Moving M4 type chassis
 

I have been asked to move our sexton and Grizzly over to the main museum. Neither have been run up in a decade or more. Is this going to cause problems in the transmissions if they are moved without the engine running? I do not intend to break track for this, so the gearboxes are going to turn. Or is there a way to disconnect the gearbox from the final drives to prevent damage?


The distance is about 3 long blocks...about a km maybe. This is ignoring the weight of these pieces, that I can overcome.

should not be a problem if the gearbox is in neutral , as long a there is still a bit of oil in it , it will do no harm , there is an oil dipstick on the right hand side of the gearbox.

You should be fine with putting the transmissions in neutral and pulling them slowly. Sometimes the brakes stick and then they won’t move. Then you’ll either have to brake track or lift them.

Thanks for the information. Guess I'll be doing some reading as well as ordering in some of the older type oils and doing top ups.

I know that on most standard transmissions, it depends on the driven (engine side) to provide the lubrication, especially at the little bearing between the input shaft and the output shaft. The result of a 5 mile tow with the powertrain still connected (and the transmission in neutral) would often cost a transmission repair. And the M113 as well as the M109 both required you to disconnect the side shafts to the final drives if you were towing any distance, or break track if the damage was in the final drive.

M4 transmissions
 

I've got about 25 pages of *.pdf explanations of M4 steering and braking manuals. I'll email them to your personal inbox if you wish. The att is just as example.

Dont forget to check the final drives!

But of course.

I just read the manual a bit, and it says the countershaft pumps the oil, of which there is some 44 liters. So if the engine is not running, then the oil is not being pumped. I may disconnect the shaft and tow it in a suitable gear to get the oil pumping. Or I could have it in gear and have someone depress the clutch. Or am I overthinking it? I would hate to damage anything inside the transmission. I would feel a lot better at least getting some oil pumping through the system before towing. Maybe I can set up some form of an external pump into the oil line before moving the vehicle.

All we have here are photocopies of the operators manuals, and the lubrication charts are missing. I was going to ask what kind of oil goes in the transmission/final drive, but I just climbed into the vehicle and a check of the transmission shows it full (and even a bit overfull, but that could have been the oil lines draining back over the last decade). The smell is the same oil as in the CMP gearboxes and diffs. I have read on other threads where the modern gear oils will destroy the steering bands etc. This oil looks clean so I will leave it as is.

The previous (volunteer) mechanic had started working on this vehicle (and many others) so I have the pleasure of a partially torn down vehicle. The ignition system is all apart on the engine, many panels are off and hardware laying about. Not the end of the world there I guess, just a learning curve coming up. But at the drivers position he cut the control panel out. I think I saw one wire that was actually disconnected, the remainder have been cut. That will add a bit of time to the project when someone decides to spend the time to try and run this thing again. I did find the panel at the other end of this very large building some years back, and it is now located in the storage shed outside. I'll move it in the next time I am out there so it is back with it's vehicle.

Somehow I sense that getting and keeping a machine like this running could be a full time job.

Rob, as you know, any oil that has sat for a decade will look clean. The shite has all settled. Just reminding you.

Good point Lynn, thank you. For now it will be going less than a km to the main museum and a km back sometime in 2024. I'm not too worried about the oil quality for those trips but in the future it will be a consideration.

I think the transmission lubricates by splash. The pump is for moving the oil to the cooler.

I have not seen a path of flow for the oil in the transmission. Does the oil merely go through the cooler then get dumped back into the case? Or do they take advantage of the coler oil and use it to lubricate some key points?

I guess I had better find the maintenance manuals. I may even have something in my library here at home. I think I saw the parts manual at work, but I think it covered assemblies as opposed to complete teardown of the transmission.

The gears will take sufficient oil with them to lubricate them for slow towing ,the gears won`t get anny presure on them when towing .
in the complete drivetrain there is 160 litres of oil . Final drive gears also survive easy. Don`t worry , They even survived the abuse as a yarder .