I rebuilt my trans last year and have had zero issues with it. Tonight I had to haul my brothers F250 7.3 and when I finally got home (approximately 20 miles) with his truck on the trailer I was backing in the driveway and went to go straighten up I put it in drive and it felt like the trans was slipping. I put the trans in drive started rolling back put it in 1 you can feel it grab but still felt as if it were slipping. You can smell trans fluid. We pulled the trans dip stick and it does not smell burnt and is clean. I am at a loss of what it might be. I have 2 theories: torque converter going out or trans got too hot. Can you please help me. Thank you

Side note it was pulling fine up hills just once I got home and took it out of drive is when it started giving me issues.

It has stock torque converter with sun-coast internals.

 

Sorry, I'm not much help w.r.t. your particular situation, but I believe an upgraded torque converter & valve body will help even a stock tranny last longer than it otherwise would when towing heavy loads, so might be worth looking into if funds allow and/or you tow on a regular basis.

Also, a tranny temp gauge is a useful tool, is not super expensive and is a worthwhile investment. Tranny life (that just sounds wrong!!) is roughly inversely proportional to its temp, so an upgraded tranny cooler might be worthwhile if you tow regularly too. Occasional temps up to 180 or even 210 aren't the end of the world, but if you hit 230, your tranny's demise is probably not in the distant future. Anyway, I wouldn't have thought a short trip like 20 miles would likely to have caused excessive tranny temp, even when towing a relatively heavy load, unless under more extreme circumstances e.g. long windy steep grade mountain pass, so perhaps your torque converter theory is more likely.

 

That's not right. 230F won't significantly shorten a transmission's life.

Because it had an ATF smell I suspect it overheated. What does it have for transmission cooling? Does it go to a radiator cooler and then to an aux cooler?

 

Good to know, I stand corrected.

 

Mark it goes right to the factory aux cooler.

 

Mark is the expert and will have the best advise. It looks like you have a 99 like myself. It only has a small 9 row cooler located between the condenser and inter cooler. If you are going to be towing much with it, you should defiantly think about getting a gauge. You also should think about maybe putting it a new radiator with the trans cooler built in. If that still isn't enough cooling, you can put in the 6.0 cooler or an aftermarket unit like the Tru-Cool.

Like Mark said, it sounds like you may have overheated it. Did any fluid leak out up around the front of the tranny? Sometimes when they overheat, they will leak fluid but once they cool down, it is fine.

 

Yea my truck is a '99 F350 DRW 2wd 212K miles. Did not leak any fluid, just smelled fluid so immediately I checked to see if any leaked out and nothing. I smelled the dipstick did not smell burnt.

 

You probably need more cooling. The original trans cooling system on a '99 was inadequate. Changing the radiator for one with a cooler may be enough, or you might need to change the 9 row cooler for a 6.0L cooler.

You should check the cooler for dirt or obstructions. If it can't get enough air the trans will overheat.

 

OK, great thanks I will fix this issue asap and get a set of gauges. I dont need to happening again.

 

Well, we unloaded my brothers truck and my truck is hurt. I went to put it into drive and she rolled back so I go to 1. When I go to 1 she will go so I try manual shift to 2 then drive and both you can feel that the trans is not grabbing and you can hear the rpms go higher like she slipping. I dont know what to do now.

 

All that is left now is to pull the trans, tear it down, and find out what broke. This isn't anything electrical, something mechanical broke inside the trans,

 

Well now its weird. Last night we had a cold front come through of maybe 30's and I started the truck up put it into Drive and it pulled as if nothing was wrong I drove it down the road and still felt fine. I dont get it.

 

It could be a damaged seal in the forward clutch. When the fluid is cold it's thicker and the seal can hold. Once the fluid warms up it thins out and flow right past the seal. That's my theory until the trans is torn down and I'm proved right or wrong.

 

Got a question Mark, if it was the forward clutch seal after the tranny is warm wouldnt it act up at a traffic light when Im driving it? However, I would be at a stop light and it was fine only when I turn the truck off and let it sit and only then it would be maybe the 10th time I turn it off and go into drive would it act up. But now, the truck is cold and it will not go into drive it just roles backwards. I have Park, Reverse, and Neutral.

 

I read somewhere that the torque converter could have been put under alot of stress and the veins could have gotten bent. When this happens, it feels like the transmission is slipping. It takes a lot of gas to get the vehicle moving. In a severe case, the vanes could be bent so much that the car will just rev up, but it will not go anywhere.

The other resulting failure will cause a higher than stock stall by bending the vanes just enough. When the vehicle takes off from a stop, you will notice that the rpm will raise higher than normal before the vehicle begins to move. This however, will still work fine once the turbine has caught up. It indicates an impending problem.

The above I actually found on ehow and describes everything my truck has been doing