98 5.0 AWD Slipping in Overdrive

[dinas5pt0]

How about this Guys:

I take the Wife's 98 5.0 AWD X to Home Depot this weekend for some stuffs. Haven't been in the truck for weeks. Feels a little weird, bucking/jerking in Overdrive. I get home and question her: "Yeah, I meant to tell you about that. I noticed it a while ago"...


So, when going up hills and/or when under load we get this bucking/jerking action. This only happens when in overdrive.

I can hit the O/D off switch and punch it up a steep hill w/no problem at all. Never saw the O/D light flash. We had the tranny fluid changed, no metal filings found ...same issue.

Not sure if related: We had a Check Engine a month ago that came and went on it's own, code pulled said something about the canister [this is according to the Mechanic]

Always Ford serviced. Engine purrs like a kitten at idle and roars like a tiger when you get on it. Truck drops no fluid.

Is there a separate computer for the tranny that tranny shops pull codes from?

What do you think? Should I leave the Wife?

 

[V8BoatBuilder]

What are your RPMs when the bucking occurs? If the tachometer is reading under 1500, or your foot is off the gas pedle when it happens, there is a real good chance that your IAC (do a search) is clogged or broken.

It regulates air, and if stuck closed, starves the engine of air. You can try cleaning it, or putting a new one on.

I had a similar problem, cleaned my IAC and the problem became less noticible, but still there. I'm going to just replace the IAC, it was VERY dirty.

 

[dinas5pt0]

Lower RPMs ...usually just as O/D pops in @1300 or so, just above 40mph. I can feather the gas on level ground and get it to stop as I reach higher RPMs. If I'm going uphill I hit O/D off button and proceed.

I think I started this thread in the wrong area. I don't have access to delete.