I have a question for all of you that know more about the F-150 then I do. I have a 88 F-150 4X4 with the 4.9L and 5 speed manual trans. After leaving it sit for 3 days without being started or driven I noticed a shaking in the steering colum. At frist it was real bad at about 5-10 mph but after a week or so it happens now mainly when I am at low speeds ( 25-30 mph ) in 3rd Gear. then it continues into 4th gear. Seems to be real bad right between 1500-2000 rpms. If I am stuck in a slow traffic and down **** and run the engine up to higher rpms it seems to go away. But at times it almost feels as if the truck is shanky it self to pieces. It starts and seems to run great ( been below 0 for a few days and no problems staring in the a.m.) and even when the shanking is going on it sounds as if the engine is running fine. None of this was happening when I parked the truck but does have 170,000 miles on it. Any help anyone could give me would be great!

 

When was the last time you changed your spark plugs and wires? What about cleaned your injectors?

My 302 had a pretty bad buck when one of the wires came loose from the plug after a plug change. This was under light acceleration at relatively low RPMs--couldn't even tell it while driving normally.

-Mike

 

Changed them this past summer. It feels more like a suspension shake. I did notice this evening the it kind of surges, when I was in 2nd gear 4 wheel drive at about 15 mph, I'll check the plug wires tomorrow and see if I can find anything. Thanks..I'll let you know.

 

how olds the clutch? I've seen some shakers with bad or loose clutches...

 

Not sure about the clutch. I was told it was changed about 6 months before I bought the truck and that was 2 1/2 years ago. Guess it could need replacing. Any ( I hate to say it ) easy way of checking the clutch without ripping the whole thing apart? I did find some other info too. Read in a manual that i have to check the tach in each gear to see if the shaking/vibration is at the same RPM in each gear. Says that may help rule out driveshafts and axles. I'll let you know what I find on that when I drive it tomorrow

 

I tried the test that the manual I have suggested. It seems to be the worst at 1500 to 2000 RPM's when I am starting out. If I am on the hwy and going about 70 its pretty smooth. I also noticed its a great deal worst when in 4WD. We got lots of snow and blowing today. Going to try the plugs and wires tomorrow and switching the front and rear tires. I real hope its not the clutch, but if the plugs and wires don't help I think thats what I am leaning to. Do any of you think the front diff would make it do this even with out the hubs locked and the 4 wheel drive disengaged?

 

Maybe its a bad motor mount? Usually it is the one on the driver's side that goes bad. Have someone rev the engine up while you look under the hood. If the engine really jumps to the right when they hit the gas, that would be a bad motor mount (some movement is normal)

[This message has been edited by dirt bike dave (edited 02-01-2000).]

 

Well I did a complete tune up, new u-joints on both the front and rear axles, changed the fluid in the tran,transfer, and both diff. and the shaking is gone. Not sure what part did it I'm just glad I don't feel like i'm in a disco anymore when I am driving down the road. Thanks to everyone for the help!