Synthetic lubrication verses performance

[Montana_89]

A full-time rv'er stated that by using "synthetic oil" in the transmission, engine and rear axle, the temperature and wear is decreased greatly! Being an old time trucker, he sounded credible...is there any significance to this?

[Flastro]

Yes, in some case's lower operating temps can be achieved, will it decrease the temps greatly, depends on applications and driving habits and conditions. Wear may be reduced some, i know people who will swear by it, and others who will disagree. proper Maint still needs to be done to get the results you may be looking for. Based on the increased cost of synthetics, you will need to determine once you have priced it out and compared the results.
One note, beware of extended drain interval claims on the engine oil , certain manufactures require certain procedures if you are to do this and still expect them to warranty the engine should a lubrication issue arrise . Just a word of caution, do the homework and you will know if its right for you.

[Flastro]

One other note, some of the trucks we own already have synthetic axle lube from the factory. You may want to check with your dealer before changing the axle lube, would hate to see you spend the $$ when it may already be there.

[NJ Hillbilly]

I run synthetic oils in the rears, trans and motor. The trans does run slightly cooler and does cool down a little faster. I use synthetic in the rears (factory fill in the rear diff, though I have changed it a few times) to help stay cooler and synthetic performs better at higher temps.

I use the Shell Rotella Synthetic as a trade off since it is not true synthetic (man made) but hydrocracked dino oil that meets the specs (and is cheaper) so if I don't strictly adhere to oil change intervals it's not the end of the world. I also like the cold weather properties of the synthetic since I am not fortunate enough to chase the warm weather, cold starting id easier and oil pressure builds faster.

I have run more expensive synthetics (Mobil Delvac 1 and AmsOil). Many higher priced oils will advertise extended drain intervals BUT only with regular filter changes (remove the dirtiest qt or 2) and with regular oil sampling to determine if all of the additives are used up. If the additive package is shot then the oil can't sufficiently clean the engine, suspend particles and maintain a stable viscosity.

Extended intervals work better in big rigs since they are miles ahead in filtration and are generally cleaner running. These light duty engines are dirty ones and contaminate oil rather quickly. I have a friend with a 3116 Cat motor in a Top Kick machinery service truck. The truck idles a lot(runs a crane and a hydraulic air compressor), he has run Delvac 1 since day 1 and his oil is golden yellow to this day. Cleaner running motors and better filters.

I run a secondary fuel filter because of the high injection pressures but I have yet to add a secondary bypass oil filter yet. Someday I might when time allows(money too).

John

[Montana_89]

Thanks for the responses!

[Flastro]

NJ Hillbilly, great comments!, cutting to the chase, In big rigs its very expensive, 600.00 oil change vs a 150.00 oil change is a hard sell, especially considering you still have to perform scheduled oil sampling and routine filter replacement with extended drain intervals. The diff between million mile overhauls and 800,000 mile overhauls. is it worth it?, not to mention should you encounter fuel dilution or coolant contamination. You just trashed that expensive oil, and manufactures will not reimburse for this. only their brand oil. In Cat's case anyway.
In our situation, depending on the engine, 12 to 15 qts is a little easier to handle.
It all boils down to preferance, just make sure the oil meets the engine manufacturers requirements and specs. There is no substitute for quality maint.

[Bob Pasternak]

I use Mobil Delvac 15-40 in my Cummins with a 5000 mile drain interval and it seems to stay clean. Since my truck is used almost exclusively to tow the 5er, I change tranny oil and filter every 3rd oil change. Oil is cheaper than trannys. One thing I did find out was that whoever had my truck before had the differential oil changed and who ever did it didn't put the compound in for the clutches on the 'limited slip' and I was starting to get a chatter when I went around corners. Caught it before any damage was done.

[sreigle]

I hope nobody minds me asking a different, but related, question. What temperature range (transmission) do you consider "normal" when towing? At what temperature should I start to keep an extra close eye on the temperature? Ours runs 125-140 in cool weather solo, 140-150 hot (90's) weather solo. Towing flatlands it will sit on 145-150 regardless of outside temperature. Pulling long (several mile) steep (to 9%) grades in 90+ degree weather it will sometimes climb to 165, occasionally 170-175. Once and only once it hit 180 then came right back down and sat around 170 the rest of the climb, cooling down to 150 on the long downhill side. Is this a "good" range? Thanks.

[8.1al]

Those temperatures are so low that I wonder if your gauge is right. The Allison in my2500HD will run 140-150 empty,160-180 towing depending on the weather and will climb up to 200 on a long steep grade, but never over. If the temp. gets up to 240 or more then you have to start worrying.

[sreigle]

Now you have me wondering, too. The gauges (autometer in a pillar pod) were installed by a truck accessory shop last December. The sender for the tranny gauge is in the pan of the tranny. They cut a hole in the side and welded in the socket for the sender. If I recall, one magazine commented this transmission runs "cool" but they didn't give any numbers.

Anyone else with the torqueshift transmission have a tranny gauge and can tell me what yours runs? Is it my gauge? Or does this transmission run that cool?

For now, if 240 is the number to be concerned about, then I'll use 200 for that threshhold until I'm convinced my gauge (or sender) is reasonably accurate.

Thanks.

[NJ Hillbilly]

Your pan temp is going to read pretty low. The customary location for the sender is in the "to cooler" line. This way it tells what the temp of the trans is in the hottest part, the output from the torque converter. The pan is holding already cooled fluid so if it was high I'd be really worried.

John

[Flastro]

Steve, I have always used the 210 to 220 deg baseline, anything over than requires backing off and letting it cool down, once the fluid exceeds that temp then breakdown of the fluid will begin causing the dreaded burnt smell. Once that happens, you pretty much have to keep running it until time to overhaul. If you attempt to service an auto tranny with badly burnt fluid, clutch slippage will begin to happen. Along with *morning sickness* thats when the seals in the clutchs and hubs begin to crystalize (hard seals) allowing fluid to by pass the seals resulting again in clutch slippage and slow gear engagement. As for the exact max temp on the torgueshift, we will have to investigate. But those temps are what I have used until now. I rebuilt many an old C6 and C4 trannys when i worked for Ford years ago and have seen many a burnt up auto tranny due to overheat.

[sreigle]

John, thanks. That explains why the numbers are lower.

Kenny, looks like maybe you have the torqshift transmission. Do you have an aftermarket trans temp gauge on it? Where is the sender and what temps are you seeing?

Thanks.

[Flastro]

Steve, i do have the torqshift, but currenty have not installed an after market gauge, its on the to do list. The temps I suggested were from past trucks and diff models of trannys. My current truck still has the factory gauge with no numbers. but the temp reading on it has never gone past half way even in long hard pulls. As soon as I install one Ill let you know, on the dieselstop.com there is a few posts in regards to gauge and sender installation. I think i recall it being near the return line exit in the tranny case. dont hold me to that. I have not spent a lot of time under this truck yet...thank goodness

[Montana_1152]

Steve,

I have the Ford 4R100 transmission on my truck with the Bank's Transcommand module connected to it and Bank's DynaFact pillar mounted gauges (EGT, transmisison, Turbo boost). My transmission temperatures are similar to yours, though I have never topped 160. It seems to run very cool and only starts climbing on long steep hills and heavy stop-in-go California bumper to bumper freeway traffic.

The transmission module is very cheap insurance for long lasting cooler transmissions on the 99-03 Fords. Every ambulance and a good many delivery service trucks in my area all have them installed when the vehicles are first put in service. I was told this and did some checking to verify it. By the way... I don't work for Banks.

The techs who installed my system at Banks told me 240 degrees was the critical temperature to avoid in the transmission. So far, I have not come close to that.

I am heading to Yellowstone National Park next week in a fully loaded truck and trailer. There will be lots of steep grades and the desert heat to get through on the way. I will keep a close eye on the temperatures and advise if they get "critical."

[Flastro]

Found this on another forum in regards to temps and sender location***************

Q: I want to install a transmission temp gauge. Where to I access it from?

A: The port is on the Driver's side of the transmission, right above the pan. There is a black plug in the port. A spacer is a good idea as some sending units can bottom out in the pan due to a very shallow depth. Normal operating temps are about 40°-100° above ambient temps. But that can vary based on how you drive.

[sreigle]

Thanks, everyone. I wonder why the gauge installer didn't use that port?

Do-dog, thanks for the info. Is your gauge sender in the pan, the line, or a port? Don't go hunting for it if you're not sure.

Kenny, that factory gauge will go way up if it gets hotter than some preset threshhold. Otherwise, once it warms to a certain point it moves to a near-center position and will stay there. I've read this in a couple of places and have verified that when my autometer gauge moves around the factory gauge needle never moves. I was afraid that relying on the factory gauge to tell me when it gets too hot would be too late. I am more comfortable being able to watch the aftermarket gauge and adjust driving when it starts to climb. I've heard this transmission runs cool but since the sender is in the pan I'm not real sure at what point it stops being "cool". I guess I'll use 180 degrees as my point of concern since apparently the oil in the pan is not the hottest location.

Thanks everyone.

[Montana_1152]

Steve,

The sending unit is in a port just above the pan on the driver's side of the transmission, just as mentioned by Flastro.

[sreigle]

The installer for the autometer pillar pod gauges drilled a hole in the pan, then welded in a threaded socket, then screwed the sender into it. I wasn't real happy about him doing this but I didn't ask about it in advance and it was too late when I saw how they'd installed it. Since the torqueshift is pretty new I'd bet they got the installation package for a previous transmission or got a one size fits all install package. They did install the EGT probe in an existing port in the exhaust manifold.

[sreigle]

Been doing a little online research looking for any "official" type recommendations for tranny temp for the torqueshift. I haven't found anything I'd consider official but did find a couple of comments in a TruckWorld test including the 2003 torqueshift. The article is at

http://www.truckworld.com/Truck-Test...werstroke.html

and the quotes are --
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Five-speed automatic is considerably stouter than the four-speed automatic found in the 7.3L diesel. The new transmission runs considerably cooler and has a much higher load capacity.
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Freese also explained that new radiator and engine fan design (10,500cfm), much larger oil pump and larger passages in the transmission allow the new powertrain to run as much as 80-degrees cooler than the 7.3-liter diesel.
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I guess the sender for my gauge is not in the optimum location but maybe the low temperatures I'm seeing (for that location) are pretty much in line with what to expect, if this article has any degree of accuracy. So I guess the best bet for me is to know what is "normal" for my rig and watch for signs of it going 'abnormal' on me.

Thanks everyone for the input. As always, this group is terrific.