FJ 60 Vibrating at higher speeds - Help (1 Viewer)

[HankThe60Beast]

My 86 FJ60 vibrates/shakes once I get it to higher RPMs and above 55mph. It did not do this when I first bought it and I am looking for some ideas on what might be going on. It started vibrating at higher speeds when my old mud terrain tires cupped out. I rotated and rotated but ultimately I had to get new tires. No big deal. I threw on some BF Goodrich KO2 All Terrains thinking that should help sort things out but the truck still vibrates/shakes. Thanks to a tip I went ahead and rebuilt my knuckles and replaced the wheel bearings in the process thinking that might smooth things out. Nope. Had the tires rebalanced, still vibrates and shakes.

It does idle much rougher than my buddies 60 and I am almost wondering if I need new motor mounts or something...honestly I am stumped. Any ideas are more than welcome here.

 

[toy_tek]

Bent rim? Driveshaft? Bent axle shaft?

I had the same problem on a 4Runner. Chased the vibration for way longer than I would like to admit. Turned out I had a bent axle shaft. Interestingly, the 4R manual showed measuring runout at the flange face, the LC manual shows measuring runout mid shaft. But I think you should initially be able to check the flange face in lieu of removing the axle.

 

[84Landie]

Warped drums caused a similar issue with mine.

 

[micruz60]

Dried mud in the inner side of wheels?
Isolate the symptom - rear / front axle / driveshafts / in-gear coasting / out-of-gear coasting / leaf-spring pins frozen or lubed?

 

[lcwizard]

Since the tires are new the tires are probably ruled out so first check driveshafts . Bad u-joint or joints, Out of phase driveshaft. Since it did this from day one with you,is it lifted? Does it have excessively long shackles at one end or the other?

 

[toy_tek]

All good suggestions above. I forgot I had a warped drum once which also caused some vibrations, as previously mentioned. Turned out the parking brake was misadjusted which caused the drum to warp.

 

[HankThe60Beast]

Dried mud in the inner side of wheels?
Isolate the symptom - rear / front axle / driveshafts / in-gear coasting / out-of-gear coasting / leaf-spring pins frozen or lubed?

No dried mud. It seems to be coming from the front but I can't quite figure out if its one side or both. I can certainly check the leaf-spring pins.

@lcwizard it actually did not do this when I first bought it. No excessively long shackles either, just the standard OME 2.5 lift. I will say the shocks are old and likely need replacing. However I don't think that would be the cause of my problem.

@84Landie maybe its warped drums? I honestly wouldn't even know how to check that. I'll look into that as well.

 

[open country]

I'd inspect u-joints - if the OME lift is relatively new, it's common that old u-joints start to fail once they're running at a new angle.

 

[micruz60]

Drum brakes are on the rear axle. How about when you brake hard, does the shudder worsen? Front disc brakes could be warped but that does not gibe with high speed vibrations. Try lubing the u-joints and propeller shafts with fresh grease.

 

[bcolvin]

I have been chasing down a similar vibration. My rear drive line was/is the issue. Shims lifting the nose of the differential helped.

The process I have been doing to chase the vibrations was check/replace u joints (these probably need a replacement) check tires to make sure no funny business, pull rear drive shaft and drive in 4 wheel to see if vibration is from front or rear (although I’m not sure I would do 55mph without my rear shaft), also push in the clutch when you feel the vibration to see if it goes away.

Once I found that it was my rear drive shaft then messing around with shims to fix drive line angles.

If it is in the front may need shims for caster angle but that should not cause vibrations. Could be wheel bearings too.

Anyway mine was not a quick fix and a sh!t ton of trial and error. What ultimately helped was do some of the opposite advice and putting in shims backwards. So really try with the easy stuff first.

 

[cps432]

I’m fairly certain this is not the cause of your issue, but, changing the body mounts made a tremendous difference in how much vibration made it into the cabin.

My vibration was in the rear differential. I had some old damage to one of the leaf spring hangers and over time it allowed the rear axle to walk back and forth which destroyed the pinion bearings. The first thing I changed was the body mounts. Didn’t fix it, however, the difference was very noticeable.

Fixing the leaf spring hanger and replacing the suspension made a big improvement, but ultimately I had to install new differentials and the issue completely resolved itself.

 

[HankThe60Beast]

Drum brakes are on the rear axle. How about when you brake hard, does the shudder worsen? Front disc brakes could be warped but that does not gibe with high speed vibrations. Try lubing the u-joints and propeller shafts with fresh grease.

Ha, im aware of where the drums are just unsure of how to determine if they are warped. I can look into it tho.

Do you guys have a recommended grease gun? Don't currently have one and have been meaning to pick one up.

Going to check U joints. Suspension is old, not new, so everything should be around the same age...37 years old. Honestly, this thing sat in a garage and only had 25K miles put on it in 12 years before it got to me. I daily it and take it on some easy to medium trails pretty often. I think it's just starting to show its age.

I just want to resolve this problem because I know the vibrations are taking a toll on the rest of the truck.

Front shims could be off too I guess. Maybe I should find a centering tool and ensure they are aligned?

 

[micruz60]

You mentioned the motor mounts- check them by having someone rev the engine while you watch from the side with the hood up. If the driver’s side lifts up under torque then it is the mount on your driver’s side- replace both.

 

[4runner2FJ60]

Drive shaft balanced? Mine did this anything over 35mph when I first got it. One day I got curious and found only 2 bolts on holding the pinion end of the rear shaft in place, and one was loose! You could feel the vibration in the floor.

 

[lcwizard]

No dried mud. It seems to be coming from the front but I can't quite figure out if its one side or both. I can certainly check the leaf-spring pins.

@lcwizard it actually did not do this when I first bought it. No excessively long shackles either, just the standard OME 2.5 lift. I will say the shocks are old and likely need replacing. However I don't think that would be the cause of my problem.

@84Landie maybe its warped drums? I honestly wouldn't even know how to check that. I'll look into that as well.

You're looking for a rotating mass. Warped drums or rotors you'll feel through the brake pedal. The pedal will pulse under your foot.
You're heaviest rotational mass is tires. Crankshaft is probably next. Most common vibrations come from driveshafts followed by very worn gear sets.
Differentials will generally vibrate more than transmissions. Transmissions and transfers tend to howl when worn. Differentials have to transfer power 90 degrees
so you can get pretty ugly vibration from a bad one .
Driveshafts can vibrate from bad ujoints, balance issues, improper angles or bent

 

[Dr. John]

When it happened to me....U-joints.

 

[HankThe60Beast]

Rodger that guys. Ill be attacking this in order. Check/grease U joints. Check engine mounts. Leaf spring pins. And then go from there.

 

[lcwizard]

when you check the driveshafts , make sure you have correct phasing

 

[ChangingMan]

I’m also chasing the cause of a vibration. Mine’s a bit different as it’s worse at very slow speeds both when slowing down and taking off.
I’ve had the car up on stands and spun all the wheels and find no sign of bearing trouble. I’ve tried rolling down a hill in gear, out of gear both with the engine running and with the engine off. I’ve tried with the front hubs engaged and free. I’ve completely removed the rear drive shafts (so am in 4WD but actually only using the front wheels). I’ve had both rear axle shafts out.

It’s not UJs, it’s not either diff, it’s not wheel bearings, it’s not the gearbox, it’s not engine mounts but what it definitely is is that it’s driving me crazy!

Could it be the shocks? Do I have to pull them out to test them, and how can they be tested?

I’ve looked at body mounts and the leaf spring hangers etc. It all looks ok but I don’t really know how to test without simply pulling it all off.

Any suggestions? It’s killing me

 

[84Landie]

I’m also chasing the cause of a vibration. Mine’s a bit different as it’s worse at very slow speeds both when slowing down and taking off.
I’ve had the car up on stands and spun all the wheels and find no sign of bearing trouble. I’ve tried rolling down a hill in gear, out of gear both with the engine running and with the engine off. I’ve tried with the front hubs engaged and free. I’ve completely removed the rear drive shafts (so am in 4WD but actually only using the front wheels). I’ve had both rear axle shafts out.

It’s not UJs, it’s not either diff, it’s not wheel bearings, it’s not the gearbox, it’s not engine mounts but what it definitely is is that it’s driving me crazy!

Could it be the shocks? Do I have to pull them out to test them, and how can they be tested?

I’ve looked at body mounts and the leaf spring hangers etc. It all looks ok but I don’t really know how to test without simply pulling it all off.

Any suggestions? It’s killing me

Have you checked your rear drums?