Buffeting

[love2fly]

Have a question to any 45 owner in regards to high speed driving (50-60 mph and up) on a paved road. Question is when driving with a slight head or cross wind do you guys or girls experience a slight to moderate bit of buffeting (shaking) in the front end of the truck. I have owned lots of 40's and this is my first 45 and never really experienced this with a 40. At first I was thinking it was wheel problem as in wobble or tie rod. I can only think it is the front wheel fenders sucking air up under them trying to get the front end airborne, or maybe the old thought that the air is slamming into the old flat windshield and then vortex's into the LWB in back pushing into the tail gate. It's a little unnerving at times.

 

[woytovich]

Can't answer your question but try driving at speed with the tailgate down... that will tell you if it has to do with the bed.

 

[love2fly]

sorry I was thinking I mentioned I did drive with the gate down, when I did, no change.

 

[Tancruiser]

check your shackel bushings I had that problem replaced the bushings and the problem went away.

 

[Gumby]

It could be a million things. Telling us what you have done would probably be easiest and even then it might just come down to an old truck.

Center pivot
TREs
RREs
correct shims on the knuckles
Toe properly set
Aftermarket springs causing caster issues
Hard, worn out, or tight spring bushings
shackle extensions
old, worn or oversized tires
out of balance tires
broken belt in a tire
u-joints
out of balance or bent driveshaft
transfer case output shaft
pinion bearing
wheel bearing
trunion bearing

Hubs locked? That would add in about five more things.

Got a TJ on the hoist right now that has the steering box ripped free from the frame. He was getting a vibration too.

I'm sure I'm missing things. Could be anything. We need way more information.

 

[love2fly]

I agree Gumby that it can be almost anything, to possibly help with that, I will include some of what you have offered as a possible suspect with an answer:

Center pivot- New and adjusted twice after a few miles for setting in
TREs- All new
RREs - ?
correct shims on the knuckles - set with the official Toyota tool - good
Toe properly set - set to factory specs
Aftermarket springs causing caster issues- re arced to near standard high, not jacked up.
Hard, worn out, or tight spring bushings - new pollys, all allow movement without being over tight.
shackle extensions- stock
old, worn or over sized tires- new tires
out of balance tires- balanced
broken belt in a tire - 10 ply ?
u-joints - all removed on build and inspected (good) installed
out of balance or bent drive shaft- D/S tube replaced with new
transfer case output shaft -will check
pinion bearing - will check
wheel bearing- new and set
trunnion bearing - new

New shocks F-R
All front end items are all tight, and torqued to Factory I/A/W manual
Has new disc brakes installed from FJ62 that show no abnormal scoring or wearing
Tire wear looks normal


Hubs locked? not locked, rolls free, and locked when locked

Good stuff to check will see about the one's you mentioned that have not been checked or replaced.
Big Thanks

 

[65swb45]

Free play in the steering box?

 

[Gumby]

Ten ply tires? I could see that causing lightness at speed. Those are some heavy duty tires.
With stiff springs that could cause skittishness, especially with higher tire pressures.

Sounds like you have a pretty well sorted truck.

 

[love2fly]

Thanks again for the help, the tires had be balanced just last month with no discrepancies from the tire person. The springs being reworked and the tires maybe the combination that possibly may be causing this condition.If so it maybe just a break in time for both items to settle as they are new. I am still going to look at a few other areas as mentioned, and again at the steering box 65swb45. I had set this while the cab was off and again after rebuild completion, but one never knows. Oh yeah I forgot to add that the front steering stabilizer was also checked and is working fine, not sure if I need to go to a HD type due to the tires.
Thank you

 

[Gumby]

What tire pressures are you running?

 

[love2fly]

Street presure of 35psi.

 

[45Kevin]

I have a 2" lift on mine and do not recall anything like you describe. I have driven my truck in all conditions. 60 to 65mph is my max, with normal speeds of 55-60.

I have always thought them to be very stable in the wind. Maybe you had abnormally high winds. Everything has its limits.

 

[Gumby]

35 isn't so bad. A lot of guys run them at 80 because thats what it says on the side of the tire. They don't read the whole line where it says max inflation for max load.

Then they blame the truck for riding rough and being skittish.

Have you played with the tire pressure at all? Ten pounds less wouldn't be dangerous and might help those massive sidewalls break in a little.

 

[love2fly]

Took the old gal on the freeway tonight on a 5 miles drive to the store with the tailgate down, full load of fuel, and pushed it to 65 mph without any buffeting at all, but it is also calm of winds tonight. On the way back with tail gate up, and 65 mph still no buffeting. So that tells me that this most likely is a high wind related problem 10 mph up. Its funny when it happens it feels like the truck is wobbling like you would feel during an earthquake (if you have ever experienced that its weird). I am looking into the steering stab to see its condition. Will pull it off tomorrow and retest it. As noted by a Mudd member not all rigs are the same some may have its own little quark. I am still leaning towards the wind getting up under the front fenders and causing havoc. Give me a few more days, and one with wind, and I should have a conclusion, I hope
Thanks guys.

 

[In2cruisers]

Use your flaps and crab a bit

 

[love2fly]

"And enter a STALL", "ah", no thanks, Ha!
I think I will just drink more beer and go faster, won't notice anything then.