After I get home Thursday I'm completely retiring my truck from long haul driving.... I am completely upset with the lack of ***** this thing has.

I just took a trip to/from Hartford CT, up to Newark VT. There were quite the hills and mountains and they ate my truck alive. I usually will cruise 73 MPH. When i hit the hills there goes OD, then drops gear. Sitting at 3 grand cooking away I watch the trans temp just bury itself. I think I got the trans up to 210 on this hike. cant even maintain a certain speed up a slight hill. Most of the time I see a hill coming and build up to about 85 and then hit the hill, but still I'll have to drop OD...

those that dont know, 98 expy, 5.4, 4r70w(i think), 3.55, 285/75/16


anybody else feel my pain?

 

I never had any complaints w/ my 04 Navi......maybe it had a little more power than you're Expy though

 

The best thing for a transmission is to turn the OD off when it is under a load. The trans would actually run cooler in 3 than with the OD on.

 

Whine whine whine - whaddya expect with a 3 ton tank with a small V8? Get a car or a diesel.

My little ole V-6 does just fine out west, where the mountains make the ones you were in look like speed bumps.

 

well I have a 99 f150 with pretty much the same set up the only real mod I have is a gryphon tune and while my truck is by FAR not the fastest vehical I've had it will maintain 75-80 in the mountains around Utah most of the time. Its fast enough to get out of its own way.. Same gears and all except I think I have the 4r75

 

Do you keep it under 2k at 55 in the mountains? Just curious. That standard transmission make a big difference in the hills.

 

Run with OD off?

When its under a load it drops out of OD anyway, so why bother shutting it off? right?

 

Yes they will kick out, but only when the load on the trans. is heaviest. It is a little better to kick it out manually.
I always turn it off when towing, but that's just me. It is what I was taught.

 

keep it in mind for the trip home... stay out of OD all the way through PA... haha

 

Kicking out overdrive manually allows the convertor to lock, leading to cooler trans temps

 

I did last fall, when I moved back to Michigan from - well, around where your at (Kentland/ Watseka area IN). BUT! -Yea, mine was downshifting pulling an empty trailer (1900 lbs) in OD. I've had that trailer since 2001 and have always been able to pull it empty on the e-way in OD without downshifting constantly on the hills. Same goes for the Car Hauler I used way back when. I ran thru the mountains in PA with it - Empty wasn't a problem.

Trucks shipping weight was 4600 lbs + Trailer 1900 lbs + myself 200 lbs = What I can do in OverDrive on cruise without a problem ( 6700 lbs) . So , that's the way I figure it anyway.

Anyway, last fall it started this downshifting crap - all of the time. So I tore it down last winter and replaced all of the pulleys, fan clutch, plugs, coils, ported and polished the intake - (Again, just took more material this time), changed the muffler - Installed a larger Magnaflow to pick up a little torque (hopefully).

After all that , she's back to what she was, but I'm not sure what the problem was exactly. The only parts that had definite signs of ware was the plugs that had only 20,000 miles on them. - Running on the lean side, you can take the life out of your plugs pretty quick. I still need a tune. All my pulleys were bad , fan clutch marginal, but it seemed to be ok for the most part.

All I have to say that may help you, just make sure you have the OEM sensors, plugs and whatnot. Amsoil in the drivetrain is a Major plus as-well, -specially inside the tranny.

BTW- It could be something as simple as a bad tank of gas or maybe something is stuck on the MAF.

 

What engine do you have? You state it's 5.4 but your profile states that the Body is 4.6L and the Trim is XLT 4six!!! I'm confused...

 

5.4 swapped...


Yea Brew I hear yea. I got the Amsoil in the engine and diffs are full synthetic. Plugs are new, I put em in before I dropped the engine in... MC ofcourse. I dont think I'm having a problem anywhere, its just a dog. . . . I dont know what to do. Soon enough this thing is getting tires and a lift, than its definately done for highway wise... All I have left is gears and a blower setup. . . and those will be a MUST with any bigger tire

 

Yea , I tried Amsoil in the crankcase,- it kind of ticked me off at first until I was informed what had happened. I've always ran Castrol since new, then received a case of Amsoil motor oil as a gift. Tried the Amsoil and it cleaned the inside of the motor so well, it plugged the PCV system up lol.

To many miles on this one for that stuff I guess ..

Back to Castrol -




+ 1 on the Super Charger. A roots Eaton would do it wonders

 

unless you swapped it in yourself you dont have that transmission. you have the 4r70w just like most of the non lightning auto 97-03 F150's

04+ started using the 4r75

But to the OP i be a gear change would do it wonders aswell. i bet 4.10's would even help. but with lift and tire plans go with 4.56's or lower!

didnt read everyones post so i might be reposting.

+2 on the roots blower