Tranny Issue

[RandyH]

Well, the 4th of July trip to the mountains may have just cost me more than just the expensive fuel. I was pulling the 35' fifth wheel toy hauler (probably about 11.5K loaded) from 5000' to 10000' elevetion over about 45 miles distance. Typically when I do this trip, I watch my trans temp gage and stop when I start getting between 200-210 degrees. I did the same this time and let it cool down, then started up the last long grade to our campsite. When I pulled into my spot it was getting up over 200 degrees again and I turned if off after my EGTs dropped below 400. When I went to move it again 10 minutes later the tranny wouldn't engage in any gear. I found that it had puked out 1/2 gallon of trans fluid in the last 100 yards or so. After allowing it to cool down completely and re-filling the fluid, I was able to move the rig to park and unhook the trailer. However, I noticed that it was slipping in both forward and reverse gears. After a longer test drive, it seems to not slip as much or consistently in forward gears but is more likely to in reverse. I have to rev the engine slightly to engage the tranny. Seems to pull fine once engaged. It also periodically seems to lock the TC when I let off the throttle so it trys to keep moving and even kills the engine once in a while. I know very little about transmissions but I'm thinking I may have damaged the torque converter? Is it possible that this type of problem would go away with a fluid flush and refill or would that just be wasting money on fluid? Sorry for the long-winded story but I wanted to give some details to help in diagnosing the problem. Am I on the right track?

 

[RandyH]

Any ideas on the next step?

 

[CHPMustang]

Randy,how many miles on the current transmission?
How many miles since the fluid and filter was last changed?
Have you installed an oversized fluid cooler yet?
Are you running synthetic fluid?
Any upgrades done? Sonnax,Tricumulator,Valve body upgrade,heavy duty TQ?

 

[trackspeeder]

The torque converter is telling you it's tired. .It needs to be put out of it's misery.

 

[RandyH]

Ford Reman tranny has about 35K on it. I was planning on doing a flush and filter shortly after this trip. No upgrades to the tranny at this point. When I fried the original tranny at about 98K, Ford replaced all the lines and upgraded the cooler. Not sure how big it is. I'll check the paperwork and see if I can tell. I'll post again after I check. I was hoping to get off without another big $$ hit but it isn't sounding good. Am I trying to pull too much weight with a basically stock trans? Thanks for the input.

 

[RandyH]

I found the invoice for the reman job. They installed a "XC3Z*7A095*BA Oil Cooler Assy" ($149) along with the reman tranny in Nov04. Not sure if you can tell from the PN how much bigger than stock it is. They also "updated" the radiator at the same time.

 

[RandyH]

I googled the cooler PN and it appears they replaced the stock trans cooler with the same one. The upgrade they told me about must have been the radiator update. Looks like I should put in the 6.0 cooler I've seen recommended by several on this site.

 

[BJS]

Since you're an early '99 you were lacking the oil to water cooler part in the radiator, or at least some early '99 trucks were. So all of your cooling is limited to that tiny little thing that Ford wants to call a transmission cooler, that's roughly the same size as the one that they put on my explorer in the early '90's also. Upgrade to the 6.0L transmission cooler for an easy bolt in option that will require only plumbing work to be custom.

Since you got your transmission very hot and it started puking fluid more than likely the puking occurred at the torque converter seal which is notorious for getting brittle after getting hot. So would be a good idea to pull the transmission out and replace the torque converter seal. Do NOT have Ford do this as I've discovered that the current seal from Ford is still prone to this problem while the good aftermarket seals are not.

 

[RandyH]

Thanks for the info. I did a quick on-line search and it appears there are both 25 and 31 row 6.0L coolers. The 31 row cooler (5C3Z7A095B) runs anywhere from $300 to $400 (w/line adapter kit). Are these aftermarket coolers sold under this PN different or are they the same as the OEM cooler you buy through Ford?

 

[BJS]

unfortunately you have discovered that Ford is very proud of thier coolers and yes they are expensive.

If you're comfortable with doing some fabrication of brackets and other such then look at the aftermarket coolers.

I have a Tru Cool 4590 from Makco distributing that's plumbed in series with my oil to water cooler and a screw on auxillary trans filter. This combination keeps my trans pretty cool but I can heat it up quickly in reverse.

You might want to look at the tru-cool max units that'll give you a bit of cooling capacity to spare.