1990 F150 351W 4x4 E4OD Auto Tranny Ext Cab Short Box on 33's (only been on for a few days)

So yesterday I was on my way home from work and was working on getting on the highway. I was in the wrong lane for the onramp, so I did what any sensible person would do.... I punched it. Dropped the truck into first and shot in front of the Chev dually next to me. Immediately when I slammed on the throttle my truck boggs, RPM's dropping to about 500, then they shoot right back up and I'm at 4K, shift into second, then into D (OD was on). I no sooner get onto the onramp and my truck starts rattling like it's going to fall apart. Scared the living you-know-what outta me. It felt like my entire rear end was going to fall off.

My initial thought was my U-joints as I have not replaced them since I owned the truck (about half a year now). When I swapped my new tranny in I did an inspection and the U-joints looked near new and were properly greased.

I don't know what could be causing this..... Perhaps my torque converter isn't aligned right? I did install the transmission myself so there's an itching feeling in the back of my head that it may not be on just right.... On the other hand, she's been running ten times better since I did it.

Things I've done to my truck (under the hood) since I got her:

- Swapped tranny's from my 91 FSB (had a 5.0 and same tranny)
- Oil change
- New Autolite plugs, MSD cap and rotor, and wires
- Air filter

There are a few things wrong with my truck that I cannot afford to fix at this time that I think may be a contributing factor in my problems. Both of my exhaust manifolds have hair-line cracks (drive side is the worse of the two), I think my rockers are making noise but I haven't inspected them yet. I also believe I have a short in my fuel pump relay, as on occasion the fuel pump will kick on when the truck is off, no key in - usually will do this when the truck is rattled, example: shutting the door.

So to close this lengthy post: Does anyone have a solution, or at least a place where I can begin troubleshooting, to explain why my truck bogged out on me when accelerating, and why it started shaking like the world was coming to an end?

Now I love my truck - she is my pride and joy, and I do not want to be the guy that loses a driveshaft or axle while going 75mph on the highway to work. I need some help here guys.

Off to work now. Keeping my fingers crossed she does okay today.

Thanks in advance!!

 

does it shake now in all gears at any speed, or it does it in one particular gear and at a certain speed? What about idle in park/neutral, does it do it then too?

 

Sounds like converter shudder, a common issue with the E4OD......better pull codes to be safe.

 

I did a lot of driving around yesterday, partially testing the truck, partially getting errands done, and I discovered that she doesn't shake at low speeds, or at least she doesn't shake any more than usual. I was on the highway yesterday when it started up again. I was going about 55mph, which is pretty dang slow for me on the highway. The shaking was worse between 50-60, but not totally bad at 70 mph. My old FSB had a similar problem, but her issue was the harmonic balancer and would feel like she was going to fall apart at 4K rpms, but not so bad at 2K, like the F150.... Could the F150 have the same problem, or is the torque converter a more appropriate culprit?

It doesn't help that the truck rattling knocked my steering wheel loose a bit. There's so much play in my wheel now it's ridiculous. Don't really have time to work on her until Saturday, but the shaking is not continuous, I found out, but situational - only on the highway, only between 50-60 (it seemed at least) and it was unbelievably bad while taking corners. She would shake a little while accelerating on arterial roads, rpm's at 2K going about 35-40 mph, then would settle down.

And then she would stop all-together. There was a point where I drove a good 15 miles on the highway without any violent rattling. This seems bizarre to me.

I'll have to pull codes as soon as I can. Honestly, I think it'll be the first time I've ever pulled codes before. Someone have a link to a how-to for pulling codes with a test light? I don't have a code reader, but I hear you can do with a paper clip, so I have high hopes!

Thanks for the replies guys. This truck is starting to scare me!!!

 

I'm told the E4OD converters tend to fail at low engine speed just as you start to put a load on them. If the issue you're experiencing is most apparent at 50-60 mph and it don't matter if you're in 3rd gear or OD I'd say you're looking for something not transmission-related, as converter cares for engine speed and not vehicle speed. What does care for vehicle speed and not engine speed is the suspension and the driveline - the fact that it's particularly bad while cornering suggests to me something is wrong in the front end, possibly a wheel bearing or more likely a radius arm or traction beam bushing. Kinda sounds like a case of death wobble actually, which is typical for the F350 4x4 trucks but I'd imagine with worn front suspension bushings an F150 can get quite unstable too...

On the balancer question, yes they do go bad, the rubber cracks and the outer collar slips with respect to the inner hub, or flat out falls off. Your truck is 20 years old now, rubber don't like aging, so I'd suggest that you have the balancer replaced as a preventive measure anyways, well after you're done with the suspension mess that's at your hands now.

 

I'm leaning towards a suspension/steering problem also. Tie rods maybe.

Chris

 

I had out of balance drive shaft do that to me once. it vibrated the car doing 50-60mph but wasnt so bad doing 70. the tailshaft bearing was bad also.

 

I wouldn't be the least bit surprised if it was my entire front end suspension. The truck is getting old, and the PO didn't take care of her very well. The frame underneath has some pretty hardcore surface rust, identical cancer and rust spots on the cab, so on and so forth. I've been slowly replacing the worn and wearing out parts. The motor is still strong as an ox, but it seems everything else is falling apart, heh.

I'll have to climb under her this weekend and do some heavy inspecting. If it is a suspension problem that gives me an excuse to finally throw some 3/4 ton springs and shocks under her.

Thanks for the help fellas. I'll be busy this weekend tinkering!