I got a 963 that is filling up the bell housing with tranny oil, anyone know about how long to replace seal on tranny, and should pull tranny or engine to repair, can buy machine at good price but needs repaired. Thanks Newt
First off make sure the drive case between the engine and the HPCU(trans) is holding it's oil at level. Be careful topping it up, only takes a gallon. If the drive case is off the dipsqtick or over full on the dipstick, it could get expensive. The case can't make the flywheel housing overflow with oil. If there is oil on the dipstick and the flywheel housing is overflowing then you need to resealing the drive coupling. At this point run the machine to see if you want it. The best fix is pull the HPCU.The cab needs to be flipped over fully and you need a Crain or two comalongs, one to pull forward and one to hold back on the cab as you tip it. Clean out cab items on floor will go through the windshield. Be careful of throttle extension, it will come apart on full flip. When you get it out the drive spline needs to. Be pulled out of the adapter plate on the flywheel. The early splines had one morning groove newer ones have two but the big oring in the adapter also needs changing. Lift rear of engine and block with 2x4 crossways on motors under oil pan plate. Later Bob
So the only parts would be a couple seals to fix this problem, they are telling me it is coming out of the breather on the bell housing. Thanks for responding Newt. The work I will do I just never ran in to this problem, and I never had a tranny out of a 963.
Just make sure the drive case has oil in it near the full mark on the stick. If it's flooding too the cost could be very high. That might indicate the center gear bearings have failed and that's a lot of work. Later Bob
Is this actually the torque convertor on these machines.
They don't have a torque converter Newt. They use a closed loop system. A piston pump that is rotated in one direction but can pump oil in either direction into a motor that is connected to the final drive. The pumps are in the HPCU housing and the motors bolted to the final drives. The HPCU senses the engine speed and throttle position and then controls the travel speed to keep engine load constant. This is all done hydro mechanically not with electronics. Later Bob
Thanks for all your help, greatly appreciated.
Your welcome Newt. The loader is a closed loop hystat drive most excavators are a hydraulic drive with a spool valve directing full oil flow to a motor and controling the direction of travel. Later Bob
Bob, if the center gear bearings have failed, how much roughly do you think to fix this, the machine I can get for 12,000, it is very smooth and pins are tight just has tis oil leak, that's why I was wandering how much roughly to fix even if it is the center bearing. Thanks Newt
You will be getting into some expense there Newt. The rear bearing/cup bore is likely beat out and needs repeating too. That requires taking the piece off for machining. To do that right you are almost into an over haul of the HPCU. Best to run this by your local dealer. Be careful who you let work on the HPCU. Later Bob
Is the machine worth it for 12,000 even if we had to do the overhaul or get it machined out, the machine is very smooth and tight. Thanks Newt
I don't know machine values very good Newt. But here is something to keep in mind, you could buy what appears to be a "good runner" and have that happen in a month. With the HPCU overhauled it is a great machine. Maybe a fair price would be half the price of an overhaul less than the asking price for one in working condition. Later Bob
becareful I had one about 17 years ago that was doing same thing. I end up getting it back from cat dealer in a couple boxes after I took him running transmission that had no other problems other than the same leak after He got it tore down He tried to charge me $ 25,000-$30,000 and a bunch of B.S. when they get done with there sales pitch you will wonder how machine even started
Hi Newt, Bob is correct, it could be a big repair. It could also be some bearings and seals, I have done quite a few and haven't had any housing problems so far. Its a pretty common repair.
Any closed loop system repair can change in a hurry once you open it up. If the bearing bores are ok you don't have to go into HPCU.
We see alot of 973s here in stone quarrys. Some of the worst conditions you could think off , no maintenence, if it starts they run it, repair only last straw that broke, not the the whole bale. Drain extra oil from pump drive into used coffee cup, dump back into hcpu. Then work for day do again tomorrow. Can't fix machine, gotta by beer for the weekend.
Newt, chances are if machine is from down by you its only see dirt work. Thats small money for a good machine. What serial number prefix and how many hour, any service records. Run the serial number through Cleveland Bros to see what they have done to it.
Someone changed the head or put a head gasket on. head is different color, Ser# is 21Z01072 has 17,262 hrs on it, but it is very smooth in forward and reverse and steering is also smooth not jerky like some I had run. how much roughly for parts for either fix, so sounds like it would be a good buy, it does need chains . Thanks Newt