Hello, We are looking at buying a Champion 740A grader. It was in working order, but now one set of rear wheels is not driving. Its sounds like one of rear axles is broken between the diff and the outer drive (according to the seller, who seems very genuine) Machine still drives fine, only power to one side. Guy doesn't have time to fix it, but said when they jacked it up to have a look he noted the wheels both still turned freely (together - chains not broken). He said there wasn't an easy way to take off a cover and have a look and he didn't really have the time to pull it all apart and get it fixed - it looked like a major to pull apart, but his gut feeling was that the axle was broken. Can anyone shed some light on this? Does that sound like what the problem might be? What would be involved in removing the axle and replacing it. How easy are parts to get? Would something being wrecked suffice? Any comments appreciated. Need to know if we're opening a can of worms, or whether its worth trying to fix. Cheers Will
Sounds like the axle, although it is quite a substantial chunk of steel to break! Like you say if the wheels turn together then the chain is good. It should not drive unless the diff lock is engaged (if it has one). I've had a tandem off before, think it was a 740 although already branded a Volvo. It bolts on to the diff from the rear of tandem, make sense? LOL.
It sounds like the axle could be broken, but you said it still drives, if the axle is broken, it wouldn't drive unless the diff lock is in, perhaps it is. A broken axle is no big deal, we have a Champion 720A and have broken both axles at different times. After years of use, shunting from forward to reverse, the axles fatigue, maybe the Champion ones are a little lighter than they should be. There should be a circular plate on the side of the tandem case, that the axle can be pulled out through, I am fairly sure the mechanic didn't take the tandems off. We also had a local engineering shop machine up new axles for us, they were quite a bit cheaper than genuine ones and just as good, if not better. RnR.
Some graders don't have a diff. Galion and early Komatsu graders just have a solid centre bevel gear drive axle setup, constant drive to both tandems. I don't know if the Champion is the same, but if it is, it would explain why it could still drive.
Thanks, yea he mentioned it had no spider gears. Does this mean it doesn't have a diff? Please excuse my ignorance, I've never seen the internal working of an axle or diff. Is the axle in 2 pieces if there is no diff, or is it one axle from wheel to wheel? Sounds like I should just be able to track one down at a wreckers, hopefully!!!
If it has no spider gears, it doesn't have a diff. There should be an axle for each side left and right. I have seen an old Komatsu which wore the splines where the axle goes into the crownwheel housing so badly that they stripped. Yours could have done the same, or could be a broken axle like you suggest.
Try Jad equipment. I think there in Canada but the are great source for champion parts!
I have a Champion 740 that had similar issue. It was a broken drive axle and I ended up getting a local engineer to make a new axle, which was heaps cheaper than sourcing a new one. I tried to get a used one but had no luck so maybe they are a weakness in this particular grader. We used EN36 steel to make new axle and so far have done 2000hrs without failure. I agree with MackTruck907, JADE Equipment Canada seem to specialise in DRMCO Champion.,
To get your machine tandem problem solved, give the serial number of the Grader. It is locate in the main frame in front of the cab. Failure must be inspected and indentify the trouble, no need to be a great mechanic it is very straight forward to know what is broken down. Remove the inspection plates and do a test by rotating the wheels. Also inspect the central gear which translates power to the wheels, some time the bolts get loosed and damage the grooved shaft? Attached it's an overview of the mechanism. Not a problem for parts, in Canada we have it all. DL
Sorry my friends I inserted the attached document outside down. It could because by too much red vine, hope now would be fine? DL
Awesome! Thanks for all the info. Grader is being delivered next week. Will let you know what we find...Cheers
OK fine, we will assist you if needed.
Does anyone have an exploded view of the ring and pinion setup for an 86 champion 720a? The pinion bearing went out and got after it was tore apart and cant find anywhere how to setup the pinion bearings which it has two of them.