Tranny Temp Readings

[Diplomat Don]

I'm sure a lot of you get lousy readings from the Trans Temp gauge on the dash. Mine moves so little that you can't really tell if it's working. My VMSPC system now gives me accurate readings, but I would still like the gauge to read properly.


I found this info on another website and it makes sense:

"I have owned a '02 and a '07 Endeavor. In both of the coaches the transmission temperature gauge showed very little response. I did some research and found that Monaco had installed a transmission temperature sender with a range of 0 to 400 degrees. They used a VDO brand sender and I was able to locate a VDO sender with a range of 0 to 250 degrees. My Alladin system shows normal operating temperature to be less than 185 degrees. Most references to max transmission temperature show over 250 degrees to be detrimental to fluid and transmission life. I found the VDO Part# 323-095 sender at the following URL.http://store.42draftdesigns.com/250F-Water-Temp-Sender-18-NPT_p_90.html. I installed the sender with the transmission cold and lost only a few ounces of fluid during the sender exchange. The new sender is slightly longer than the old one. The advantage of having the gauge work properly is a quick glance provides quick feedback of the temperature while the Alladin screen can be a distraction to find the right information."

I ordered one today. As soon as I get it installed, I'll give an update.

[Dixieray53]

My Workhorse Allison Tranny temp gauge works great !!!!! And I own a Gulf Stream !!!!

[Tha_Rooster]

My trans temp gauge and digital read out gauge read the same and work very well.

[bluepill]

Don - What transmission do you have?

[Diplomat Don]

Guys......I have the Allison 3000 and this is a Monaco issue. Apparently, Monaco installed/spec'd the sending unit.

[LeeB]

Don I for one will be watching this thread and see what happens. I believe I have the same Transmission as you and have the same issues...

[walt2137]

Your gauges may be accurate but it a good possibility they are not, what D Don is using is a Silverleaf sys that reads from the engine and Alison computer and lots more accurate, I think you would be surprised at the difference. You can get a device for the gas coaches OBD ll plug also.

[WindsorDave]

Quote:

Originally Posted by Diplomat Don I'm sure a lot of you get lousy readings from the Trans Temp gauge on the dash. Mine moves so little that you can't really tell if it's working. My VMSPC system now gives me accurate readings, but I would still like the gauge to read properly. I found this info on another website and it makes sense: "I have owned a '02 and a '07 Endeavor. In both of the coaches the transmission temperature gauge showed very little response. I did some research and found that Monaco had installed a transmission temperature sender with a range of 0 to 400 degrees. They used a VDO brand sender and I was able to locate a VDO sender with a range of 0 to 250 degrees. My Alladin system shows normal operating temperature to be less than 185 degrees. Most references to max transmission temperature show over 250 degrees to be detrimental to fluid and transmission life. I found the VDO Part# 323-095 sender at the following URL.http://store.42draftdesigns.com/250F-Water-Temp-Sender-18-NPT_p_90.html. I installed the sender with the transmission cold and lost only a few ounces of fluid during the sender exchange. The new sender is slightly longer than the old one. The advantage of having the gauge work properly is a quick glance provides quick feedback of the temperature while the Alladin screen can be a distraction to find the right information." I ordered one today. As soon as I get it installed, I'll give an update.

Don,

My 2001 Diplomat with Allison 3000 and ISC 330 has had this problem for at least as long as I have owned it. About a week ago I saw the post that you referenced above and smacked my forehead real hard.

Though there were no fault codes shown in the transmission diagnostics I had decided to replace the sending unit on the premise that it would be a whole lot easier to change it than changing the gauge itself. Like yours, my gauge moves a little bit so I reasoned that the wire between the sending unit and gauge was OK

While in Coburg three weeks ago, I went to the Allison dealer and tried to buy a sending unit. They said that it would have to be purchased from Monaco because they had no way of knowing what gauge was actually being used. OK, fine, I went up the street to the Monaco plant and, sure enough, they had the replacement sending unit in stock which I bought at $36 and change.

Days later, not having had the opportunity to replace the sending unit, I read the post you mention above. So I'm sitting here with a brand new, but apparently useless, VDO 400*F sending unit for which I paid way too much!

I'm really interested in how your new sending unit works out. One thing that gave me pause was that it appears that the 250* water temp sending unit has a different length and I did not know if it may somehow restrict the flow of transmission fluid through the fitting in which it is installed.

Please keep us posted.

Thanks,

[Robi.1014]

Don,
I (and my other recent QZ friends) await your discovery. I'm hoping someday to get a tranny temp reading of more than 139 degrees on my dash meter!! It's been that way since I bought it.

[Radarman]

Exactly the same issue here D Don and Robi. Don't think I've ever seen the indicator dial read above 139

[Diplomat Don]

I installed the trans temp sending unit and tested it. It's placement is odd. The unit is threaded into one of the two hose lines at the front of the transmission. The two lines are the in and out for the trans cooler. The original sending unit is about 3/4" long and about a 1/2" overall in diameter. There's a large nut making the hose connection at the front of the trans and the temp unit screws into the side of the nut. The head and threads of the new unit are identical, but the probe end of the new unit is about 3/4" longer than the original. I was a little concerned that it would partially block the hose passage. It was very easy to unscrew the old one, put my finger over the hole and then install the new one. I lost less than an ounce of fluid.

For the first time since I've owned the coach, the trans gauge actually moved. That was the good news. The bad news was that the original sending (0-400 degrees) must be calibrated to the gauge. The new unit (0-250 degrees) made the gauge read too high. My VMSpc said I was at 181 degrees and the dash gauge said about 280 degrees.



The temp setting above was while I was backing my coach up the hill into my backyard. On my road test, the dash gauge was reading about 250 degrees while the VMSpc was reading about 150 degrees. I know there might be a difference from where the sending unit is reading the hose temp and where the VMSpc is getting the temp reading, but probably not 70 degrees.

I'll list this as a failure unless you have a gauge that just has marks and no numbers. If you just have marks, you would at least be able to see the gauge moving. Luckily, I only paid $10.27 and it took me less than five minutes to swap out the unit.

[WindsorDave]

Quote:

Originally Posted by Diplomat Don I'll list this as a failure unless you have a gauge that just has marks and no numbers. If you just have marks, you would at least be able to see the gauge moving. Luckily, I only paid $10.27 and it took me less than five minutes to swap out the unit.

Dang! I was hoping that your effort would pan out. Well, I'll call Monaco Monday and see if they'll take the 400* VDO unit back. It's still in the unopened display card.

Thanks for posting your results, Don.

[Perry White]

Here's how I monitor mine.

[observer]

Don, et All,
I am the original poster of the sender change. The temperature gauges on my '07 Endeavor do not have number readings. The labeling on Don's gauge is calibrated for the 400 degree sensor. If you look at the picture of his gauges in operation you notice the gauge needle is in the same relative position on each gauge, because both senders are 250 degrees. His digital readout also shows similar temperatures for water and transmission. With the new sender the gauge is now 250 degrees full scale. He would have to change the legend on the gauge to make it look proper though the gauge is giving him what appears to be an incorrect reading.