My son turned 16 in November and now has his DL. He has basically taken over my 7.3 and loves it. He grew up in that truck and now he thinks he is all grown up driving it. Any way he has been taken it to school and this morning He called me that he was stranded on the highway. Luckily it was close to home and I was able to tow it back to the house. He said that he was getting on the highway and as the truck was picking up speed it shifted real hard and then loss power. Engine stayed on but would not respond to throttle. Truck would not move in any gear. Didn't have time to really check things out this morning but when I get home will take a good look. Any suggestions to start with? I really hope its not the tranny. Maybe a TPS? Any help/advice would be greatly appreciated. Thanks

Gilbert

 

Transmission input shaft or transfer case range fork.

 

It's L99 with auto transmission. 415000. Miles

 

dammmm 415,000 miles.. is that original trans?? WOW..

 

If that is the original tranny it deserves a place at the Smithsonian.

 

Well, if I had to guess (and that is exactly what you're asking us to do), I'd say your trans is toast and a replacement is in your near future.

There are several suggestions we can make for 4R replacements, if that indeed turns out to be the case.

Stewart

 

This makes me wonder if something else is going on. Anyone know if a blow tranny can affect throttle response?

 

Original transmission. Truck has been a great truck. Gauges al work except speedometer of course. If it was broken trans input shaft wouldn't there be some grinding or metal making noise when in gear?

 

Unlikely.

I wouldn't expect there to be any....seen it a lot.

 

Is there any way to trouble shoot for a broken input shaft?

 

Yes, there is. Get a 0-350 PSI gauge with a 1/8" NPT thread. Install it in the test port on the driver's side of the transmission. Verify that there is no pressure at this port with the engine running.

The only other way I know of is to remove the trans and look at the input shaft.

 

I've blown my input shaft twice. Both times there was a hard downshift right after an upshift and then it was like I popped it in neutral. I still had throttle response as far as the engine revolutions though.

 

OP- did I read that correctly that you have no throttle response at all, just idle, or do you mean the engine revs up but the truck doesn't move when applying throttle??

 

Thanks Gentlemen for the responses.

The engine works and stays on and revs up. No problem there. Will do it in all gears.

Finally had a chance to take a good look yesterday. Looks like I had a leak in the back of the trans pan close to where it meets the TC. It was very low on fluid so I put in 3 qts of Transmission fluid and did not budge. I had just did a oil change a few weeks ago and all fluids were good. My transfer case fill/check plug is stripped so I could not check level. I was able to open the drain plug and it had fluid I just could tell how much. I did not want to empty it at this time.

I have not verified it yet but my son said that when I put it in gear that the transfer case would move? Not sure what that means.

Have a lot going on right now so Im not sure what I will do. Would like to remove TC and Transmission but I have never done that before. Wish there was an Easy Button I could use.

Thanks everyone I really appreciate all the advice and info.
My Truck has over 400,000. miles on it and up until this happened was a very reliable truck. I have owned the truck since it had 60,000 miles.

I owe the success of this truck to this AWESOME site and to the members.

Thanks again

Gilbert