1975 C-100 rear axle flush

[PGRNPA 0]

Hi all, just found this forum! I have a 75 C-100 manual that has a whitish milky look to it's rear axle oil. I finally found the allen drain plug but do I refill through the dipstick or that what appears to be a filler on the left rear side at an angle? Also what weight oil is appropriate. Unfortunately this was obtained without a manual. Thanks!!! Jeff

[nylyon-(Admin) 7,329]

I have always filled through the dipstick, but it can be painfully slow.

that cover most years. Often the rubber shifter boot cracks allowing water into the transaxle causing the milky fluid. Search around the forum for flushing trans's, a lot will recommend Kerosene (you can search for that too).

[Tankman 3,518]

Use 90w gear lube, I've been using 85 w 140 gear lube lately. Don't know

why but read it somewhere. Anyway, the Horse moves slow most of the time and is

always indoors when not in use. Like nylon states, painfully slow, use a funnel too!

1/4" Allen socket screw, drain plug, drain and then fill through the dipstick.

I think your manual trans'll take two quarts of gear lube.

I haven't seen a filter on a WH manual transmission.......yet.

I just replaced two shift boots 'bout $6 each from www.partstree.com.

Mine were cracked and worn but, Horses are indoors.

Welcome to the forums! Where in PA? I'm 'bout 15 miles south of Allentown.

[rmaynard 15,609]

Since the hole in the dip stick tube is so small, I unscrew the tube and remove it. Then you will have a larger hole to put your funnel in. If you are going to replace the shifter boot at the same time, you can remove the shifter and fill through the shifter hole as well.

Also, when draining the transmission, you will never get all the oil out if you keep the tractor level. There is a hump in the middle of the transmission that prevents all of the oil in the front from making it's way to the drain hole. Jack the front of the tractor up as high as you safely can. This will assist in getting the oil to the back.

Edited November 20, 2012 by rmaynard

[tunahead72 2,433]

Jeff,

Good advice so far. Before you get started with draining the old fluid, clean the drain plug really well with a tiny screwdriver or awl, where the allen wrench fits inside, it will make it easier to remove the plug.

And like Karl (nylyon) mentioned, do a search on flushing the trans, you'll get lots of different points of view. Some guys use kerosene, others diesel or automatic transmission fluid. And there's some debate about whether it makes sense to drive the tractor around for a few minutes with the flushing fluid still inside, or to just jack up the rear end and (carefully) run the trans through all the gears, either manually or with the engine running.

Here's a couple of threads to get you started:

And finally, So, what part of Pennsylvania did you say you were from (hint)?

[Tankman 3,518]

Years ago I drove a TT delivering oil products to UPS terminals for their trucks.

UPS keeps a huge data base on vehicle maintenance. A racing friend was getting one race per tranny using 90w, gets three races per tranny using 80w90 synthetic gear lube.

For their tranny's they use 80w90 Mobil synthetic gear lube. UPS states they get better service from their delivery vans using synthetic.

Thoughts?

My horses never move fast and, I use 85w140. Shift boots are inexpensive, replace as needed. Simply remove the shift knob and pull the boot off. I can remove the boot even through the panel on my 414 and 416 too.

[rmaynard 15,609]

Years ago I drove a TT delivering oil products to UPS terminals for their trucks.

UPS keeps a huge data base on vehicle maintenance. A racing friend was getting one race per tranny using 90w, gets three races per tranny using 80w90 synthetic gear lube.

For their tranny's they use 80w90 Mobil synthetic gear lube. UPS states they get better service from their delivery vans using synthetic.

Thoughts?

Considering how slow a tractor runs, almost any oil will lubricate. The most important thing is to keep the water out of it so that it doesn't freeze. Look at the old Wheel Horse manuals. Some say 90W others say 85W140 and the Uni-drives have virtually all the same innards! Go with what you want. I see nothing wrong with synthetic, however, I have to tell you that every time UPS delivers to my house, they leave a puddle of oil in my driveway. :disgust:

Edited November 21, 2012 by rmaynard

[Kelly 1,029]

I use synthetic in all my keepers, even the hydros, as for weight in the sticks, What Bob said any weight gear oil will work.

[Anglo Traction 761]

Yep, all very good advice here. I haven't experienced water in my 2 WH rebuilds personally (lucky?), but I recall the recommendation from a previous discussion on this issue was to drive the Tractor around for 15 mins or so before draining the Tranny.

The reason was that the water separates and settles to the top on the oil below. driving it around first mixes it up again and allows more of it to be removed.

[PGRNPA 0]

Hi all, thanks for all the info. Really informative. I have performed this prior to receiving these posts and all appears to have gone well. I am confused by all the different weights of gear oil people use though. I had called a dealer as I don't have a manual and he recommended 2 qts. of 80W-90. I've seen posts of 90W-140, thoughts?

Happy Thanksgiving to all!

[rmaynard 15,609]

The reason was that the water separates and settles to the top on the oil below. driving it around first mixes it up again and allows more of it to be removed.

I'm going to have to correct you here. Oil is less dense than water and will sit on top. Water will sink to the bottom if left alone. Mixing around in the transmission causes the oil and water to become emulsified, but it will eventually separate with oil on top, water below.