Gary Omel and I have been trying to get the temperature of the retarder oil to show up on the VMSpc. I think we have finally succeeded. Could be wrong, but it looks like it is working. The PID is 120 which was undefined in my version of VMSpc. However, it is an easy matter to define... see below. Once that is done, the next step is critical. You need to download an updated version of VMSpc.exe. Evidently, the old version had a software glitch that would not allow PID 120 to report correct values. Now that is fixed.
Here are the directions from Silverleaf....
"Here is a Link to Download the "fixed" version...
VMS PC 2012-01-12 (http://173.164.87.235/temp/VMSpc/VMSpc_20120113.zip)
The Version is still V2.5 B10, but the Date is todays, so you are Special, being the Second person with this version..
Download the .ZIP file, copy out the VMSpc.exe file and replace the VMSpc.exe file in your C:\VMSpc folder, after you have exited the VMSpc Program, AFTER you have saved any changes you have made... Now you can restart VMSpc.. The value will be Constant and Correct."
Note that PID 120 is not defined as Retarder Temp by Silverleaf. That is my name. You can find the "official name" by looking for PID 120 in the "sniffer." I don't recall what Silverleaf called it.
George
George,
Can you or Gary elaborate on the value issue? What was incorrect about the previous values? Steve had enabled PID 120 and set the scale on ours this past summer and everything seemed to work fine.
Thanks,
Michelle
Gary was the first person to get the updated software after he contacted Silverleaf about some problems he was having. I couldn't get it to work either.... the values for PID 120 just didn't make sense (way too low). So I called them thinking I had PID 120 defined improperly. That is when I heard about the software update. Evidently Silverleaf looked into the problem that Gary reported and found a coding error.
When I tested it today with the new software the temps from PID 120 seemed appropriate.... generally higher than the trans temp and went up when the retarder was used. I tested it on relatively flat highway, but there were some traffic lights where I used the retarder. At times there was about a 20 degree difference. It will be interesting to see how things look after descending some good hills. We leave for Quartzsite tomorrow.
George (and Gary),
Thanks for digging in to this and posting the update ... I'll have to install it and give it a try.
I had enabled the 120 PID back in October and it system recognized it right away. I know the values responded with retarder usage, the temperature values went up very quickly when you engaged the retarder. Actually the numbers went up at an alarming rate, and took a while to recover, so I was not really sure what to make of the values in terms of limits.
Be interesting to see what this new version does to the values ... thanks again ^.^d
Yesterday I had a chance to check out the retarder temps on our trip from Tucson to Quartzsite. It seemed to provide consistent results....same as trans temp when the retarder was not in use with an almost instantaneous increase when it was on. As Steve noted, the temperature increase can be alarming, going from 168F (normal trans temp) to over 240F very quickly when applying full retarder on a freeway off ramp. It will be interesting to see that the temps are on a long hill.
I've never seen my retarder temp go up that fast. And often been surprised at how slow it is to rise.
1999 40ft U320 M-11 with Transynd in tranny.
best, paul
From my checking into the subject of transmission temps, have found the temp sender is in the sump, and max temp is not to exceed 250f. using the Transynd fluid.
My GUESS is the scaling is incorrect because my temp goes up very slowly and comes down slowly on my 01 320.
Just my OPINION or FWIW
Just back from Quartzsite where internet communication was very limited. Anyway, I think there is some confusion here between transmission temp (PID 177) and retarder temp (PID 120). I have both on my screen as shown below. You can also see a short video here (best to view as full-screen)....
Foretravel Retarder Temp 59mph to 45mph (http://vimeo.com/35546149)
which shows how the temperature of the retarder oil increases rapidly when it is engaged. This makes sense given all the kinetic energy that is being transferred to the retarder oil. The video shows the retarder slowing the coach from 59mph to 45mph. Note that before the retarder engages (message box top middle of screen) the trans and retarder temps are equal. As soon as the retarder comes on, its temp rapidly increases. It also falls off rapidly when the retarder is disengaged.
Not sure what all this info on the retarder temp means. I have always kept an eye on the trans temp and not the retarder temp when going down long grades.
(P.S. Thanks to the "Washer Lady" (Pat) for taking the video while I was driving!)
George, that is a good demo, I do not have a read out for the retarder or never found it yet, one thing I do notice is your transmission temp did not appear to change from the 174f. More to it than I know as I do not have a retrader sendor for temp, it just shows up in the transmission oil sump temp. So who knows ?
My transmission temp runs about 5 degree above the water temp, normal.
Also, never had the trans temp over about 215 even on a long steep interstate mtn, when held it to 55mph
Good luck
Dave M
Found this on Barry's site concerning retarder temps.....
Allison Retarder Temperatures (https://wiki.foreforums.com/doku.php?id=technical:transmission:temperatures)
George
Interesting indeed, now I wonder how to access the retarder temp seperate from the sump temp, Most interesting.
Assume it is hidden within the VMSpc somewhere.
I do beter with wrenches than computers.
Thanks
Dave M
Hi Dave M,
I also have my transmission temp running about 5 degrees warmer than my water temp with my M-11 450.
Raymond
George,
Does your transmission temp and retarder temp read the same value with the retarder off? I just got my retarder temp working and I notice it's normal temp is around 218. In your video the beginning temps were the same and then after the rise with retarder use it came down to 218, then the video stopped. I'm curious if my sending unit in the retarder is off or does the retarder temperature always read higher after warm up.
I checked with Mark at Silverleaf and he stated my parameters for PID 120 were correct.
Thanks,
I have only driven to Quartzsite from Tucson and back with the retarder temp recording on the Silverleaf. So I don't have a lot of experience. But if I recall correctly, the trans temp and retarder temp were almost identical (within a couple of degrees) when the retarder was not in use. Gary Omel explained how the retarder oil is cooled and his explanation is consistent with what I have seen. You can contact him directly if you want to know more. I'm no expert! Gary is a member of the forum.
I now have some experience with the retarder temp after long, steep grades. The drive up to Payson, AZ from Phoenix on highway 87 gains several thousand feet of elevation, but there are also several fairly long 6% downgrades. The Silverleaf retarder temp shot up as it normally does when it is on, but leveled off at about 275 degrees. For these grades I was in 4th gear at about 45mph and the engine was at about 1800 rpm. Evidently this engine speed produces enough cooling to prevent the retarder from getting hotter. After finishing the grade, the retarder temp quickly returned to normal (close to the trans temp).
We just did a 9 mile six percent grade. I was in third and fourth with two or three clicks back on the retarder for the entire time. I had been concerned about elevated trans temps but now that I know the actual mechanical limits of our engine I, like George, kept the revs up. The trans (sump) hit 216 which is fine with me. On ours, however, the trans temp doesn't return to normal quickly. Not sure why.
jor