I'm interested in your winch bumper. I sent you a PM.

By the way, if anyone is interested in the custom winch bumper that i'm not using, let me know. I don't recommend it if you are towing, but if you aren't, or you have an older G without the bumper oil cooler, it would be fine. I posted some pictures already, if you search for my postings. I'll let it go real cheap.

 

looks good. i also thought about this set up. I think you could aslo use the behind the skid plate deal and put a fan on the cooler. Some of the B&M trans coolers have them.

 

What have you done to monitor the tranny oil temp?

JW

 

I'm planning to add a VDO gauge, but I haven't yet summonsed up the courage to put a hole in the transmission case. I'm trying to find an in-line adapter to put in the oil hose, but no luck yet. Everything available here in the US is non-metric.

So for my experiments I have been using two things, shown in the picture. On the right is a Fluke 62 infrared thermometer. This is useful for finding hot spots. It will also log the hottest temperature it sees while you have the button pressed. The disadvantage is that you have to get out of the truck to use it.

On the left is a datalogger I bought to log the temperature as I drive along. I have three thermocouples clamped to the oil cooler hoses to measure the temperature at differnt places. This setup can measure the tempertures every second for hours at a time, and gives you a log file you can open in Excel. This is good for experimenting, but it's not a replacement for a permanently-wired gauge.

One interesting thing I found out is that the oil inside the differentials is the same temperature as the differential case itself, measured on the outside. You would think that the inside would be much hotter than the outside, but it isn't. I measured both when I was changing the gear oil last wek, and there was no difference. This makes me think it might be unnecessary to put the tranny oil sensor right into the oil - the temperature of the pan is probably very very close.

When I get time to graph all the Excel files, I'll let you know what it reveals about the tranny oil cooler performance.

 

Get that temp gauge!

Those coolers are probably better than nothing. The only way they could be worse than nothing is if they gave a false sense of security after they got plugged up. All those low-hanging hoses give me the willies too. I know the skid plate covers them, but that wouldn't help me sleep much.

If I had to do an additional oil cooler on a G that saw a lot of off road use, I think I'd put it in the top of the fender with some ducting to create sort of a "Z" shaped air path from the fender top, down through the cooler, and from there toward the rear of the wheel well. Maybe even adding a fan like Kerr suggests.

Another great option is the oil->water coolers like most cars use where the trans sheds heat into the radiator tank. A good custom radiator can be built to fit in the stock location, cool the engine better than stock, and take care of the engine and tranny oil duties as well. Makes for a super clean setup.

Every hose and coupling is a disaster waiting to happen. At the very least, minimze them, using hard lines wherever possible and flex only between components that need to move in relation to one another.

Oh yeah, and Isspro makes a nice trans temp gauge that combines the best of both worlds - electical movement so there's less danger of the gauge works providing an out-path for oil, and a nice readable 270 degree sweep. I got all my Isspro stuff through Diesel Injection Sevice in Lubbock, TX:
http://www.dieselpage.com/issev3.htm

-Dave G.

 

w5yk - 2/11/2006 9:44 AM

....One interesting thing I found out is that the oil inside the differentials is the same temperature as the differential case itself, measured on the outside. You would think that the inside would be much hotter than the outside, but it isn't. I measured both when I was changing the gear oil last wek, and there was no difference. This makes me think it might be unnecessary to put the tranny oil sensor right into the oil - the temperature of the pan is probably very very close.....

Your findings are no doubt true after the truck has set idle for a few minutes with the diffs not in moving air and no new heat being generated. The steel soaks out quick enough when the truck is stopped. Personally, I wouldn't carry that logic into transmission temps. Trans temps rise pretty quickly when towing under adverse conditions. I wouldn't want to wait for the outside surface of a pan in a moving air stream to soak out before giving me warning of upwardly trending temps. An in-oil temp sender can be done, and done well and safely with some thought. That'll get you the best data for sure.

Your little data logger thing has got me wondering. I wonder if the information to/from the Isspro conversion boxes could be mined and fed to a logger like that....Interesting!

Thanks bud!

-Dave G.

 

Water Cooling

Hipine - 2/11/2006 1:49 PM


Another great option is the oil->water coolers like most cars use where the trans sheds heat into the radiator tank. A good custom radiator can be built to fit in the stock location, cool the engine better than stock, and take care of the engine and tranny oil duties as well.

On the G500, the ATF routes through the engine coolant radiator before it heads down to that small transmission radiator and back to the transmission.

 

RE: Water Cooling

Take a look at the EPC for the 96->2000 G300DT. It has a large fan driven engine oil cooler hidden behind the right front headlight. Those parts, or at least the location could be used for a very effective and risk free transmission cooler.

 

RE: Water Cooling

AlanMcR - 2/11/2006 7:55 PM

Take a look at the EPC for the 96->2000 G300DT. It has a large fan driven engine oil cooler hidden behind the right front headlight. Those parts, or at least the location could be used for a very effective and risk free transmission cooler.

It would be very tight as the radiator overflow reservoir and the right side engine air intake are located there on the G500.

 

Dave - good comments, thanks for the feedback. I think you are right about the sensor needing to be inside the tranny to get a faster response to change. Hadn't thought that one through properly.

The two oil coolers aren't as dodgy mechanically as I probably made them sound. I used one extra hose, and got the proper MB one, with the wire coiled around the outside to protect it. All the connections are proper MB banjo fittings, torqued correctly, and it's all pretty tight looking. I'm confident in it. Wait, let me just go check it again....

That Daqpro logger will take pretty much any thermocouple, up to eight of them at the same time. You can calibrate them on the logger, or afterwards in Excel. Quite a machine.

Thanks for the Isspro link - not only did I find the oil temp gauge, I also found a 5" speedo for my Unimog. VDO stopped making those ages ago. That was a great lead.

I did think about the fan-cooler in the fender, but decided it was too much engineering for my limited abilities. Probably a good way to go though.

 

RE: Water Cooling

DUTCH - 2/11/2006 6:49 PM

AlanMcR - 2/11/2006 7:55 PM

Take a look at the EPC for the 96->2000 G300DT. It has a large fan driven engine oil cooler hidden behind the right front headlight. Those parts, or at least the location could be used for a very effective and risk free transmission cooler.

It would be very tight as the radiator overflow reservoir and the right side engine air intake are located there on the G500.

I measured this out once. My intention was to implement the G500 right-side air intake for my truck. The oil cooler has a duct that exhausts throught the fender vent that the G500 uses for intake. From my analysis at the time, it seemed that venting the oil cooler into the fender area would work fine with some minor work on the plastic fender liner. Removing the exhaust duct would leave space for the G500 intake ductwork.

 

And thank YOU

Even more off the track than you finding the speedo for your mog, was me tracking down those daqpro loggers. I have an archaic system I use at work because it's simple and does what I need. But I'm getting tired of hauling a 386 pc and pen plotter around on a cart to use it (only thing the card is compatible with). The daqpro stuff is a little spendy, but I think it may be the right step for me to do the data collection I need without the full blown Labview approach. I know Labview is good stuff, trouble is it's way overkill for what I need and I can't afford to keep the programming expertise up to date.

Anyhoo - thanks for that!

-Dave G.