significant vibrations (1 Viewer)

[Blue60]

Hi,

I have a 86 FJ60 with about 95K. BDS 1.5" lift kit with new shocks shackles etc. I also installed the HF55, and MAF ceramic coated headers, exhaust system, iwthin the past year.

Problem: accelerating thru 25 mph I get a transit vibration which disappears after about 28 mph, at 55-60 mph it is a significant vibration which increases noticeably if I clutch in and l let it decelerate thru the same range of 55-60 mph. Not noticable when I repeat going thru the 25-27 mph range. No difference in vibrations thru either ranges accelerating or decelerating in left or right hand turns. The u-joints seems O.k. (a little slop), and I can't see any weights missing or deformations on the drive shaft.

I'm open for ideas...I've checked the front wheel bearings, but don't know really where to continue trouble shooting...

Thanks

Dave

 

[Landpimp]

WHen did it start? after which mod/change? or did it start just recently long after any cods/changes had been done?

Worse with the front hubs locked?

If after the lift then I would suspect the u-joints/drivelines.

John H

 

[CruisinGA]

Check phase of the driveshaft, nearly exact same problems as you when I checked mine, put it back in phase and voila, problems gone. The u-joint cups need to be aligned, ie if you put a pipe through the u-joint cups at both the t-case and rear axle end, the two pipes would be on the same plane.

 

[Poser]

Please define "a little slop"...

Any "slop" in a u-joint is not good. It should pivot on the bearing caps, which should be pressed into and not move inside the bosses or the driveshaft yoke and the companion flange end of the driveshaft assembly.

Is this only in 2wd, or are you running with the front hubs locked?

You had this shaft shortend when you installed the five-speed?

Is there any chance that it is not in phaze?

Help...

 

[lowtideride]

that same thing happened in my dads jetta at 55 thru 60 was a horrible vibration, after climbing under and saw nothing wrong we checked the tires it turn out to be the tires so it might not be a bad idea to check them out becuase it only did it 55 thru 60 , so for a while we just avioded that speed. good luck....al

 

[John S]

One easy thing to do is swap tires front to back. That will atlest tell ya if it's a wheel out of balance. My friend changed U-joints and had his driveline balanced before finding his new BIG O tires were crap.

 

[dd113]

I would look at the shaft, RR TC bearing, RR pinion bearing,

 

[hammerhead]

Also check slip-joints

 

[Blue60]

Thanks for all the input...will go check the driveshaft phase and swap tire positions...do a road check and repost. The vibrations began well after I had done the mods (about a year) and after putting on about 3000 miles of highway/intown driving. All in two wheel high range, without the front hubs engaged.

Dave

 

[FJ60]

I had a irritating bounce that dissapeared after tire rotation

 

[Cruiserdrew]

I'm a little late replying here, but I had exactly the same issue with a pinion bearing that had lost its preload. Try dropping the rear driveshaft and tighten the pinion nut if loose ( after unstaking). Do this carefully and measure the preload on the pionion bearing with an inch pound torque wrench. When you get to the right preload, go no further. If that solves the problem, your pinion bearing is on the way out, so start saving your $ for a diff rebuild. Your mileage is low for that, is there any history of neglect? I hope you get lucky and it's just something like a drive shaft out of phase, or a U joint. You said there is some "slop" in the u joint. Do mean slop in the u joint, or slop in the rear diff (backlash)?

 

[Blue60]

significant vibrations - update

Thanks for all who chimed in with suggestions and experiences. The "slop" turned out to be just a little backlash. The real problem was that 4 out of 4 of the rear driveshaft bolts which attach to the rear differential companion flange were just about gone! There were just a few thread turns left on all four nuts! I couldn't believe it. Anyway, they are now torqued to 65 lbs per Toyota body and chassis manual specs. I noticed that the washers under the nuts were not split washers or some type of lock washer. Maybe a better solution if these nuts come loose again. By the way, pinion is good, no play, no leaks... same with U-joints...

Anyway, thanks again to all who shared their opinions.

 

[Poser]

Blue locktite. Works great, on these and many other fastners that you do not want to come loose, but want to take apart sometime.

-Steve

 

[IDave]

I'd get lockwashers and put them on now Even if you are torqued to spec, I bet they'll come loose without something to hold them.

 

[dd113]

Blue lok tite, split washers and new Bolts! Buy them from the dealer. Cheap!