Hey everyone. I just picked up my first Ford vehicle ever last week. A 1999 F350 7.3L Diesel 4x4 Automatic Crew Cab with about 257,000 miles. I love the truck so far and I'm looking forward to a long life of use out of it. I will not do any heavy towing in the near future, this truck is a weekend truck for loading stuff in the bed and light moving.

I'm having some issues to start off with. I knew going into buying this truck there would be some repairs, and I'm trying to handle as many of them as I can myself. So, if anyone can help advise a Ford newbie, I would greatly appreciate it! Thanks in advance. I will do my best to describe the symptoms in as much detail as possible.

Issue #1 (I'm assuming these items are related): Grinding/humming sound coming from left front wheel. Slight vibration felt in steering wheel. When braking at slow speeds the truck stops with a pulsing sensation at the frequency of the wheels spinning.

I replaced the left front wheel bearing, still am experiencing the symptoms above. I must note that I did not feel the pulsing before replacing the wheel bearing, but it started afterwards.

My conclusion is that I DID have a bad wheel bearing and I DO have a warped brake rotor. The bad wheel bearing was able to flex with the warped rotor so that is why I did not feel the pulsing in braking before the fix. So my assumption now is that I need to replace the brake rotor. Can anyone else corroborate this and what is a good medium duty rotor to buy?

Issue #2: When the truck is warm there is a shifting issue when shifting from 3rd to 4th gear that happens occasionally. When upshifting, the engine will spike in rpm's very quickly, then very quickly drop back to normal and then transmission will shift. There is no check engine light on. I'm worried the transmission is going out, but this doesn't match descriptions of slipping transmission I've seen elsewhere where the rpms will spike but then the tachometer will very SLOWLY go back to normal.

The truck shifts well through 1st and 2nd, a little hard on 3rd and only does the above sometimes on 4th (I think it might have done it on 3rd but I can't remember). The truck always accelerates fine too. I've never encountered a symptom like this in a vehicle before (other than maybe my cam shaft sensor going out on my Dodge Stratus).

Any advice would be very much appreciated. Thanks folks!!!

 

Welcome to FTE!!!! being as you have changed the bearing i would do both front rotors at the same time to create and keep even wear..

Brake Drums & Rotors - 1999 Ford F-350 Super Duty | O'Reilly Auto Parts

on your brakes make sure you get the right sized rotor for you r vehicle.. these are the ones that i use and they have worked great.. but i also go the brake hardware kit to go along with it. and greased and replaced all related parts.. BrakeBest® Select™ - Brake Rotor for $63.99 are mine.. great rotor and have been great.. right before the two year free repacement was up i pulled them off took them in for some new ones and i have brand new rotors and pads again.

I always change both fronts at the same time to keep the vehicle having the same material thickness on both sides to prevent a pull to a side while braking..

again welcome and i am sure more will chime in...

 

the tranny i am not sure of.. i am not a tranny guru by any means. i change my fluid when required and keep it full. thats all i can tell ya on that one.. sorry

 

I see your thought process, but a bad wheel bearing isn't going to mask a warped rotor. Depending on thickness you may be able to have the rotors machined which will take care of the pulsing. My local auto parts shop would do that for $15 each.

How does your transmission fluid look? Doesn't sound to me like your transmission is slipping, and I'm not sure of all the things that can cause a shift flare. Have you had your transmission fluid flushed?

 

Crazy001 and Bigol04: Thanks for the replies and the warm welcome!

I'm leery about turning rotors on these big trucks. I don't plan on doing any heavy hauling, but is it safe with these big, heavy trucks to turn a rotor? I guess I could do it and if I have problems just buy new rotors.

I'll keep asking on the shifting issue. Please throw out some prayers that it isn't a tranny rebuild!

 

The size or weight of the truck has nothing to do with it. Every rotor has a minimum thickness that determines if its safe to have them turned. As long as they aren't cut past minimum thickness there is no possible safety issue.

 

I think the tranny is fine, I think your feeling the TC lockup after the shift to 4th. If your accelerating fine, then that is what your probably feeling. The TC will not lockup until after the shift to 4th under acceleration, and it is a BIG drop in RPM when it does. I actually do not feel the shift from 3 to 4 as much as I feel the TC lock up. If you hit the Overdrive cancel button on the end of shifter, and get up to around 40mph in 3rd, you will notice a small drop in rpm's when it locks up. Any speed under about 37 mph will cause the TC to unlock and shift back from 4th to 3rd. This is to protect the transmission and TC from low lube pressures at slow engine speeds. I have 270K on mine, and it acts the same way.

 

Ok, that's good news then. Thanks for the reply! Is that a sign that the TC is going out, however?

 

ours does this too. unless we back out of the throttle quick, when shifting from 3rd to 4th the rpm will jump a few hundred and fall back down. this is on a fresh tranny(under 5000 miles) with high performance internals. the TC locks in 3rd, and then does a unlock-shift-lock into 4th

mind you this is not with stock tuning on the computer or valvebody.

 

So, I was able to determine what the grinding actually was and specifically where it was coming from. While taking the truck in to get an alignment it was discovered that all 4 ball joints were shot and needed replacement.

I proceeded to replace all the bearings starting with the driver's side (I had already replaced the wheel bearing on this side). After the driver's side was completed, I moved to the passenger side ball joints. When I pulled the wheel bearing on that side, I discovered that IT was the bad bearing, not the one on the driver's side. In fact, the one on the driver's side wasn't bad at all. The passenger side had grease leaking out of it and you could feel a very significant grinding as you spun it by hand. The diver's side was clean and turned smoothly. I would have never discovered the passenger side had I not opted to put in new ball joints.

After new ball joints, an wheel bearing and an alignment the results are smooth riding, no grinding, and an increase in MPG.

Lesson learned: Just because you thinking a noise or vibration is coming from one location does not mean that the culprit is in that spot. Noises and vibrations can translate across surfaces sending you on a wild goose chase.