transducer but have a gas engine in your truck you can remove the fill plug, or on a hyd. tank the breather, cobble up some fitting to install a air line to the fill port and then connect it to one of the vacuum fittings on the truck engine. Start truck up and let it idle while you do what needs to be done. Only possible problem is if the oil level is a bit high it can be sucked into the trucks intake. Don't ask how I know! No mosquitoes in the area for about a mile down the road. This could also be a problem with the "vacuum transducer" method. Another option might be the "Suck Bucket"
Sorry about the repost, fumbles fingers this morning!
I have used the vacuum pump on the 7.3 in the older ford trucks to pull a vacuum on hydraulic tanks it works good
Well I got a couple pumps and some coolers with fans coming. I will update once I get it all together.
When you go to install the cooler piping you'll need to drain the oil. I strongly suggest you refill with TDTO SAE50 oil, it will give you an added edge in your application.
Thanks nige
First time poster!!!! On the cat wheel loader if you use the LEFT brake pedal it will down shift and eventually neutralize the transmission before applying the brakes this will reduce on the heat in the axles. Try that first to see if it fixes the problem, there might be a rocker switch that turns this feature on/ off
However if you're travelling downhill then you want all the engine braking you can get, I find it difficult to see how decoupling the transmission would help with brake overheating. On the larger Cat machines we always got best results on axle temperatures by only using the right pedal.
Hmmm...good point, I was thinking more about the down shifting as it will help slow you down, as long as you don't keep your right foot on the throttle while you brake with your left, you should be ok using the LH pedal or am I missing something? Quoting the 972H brochure: "Integrated Braking System. The Cat exclusive Integrated Braking System reduces axle oil temperatures and improves transmission neutralizer smoothness. IBS has a direct impact on durability of the axles and brakes especially in applications involving long distances and/or heavy braking."
I've only ever advocated using the right pedal when descending long grades. The caveat is that you need to select the best gear to descend the grade right as you hit the crest and don't try to shift gears from that point until you hit the bottom. To me the best gear to descend is the same gear that the machine will climb the same grade in the same condition. In other words if you're descending with an empty bucket then it's the gear you can climb the grade with the same empty bucket and ditto for a loaded bucket.
Makes sense; I think it will ultimately depend on the layout of the site; I was just thinking there is a feature on the machine that might help with the situation that should at least be tried before staring to make mods. If I recall correctly the axle cooler on the 972H uses a coil inside the axle and pumps hyd oil from the fan circuit through that coil to cool it, which doesn't sound fun to retrofit. The system on the 980 has the engine driven pump that pulls the oil out and pipes it to an external cooler. I am curious what kind of system loweredf1 comes up with and how well it works.
Alternatively the OP could do the same as the installation on something like a 992G and simply suck oil out of the differential housing using a pump and pass it through an external heat exchanger. That would need a 2-section pump (one section for each axle), a separate set of lines for each axle, and 2 coolers.
Any interested on selling your 972H ?