GX75 RER refurbish questions

[Edzell]

Hi; I'm new here and glad to have found this forum.

I have a GX75 bought used and I love it. It began to have starting (electrical) problems and I've decided to refurbish the whole machine as far as practical. I have a .pdf of the repair manual but have a couple of questions right away. I'll be grateful for any advice or experience others can relate.

1. Took the rear wheels off for a start. Both stub axles were completely coated with lubricant - a very black fluid, consistency somewhere between heavy oil and light grease. As the wheels are keyed to these shafts, and don't rotate on them, I'm puzzled why there's any lubricant at all. Should it be there? Could this be leakage from the trans?

2. Related question: How does one check and if necessary top up or change the trans fluid?

3. The clutch engages with a fierce jerk. Is this normal or something I can correct as I rebuild?

 

[davesl708]

Hi. Welcome.
Great project. The grease on the axle may be for anti seize purposes so the axles don't lock on the hub.
If you bought the machine used and do not have the maintenance records I would plan to replace all the fluids so you have a record and can schedule your own maintenance based on that.
The clutch, other's on here may have better inpute but may be dirty fluid or the wrong fluid in the trans. Make sure the linkages are moving smooth and clear.

 

[Edzell]

Daves1708; Thanks for the response.

I think we're talking about different types of machine. The John Deere GX75 "clutch" involves simple increase/release of tension in a drive belt around a driven sheave; no hydraulics involved. The concept of axles locking on hubs also doesn't seem to apply to this machine. But thanks for the suggestions.

 

[beenthere]

I also think the "black" fluid is anti-sieze. The hubs just slide on and off the axle and you don't want them to rust together.

I'd suggest you get the operators manual for your tractor.

The ?? 3 may mean you have a worn belt that grabs.

 

[Edzell]

I also think the "black" fluid is anti-sieze. The hubs just slide on and off the axle and you don't want them to rust together.

I'd suggest you get the operators manual for your tractor.

The ?? 3 may mean you have a worn belt that grabs.

Ah yes, I guess the anti-sieze would make sense (thanks beenthere and apologies to Dave ) I do have the operator manual but don't think it mentions the anti-sieze. Also it and the repair manual seem to be mum on the subject of how to check or change the trans fluid. I'll have to do another search.

I've got the trans axle out - quite a wrassle - and a quick look at the belts (not out in the daylight yet) suggests they're not in bad shape. It's going to take a while to get the tranny case clean enough to open it, which I think I have to do, to deal with the alleged brakes .

Many thanks for the replies; all help greatly appreciated.

 

[beenthere]

I'm thinking the brake pads are external to the transaxle...but don't have anything to go on other than the jdparts.com schematics that you can also look at. Shown in attachment.. and item # 59 is the kit for brake pads and disc I believe. Part # AM116883

Before opening the transaxle, maybe learn a lot more about what is in there..

 

[Edzell]

From the repair manual; to replace pads, remove disk ....



To remove disk, dismantle trans case ......



Sorry, I haven't managed to get the images the size I want but I'm sure you'll "get the picture." Anyway I'm delighted if you have conflicting information that lets me renew the brakes without splitting the case. Can you spell it out or refer me to the details somewhere?

(I'm using the John Deere Technical Manual TM1491 (July 99))

Thanks again for your interest & help.

 

[Richard001]

This a rather straight forward simple transmission similar to transmissions used in other lawn/garden tractors.

You do not have to disassemble the transaxle to replace the brake pads. If, for some reason, you need to replace the brake disk, then yes, you have to split the case. I have replaced brake pads on similar transaxles and did not have to split the case.

I also wonder why you want to disassemble the transaxle. You should only have to take it apart if it is not working properly. You may want to lube the transaxle, but you should not have to dissemble it for that. If you can not find a lube filling plug, then you will have to create one.

It is rather simple to do. First find a spot on the top of the transaxle that is flat and not immediately above a large gear. Get a small rubber stopper from a hardware store, maybe about 1/4” in diameter. Drill a hole in the above selected spot. Be careful not to let the drill penetrate into the case any further than necessary. You don’t want to drill into a gear. To keep the chips from falling into the gear case, put some heavy grease on the case and on the drill. Clean the drill several times as you are drilling. You may want to practice on a scrap piece of metal to make sure that the plug will fit the hole.

Now that you have a convenient oil fill hole, I usually add about a cup of 30W motor oil and a bunch of grease from a grease gun. When done, plug the hole with the rubber stopper.

One other thing you might want to do, as long as you have the transaxle out, is to remove the input pulley so you can get some oil on the input shaft. This shaft takes a lot of stress. Not only does it have the tension from the drive belt, but it also has to work with the bevel gear inside.

 

[Edzell]

Richard001, thanks for the comments.

I mean no disrespect but have you changed the brake pads specifically on a GX75, or only on similar transmissions from similar tractors? My reason for thinking I have to split the case is simple: the technical manual says so, as shown in the excerpt I attached. I'd love to discover that the manual is wrong about that. So far I've got no further than getting the trans out onto my bench and starting to clean the filth off it for inspection. Already have the big sheave removed. We'll see what we see next but I won't get back to it for a couple of days.

Oh, and I don't think I'll risk drilling a hole in the casing.

 

[Edzell]

Does anyone here have real experience or specific information, on strictly the GX75 - as opposed to "similar" - trans axles and brakes? I see no way to get at the brake pads without splitting the case.

Several helpful folks have already offered opinions/advice but it's hard to reconcile their comments with details of the tranny I'm looking at on my bench. I can only conclude they haven't seen or worked on one that's the same.