Experts Only - Desperate Plea for Help - FJ40 Driveline Vibration. LONG Post.

[lcwizard]

start with a 2 deg caster shim in the rear. If it gets better you're going in the right direction , if not, take it out.
Most 40's don't have much trouble with a 2 1/2" lift but it happens occasionally. A caster shim will usually do the trick. I'd think 4 deg would be excessive for that lift. It wouldn't take much time to try.

I doubt you're out of phase, usually an out of phase driveline has vibration at all speeds. The one oddity
in that theory is the FJ80 front driveshaft. It comes to you from Toyota out of phase and vibrates like hell if you try to put it in phase.

 

[kiwidog]

naz

If it's the angle of the the rear pinion because of the lift, then try a different angle. Easy to slide a piece of 1/4 x 3/4 flat about 2 1/2 inches long under the rear of the spring pad. Loosen the u bolts and slide it in the back. This will push the pinion flange down and more parallel the TC output flange Tighten the u bolts back down and drive it If the vibration is gone or reduced theres the problem. Then you can fix it permanently with wedge under the diff. spring pad.
That's what I did with my 1980 and the pieces of flat are still there after 15 years or more.

Thanks jb

 

[Southeast Overland]

I had a very similar vibration but it was in the front - would only happen in 4WD and when I was decelerating. I looked at a bunch of stuff - ended up my U bolts were LOOSE as heck. Tightened them up and the heavy vibration (I would call it shaking) went away.

See you at UPO 2010.

 

[nazdackster]

From another thread:
Originally Posted by Poser
"If you do not want to knock out the studs on your parking brake drum and drill new holes for the different mounting flange pattern of the minitruck CV, and then press the studs back in and possibly need to tack weld them into position, your only real option to try and stay with Toyota components will be to find a pre-1985 FJ-60 front drive shaft as this should have the identical bolt pattern as your parking brake drum, provided your truck is not a mix of parts and that you are currently running the four speed style drive shafts and flanges"

-Steve
OK so I need a pre-1985 front FJ60 shaft, and I will need to shim the rear to get the pinion pointed at the T-case (make the new shaft straight with pinion there). Is this a bolt-in other than that? Do I need to shorten? Do I use part of my shaft (the male slip joint part?). Not sure of what all I will need, lots of threads but no clean solution. Just need to get stuff lined up if I buy one, there's one in Toledo and a few other places. How close do I need to be on the angle getting the diff pointed to the pivot point?

I'll try the shim idea first and point it more parallel with the ground. I hope that's it, but it didn't vibrate much before I did this other stuff, which makes me think it's something else. It's going to make the shaft longer too, I hope I have enough spline engagement left... Pictures coming soon...

THANKS TO EVERYONE WHO HAS RESPONDED SO FAR!

Eventhough - nice to see you here, see you AT UPO in either an FJ40 or a CJ7!

 

[Poser]

start with a 2 deg caster shim in the rear. If it gets better you're going in the right direction , if not, take it out.
Most 40's don't have much trouble with a 2 1/2" lift but it happens occasionally. A caster shim will usually do the trick. I'd think 4 deg would be excessive for that lift. It wouldn't take much time to try.

This is easy, try it before you do anything else...




No reason to spend all sorts of money on a custom drive shaft if you do not need it..

 

[nazdackster]

This is far more important that you have been lead to believe.

If you do not own an angle finder, purchase one and post up what your rear output on the transfer case is sitting at and what the rear differential companion flange is sitting at.

OK here it is:

The two operating angles are 7.3° different. If I make them the same, the transfer angle will increase from 9.7° to 14.6°, and the diff operating angle will change from 2.4 to 14.6°. Which might be kind of high for both. The shaft will become 1/4" longer. If I change them so they are only 2° different, I would use a 5° shim, and the transfer operating angle would go from 9.7 to 13.3, and the diff side would go from 2.4 to 11.3°. The shaft will get 0.143" longer. Kind of a compromise no matter how you do it. Any suggestions on what I should be shooting for? Something less than 7.3° I suppose. Dana / Spicer says they both need to be within 1° or the shaft will vibrate. http://www2.dana.com/pdf/J3311-1-HVTSS.PDF

Go the whole way (7.3° shim) or just try a 5 and see what happens? Or even 3 or 4? I can't machine anything today anyway, but I can stuff something in there and drive it to see.

Does my driveshaft look like it has much spline left? That looks like it's sticking out pretty far already.

Does this look bad / worse than your rigs?

Thanks again, Mike S.

It's going to lift the vehicle even further too. Right now I only have 3/8" clearance to get into the garage! LOL. Edit: Nope. Now that I see what I'm doing, it's going to lower it. Good!

 

[PGH854runner]

Is the vibration tail sharft speed or wheel speed?. I chased one in a 75series in 4wd and it turned out to be the sharft angles in the frount. I changed diff centers, rebuilt transfur case,tried three frount drive sharfts, still their. One day an old feller said you have a 2" lift yes. He said the fix is a cardernal joint. [ that is one with 3 unis 2 close together] I modfied a frount sharft out of a hilux, i think usa call them a mini truck. 4years later and 40000k of hard sand driving and no vibration. I think some comp trucks run them on the rear.

I agree here exactly from personal experience.....had similiar problem in an 85 4runner.........had an extra front driveshaft(CV) retubed and used it in the rear....no vibration....5 years later

 

[amaurer]

The two operating angles are 7.3° different.

...

Does this look bad / worse than your rigs?

Whoa, thats far worse than my truck with OMEs. Who made your springs?

7deg is a whole lotta shim. At this point I'd consider shimming the 2.4deg in the wrong direction and then using a shaft with a DC joint at the TCase.

 

[Splangy]

Don't leave the pieces of flat bar there. That's only asking for trouble. If you discover that you've found the proper angle that way, just replace the bar with the proper sized shim.

If it's the angle of the the rear pinion because of the lift, then try a different angle. Easy to slide a piece of 1/4 x 3/4 flat about 2 1/2 inches long under the rear of the spring pad. Loosen the u bolts and slide it in the back. This will push the pinion flange down and more parallel the TC output flange Tighten the u bolts back down and drive it If the vibration is gone or reduced theres the problem. Then you can fix it permanently with wedge under the diff. spring pad.
That's what I did with my 1980 and the pieces of flat are still there after 15 years or more.

Thanks jb

 

[Aussie 25]

Some of the hj47 and 60series have them on the frount. They will fit after you shorten it.

 

[nazdackster]

Whoa, thats far worse than my truck with OMEs. Who made your springs?

7deg is a whole lotta shim. At this point I'd consider shimming the 2.4deg in the wrong direction and then using a shaft with a DC joint at the TCase.

I like the idea a lot, but I have to leave Thursday night. I'm not sure I could get the shaft here & shorten it in time, my driveshaft place is first come first serve, and it took 3 days to do u-joints & balance it. I can make the steel wedges Monday (maybe I'll make a 2.4 while I'm at it and keep for later).

The springs are TPI 4x4 2.5". Then I added a leaf to the left side to cure the "cruiser lean" because I didn't want to lower the right with the spacer block (the left was already too low and rubbed sometimes). The added leaf lifted both sides, so it's probably more like a 3 to 3.5" lift in the back now. And it has extended shackles, guessing 4.5" long total, which also puts the angle the wrong way. BTW, if anyone else is reading this, if you do an add-a-leaf, it's probably best to do both sides and make the other side so it has no added lift. Now the spring rates are different, which causes an uneven bounce rate which introduces other handling issues. I sort of expected this, and it's not bad, but not ideal either.

So based on your comment, I'm getting confident this is the problem. I might just do a 5 or 6 degree shim and get it within a 2° or 1° operating difference. Think I have enough spline left? Thanks for the help, I hope it works! Are you pretty confident this is it based on what you see here?

Splangy: "Don't leave the pieces of flat bar there. That's only asking for trouble. If you discover that you've found the proper angle that way, just replace the bar with the proper sized shim."

Yep, I have some 1/4" aluminum I could stick in there just to drive around a couple miles to see if it helps. Then I think I'll take it back to the spring shop to install the wedges. I'll probably just wait and let them do it all. I have to buy new spring bolts and U-bolts anyway to fit the wedges, and they can do this in minutes, it will take me longer to lift it off the ground than for them to finish it. They'll use the flame wrench on the old bolts. The wedge, if 5°, will be .443 thick, so my U-bolts won't fit anymore. Here's what I'm putting in (if I do 5 degrees)

Aussie 25: "Some of the hj47 and 60series have them on the frount. They will fit after you shorten it." Hopefully this works well enough, otherwise I'm trying the FJ60 shaft when I get back. It sounds like 7 degree difference between 2 ends could cause all kinds of problems. I probably never felt it before because I had other loose things in the driveline, like loose gears in the transfer. I'm hoping that it got pronounced now because everything else is finally right. The vibration was there before I added the leaf on the left though, right after I changed tranny and transfer.

Thanks!

 

[Mudguts]

Hi peoples the dreaded cruiser vibration every cruiser ive owned putting OME suspension on them which is ok but ive allways got a vibration out of it but you can tell its not a death rattle ,my latest bj42 got the same vibration to at similar speeds , i just make sure the gearbox and transfer are topped up and diffs and add a additive , other times vibrations have been from loose pinion bearing i think its called basically the big nut on the diff you see when you pull the shaft off ive had that come loose and replaced the bearing a few times , lots of water crossings kill the bearings fast specially if you stop in the water like i used to , also with this lift this time i put a 5 degree wedge in the front and that helped the vibration a little to and the chronic over/under steer and i dont recomend driving highways on just the front diff it can be done but causes undue wear to the drive line but its handy if ya blow ya rear i did it once spat the tailshaft 200 metres down the rd and a fist size hole in the diff pumpkin , but it was a highly modified fj40 v8 and i was test driving it to maybe buy it lol it had a bad vibration from bad angles with a spring over thought id test it doubled the clutch hard into 2nd and bang god dam missile / tailshaft going flying down the main street , i rang the owner i told him id figured out what his vibration was from and thankfully he was ok about it we drove home on the front diff but goodluck bud if it aint a death rattle check oils and go for it its a toyota

 

[lcwizard]

Once again, start with a ~2 deg. shim and drop the nose of the diff then test drive it. You may need a 4 deg but probably not.

OK here it is:

The two operating angles are 7.3° different. If I make them the same, the transfer angle will increase from 9.7° to 14.6°, and the diff operating angle will change from 2.4 to 14.6°. Which might be kind of high for both. The shaft will become 1/4" longer. If I change them so they are only 2° different, I would use a 5° shim, and the transfer operating angle would go from 9.7 to 13.3, and the diff side would go from 2.4 to 11.3°. The shaft will get 0.143" longer. Kind of a compromise no matter how you do it. Any suggestions on what I should be shooting for? Something less than 7.3° I suppose. Dana / Spicer says they both need to be within 1° or the shaft will vibrate. http://www2.dana.com/pdf/J3311-1-HVTSS.PDF

Go the whole way (7.3° shim) or just try a 5 and see what happens? Or even 3 or 4? I can't machine anything today anyway, but I can stuff something in there and drive it to see.

Does my driveshaft look like it has much spline left? That looks like it's sticking out pretty far already.

Does this look bad / worse than your rigs?

Thanks again, Mike S.

It's going to lift the vehicle even further too. Right now I only have 3/8" clearance to get into the garage! LOL. Edit: Nope. Now that I see what I'm doing, it's going to lower it. Good!

 

[nazdackster]

Hi peoples the dreaded cruiser vibration every cruiser ive owned putting OME suspension on them which is ok but ive allways got a vibration out of it but you can tell its not a death rattle ,my latest bj42 got the same vibration to at similar speeds , i just make sure the gearbox and transfer are topped up and diffs and add a additive , other times vibrations have been from loose pinion bearing i think its called basically the big nut on the diff you see when you pull the shaft off ive had that come loose and replaced the bearing a few times , lots of water crossings kill the bearings fast specially if you stop in the water like i used to , also with this lift this time i put a 5 degree wedge in the front and that helped the vibration a little to and the chronic over/under steer and i dont recomend driving highways on just the front diff it can be done but causes undue wear to the drive line but its handy if ya blow ya rear i did it once spat the tailshaft 200 metres down the rd and a fist size hole in the diff pumpkin , but it was a highly modified fj40 v8 and i was test driving it to maybe buy it lol it had a bad vibration from bad angles with a spring over thought id test it doubled the clutch hard into 2nd and bang god dam missile / tailshaft going flying down the main street , i rang the owner i told him id figured out what his vibration was from and thankfully he was ok about it we drove home on the front diff but goodluck bud if it aint a death rattle check oils and go for it its a toyota

That's hilarious!

 

[amaurer]

The springs are TPI 4x4 2.5".

I thought TPI only sold OME springs in 2.5"?

 

[Volcano cruiser]

OK here it is:

The two operating angles are 7.3° different. If I make them the same, the transfer angle will increase from 9.7° to 14.6°, and the diff operating angle will change from 2.4 to 14.6°. Which might be kind of high for both. The shaft will become 1/4" longer. If I change them so they are only 2° different, I would use a 5° shim, and the transfer operating angle would go from 9.7 to 13.3, and the diff side would go from 2.4 to 11.3°. The shaft will get 0.143" longer. Kind of a compromise no matter how you do it. Any suggestions on what I should be shooting for? Something less than 7.3° I suppose. Dana / Spicer says they both need to be within 1° or the shaft will vibrate. http://www2.dana.com/pdf/J3311-1-HVTSS.PDF

Go the whole way (7.3° shim) or just try a 5 and see what happens? Or even 3 or 4? I can't machine anything today anyway, but I can stuff something in there and drive it to see.

Does my driveshaft look like it has much spline left? That looks like it's sticking out pretty far already.

Does this look bad / worse than your rigs?

Thanks again, Mike S.

It's going to lift the vehicle even further too. Right now I only have 3/8" clearance to get into the garage! LOL. Edit: Nope. Now that I see what I'm doing, it's going to lower it. Good!

Ok, I know this response is not deep technical like the rest of you guys but am I the only one blown away by the fact that diagram came from an I phone. Jeez I guess my kids are right, I gotta climb down off this volcano more often BTW sorry for your troubles but thanks for posting up this is super informative.

 

[Papa Smurf]

I had the same problem earlier this year. 1st thing that I did was change to double Cardin. did not help. 2nd lifted the diff angle by 7,5 deg. Sort of helped, at least it was drivable but the vibration was bad on accelaration and de-acceleration. Then replaced the gearbox mounting. Wow!!! 90% improvement.
Then because the HC springs were too hard for the wife, I took out a leaf all round - 2 nd blade from the bottom. - Then We went on a long trip with a heavy load. A lot of off road - river bed stuff, axle twisters etc. But because we had a heavy load the rear dropped about 30mm over a period of 2 weeks and the vibration went away 100%. But the 33's were touching the body every now and again. When back home without the load I replaced the rear leaves. Immediately the vibration was back. If I load the rear with 300KG's (6 bags of Cement) the vibration is gone - even under heavy acceleration. So it seems the short rear propshaft (even with the double cardin) doesn't like the 2,1/2" lift.

 

[nazdackster]

I thought TPI only sold OME springs in 2.5"?

When I bought them they had a TPI "Smoky Mountain" brand. They still sell a 2.5" kit. I only did the rears.

Do you think this is the issue? From what I've read, 7 degrees is way too much difference. I'm thinking I should go at least 6°, since ideally the pinion should be lower than parallel by about a degree, so that when it's under load and it lifts up, it's parallel. So theoretically, I should go 8.3°, but if I go 6°, I'll still be within 2 or 3 degrees when cruising (with 1° or less being ideal). A longer shackle alone could cause a 5° problem, which I have, so I don't see 6 as being too big, other than the fact that both angles will increase quite a bit, but they will at least be closer to parallel.

Looking for a consensus on the best angle to try. I plan on doing this once. It will mostly be loaded to the gills for long trips anyway. I see lcwizard says start with something small, but I'm thinking I should get within 3 degrees or better of equal angles, preferably even better than that.

Volcano Cruiser:
The diagram was done in AutoCAD... I wanted to see how much longer the shaft would get if I rotated the diff with wedges. There is an angle finder app for the iPhone that has a bubble for flat surfaces, or an angle finder screen for big angles. It's way cool, can be calibrated, and seems to be quite accurate. Just hold the phone's edge up to what you want to measure.

Note that you really need a sketch with the lengths of the diff nose and driveshaft to see what a change will do. Change one, it changes the other. I used 13" nose to center for diff, and 19" for the shaft, which was pretty close to actual.

Papa Smurf - Are you saying the engine mounts by the bellhousing? (assuming you have an FJ40) I did tighten those up a bit since one had a nut I could move by hand. Probably tightened 1/8" and added a washer. So they are stiffer than before. Maybe I should back those off some. The rubber is in good shape. Seems like driveline. I'm banking on the shims, just haven't decided what angle to use.

 

[Splangy]

Hi peoples the dreaded cruiser vibration every cruiser ive owned putting OME suspension on them which is ok but ive allways got a vibration out of it but you can tell its not a death rattle ,my latest bj42 got the same vibration to at similar speeds , i just make sure the gearbox and transfer are topped up and diffs and add a additive , other times vibrations have been from loose pinion bearing i think its called basically the big nut on the diff you see when you pull the shaft off ive had that come loose and replaced the bearing a few times , lots of water crossings kill the bearings fast specially if you stop in the water like i used to , also with this lift this time i put a 5 degree wedge in the front and that helped the vibration a little to and the chronic over/under steer and i dont recomend driving highways on just the front diff it can be done but causes undue wear to the drive line but its handy if ya blow ya rear i did it once spat the tailshaft 200 metres down the rd and a fist size hole in the diff pumpkin , but it was a highly modified fj40 v8 and i was test driving it to maybe buy it lol it had a bad vibration from bad angles with a spring over thought id test it doubled the clutch hard into 2nd and bang god dam missile / tailshaft going flying down the main street , i rang the owner i told him id figured out what his vibration was from and thankfully he was ok about it we drove home on the front diff but goodluck bud if it aint a death rattle check oils and go for it its a toyota

OMG. That's the longest sentence I've ever seen. There wasn't one period in that entire thing!

 

[Poser]

Once again, start with a ~2 deg. shim and drop the nose of the diff then test drive it. You may need a 4 deg but probably not.

Listen to this Man.