I picked up an '89 F250 ex-cab 4x4 yesterday. It has a 460 and a C6...decent shape and a steal at $800.

Driving home it has a vibration that is really bad at 30-35mph, but is non existent under that and is there but not as bad faster than that. It tracks straight down the road, so I don't think it needs an alignment...is it just an out of balance wheel? I'm just looking to see if anybody has experienced this for a good starting point of fixing this problem.

Also, the cruise control works, but the truck surges? Any ideas?

I'm new to the 4x4 game, but my wife wanted a bigger truck than my 85 F150 so who am I to argue?


[IMG]file:///C:/Documents%20and%20Settings/john/My%20Documents/My%20Pictures/Truck/Truck%20011.jpg[/IMG]

 

My suggestions would be to have the wheels balanced for the vibration. If not that, then look at ujoints and balancing the driveshaft.

For the surging, it could be the tps. There is a way to check it with a multimeter I think.

 

She wanted a bigger truck; she got it. I picked up a '91 F250 with a 460 for the same reason last week. My wife is beginning to see what she asked for, when she realized that it gets 11 mpg.

Vibrations can be caused by many things. If the truck has been sitting for awhile, the tires may be flat-spotted, but that will work itself out as you drive and the tires warm. Vibration may be caused by a bad driveshaft center bearing (if your driveshaft is long enough to require one) or one or more bad U-joints. If you feel the vibration more through the seat of your pants than through the steering wheel, then look to the rear suspension or driveshaft for the cause.

If you feel the vibration more through the steering wheel, look at the front suspension for the cause. You may need an alignment, or new ball joints, or new steering link ends. Alignment shops will often do a free diagnosis of front end vibrations out of the hope for being paid to make the repairs. That's a very handy service, even if you do the work yourself.

Also, a wheel may have simply thrown a wheel balancing weight. Or a tire may be out of round. Watch out for that, because tire cord separation can really ruin your day. Look at your treads for uneven wear in one place in the tread, or for a bulge in the sidewall.

Good luck.

Scott



P.S.-- We can't see pictures on your own hard drive. Look up how to make a gallery on this web site, or use a picture sharing service to hose your picture.

 

Thanks for the great start. I was dreading that it might be the torque converter or the 13-56 had spun the pump.

I created an album on the web to get a picture up. Ford Truck Enthusiasts Forums - JMC302's Album: Garage - The Beast

 

that's a nice rig for $800!

 

post some pics

 

Just posted the rest of the few pics have to my garage.

Took a quick glance at the engine today and noticed at least three vacuum lines just floating in the breeze...and could here them sucking too. So a diagram for those is going to go a long way. The big job right now is the rear main seal, and I plan on hitting that next weekend.

 

again after seeing a few more pics that looks to be a nice straight rig for $800. You got a hell of a deal!

 

Sorry for the long delay, work had me traveling extensively.

Thanks for the compliments on the truck... i finally got the F150 sold, and have a good start on this rig. The MAP sensor was bad, so the previous owner had simply disconnected it. That, and a myriad of vacuum leaks have been fixed and it has made a huge improvement in how it is running. I am double checking the that I tested the TPS sensor correctly yesterday...as I read it yesterday it is needing to be replaced.

From the earlier advice I can say the vibration is in the rear, goes from 30-45mph, and the truck is smooth as silk at highway speed. Also, the vibration only occurs when I am putting pressure on the gas pedal...at those speeds it does not vibrate while coasting.

No improvements that warrant photo's yet, but I have a large shipment of parts on the way and will be sure to post pics as I fix her up.

 

Wow, I missed this post last month. Awesome deal on that truck! Heck, just the newer style Superduty wheels and tires are worth what you paid for the whole truck!

Your vibration issue... I would check the u-joints, carrier bearing, and driveshafts. Perhaps just a bad u-joint or bearing, or the driveshaft has thrown a weight.

Good luck with the progress!

 

its your muffler bearings trust me hahaha no um thats strange tire improperly balanced?

 

I snuck away from work for a few minutes and lubed every Zerk fitting I could find on the drive shaft(s)...HUGE improvement! Still there, but it doesn't feel like the truck is about to rattle apart at those speeds anymore, so st least the source has been isolated. I couldn't get grease to come from all four caps on the U-joints, so I will go ahead and replace them...especially with how much wear they must have from being driven in that state.

 

BTW- the rubber isolator that holds the rear of the front shaft, does anybody know where to pick up a new one of those? I might as well replace it while I have everything apart.

 

snuck away from work? you gots you one of them there fancy city man jobs?

 

Yeah, no denying that I'm a certified desk jockey these days.