Kenny13200

Alright guy so I posted earlier before almost 6 moths ago that I had a jerking problem. Well I had tried a few things that was said and I did. I have done/changed the following;

-New Spark plugs MotorCraft coppers
-New Autolite Wires
-Throttle Position sensor
-MSD Ignition Coil, Cap, and Rotor button.
-Had my timing done.
-Replaced shot transmission mount

The truck is a 1989 F150 with a 302 118XXX miles on it.

Heres the video link, hopefully you guys can point me in the right direction. http://www.youtube.com/watch?v=x4g9U...ature=youtu.be

Chuck McDonald

I would suggest that it's maybe a tire out of balance. I wasn't a member 6 months ago, so I don't know what all was suggested to you. If it does this when you're not moving, it's not the tire.

Warlockk

I believe a few people suggested a problem with your torque converter. That is my suspicion. The broken trans mount is probably a symptoms of the vibration. I always say check the simple first. Check your remaining motor mounts and your u joints and drive shaft(s). Does the motor shake in idling at 1100 rpm or does it have to be moving. Also try blocking the wheels and applying the brake then place the trans in drive and bring the Rpm up to place a load on the motor. If it shakes its motor related. If not its in the driveline. Be careful not to brake free and kill anything. Check the trans fluid for metal. If the essay stuff checks out I would pull the trans and check the converter and flex plate for damage, missing or broken bolts or bad balance.

Warlockk

Oh last thought is broken axles. Secure the truck on good jack stands and put it in drive. Let the wheels spin and watch and listen. This would help with drive shaft vibration too.

f150cam

im guna say torque converter. iv never seen a truck vibrate that bad before and it not be a torque converter, a out of balance drive shaft is a very light vibration, my torque converter started slipping and it was exactly like that.

Kenny13200

I had all the tires balanced when I put them on. I'll do the what you said Warlockk and inform you guys of the outcome.

cedae5299

Try Dr. Tranny.. ...It can be found at your autoparts store. I had same problem on my 92 xlt. I was told to rotate and balance tires. I had changed ujoints and paid for an alighment but none of these could fix the vibrations. Finally someone told me it might be my Torque converter and to try Dr. Tranny. I tried it and she hasnt vibrated since. that was almost 2 month ago. i have also noticed that i am recieving better gas mpg . currently im averaging about 13-14 mpg

Kenny13200

Ok so I put it in gear and accelerated to 1100 +/- rpms and the truck vibrated but not as bad as it would do as if it where on the road. I did it at Idle and it vibrated but very minimal, once I get the video on youtube Ill post it on here for you guys to see.

I'll try the Dr. Tranny.

Warlockk

The vibration while holding still eliminates the running gear.( wheels,tires,ujoint etc. So were left with things that spinning with the engine. Have you checked your motor mounts. Another easy check is your harmonic balancer and cooling fan. Although I doubt the fan could shake the truck that much and I would think the balancer would get worse at higher rpm. But its worth a visual inspection. I'm not familiar with Dr trans or its function,.but if you go that route at least check the trans pan for metal.

Kenny13200

Well I got it diagnosed from a guy who works on transmission for a living and a close family friend. I let him drive it and 30 seconds in he had a conclusion. It's a 3 part problem that has developed over time. Since I have a exhaust leak on the manifold it's causing my valves to go bad. Thus why cylinder one is firing horrible. The jerking is created because the transmission is shifting to quick and the motor isn't making enough power. He said imagine a 5-speed car, you shift from 2nd then to 5th. He moved some cable on the throttle body and changed where the gears would change and it's running a bit better. I have to get the exhaust leak fixxed first.