Hey everyone,

Looking for some advice with an issue I am having with my 2001 F250 7.3 crew cab w/ ambulance package auto trans. Today I was driving along and notice that when I gave it gas my truck didn't accelerate. I coasted into a parking lot and notice no matter what gear I was in nothing would happen! I had no change in load on the motor and it was like I just was in neutral. My transmission is great! low miles and the fluid level is good. I never had any slippage or issues with hard shifts. If the truck is off for a few minutes and then start it back up the selector works and I can go into gear and start driving(also if feels perfectly fine when going at this point) for a bit until blam! acts like it is in neutral again, i don't think its the Tcase because when in park it is in park (can't move it). So I towed it home and put the rear on jacks stands and then turned it on and let it drive at 15mph and kept going no problem for over 10 minutes. So at this point I figured I have to start messing with it. Did some brake torquing which it had no problem with. It wasn't till I start messing more with my gear selector more that at some point it stopped responding and acted like it was in neutral again.

This is where I am at and I am wondering what I should dig into next for testing, I checked my harness on my transmission and it has some sand that I cleaned out. Also I live in upper Michigan with a lot of snow right now. I also have a Hydra tuner with the provide tunes, and I mainly just use daily driver, towing and high idle. I did return it to 00 which is stock for the testing sake. I do wanna not that sometimes when switching tunes with my Hydra the truck will almost stall and post the waiting for start light. Maybe related but I don't think so unless it is some sort of low voltage issue. I have good batteries and bolt alternators seem to be working correctly.

Any suggestions would be great! I'll check back often for updates and such. Thanks again!

 

Its been me mentioned that the feed bolts under the valve body becaome loose, giving off your sympron...

 

I need better definition of this. When "nothing would happen" does that mean when you press the accelerator the engine speed doesn't rise? It stays at idle? Or does the RPM go up?

 

First off thanks for replying, sorry Mark for not being more clear. When by nothing it just revs up and the rpms rise but does not effect the speed of the truck.

So what is still be the feed bolts even though it works fine on jack stands even when I hold the brakes and increase throttle to break free and that works. It seems messing with the shift or possible vibrations or bumps are causing it to stop. Which I thought was a short but maybe those feed bolts do that. I am not against tearing it down but also can I check the feed bolts with the tranny in the truck? or should I pull it?

Thanks again

 

The feedbolts can be checked with the trans in the truck. Take off the pan and the valve body and the feedbolts will be accessible.

There is no short that can cause a neutral condition. It has to be something mechanical. Everything works on jackstands because there is no load. When the feedbolts are loose and leaking pressure there is minimal pressure to hold the clutches. With the tires in the air you need almost no pressure on the clutch to hold it. It's a different ballgame when the tires are trying to move the truck. That takes quite a bit of pressure to keep the clutches from slipping.

 

Thanks mark,

I ordered a rebuild kits with gasket and seals. So I'll tear down the to the valve body this afternoon and check the those bolts torque specs. Anything else I should look for while I am down there?

 

Either those are loose or it needs a rebuild.

 

So is it safe to say a full valve body rebuild will cover the issue? the kit I got have new feed bolts as well. I really dont think there is anything wrong with the plates or TConverter judging by how it seems to work fine when it does. Also draining the fluid I notice it is a little dark but no metal shavings

 

A valve body rebuild won't have any effect on the issue. I don't see where there is anything wrong that could be caused by the valve body.

 

That is very strange that it could work just fine for a while and just nothing. That is if it will recover. If you try to drive it in the AM will it work OK, or is it just dead.

 

*update*

First when I finally get it all apart I did find metal shavings not dust which was odd, also why I didn't see much metal in the fluid. The filter was clogged from the shavings and when the truck was sitting the metal would fall back down out of the filter allow it to work for a bit till it clogged up.

Now here is the weird thing. I cleaned the fluid and put a new filter in for ****. Now the truck works fine?! I went for a small test ride and its shift even better than before and doesn't make any noise still.

*note* when I was in the the bottom of the tranny I found they engraved when it was down which was about 32,000 miles ago. So what is wrong? It works, I even did a burn out for testing and it had no issue with that. I haven't went for a long ride but it was working up to 50 MPH. I was thinking maybe they didn't do the new tranny properly? like possible not cleaned out everything leaving shavings from the old exploded transmission? I am also wondering if maybe their is a wear in procedure from the new one and they never flushed it.

So I am going to put 200 miles on then flush it again. Then put 500-1000 and then check it again.

At this point I am all ears to idea's and suggestions.

I'll be pressure testing it this weekend

 

Just another update, I've put on 150 miles so far and I have no issues. Truck shift great and super smooth, also I need load up a 10,000 trailer and pulled that for about 20 mile with no problem!

So I am still confused on this whole thing, so are my other mechanic friends as well. I will be dropping the pan in another 100 miles. Will post what I find.

 

Maybe there was stuff left in the trans or cooler from whatever happened to it that required it being rebuilt. When a trans is rebuilt it's standard practice to replace the cooler or at least flush it out and put a filter in the return line to catch any stuff coming out of it so it doesn't hit the trans. I assume the inline filter would have to have a by-pass so even if one's in place it might have filled up and let stuff past it. Check for that filter.

If you drop your pan & filter again and there isn't more crap in it then it's probably fine and just had leftover crap in it.

 

What d o you know of the trucks history?
How many miles have u put on it? I would be rather concerned.

 

Very strange. With that much metal I would of pulled it a part or had it rebuilt. Hope it works out.