933G transmission issue

First thing to check is the transmission brake. Should stop the transmission gears from spinning when shifting. Works by pushing the clutch lever forward to brake before engaging gears.

And I thought I was the only Crazy - Mine is a 933A - have the parts book some experience on this machine if you need any help - Old Magnet is correct. Bob

There are lots of things to adjust to get the old girl working as it should. A owners manual is what you need. Your machine is a 42a XXXX and it is some different that the earlier 11A machine. Ebay is the place to look for manuals (that's were I got mine). Adjustment for the trans brake and engine clutch are in the shop manual, but owners manual has much more. I have run my 933G probably 100 hours this year and lots more to do. I do have a parts machine.

John

fwd and rev is a sliding gear on a separate shaft so you have 4f and 4r gears, same gearset is used in any combination of the speed gears., they are not particularly wide or strong and an abusive operator will soon kill them. Have seen 2 machines with this problem and result was same, teeth stripped from the f/r sliding gear.
The 933 would be one of the most evil and difficult machines to work on that caterpillar ever made, esp involving the clutch/gearbox/bevelgear repairs. Any of these repairs are ALOT of very difficult work. In my view anything much involved to work on the gearbox is to first remove the whole loader frame and then work on it. [gearbox is part of chassis, u can,t just remove/replace it] 😞 Also gears are going to be made of 'unobtainium ' unless you are lucky enough to find a 2nd hand 933 and then half of them will probably have the same problem.
933G was a mighty pocket rocket when going and could do a lot of work, but ooooh when it stopped. I had 42A8662 and spent a lot of time in, on, and under it. First things to get will be a service manuel and a parts book, a great sense of humour and extreme patience.
Good luck and cheers with it

Thanks guys. I just got the service manual today. I'm still waiting on delivery of my tractor. :mmph: I hope for nothing major. Time to work on it I can deal with. I just hope it's not a major expense.

The post above is right. It is a very hard machine to work on. Here are some things I didn't know until I found a operators manual. Start the engine with gear shift in neutral and after starting engage the clutch. The lubrication to the clutch bearing and shaft is oiled only when the clutch is engaged. If you are going to idle for a while, place transmission in neutral and engage the clutch. If you don't, you will see brass and steel floating in the oil in the clutch housing before long. Cat does not service parts to repair this. Dip stick for clutch housing is just in front of gear shift on floor between your feet. Check for floating metal after running a little.

The hydraulic pump is driven off the front of the engine thru a double universal joint. Make sure you grease it right away. Should be a hole in front pan just back of radiator. If the joint is frozen pull it out and free it up. If you don't the joint will break and wear out the splines on the hydraulic pump. It is hard to use the machine after this happens and parts are very hard to find for this problem.

If you run the machine without the engine side curtains, in muddy or even dry conditions, the tracks will fill the engine compartment with dirt. It will pack around and under the engine. Add in a couple of oil leaks, hedge and locust branches and rocks and it gets really enjoyable to work on. If the right side curtain is off, the fuel sediment bowl will get knocked off and fuel at $4 a gal is added to the mix. The only fix now is remove the front undercarriage plate to remove the junk. Now you will need the machine raised up at least a foot to get under it. 2 ft would be better. WARNING the junk and plate now weigh 500 pounds. The up side is that now it will be easier to pull the radiator and front grill to fix the hydraulic pump and u-joints. While doing this you might as well pull the engine to get the shaft, housing and bearing on the clutch fixed.

While the engine is out you will be able to see the next problem with these machines. The front cross member support for the engine and the front of the track rails will probably have broken or loose bolts. follow that cross member out over the track springs and you probably will notice both sides are cracked, broken or repaired. I fixed mine by forming and welding 1/2 in. plate over breaks. When the machine is turned the pressure is more the design will allow. You may also notice at least one of the track springs is broken. It had a cover when it was new in 1969. Now it is packed with dirt and not able to work. Now look at the back track support. It is a 4in bar and hard to believe it would ever break, but mine was. Now to make welding easy you take the track, rails and roller apart. New cat bolts and thread inserts will also be needed. About $300 to do that.

Now that you have looked over your machine and not found any of these problems yours is a easy fix. The clutch brake is out of adjustment or broken in two. adjust or weld back together and adjust. Think I know where a used brake is. Your shop manual for the 42A machine will show how to do this. Also there is an adjustment for transmission shift forks. Also in manual.
I have had to do it to my machine.

The clutch and brakes will need to be adjusted every 100 hours or less. Get machine inside or under a shade tree because it will a long while to do.

Hope I haven't taken too much shine off new machine. My machine is now a very good machine. Walks thru cedar trees and brush. Great for pond building or cleaning out. It will get buried because of narrow tracks. Had mine down past top of tracks. No I will not post pictures. The biggest tree that I have taken down was 65-75 feet tall and 6-8 ft around. Old elm tree. Maybe I should tell you my machine has a Wear backhoe attachment. Dig with both end and anything will come down.

Ask if you need to know more.

John

Now that thread produced a smile john 👍 I can very much relate to a lot of that esp the bits about the trackframes, and the narrow shoes [can,t fit wider ones] they bog easy. Only thing I will add is while the trackframes are off pull the final drive and brake drum assembly and reseal the pinion outside of the brake drum; and pull steering clutch to replace bevel gear seal.
On there positive side, they will build character in you; you will be a good operator real fast [even faster if you break it and you have to fix it] Theres 9 levers sprouting out of the sides and floor [ 8 if no 4/1 bucket] and you will need every one of them plus a pedal for each foot.
They can dig and certainly lift for there weight . not many machines will lift a third of there own weight 👍
A old 941 was absolute heaven after a 933, but couldn't lift bugger all more. And drank double the diesel to do the same amount of work. And then diggers came along and track loaders became history [ in NZ anyway] although could be argued that the small skid steer loaders do a lot of the smaller track loaders 'clean up' work.
cheers merv

Love these posts, and the comments regarding lots of issues faced in repairing a 933g can easily be applied to almost any old Cat, as I have found out with the D4 30A. The problem begins when you begin to explore 'issues' and before you know it,the whole thing is in little bits and pieces all over the place and your wife has divorced you!.

Character building indeed!!

I've been able to study the service manual and now understand how the tranny system works. Pretty simple. However, it raises new questions.
I still don't have the machine yet (transportation issues) so I've haven't been able to look at it yet. Being that the forward-reverse gear is a separate operation from normal shifting, it seems to me I may have two issues; one, why it it grinds in reverse in both 1st and 2nd and two, it works fine forward in 2nd. It seems to me I have a problem with the reversing gears and the 1st-2nd shifting operation.
Any insight on this?
Thanks