1988 F250 302 5 speed

When I put my truck in gear it vibrates and shakes. When I put in the clutch while moving, and rev the engine it's runs perfectly smooth. It only happens when in gear. The engine is tuned up and timing right on spec's 10 degrees BTDC.

Maybe it's a bad engine mount. Did anyone have this problem?

How can I troubleshoot this problem.

Any help here would be great.

Thank you!

Runner

 

Use a big pry bar get under the truck and check to see how much play is in the mounts including the trans mount.

 

While you're under there check the u-joints too.

 

Thanks for the quick reply!

Just check the U joints and both the trans and motor mounts look good and in intact.
wonder what it could be.. Also when I tried to slightly life the motor from the oil pan, there was NO play at all. Is it supposed to lift off the mounts when I lifted the motor?

Also while I have you guys on line, can you tell me where this wire might plug into? I don't think it ever was plugged into anything. Maybe its a wire that would be used for an option that my F250 does not have. Thought I would ask.

Plug 1_zps7kmvidql.jpg Photo by jagrunner2602 | Photobucket

Plug 2_zps7lgkmktp.jpg Photo by jagrunner2602 | Photobucket

thanks for helping here

 

For those without a score card:
Plug view1


Plug view2

 

It's only 1 plug but two pictures showing different angles.

Again. I don't think it was every plugged into anything.

 

Pretty sure that is the AC compressor plug.

Does the truck have AC? If does, does it work?

 

Does it do it in neutral with the clutch engaged?
Edit. I know you said only in gear, but typically the only time you really have the clutch out is in gear. That's why I was wondering

 

No AC.. I thought so that it was a plug for an option I didn't have. That answers that.

Thank you so much!

Now I got to figure out the vibration thing. I love my truck. The truck runs great.

 

"Does it do it in neutral with the clutch engaged?
I know you said only in gear, but typically the only time you really have the clutch out is in gear. That's why I was wondering"

thanks for your help Mudsport!

Good question! It does not have that shaking in nuetral. only in gear.

At first I thought maybe it's the clutch. I have no slipping etc it grabs very well. However, I replaced the clutch back in 2005. (What a job!) Would do it again though if needed.

I use my F250 to plow only my driveway(Bad Bad winter in New England in 2014/15.

Could it be the Clutch???? Would I get that symptom I'm getting even though it goes in all shifts with no issues?

How can I be test that?

thanks again for taking the time to help

Runner

 

Could it be that vibration I'm getting is "Clutch Chatter"?

Googled this.

CLUTCH CHATTER
Chattering is a grabbing or jerking condition that occurs when the clutch is engaged. Clutch chatter is often caused by oil or grease on the clutch linings, but it can also be caused by burned or glazed linings, a warped or grooved flywheel, missing flywheel dowel pins, a worn pilot bearing/bushing, a worn bearing retainer, worn or damaged clutch disc or input shaft splines, bent or broken drive straps on the clutch, a bent or distorted clutch disc, a loose clutch cover or even missing flywheel dowel pins.

I checked out all this stuff and all looks good. thanks to My4Fordtruck and Mike1

External causes of clutch chatter include loose or broken engine or transmission mounts, misalignment of the chassis and drivetrain components, worn or damaged U-joints or CV joints, a loose transmission crossmember, a worn or bent release fork, or loose rear left spring bushings or spring U-bolt nuts.

 

You said you did a tuneup, plug wires? If it only shakes under load could be plug miss or wires in wrong order. Just a thought

 

Does your truck have a tach? Get to a speed where you are just about idling in third on dry pavement, preferably in four high for max traction and stand on the gas. If there is clutch chatter/slip you should see the tach jump as long as no wheel spin occurs you have a clutch problem. I'm also wondering if maybe your input shaft front bearing is going out. play=vibration

 

Thanks Wag53

I wish that was the issue. I made sure the wire order was correct many times. So I decided to replace all the wires,cap,rotor and plugs and still had the issue. Also I get no engine check lights. My 302 runs unbelievable!

That's a good thought though.

thank you!

 

thank mudsport!

"Does your truck have a tach? Get to a speed where you are just about idling in third on dry pavement, preferably in four high for max traction and stand on the gas. If there is clutch chatter/slip you should see the tach jump as long as no wheel spin occurs you have a clutch problem. I'm also wondering if maybe your input shaft front bearing is going out. play=vibration "

I do have a tach. Actually I had the F250 in 4 high today and didn't notice a slippage and only chatter. However, I was not looking at the tach while in 3rd gear. I'll have to test that on Sunday and see if the results are what you state.

would be nice it it's not the clutch but seems to be going that way.

Also, How can I test the input shaft? Are you talking about the Pilot Bearing/bushing?