4R100 No Forward drive

Denver · Oct 28, 2011

Well I lost all the forward gears in my truck. Reverse still works great. I've notice some slack/slap on take off and when stopping and thought it was the driveshaft. Everything was good and went to leave the Ford parking lot (of all places) and it just gave out. I did rev it up and it grabbed a little and did all the manual 1 and 2 stuff but it's gone. What would cause this? Snap ring? Clutch disc? Truck has 165K and hasn't towed much.

Heavyhaul · Oct 28, 2011

Is this a 2001?

Denver · Oct 28, 2011

Model year 2002 but built 10/2001.

TyCorr · Oct 28, 2011

You'd have to hook it up to ae and look at turbine, intermediate shaft, and output shaft speeds to see what sh!t the bed. A rebuild is due most likely. Unless the conv is shot.

Heavyhaul · Oct 28, 2011

Well this may apply then. In 2001 they did a experiment in the trans. It was called a sprag or something. I cant remember . But they just take a carp at random and you have to back date it or it will happen again. If it didn't have it I would say your forward clutch is out.

BigAlsPSD · Oct 29, 2011

Usually the Sprag, mechanical diode issue causes it to not shift between 1-2 without letting up on the throttle.

OP, is the fluid level good, look clean? Will it go into a lower gear, pulling down into low?

Denver · Oct 29, 2011

Fluid was down a quart but it looked clean and didn't smell burnt. Manual 1 or 2 doesn't go anywere.

VC-Racing · Oct 29, 2011

Did you get a flashing OD light? If so could be the converter gone bad. Thats what happened to mine the 1st time. You'll need to get a sample of fluid or drop the pan. If the fluid looks like metallic paint you'll have to rebuild it anyway to get the metal shavings out of the case..... Best of luck... I know mines been a mess.. Wanna see what Ford did to mine back in 04, check out http://powerstrokearmy.com/forums/showthread.php?t=8039 ..

Denver · Oct 29, 2011

No Flashing OD light. I think the TC is good because reverse is strong but nothing in forward. I'm planning on getting the trans rebuilt but just got to get it 300 miles to trans shop.

Denver · Oct 29, 2011

I've been doing some research and have come across some info on the 3 center support bolts. I'm going to look into that before a rebuild. If these bolts are loose would it also cause drivetrain slack/slap when taking off from a stop and when I some to a stop? I just don't think the trans is toast because the fluid is fine and doesn't smell burnt and the issue just happened all a sudden instead of something happening over time.