Potential Automatic Transmission Problems Questions...

[Califjim]

2000 Ford Super Duty, 7.3L Turbo Diesel, 4 Spd Automatic, Crew Cab, 88K miles

Need some input on a transmission question. I pull a 10,000 lb fifth wheel and monitor transmission oil temp (after market gauge on column pod). It typically runs at 165 when running on flat land. This last time it was running closer to 180, and when I was going up a grade in 3rd gear it went up to 200. At one point it hit 210, and that's when I pulled over, put it in Neutral, and let the engine run at 1200 rpm. Temp "coasted" up to 230, then after about 20-30 minutes it dropped back down to 190. For the rest of the grade I dropped into 2nd gear when the temp started to rise and it never got above 210.

Driving home I monitored the temp on the flat land, and again it was around 180. Outside temp was around 85.

I am not seeing any other problems with higher temp when not pulling, or shifting, or hesitation.

Does this sound right? Should I be concerned about the transmission? Seems like it shouldn't be as high pulling 10,000. It should be able to pull more than that, so this should be fairly light weight.

I went by the transmission shop that has serviced it, and the owner said I shouldn't be concerned. If I wanted to do something preventive I should look at having the radiator (water, not transmission) cleaned out, not just flushed. The transmission uses the radiator for part of the transmission cooling, and if it is not flowing freely that could impact transmission oil cooling. Does this make sense??

I appreciate your input. Any other forum(s) that I should consider asking these questions?

 

[JRJ04]

Hey there, welcome to SDD!

10k lb is a pretty good load to have behind it. When is the last time you have had the fluid flushed? Are you running conventional or synthetic transmission fluid?

If anything, I would recommend installing a bigger transmission cooler. The stock one on our trucks is sub-par at best and you really need a bigger cooler when you start putting a load behind it.

I recently installed a transmission cooler from a 6.0 (3x the size of my stock one) and I have yet to see my transmission go over 170 (and thats with outside temps at 110*+)

In any case, I would check your fluid and see how it looks. If it looks or smells burt, drop the pan, flush the fluid and change the filter out.

Good luck and let us know if you have any other questions!

 

[BJS]

The general rule of thumb for transmission temps is 100° over ambient temperature when you're working the truck.

I will say that mine usually runs in the 160-180 range with the temp probe in the pressure test port. My trans temps are related to the speed I'm running also. I notice higher temps, slightly 5-10° between 60 & 75.

pull the output line off of the transmission cooler and measure the flow delivered spec is minimum of 1/2 quart in 30 seconds at idle. That'll tell you if your cooler stack is plugged.

 

[Califjim]

Jourdan, thanks for input. Trans was serviced 5K ago. Fluid looked good at the time according to the trans shop. I had a problem on a windy hill a year ago where temp got up to 210 and I pulled over to let it cool. It coasted up to 230 at that point then came back down. Other than that I haven't seen it get up to 210 since I got the truck in 2000.

On the new cooler, did you get it new from Ford? If so, how much did it cost? Did it fit in the space where you took the old one out?

Thanks.

 

[Califjim]

Brandon,
Is general rule of +100 running on flat ground? If so, then I can expect slightly higher on up grades.

I'll check flow. Thanks for the suggestion

 

[BJS]

that rule of thumb is average, On the east coast hills/mountians or flats of FL as long as my converter stays locked the trans temps are constant, maybe a 2-3° rise when I'm heading up hills.

If you are seeing temps climb when you start going up hills with the torque converter locked then you are seeing t/c slippage (or somewhere else t/c is most likely)

for the cooler you pick up the factory cooler for a 6.0L truck and it will bolt into factory locations on your SD and keep things much cooler. Other alternatives are a bit cheaper but require fabricating your own mounting points.

 

[Tbar]

Are you running a synthetic tranny fluid or dino oil?

Synthetics like Amsoil will handle those temps with out a problem.


Tbar

 

[dmd]

If you are seeing temps climb when you start going up hills with the torque converter locked then you are seeing t/c slippage (or somewhere else t/c is most likely)

Trans will heat up when climbing even without slippage. I have a AIC
and the RPM is solid when climbing. With the extra power going through
the trans when climbing, there has to be more heat.

 

[JRJ04]

i would recommend the 6.0 cooler from ford. its a bit more expensive, but for your money, its the best. There are not any other aftermarket coolers out there that im aware of that offer that size of cooling capacity and directly bolts in. That was the nice part about it...it just bolts right up and you have to re-run the tranny lines.

 

[Califjim]

A Ford mechanic on justanswer.com had the following to say when I asked about putting in the 6.0 cooler:
"The torqshift from the 6.0L does have more surface area but the plumbing is larger. I have also heard that the trans can develop air pockets from using this cooler on 4R100 transmissions because of the larger diameter tubes. You definitely do not want any air pockets in the valve body of aerating of the fluid in the clutches because the air can compress and cause the clutches to slip and cause shifting problems in the valve body." Your comments and thoughts?