While towing for the first time this weekend on my new '01 I noticed a shudder/vibration severe enough to vibrate the steering wheel as well as most of the interior. My setup included a Polaris TrailBlazer ATV in the bed of the truck, and a Triton 8x10' trailer with a Sportsman 500 and XPress 300 ATV's on it. I'd guestimate the total weight of the trailer and all 3 ATV's to be about 2,500lbs.

This shudder/vibration seemed to start around 45mph and would pretty much go away when slowing down or coasting. It didn't seem to matter what gear the trans was in either.

Could this be the infamous "Trans Shudder" that I just did a search on and read about? My first thought was that the trailer could be causing the vibration, but if that were the case I'd expect it to happen even while coasting.

Another bit of wierd behavior that I noticed and I call it wierd because my old 2000 didn't do this. When I turn OD off it almost appears that the trans drops back to 3rd gear and stays there. Here's what happens: With OD on, crusing at 60 the engine turn ~1600rpms, pressing the accelerator to kick out of OD only revs the engine to ~2100rpms, but manually turning OD off (using shifter) causes the engine to turn ~2500rpms and stay there.

Any explanations?

Thanks!

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My New Baby: 2001 F-150 XLT Sport 4x4. 5.4L, S/C, S/S, Bright Red, Dark Graphite Int., 3.55, Class III Tow/Heavy Duty Cooling, 4 wheel disc ABS, Overhead Console, Factory In-Dash CD, Remote Keyless Entry.

Mods: Ziebart Rust Protection, Ford Bug Deflector

Future Mods: Running Boards, Superchip, Air Force 1, Cabin Air Filtration, Ventvisors, Spray-in Bedliner, and Retrax.

2000 Polaris Sportsman 500, Camo Green, 4x4, 499cc 4-stroke, independent suspension, shaft drive, 4 wheel disc brakes, etc.

 

Anyone?

 

Hi Y2K,
About shutting off the overdrive, It does drop the trans down to 3rd gear. Hitting the throttle unlocks the torque converter increasing the rpm's by 4-500.

Not sure about the vibration, maybe an out of balance driveshaft? Or a torque converter problem?
Sounds like a trip to the dealer.

Hobbit

 

If the vibration occurs at around 45mph regardless of gear, then it has to be independent of engine rpm which kind of rules out the transmission. I would check the wheels, tires and wheel bearings on the trailer. Also, check all of the hitch/receiver mounting bolts. I still think it's the trailer though.

This is why Ford recommends turning off the OD when towing. It's better for the trans when the TC is locked in 3rd rather than unlocked in fourth. All of that slipping generates heat.


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'00 5.4L AUTO 4X4 F-150 Lariat
'98 4.0L 5spd Jeep Wrangler Sport
'95 3.8L SC Thunderbird
'02 F-350 PSD CC DRW 6SPD 4X4 Lariat (order this year)
www.hawthorn-engineering.com

 

Thanks for responding guys!

You have a good point and I will certainly go and re-check everything tomorrow!! The only thing that bothers me is that I've read about the tranny extension housing being a problem, drive shafts that are too short, and torque convertors that slip or chatter when they're supposed to be locked up.

I'm thinking that it could have something to do with the driveshaft or something as the mechanics of the rear-end changed when I put the ~400 lbs in the bed. But I'm hoping a test-drive with the dealer helps shed some light on things.

But I will definately go back and check everything out with the trailer!! Thanks again for the help!

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My New Baby: 2001 F-150 XLT Sport 4x4. 5.4L, S/C, S/S, Bright Red, Dark Graphite Int., 3.55, Class III Tow/Heavy Duty Cooling, 4 wheel disc ABS, Overhead Console, Factory In-Dash CD, Remote Keyless Entry.

Mods: Ziebart Rust Protection, Ford Bug Deflector

Future Mods: Running Boards, Superchip, Air Force 1, Cabin Air Filtration, Ventvisors, Spray-in Bedliner, and Retrax.

2000 Polaris Sportsman 500, Camo Green, 4x4, 499cc 4-stroke, independent suspension, shaft drive, 4 wheel disc brakes, etc.

 

My boat trailer does this due to flat spots on the trailer tires that developed in winter storage. It starts to resonate around 40-45 and then goes away...its worse when I pull it with our Isuzu Trooper.

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'99 f150 S/C 5.4L
Tow package, L/S, 3.55

 

Y2K, a vibration occuring at a certain road speed doesn't necessarily rule out the tranny. It all depends if the vibe only occurs in one gear. Let's not forget the rear axle and prop shaft. Both will be turning at a given speed for a given road speed regardless of trans gear or engine speed.

 

and ...

and again ...

That's the point. The vibration is speed related i.e. 45mph. So it could be wheels, driveshaft, half shafts etc. An out of balance driveshaft could be the culprit, but all of the above problems would also show up when not towing a trailer so that brings us back to the trailer.

Y2K ... did you check out the trailer wheels, brakes and bearings yet?




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'00 5.4L AUTO 4X4 F-150 Lariat
'98 4.0L 5spd Jeep Wrangler Sport
'95 3.8L SC Thunderbird
'02 F-350 PSD CC DRW 6SPD 4X4 Lariat (order this year)
www.hawthorn-engineering.com

 

I had this problem with my 2000 expy. when it starts to shake the next time look in your side mirrors and see if the trailer is shaking also. if it is it is probably the trailer tires. mine were out of balence, check yours

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Later,
Scott Schintzius
extremecj@earthlink.net
2000 Ford Expedition Gibson Headers, GMS Mass Airflow Sensor, AirRaid intake, Jet-Hotted Magnaflow exhaust, 265/70R17 BFG AT/KO's, 20% Tint on all windows, PIAA Air Damn, PIAA 510's, PIAA 80's, PIAA 1400's, 3 JL W3 12's Rockford 800a4 and 800a2, MBQuart 6.5 inch components, Eclipse 5.25 components, Etc.
1983 CJ-7 Extreme CJ ZZ4 Crate 350, Ford T-18 Tranny, Atlas 2 3.8, Reverse Cut Dana 60 rear, Dana 44 Front, 6 point cage, Bilstein 7100 Remote resevoir Shocks, 38.5x14.5 SX's on 15x10 Trailready Beadlocks

 

Hey guys, sorry that I haven't responded sooner, but work had me put up in Boxboro, MA, miles away from my baby! I just picked it up today from the dealer and they had a good deal of success.

First they took care of the radiator issue (wrong size) and the overheating radio issue (new radio with fan), and made a good amount of progress on the vibration.

Apparently something was wrong with the rear u-joint with one cap being too tight, so they replaced it and the vibration seems to be about 40-50% less than before. It also doesn't happen until 50-55 now, so it looks like they're on the right track.

I am gonna inspect the trailer again, as it is certainly possible that there are 2 problems at work, and I'm also wondering if I should even bother worrying about it further if I can vindicate the trailer.

I'm also wondering if there could be some connected/related problem in addition to the bad u-joint. But who knows, I'm off to the north country to do some ATV'ing, I'll be back Sunday night! Thanks for your help!!!!

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My New Baby: 2001 F-150 XLT Sport 4x4. 5.4L, S/C, S/S, Bright Red, Dark Graphite Int., 3.55, Class III Tow/Heavy Duty Cooling, 4 wheel disc ABS, Overhead Console, Factory In-Dash CD, Remote Keyless Entry.

Mods: Ziebart Rust Protection, Ford Bug Deflector

Future Mods: Running Boards, Superchip, Air Force 1, Cabin Air Filtration, Ventvisors, Spray-in Bedliner, and Retrax.

2000 Polaris Sportsman 500, Camo Green, 4x4, 499cc 4-stroke, independent suspension, shaft drive, 4 wheel disc brakes, etc.