Can anyone help me through the basic front end alignment checks and adjustment procedure for a 1996 F-150 2 WD truck? It shakes pretty bad at speeds between 30-38MPH , smooths out for a bit around 40MPH and then goes crazy above 45MPH.
Thanks,
Tom

 

First of all it sounds like you have a wheel balance problem. I would get that checked. Next jack front end up and check for excessive play in wheel bearings, ball joints and steering rod ends. Steering alignment is pointless if you have a ball joint shot. The most common alignment problem is tracking. This is where the front wheels should run parallel or very slightly toed in. The tyres both wearing on either the inside or outside edges is a good indication or the tracking being out.

 

I agree with Lazy K ---alignment usually doesn't fix a shake ...keep in mind a bad u-joint can cause the same problem--you need to check everything !!
Gary V.

 

I replaced all 4 wheels & tires with those off of my 1987 Ford F150 which never had any issues running smoothly on the freeway going 65 or 70 MPH. The only thing that I was able to see on my own was the "toe-in" was at about 5/16" (about double the recommended amount). I adjusted back to what Chiltons said it should be (5/32") and it seemed to help some at slower speeds (below 45 MPH). Above 45 it gets pretty bad.

I will be dropping it off at a front-end shop in the next couple of days to get a professional opinion as to where the problem lies. I can't seem to spot anything even with my neighbor's help who is pretty god working on Ford trucks. Ball joints don't appear bad, but then again we will see what a repair shop has to say on the matter.
Thanks again for everyones help and advice,
Tom

 

Good move.

 

You can get a static "bubble" tire balancer from Harbour freight, they can get you close.

 

My guess is U-joints. They can be tricky sometimes. Jack up the rear axle to remove all tension. Keep the trany in park or gear. Grab each joint and check for any movement. There should only be driveline movement from the slop in the trany. Hope this helps.

 

I have already replaced the 4 tires/wheels from another F150, had the front-end thoroughly gone through by pros at a repair shop, had the rear leaf springs re-hung with new rear hangers, shackles & bolts. The vehicle still has a vibration above 30 MPH which gets really bad above 45 MPH. I have been questioning the balance of the driveshaft (U-Joints were replaced, but might not be balanced anymore), front coil springs, and the totally shot shock absorbers (front & rear). I am thinking of attacking the driveshaft first, since it is only $83.00 to get balanced from a local driveshaft company. The coil springs will cost me another $75.00 to purchase and $75.00 to get installed. Shocks I am thinking of going after last. Any ideas from anyone on this?
TOM

 

Just a thought. Do you have the dual drive shaft? If so, it's possible that your carrier bearring is toast.
My brother had the same problem with his F-150 with 280k miles. Turned out that there was nothing left of the bearring. The shaft was just flopping around in there. Something to look at. Good luck.

 

I bought the truck and it had the problem at the time of purchase. Sounds nuts but the price was right!

The truck does have a one piece driveshaft, with new Universal Joints. The assembly may still be out of balance if either of the ends were reversed when the Universal Joints were replaced by the previous owner.

I found out that the entire driveshaft fully assembled with both universal joints and both ends attached are balanced as one complete assembly (per the local specialists at the driveshaft rebuilding shop I spoke with recently).

My neighbor and I were talking about the problem and I mentioned the fact that when the overdrive kicked in at 40 MPH the vibration got worse, but if I clicked the overdrive off then the shaking got a lot less, as if low-end torque was effecting it. The shaking actually does seem to be RPM related. He was thinking that the torque convertor might be causing the vibrations and that replacing the trans filter and fluid for around $50.00 might be all it really needs. I will be trying that just as soon as I can scrape up the fifty!
Tom

 

1995 F150 XLT 2WD Had similar vibrations at 40-45 mph. I replaced wheel bearings all around. U-joints and center support bearing and tires. But it was replacing of the torque converter along with a tranny(4R70W) rebuild that got rid of the problem.

 

It could be the tranny but before investing in it, check your motor and tranny mounts. Also make sure that the cross member that the tranny is mounted to is bolted tight to the frame.

I am not too sure but I do not think a tranny can cause this kind of vibration unless it is a manual with a bad clutch. If it is an auto, then there would be other shifting problems before this type of vibration would show. Pull the dipstick and look at the fluid. It should be pink, not brown.

Another possibility is the harmonic balancer on the front of the crank. With the engine off, see if that big weight on the front of your engine moves. It will be the one with the timing marks on it. You may also want to look at all of your bell housing bolts and axle bolts. Good luck and let us know what you find.

 

I put a can of Sea Foam "Trans-Tune" in at at work last night just before driving home. It's a 45 minute drive going 30-40 MPH and believe it or not the vibrations seem to be getting better. It is still bad at 45 MPH (I had to try it once) but the slower ranges are definately smoother. The trans fluid isn't pink anymore, and without the money to spend on a trans rebuild right now, I plan to drop the pan, replace the filter and fluid and throw a 2nd can of the Sea Foam in it at that time (a week or so). Hopefully, the problem will get cleared up and I can avoid putting a junk yard trans in it. The trans that is in it has 20 bolts on it (E40D ?), has the overdrive button on the end of the shift lever, and costs $225.00 for just the torque convertor at Autozone! After being out of work for the last 18 months (Michigan hasn't been too kind to a lot of us), I am still playing catch up. Thanks again for all the advice and I will be checking all of the other items you guys mentioned to check.
Tom

 

Well, it's finally fixed and I can go on the freeway without any worries of something flying apart from all of the vibrations! It turned out to be two things bad... The first was the drive shaft had a slight bend in it (I missed it while examining the thing, but the mechanic pointed it out to me!) The second was the bushing and seal in the tail housing of the transmission, where the driveshaft yoke slides in to the trans were both worn from the vibrating driveshaft being left unrepaired for a bit too long, according to the mechanic that fixed it for me. The used driveshaft, 2 new U-Joints, the transmission tail housing bushing & seal plus labor came to $250.00, but at least it's finally fixed. I really didn't want to have to drop the trans to replace the torque converter, only to find that I still had the problem!

Can anyone reading this give any suggestions to things to look over to get a little better gas mileage out of this truck? It is an F-150 2 wheel drive with the 4.9 Liter straight 6 cylinder engine with an automatic trans. I recently replaced the wires, plugs, rotor & cap, but am going to re-check the plugs to try to find why the engine runs a little rough and seems to use a lot of gas. I haven't tried to figure the mileage yet, only because of all the other problems I have been having with the truck. I swear, if I didn't think this thing has a lot of potential... Oh well, any ideas?
Tom

 

Glad to hear you got it fixed. I had a feeling it was driveline related.

You should start a new post for the MPG issue and do a search for other posts. I am not sure on your engine but I get about 10 MPG in the city. Granted I do have a bigger truck and engine. You may want to look at your fuel pressure. My regulator was bad last summer and it was pumping fuel down the engine. I was getting about 6 MPG before I had it replaced. Good luck.