Hello all, I went camping this weekend pulling about 10K 5er up to a mountain lake. The road is steep and very washboarded. I was in 4HI because of the washboard driving at about 10-20mph. Outside temp was 77. Transmission was usually in 1 or 2nd. Edge setting was level 2. Engine temp went up as high as 212. Tranny temp went up to 250, maybe for 5 minutes.

Did driving in 4HI have any bearing on the high temp?
I had to crawl up this 6 mile stretch, what could I have done different?
What can I do to keep this from happening again?
Should I get the ATF changed? I am at 14000 miles?

Thanks

 

According to the owner's manual I think it says if heavy towing to have it changed pretty often. I would, yes, if it were mine. As for thetemps I haven't climbed a hill ike that, so I don't have any temps to compare for ya, but you could put it in 4lo so the trans can shift more if it needs to. The gearing range is a lot closer in low. I would be curious to see what the temps would have been in lo.

 

Did driving in 4HI have any bearing on the high temp?
No...The low speed does. Under 30mph, the TC is unlocked in T/H mode.

I had to crawl up this 6 mile stretch, what could I have done different?
Not sure...4 low may have changed the TC lockup points. Others may have a better answer.

What can I do to keep this from happening again?
In the same situation...theres a lot of options: 4 low, more trans cooler w/ a fan, mag-hytec pan. It all depends.

Should I get the ATF changed? I am at 14000 miles?
Maybe...What does it look like? Pink = good; Red = OK; red/brown = change soon; brown or black = CHANGE NOW.

I just changed mine at 21K, when I put the mag-hytec pan on. I don't tow much (read enough); Fluid color was red to red/brown.

Oh, yeah, sitting in traffic, mine will hit 200-210 on 110-115 days. If I can get above 30mph to lock the TC then ride the jake back to ~25mph, the trans will cool down.

Trans temp also depends on where you have the sensor placed. Where's yours?

HTH

Tony

 

well running in 4hi will cause the tranny temp to be a little higher but not enough to matter. the reason it heated up is because you were at a low speed therefore the TC was not locked up and just causing fluid friction which produced the heat. pulling at that speed up a grade your best bet would have been 4lo. if your going to be towing alot up grades you might want to install a tranny cooler with an electric fan. pulling at low speeds like that it would also help if you had a tranny controller to lock up the TC in first and second gear. as for the fluid i would just keep an eye on the color of it change it once it starts turning redishbrown or do like a couple guys i know do install a drain plug in the pan and drain a quart out every oil change and put in a new one

 

Thanks much. There were a few quick spots that the TC would lock up in 2nd and I could see the temps coming down. I thought that not getting air flow was a major problem. I think a electric fan would really help. I won't be going up to that lake again (park lake outside of Helena) until next year. I will try 4lo if I find myself in a situation like that again. I am not sure where the temp prob is. I think the Edge chip reads it from the truck computer?

 

TC won't lock in manual 1st so you are running in fluid coupling.Thats your heat source. ATF+4 is rated to take temp spikes to 325 degrees so the 250 is within its operating range IF you had the sensor in the hot line NOT the pan. If your reading pan temps your fluid is due for a change.

The synthetic fluids loose theit color fairly rapidly but not their effectiveness, You cannot tell if the fluid is bad simply by color unless it is black and/or burned smelling. Monitoring your hot cooler line temps is the best way to judge if you have exceeded the limits of the fluid. Otherwise, chnage it out every 20k if you tow much.

Too keepthe tempsdown you need to get the TC locked and keep it locked. If manual 2nd is to fast you will need to use 4lo in the slow sections.