645 payloader

Yep there is no way to get them out the top without a fire wrench

Your 645 you can gut the clutches out of the front. The cover on the front is aluminum remove it and you are in the high gear clutch pack there is a snout that sticks out and has sealing rings on it. That is how high gets its oil and they have been known to break. Then low and reverse. Take the cyl. Off and retract it will give you more room. The back side has the converter and pump drive gears and sprague. The steering pump is on the ladder side and the charge pump is under the lift pump. If you have good pressure and it doesn't shutter when in the gas trying to push
I would bet converter or sprague. The converter has a little snapping inside that the parts book or repair does not
Show if that fails it lets the two halves run into each other and they don't last 5 min. And get real sluggish. How do I know we ran 645 and 745 loaders for years and have had every bolt out of them. The sprague ass. Will get destroyed if you have a pin head in it shifting rev to forward and not bringing the RPM down. To get the tranny out
Remove hood,remove radiator and steel shell together. There are 4 3/4 bolts holding it on,set it down on 2 4x4 blocks where the frame would be that way you don't smash the lower radiator. Next drain oil out of the tank about 40 gal. Take steer pump off and feed and pressure lines off the pumps. Take shift linkage off and the temp gauge. Remove driveshafts. On the ladder side on the bell housing right ahead of the oil filters there is a 1"plug remove. Inside there is 12 3/8 Bolts recessed inside the flywheel. USE A LIGHT NOT YOUR FINGER TO FEEL FOR THE HOLES ,turn engine by hand IT WILL CUT OF THE END OF YOUR FINGER! Yes we had that happen. Take 4 bolts out of rear engine to frame remove throttle rod,battery cables,charge system. Hook chain and lift gently ,remove 12 bel housing bolts and engine slides forward take GREAT care on the flex plate on the converter as they bend easily.
At this to get the tranny out you need to jack the tranny up just lightly,remove the two oil cooler lines and the tranny mounts.THE MOUNTS are all what is left holding 1100 pounds up. If you are still alive carefully let it down to ground take great care of the valve body on the right hand side of the tranny don't hit it! Dent it and 800$ gone. Once on the ground put a come along on the top of the tranny,there is a lift point up there that you can screw a eyebolt in. Next you must raise the rear of the loader off the ground 28" block it good. Let the tranny down while rolling it towards the rear of the machine next drag it out and you have earned a days worth of work. If you take the tranny apart call me I will help as there is 4 different valve body gaskets. Do not interchange as when you go to high it will put it in two gears at the same time and stop in record time with you against the windshield. Also sprague goes in one way backward and you start all over(yes I've done that) they are a real simple tranny and work great just have to take your Time on repair.

solenoid was the problem. Don't have er back together yet, but hopefully tomorrow. Thanks for all of the help and encouragement from all of you guys on this project. Later, Darrel

To help keep the project on a positive note Darrel, they are a great loader, and as Curt said, they will be around long after all todays electronic control junk is dead and gone. While on logging trucks years back, many crews in the forests loaded us with 645`s. Some used Cat 950`s, and a few had IH loaders. The Allis was head and shoulders above the rest for lift capacity and reach. We`d arrive on their landings and skids, the 645 would grab our 3 axle jinkers, lift them clear of the truck bolster/stauntion, reverse out, line up the pole eye with truck coupling for us to drop the pin in, then with a couple of back and forward moves, stretch the pole out without us moving the truck, then start loading. In the time it took the 645`s to do that and have a bed of 40` logs on the bolsters, the Caterpillars were still stuggling with getting the jinker off coz the they didnt have the reach to get the pole over the truck stauntions - we had to drive forward for them. The IH loaders, well they were still carrying the jumper cables across the landing to get them started.

Darrel, According to my shop manual it's just three steps to repair the transmission- Remove the hood and radiator, remove the engine, remove the transmission. 
There you go, two, three days should do it!

If the starter spins, you have adequate amperage to energize the starter. Check the two small leads for continuity. This is a coil which pulls the drive into the teeth and energizes the motor. If it is open, then the starter solenoid will need to be changed. If you have 

If its a Delco starter, the engaging solenoid may be bad.  With a heavy cable, jump from the hot post where the battery connects to the post on the starter bypassing the solenoid. I started our Cat 920 using that method until we changed the solenoid. Hopefully its not engaging because the flywheel teeth are bad.

24 volt system? I'd better check into that. I know it has two 12 volt batteries, and I thought they were hooked up in a parallel, but I never followed the cables that closely. I am going to have take another look. Thanks, Darrel

Now the dad gum thing won't start. Has like new batteries and starter, cables look good, has almost 13 volts, put jumpers on it also, and all I get out of the starter is the old clunk....clunk....clunk. It has always spun over to beat hell and started right up till this morning. Where do I start? Darrel

The main problem with overfilling is the trans builds up more heat and also can cause foaming.  Depending on what you use it for, you probably can get by this winter but come summer it will crap out on you after an hour or so of running.  If you take the cover off the left side (looking forward from the back) the intake tube is easily seen.  The bracket where mine broke is up above a few inches and with a mirror you can see it.  I suspect you will have to pull the trans out and repair it.  The good side of it is that parts are fairly reasonable and easily assessable.

hope this mite help some
645 PM PRIOR TO SN 2032.pdf
645-B PM #73073134.PDF
645M PM #3055044-6-1.pdf

http://www.minnpar.com/manuals.asp


     B:-)     Dnoym

darrel, unfortunately the crack is in a place you can only see with a mirror.  I did think about trying JB weld but I just don't think it would work.   

darrel in ND wrote: one54dodgetruck wrote: If I remember right the 645 had issues with the transmission pump getting worn and having low pressure. I think it was only around $600 in parts and could be replaced in the loader Andrew    I'd be dancin in the street if that is the case. I'll have to check into it. Thanks, Darrel

If I remember right the 645 had issues with the transmission pump getting worn and having low pressure. I think it was only around $600 in parts and could be replaced in the loader

John, is there any way a person could weld it with a small wire feed through the inspection cover? Darrel