Transmission vibration

My 4WD 3litre auto has developed a worrying vibration/juddering at speed. It feels like driving on corrugations. It's not apparent at low speeds but starts at about 50mph and increases in severity as speed increases up to 65mph (I haven't pushed it beyond that), though it eases off when cruising. It's at its worst when I slightly accelerate or decelerate from any cruising speed. If I disengage gear when it's happening it carries on pretty much the same (or maybe slightly less), so I'm guessing it's a transmission and not an engine problem. It feels like it's located at the front rather than the rear of the vehicle. though that's obviously hard to say for sure.
Any advice about where and how to start looking would be welcome. Thanks!

My first guess would be tailshaft universal joints.

Thanks, that sounds a good possibility. Would I be able to check them easily myself & how?

Go under the car and check for play on those joints.

But do you feel it in your steering wheel?
Because you indicate it's coming from the front.

To me it sounds like you need to balance your wheels at a garage. That should be simple and affordable way to see if the problem dissapears.

Thanks, I'll get under and check. I'm sure it's not a wheel balance problem, I don't feel it particularly in the steering wheel, it's much more of a mechanical vibration.

That could be, it is just a cheap thing to rule out, and the issues sound the same.


Do you have permanent 4wd? or only 4wd when you engage it?

And do you have free locking hubs on the front? If you have them and you have selectable 4wd only, then try to set the free locking hubs to free and see if the problem dissappears.

Ok got it...definite play in one of the front driveshafts, know what I'm doing now!

Ah no, spoke too soon! I was assuming there's a CV joint involved somewhere but can't find a diagram for the driveshaft. Is there a CV joint at both ends or just the diff end? The parts list doesn't show a separate spider just a complete 'joint set'. I've also read somewhere that it's quite normal for there to be play in the driver's-side shaft. Any thoughts about that?

& by the way, the play in the driveshaft is rotational not lateral and quite small, I would say 5mm max, probably less.

Ok that doesn't sound like a lot. But do you have free locking hubs on the front axle? Then you should notice a difference when you put them in "free" or "lock".

It may also be a wheel bearing, but that usually makes a lot of noise.

You checked the driveshafts, but did you also check the (front and rear) propshaft? It can have play on the cross joints.
It will probably also have some rotational play, but that shouldn't be to big.

Mine's a permanent 4WD, no locking hubs. Wheel bearings are fine, recently replaced. Ok, propshafts check is a job for tomorrow!

If the propshaft or it's cross joints have no play as well (other then some rotational play which shouldn't be too big), and you got your wheel bearings already replaced, then I would really suggest just to check the wheel balancing before making additional costs.
(But you are right in that unbalanced wheels usually is felt in the steeringwheel, unless it's the rear wheels)

Rebel's first post states "It's at its worst when I slightly accelerate or decelerate from any cruising speed." That doesn't suggest anything to do with wheel balance to me, more like the change in loading somewhere in the drive train.

That's true.

It could also be a transmission mount or something like that, when you cannot find it in the drivetrain itself.

Ok, latest bulletin! Have checked both propshafts and the front tailshafts again and can't find any lateral play anywhere, just a very small amount of rotational play in all of them, which I guess is normal. So back to square 1. I agree with MalL that it's not wheel balance and it still seems most likely to be a drivetrain problem. I've noticed that the vibe effect increases as the motor warms up, hardly noticeable at first when cold but at its worst after driving a while. Another clue maybe? Doesn't make much sense to me! Maybe time to get to a mechanic...

Hmm, that is strange.

Perhaps draining the transmission oil, checking for garbage in the oil, and put new oil inside?
Same goes for differentials, maybe starting in the front. (beware, if you have a limited slip diff in the back, you need special oil)

Thanks, I'll bear that one in mind. The gearbox oil has been changed recently but the differentials...well, maybe never, who knows? But I doubt if new oil on its own will be a cure for a wobble...

True, but getting the old oil out may indicate excessive wear in the differential.

Well, this'll teach me not to jump to wrong conclusions. Got the van over an inspection pit to check the driveshafts and immediately noticed oil all over the inside of one of the rear wheels. A knackered wheel bearing, no more or less. The drivetrain is fine after all. So I'll replace the pair of rear bearings and trust I'm cured. Thanks guys for all your advice on the way...

Good news.

Ah well, spoke too soon again! Rear wheel bearings replaced, which cured the rumbling noise...but has done nothing to cure the vibration, which is still there as bad as ever. Having another look at the front driveshafts I think that perhaps there is a bit of lateral play that might be the cause. Does anyone have experience of replacing shafts or joints? Difficult and/or expensive?

Well at least you fixed something

It is quite a job I think, could be annoying when doing it for first time. For these kind of jobs I usually have it done.

But if you search for "Toyota ifs cv shaft replacement" or so, it should give something usefull. Because the system is the same on Hilux and 4Runners that also come with independent front suspension (IFS).

Thanks, that's helpful...I have some viewing to do! My days of major DIY have passed so I would get this job done...but I see that replacement complete shafts are £500 each (plus post from Japan) so I'm not sure it's worth the cost on a 22-year-old, which has already cost me loads in the past year. I guess the cheaper alternative would be to replace just the joints? I don't want to spend money without being sure of a cure.

Those replacement CV joints are pretty cheap on ebay, especially from the UK. Like 50 pound or so.

But I'm not sure where the play is. Before doing a 500 pound job I would still suggest to rule out the front wheel unbalance by getting them checked, should only be 5 pounds or so?
I mean it is likely not the cause, but before you spend the big money you should check it.

Did you check if you can wobble the front wheels? to inside and outside direction? That shouldn't be possible.

No the front wheels are firm and I swapped the front & rear but it made no difference so I think the balance is ok. Thanks, I found the joints for £50/60 so that's the way I'll probably go.