Vibration / Shutter on Take Of

[matske]

mine went away after i took out a leaf out of the leaf springs. they were a heavy spring now a medium springs and problem gone dont know how but its gone.. now i have a loud KLUNK coming from the bolt at the front of the leaf springs has been to arb 6 times and never gets fixed! they just pack it full of grease and say its fixed and give me the line i cant hear mate..then i drive down the road and hear the KLUNK loud and clear maybe i need to wave sum money in the air! trying to get new springs but just so happens the warranty guy is on holidays for a month yeh right like nobody else can approve it.. these problems goin on for 3months lie after lie after lie! ggggggrrrrr

[david allan]

i tried also putting some washers in around 5-7mm but no difference. have decided to give up & just live with it

[Skog07]

I have to OME 2'' lift and have had no troubles with take off shudder, I have noticed now that when I change gears and push the clutch in a get a clunk when the clutch disconnects and it sounds like it is the tailshaft area. Up to third gear. I have read somewhere that ( I cant remember where ) that the new diesels some sort of special dampener on the clutch to smooth out the torque when engaging. I could be completely off topic but though it would be worth a mention.
Mark

[ripin5.0l]

yep i also get this clunk through gears mainly 1st to 2nd haven't got under it 2 check it out yet though... mine is also lifted

[matske]

hmmm my klunk does not just do it when changing gears it will do it say when you go over a bump and get a bit of flex you can feel it the whole way through the car so hard to tell exactly where its comin from.. pretty sur its the bolt and bush at the front of the leaf spring cause when you totally pack it full of grease it goes away for a day or two..

[GregSR]

Here is what I have found,

Standard suspension, no shudder / vibration although Auto is harsh, slow to downshift and creates low rev vibration with petrol v6 and torque converter slow to unlock on stopping causing a thud / forward push at about full stop, noticable at traffic lights.

[GregSR]

matske,

May or may not help but, suspension fitter who reset my original spring pack left steel tube from right side front bush out on reassembly, should be, spring, bush, steel sleeve then bolt, the effect was much as you've described.

[hiluxdan]

Quote
"with petrol v6 and torque converter slow to unlock on stopping causing a thud / forward push at about full stop, noticable at traffic lights".

That sounds very much like what i get too, just could say it as well. It's come back since i adjusted the load prop. valve.

[GregSR]

Ok, another update, I spoke to an engineer, that I have known for years, specialising in drivelines, performance car not 4x4 admittedly, today.He says he has encountered this issue in other vehicles with modified heights (lowered) and where the engine has been modified to produce significantly more power, particularly more torque, i.e. the new hilux petrol and diesel compared to the superceded model.He is aware of two fixes,1/ modify or replace existing centre bearing to stop tailshaft whip. If you climb under your car and push the tailshaft at the centre bearing it will move 10 to 15 mm upwards or sideways reasonably easily, the rubber support for the actual bearing holding the tailshaft is too soft. He told me that this is not unusual but only causes a problem when the driveshaft angle is changed as the way power is applied through the uni joint, at low revs particularly, causes sideways movement and "pulsing" of the shaft. A cv joint instead of a uni wouldn't do this apparently.

[Skog07]

GregSr.
This does sound like a fairly close to a solution and maybe a remedy, but Tomuch did mention that the splines also maybe out of alignment earlier in the thread which could also be a problem as well increasing the effect of this and well worth looking at.
The whipping of the shaft does make sense with the setup of the external (flexible) carrier bearing on the lux. However if you get a custom tailshaft made up and eliminate the carrier bearing altogether it may increase the torque on the back of the gearbox and increase flex up the driveline putting additional stress on engine mounts, gearbox mounts and bearings. I cannot remember if the crossmount is on the back of the gearbox or a few inches in front of it.
How many ks are on it ???
Mark

[GregSR]

Mark,

You have summarised the issue as described to me by my friend well, the soft flexible mount for the centre bearing alows "whip" in the tailshaft causing the vibration / shudder. (If he is right!)

Tonight, in my process of elimination, I removed the rear drive shaft, put the car in 4wd and went for a drive effectively making it a front wheel drive, beautiful, no vibration or shudder, the auto is harsh and a bit clunky but the shudder was gone.

I did check the alignment of the uni's, they're fine, I've come across that issue before, not on a new car but on reassembly after work on the drive line.

Interestingly enough it creates a very similar low speed vibration / shudder.

The transfer case mounts are well back from the drive flange 300 - 400 mm I'd guess which could cause problems as you describe, if the shaft is balanced and the uni's are in good condition it should be ok, let the uni's get tired and you could be in trouble.

Before I go down the path of a one piece tailshaft I plan on firming up the dampener on the centre bearing to remove the (in my opinion) excessive movement to see if I'm on the right track.

Although given my front wheel drive experiment it's hard to see what else it might be.

I should get it done this weekend and be able to post my findings early next week.

Greg

[GregSR]

Car has done 5,000 k's.

[david allan]

Greg
Let us know how u go

This issue has also been driving me insane
I have teied so many things like:-
1. balancing the tail shaft
2. aligning / re-aligining
3. greasing everywhere
4. lowering the centre bearing by upto 10mm
5. taking it back numerous times to toyota / ARB

All of these issues have not helped at all

By putting it into 4X4 it actually does almost disappear (distributes the force)

I have basically now given up (dont know what else to do)
have even thought about putting back the original suspension but that will be stupid

[GregSR]

Ok, I'm back.

Here's what's happened so far.

My friend, the Engineer called back and said, hey, "walk me through your issue again, when we spoke I was pre-occupied and only half listening".
Great!
Anyway we talked, he had me under the car measuring transfer output flange height and angle, centre bearing height and angle, diff input shaft height and angle, driveshaft length, front section and rear section.

Conclusions,
1/ Centre bearing dampener too soft allowing too much movement
2/ Based on the driveshaft lengths expressed as a ratio (first section longer than second) 45mm of lift requires roughly 20mm of centre bearing drop to retain stock angles.
3/ If diff wedges are used, each degree is worth approx 6mm of lift at the uni centre line.

Here is what I have done and my interim results, and no, I will experiment and post results, make up your own mind from there.

1/ Dropped Centre bearing height by 23mm (thats the spacer size that I had)

2/ Wedges, not yet, I didn't have any.

centre bearing drop reduces angle of second half of shaft into diff nicely (18-20mm would be fine I'm sure)

Shudder gone, small vibration noticeable at 20 and 40 kph when engine labouring,

[GregSR]

Going forward my plan is,

Fit wedges 2 or 3 degrees, this will give me 12 to 18 mm of lift at the uni, I don't want too much lift at the uni or it may cause problems when heavily loaded or bottoming.

Reduce centre bearing drop, early calculations would suggest 14-18 mm should be good but I will recalculate once the wedges are in to confirm.

As is the car is probably smoother than stock (yes, it's that good!)

I am going to keep working through this, I reckon it can still be improved, I will post results as I go.

Might be a while, it's that good.

[hiluxdan]

Nice to hear something has actually worked.
Will keep an eye on the lastest.
Dan

[david allan]

thanks for your update.
keep us posted

[9W6VX]

Greg,

Thanks for sharing with us your findings.

It was technical though and I got lost with all the angles!

Cheers

Brendon

[david allan]

ok guys I have ruled out another situation that could cause the problem.
I had my tail shaft balanced as toyota said it is worth a try but no help (worth a try)

Question to anyone that knows what an unbalanced atil shaft feels like
- How does it feel when it vibrates, is it like the shudder we get from take off
- What speed does it usually come at

[GregSR]

David,

Out of balance tail shaft will not typically show up at low speed, not spinning fast enough to have an effect.

At low speed it would have to be bent to show up, and I doubt you would go much faster.

As an experiment, try spacing your centre bearing down by 25 to 30 mm, even a stack of washers will do for the trial (to suit 10mm bolt, you will need longer bolts too, 50mm long will do).

Sounds rough, but I am confident it will make a difference.

Spacer MUST be at least 25mm.

Should cost less than $10.00 and will take less than 10 minutes.

I wouldn't leave the washers in for long, if it works you can get aluminium bar 25mm x 25mm or 25mm by 30mm, whatever works, cut to 70mm long drill a 10mm hole in the middle, paint them flat black, looks like a factory fit.

This worked for me with a 45mm lift.

15mm spacer, no noticeable change, 20mm spacer, reduced shudder, 25mm virtually gone, I'm going 30mm next.

Just to see.

Good luck!