Unimog Repair, Maintinance and Modification

My Transmission Cooler

If you live in a warm climate, you might be interested in this.  Simply, I tapped into the bottom plate on the transmission, ran a line to a pump, then to a cooling core, through a filter, and then back into the bottom plate.  I also installed a temp sensor and gauge to find out if the cooler was working or not.

First I constructed a housing out of aluminum and stainless steel bolts.  The two round holes are for two 9" 12v pancake fans run in series.  The grille is for air intake from the outboard side of the vehicle.  If I were to do it again, I'd use 20 ga steel as it is much easier to work..

This is the pump I used.  I got it from Surplus Center.  It was originally intended for pumping coolant and is 24v.   I mounted it  on the inside of the frame by the gas tanks.

I made a skid from angle iron to protect the fittings on the bottom of the trans.  Since then my front torque tube boot was speared by a tree branch.  I'll be making a full skid plate soon.

The hose goes from the trans to the pump over the trans to the cooler thru the filter between the trans and the front output housing (tight fit) back to the bottom plate.  Easy.

This is the cooler core housing.  It has two 9" 12V fans run in series.  The core is a 1/2"  I. D.  auto trans core  7.5 by 21".

So far it works pretty good.  Holds tranny temp to 220 deg. F ( approx 105 deg C) in August in SC at 95 kph sustained speed.
That's with temps in the high 90's (and full synthetic gear oil).  Before I turned it on the temp was 250 and climbing.  The pump leaks a little  and the flow is slow but it works

Useful Stuff

As I am no wizard of web page design, new things will appear in the order I think of them.  Here is a list of parts I have gleaned from the Mogml.  Also here are some links to parts/pieces that may be helpful for your projects.

Hayden 24v cooling fan                Prestolite 24v altenator 150amp
P/N 3626                                            P/N 8SC3018V www.prestolite.com

Wilson 24v 40a altenator            Hazard bulb 3w 24v (NAPA)
(NAPA) pn# 90-01-3123               pn# 13829 (Phillipa)

Heavy duty 24v flood 5.5x4" lens    Windshield wiper blades 28cm
Northern Tool pn# 163466-B948     (NAPA) pn# 61-110

Electric fuel pump, 24v Carter (NAPA) pn# 74016 or 74018
Regulator pn# 730-2368