Community Forums

MSGulfCoast · 05-06-2025, 11:04 AM

I've been watching the hydraulic fan gearbox on our 2013 MADP and noticed that there was leakage from it appears around the shaft seal. No much but enough to get my attention. Removed the engine access panel and found it pretty easy to access. The level is just at the add mark so wasn't in danger yet but it needs fluid. Does it require a special hydraulic fluid or will any hydraulic oil be ok? TIA!

Skip426 · 05-06-2025, 04:38 PM

Chassis manufacturer may have a different spec for the fluid .

A call to the manufacturer's help line with your chassis serial number will provide the correct answer and perhaps a pdf on all requirements , fuel and air filters, belts etc.

Spartan Motorhome Support
1-800-543-4277

Freightliner Free Help line
1-800-385-4357

SafariBen · 05-06-2025, 04:58 PM

If the fluid is red, it's some form of ATF. If it's clear, it's probably AW 46 hydraulic oil, but nearly any oil would do. Don't mix hydraulic and ATF, but clear hydraulic oil could be mixed with motor oil or hytran, hygard "universal trans hydraulic" oils.

palehorse89 · 05-06-2025, 05:17 PM

Spartan OPERATION AND MAINTENANCE MANUAL for MOTORHOMES specifically calls for "SHC 75W90 Synthetic Oil"

This is what I used in mine...... https://www.walmart.com/ip/Valvoline...EaAtAEEALw_wcB

MSGulfCoast · 05-06-2025, 07:46 PM

Fluid isn't red. It's a Freightliner chassis and from other things I'm digging up it sounds like 75W-90 synthetic gear oil instead of hydraulic fluid is recommended.

NCC-1701A · 05-06-2025, 07:51 PM

The response I got from Freightliner when I asked them for my 2013 MA:

"14 oz of 75W-90 Mobil Delvac synthetic oil, 30,000 miles"

If you need it, I have the drawings for the gearbox with the seal part numbers.

SAS30 · 05-06-2025, 08:42 PM

If it has a gearbox as you stated? It will take gear oil, not hydraulic fluid.
Also check the vent on top of the gearbox.
If it is just a short piece(less than 2-3 inches) you should remove it and add a hose to extend it up higher(approximately 12 inches). It will vent the air out and not any oil at the extended height.
Oil coming out the vent is possibly caused by the expansion of the fluid when it gets hot.
Moving the vent higher gives more room inside the hose for the fluid to expand.

If you can locate them, There are other posts on this with pictures.

PanJH · 05-08-2025, 06:18 AM

From the Freightliner manual :

8. Fill the fan drive gearbox with Mobil® Delvac
75W–90 lubricant until the lubricant starts to
come out of the oil level plug hole.

https://dtnacontent-dtna.prd.freight...%20Manual_.pdf

MSGulfCoast · 05-08-2025, 07:07 AM

Thanks to all for the info. Got the job done. I used Dutch Star Don's post about the breather tube extension for guidance which helped a lot. Also on our MADP I found after worrying I was going to break something there is an Allen head drain plug in the bottom of the gearbox. It has a magnet which had a little fine metal on it. Don't think it was a problem from the looks of it just normal wear over 41k miles.

Capt. Bill · 05-08-2025, 11:28 AM

MSGulpCoast-your term Hydraulic fan Gear box needs clarification. Is your fan hydraulically or mechanically driven?

I've had both types on coaches over the years- if its a hydraulic driven fan it will use ATF, if it's a mechanically drive it will use 75W-90W Synthetic gear oil. You say its a FL Chassis- its most likely a mechanical drive fan.

Happy Trails

MSGulfCoast · 05-09-2025, 08:54 AM

Quote:

Originally Posted by Capt. Bill

MSGulpCoast-your term Hydraulic fan Gear box needs clarification. Is your fan hydraulically or mechanically driven?

I've had both types on coaches over the years- if its a hydraulic driven fan it will use ATF, if it's a mechanically drive it will use 75W-90W Synthetic gear oil. You say its a FL Chassis- its most likely a mechanical drive fan.

Happy Trails

You are 100% correct - my previous coach had a Hydraulic fan and it just stuck I guess but this is actually a shaft driven fan so it is a gearbox with gear oil. Thanks for pointing that out. Unfortunately I can't edit the original post.

johnbro27 · 05-09-2025, 09:01 AM

I'm curious how you accessed it. Our 2005 Essex has the mechanical fan drive and for the life of me I don't see how one could get at it without going through the bedroom.

NCC-1701A · 05-09-2025, 11:32 AM

Quote:

Originally Posted by johnbro27

I'm curious how you accessed it. Our 2005 Essex has the mechanical fan drive and for the life of me I don't see how one could get at it without going through the bedroom.

Sometimes that is what you have to do.

On my '13 MA, I could reach up (only because I have orangutan arms) and feel the hex head on the dipstick, get a socket wrench on it, and check the oil. I could also get to the drain and "oil fill level" screws. No dust storm shield on that one.

On our just new-to-us '21 New Aire with the dust storm shield, it's not possible to get to any of it without going in through the bedroom hatch. I suspect draining and changing the lube is a really fun exercise!

If Newmar Design Engineers had to access this STANDARD MAINTENANCE item as frequently as owners should, they'd dump the awful design they have with lag screws that strip out of thin metal and take so much time to remove on the floor piece, then the actual hatch, and perhaps come up with a hinge and latch design for the access panel! Or maybe at least have an extended dipstick in a tube to the back of the coach like the transmission fluid or engine oil dipsticks. That gearbox is probably in the top ten under maintained critical chassis items because of the difficulty of simply reaching it.

MSGulfCoast · 05-09-2025, 10:32 PM

Quote:

Originally Posted by johnbro27

I'm curious how you accessed it. Our 2005 Essex has the mechanical fan drive and for the life of me I don't see how one could get at it without going through the bedroom.

As stated previously that's how I was able to reach it. There is no way to reach and service from underneath the coach.