I am looking at 99-01 SuperDuty's with 7.3, auto, and 4x4 and the ones in my price range have over 100,000 miles, closer to 150K. How long will the Ford auto last if taken care of? I dont want to drop a bunch of money into a tranny rebuild a few months after acquiring the truck. And with this mileage will I be asking for trouble adding a chip/tuner?

 

They will last a long time with reasonable maintenance, I'm at 230,000 on mine and it still seems to be in great shape. But it's a crap shoot buying one with that many miles on it, just a few powerstands/burnouts can take out a transmission.
I guess I'd look at the transmission coolers, if it has a larger one or an additional aftermarket cooler I'd take that as a good sign.

 

The life of these Tranmissions in these trucks depends on how well you maintain it and how it was treated through its life except for the 01s which has a diode that can go out and burn up your transmission. I have seen trucks go as far as 50K on the factory tranmission and up to 300K with the only modification was added coolers. Heat kills any tranmission quick so if you can keep it cool and keep it maintained it could last you for many years, unless you can talk to the POs its a shot in the dark how long the tranmission will last in a used truck. Like Clux said add a 6.0 cooler or a different aftermarket cooler along with a BTS Valve body ( Brians Truck Shop )to really extend the life of your truck.

 

I have an 01 with a build date of 00 I wonder if my tranny has the dreaded diode?

 

Here you go Jim


Tenn01PSD350
Miller Brewing Co Join Date: Feb 2006
Location: Middle Tennessee
Posts: 7,890


Transmission Diode in some 2001 models

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Missed this on the original post. Stay away from the 2001 models with an automatic transmission with build dates between 7/27/2000 and 3/23/2001. These have about a 6 month run of a diode in them that is failure prone. Read here for the specifics.

Of course if it has been repaired, and you can verify this, no problem.

 

mike is the man!

 

Hmmmm....I need to look at the build date on my transmission again. I know that it is a March build date, but I don't remember the exact day.

 

Thanks Jd My build date is 11/00.....I guess I'm rideing around in a time bomb!!!

 

No Mike is a great man with some Boosht . Well Jeff if yours is we might be making a trip to BTS together and meet Jim while we are there. FYI if your transmission does have the dreaded diode and you put a BTS VB in the truck Brian will credit the VB off of your bill when you get his tranny.

 

I know everyone mocks auto tranny's in these, and other brand of diesel trucks, but IMHO its the massive tourque these engines make that is hard on them...

Furthermore, I've heard a few times, from different sources, that automatic transmissions being weak is more for older less advanced systems. Apparently, the newest auto transmissions are more beefy than the sticks.

Mine has 240,000 and still strong, I can think of 2 people with 6sp tranny's that have replced or rebuilt them....

Not saying this is a scientific analysys, but it isnt like a 6 sp is 10 x better than an auto.....

My .02

 

Thanks for the kind words all. Jim, I have the diode in mine and I have beaten on it on the track. You might try to get an OASIS on your VIN on the 6.0 forum if that guy is still doing that. Your's may have been fixed. Here is the TSB, click here.

 

Thanks Mike. i will pull an Oasis this week. There is so much going on now that the last thing that I need is the diode crappin out on me. I guess it's hit or miss with these things.

 

I am an over the road transporter running 500 to 600 miles per day. I purchased my 1999.5 F350 new in July of 99. The truck was built in the spring of 99, don't recall the date now. I put 613,288 miles on the truck before an exhaust valve broke and cracked a cylinder wall. The automatic transmission was rebuilt at 70,000 miles due to a one time shifting problem. It gave a horrorable jerk when it shifted gears (3/4; 1/2 and 2/3). This was a one time situation only. I continued to drive the truck with no further problem. When the weather got cold I had a problem with hard starting. I took it in to my dealer and for $50 he fixed the hard start and rebuilt the tranny. I did easy starts and locked out overdrive until I was ready for it. I had the tranny flushed every 50 to 80 thousand miles and as I said previously, no problem other than the one time shift problem. As for buying a truck with 150k on it, as to see maintenance records, pull the dipstick and smell the tranny fluid and note the color. It should be red and not have a burn smell. Have the seller take you for a ride and ask him to 'get on it' and you try to detect any slippage. That way he can't blame you for damaging the tranny. Of course you should also drive it. If you do purchase a truck with that kind of mileage on it, change all fluids (axles, tranny, transfer case, engine oil, coolant and power steering) as soon as possible unless the seller has records showing the fluids have been changed. Good luck. Those were good trucks. Only wish they were available today. My present truck is a 2007.5 Dodge 3500 with the six speed auto. Love the Cummins engine with the built in exhaust brake and the tanny. I do not like the truck. Drove an F450 PU today. Would love to have it but can't afford it and would be concerned of problems on the road.

 

Well see if you can use it to your advantage, see if they will know off a few grand for future replacement/rebuild of the tranny. If it were me I wouldn't worry about the tranny but figure that in the near future to have it fully rebuilt. Once done correctly you shouldn't have any problems with it unless you go all out with crazy power.