Sizing 12 v radiator fan for riding mower....

[DickeyJoe]

Want to add a 12v fan to increase cooling for my transaxle on my Husky yth1848xpt riding mower. The battery charger runs at 14amps. I don't know how think about what would be a safe extra Amp draw. There is a 12v power socket so I'm sure I can add something....

Any advice would be much appreciated.

 

[Treemonkey1000]

Why do you feel you need to cool it down? Is it getting that hot? Are fluids topped off in it? No accumulation of dirt and clippings on it that impede the cooling by convection?
The fan can be put on a temp sensor like they do on cars which will kick it on at a certain temp. 5amps is a approximate running current for a lot of the electric fans. Start up current will spike for a few seconds then ramp down. The fan may just blow more crud on the transaxle though.

 

[DickeyJoe]

Yes, Tranny oil overheating seems to be a problem if you get into heavy mowing, mow for long periods or mow up steep inclines. The result is loss of pulling power from the overheating, not from loss of oil.

The tranny is a tuff torq k46bn and a lot of folk seem to have this issue.

I will have to rebuild it and want to try and address the air flow problem with added air.

Eiither an external mount marine 12v 3 amp blower with about 90 cfm piped inside or a 12v 3amp automotive radiator fan supposedly rated at 1100 cfm mounted inside. The fanwould be preferred because of higher airflow but the mounting will be mucho tricky and harder to tweak.

 

[Treemonkey1000]

Not sure if you could plumb in an extra oil cooler on that or not which would be a better solution if you could do it. Then cool the oil cooler. Even one of the coolers that look like mini radiators about 1"thick by 4"x8". I am not familiar with that transaxle so I might be blowing smoke. :laughing:

http://www.tractorbynet.com/forums/parts-repairs/164892-tufftorq-k46-repair-guide-pictures.html

 

[DickeyJoe]

Yes, a better heat solution, but the tranny case is not designed for that and tuff torq give it a thumbs down.

Have found another 12v 4.5" blower that will pump 110 cfm and could be mounted through the rear chassis plate.


I still like the 8" inside mounted fan idea if I can get in there...

Thanks...

 

[DefEddie]

One of the first modifications I do to all vehicles I own is electric fans if they don't already have.
Can't speak for what size you need for a mower,but can say with certainty that a single 15" fan puts out enough CFM to cool a modified 350 chevy tahoe (even with nitrous and extremely high timing).

For an 10" or smaller fan look at trans cooler fans,they are slimline and usually around an inch thick or so.

If you would like to try somethign different,look for a couple computer fans. Usually they are about 2-4" and run on 12v,they are used pretty often on auto stereo setups to control heat.

I would ask if you've considered alternative methods though.
I use different types of internal engine coatings,and a big one right now is a heat dispersent that accelerate's heat transfer from the coated surface.
It's used on top of intake manifolds,intercoolers,supercharger cases and turbocharger compressors.
I've yet to use it on my mower or finish mower engines,but the concept is the same.

Coating the exterior and interior of the transaxle case,or just select area's that carry the most heat will defininately help.

Anyway,just a couple suggestions.
If you look at a couple truck stops you could find 12v fans of differing size's that could help also.
Good luck!

 

[DickeyJoe]

Thanks for all the input.... I've ordered an 8.25" fan which should do something!

 

[Treemonkey1000]

So have you tried the fan out yet?

 

[DickeyJoe]

So, I've got the fan as shown here....

7" Radiator Cooling Fan with Mounting Kit

Sadly one of the mounting brackets was missing which "Robie" my vendor is gladly sending out.

I fabricated some additional brackets to position the unit behind the tranny and blow on it angled slightly downward. I have to be careful to avoid the tranny release lever bar that comes out of the rear of the chassis and plan to put some small gauge hardware cloth front and bak to prevent damage to the plastic from debris or rocks. It looks like it's going to just fit nicely.

Then I'll wire up the 12 volt leads with the neutral bolted to the frame and the positive lead wired along the frame and attached to the positive battery terminal. With an inline toggle switch on the positive lead mounted under my dash I should be ready to cool.

I tested the fan and it really moves cfm!

 

[Treemonkey1000]

Can you wire it to the ignition switch so that it comes on when you are running the mower.. Kind of a fool proof method just to keep the tranny cooler if you forget or someone else is mowing.