Clunk - Clonk - Every Trip!

[GEN6GT]

I have recently bought a '98 3-door RAV4 and am generally very pleased BUT what on earth is going on in the transmission? Every time I change gear there is a 'clunck' from what sounds like a place somewhere behind me. If I feather the cluth, letting it in leg ache-ingly gently I can avoid it but it is too much like hard work!

Especially bad changing up/down 2nd to 3rd. As for cruising on on the 30 mph limit in town - well I better just hand over the plastic to the gatsos right now - it moans and groans thro' the transmission until the poor RAV staggers up to 33+ mph when all settles down again.

Is this common or just a special treat for mine?

Thanks for looking

[peterart]

Sounds very much like propshaft bearings - have a look underneath and see how much play there is.

[GEN6GT]

Sounds very much like propshaft bearings - have a look underneath and see how much play there is.

Thanks, I'll take a look asap and report back!

[sjrainsford]

Don't panic too much!

This is a common problem on the short wheel base mark 1 rav4. Actually I presume it could happen on the long wheel base just the same, but not heard of it so far.

The rear differential is held in place with rubber mounting bushes, and these fail. It just needs new ones. (If this is the same fault). I believe they can still make a small clunk with good bushes though.

The rear diff is the metal box that connects the prop shaft that runs from front to rear to the drive shafts that drive the rear wheels. They're easy to see on the Rav4 fortunately.

[peterart]

Aaaaaaaaaaah - that makes sense. You learn something every day on this site! I'll panic every time I hear a clunk now though..............................

[GEN6GT]

Don't panic too much!

This is a common problem on the short wheel base mark 1 rav4. Actually I presume it could happen on the long wheel base just the same, but not heard of it so far.

The rear differential is held in place with rubber mounting bushes, and these fail. It just needs new ones. (If this is the same fault). I believe they can still make a small clunk with good bushes though.

The rear diff is the metal box that connects the prop shaft that runs from front to rear to the drive shafts that drive the rear wheels. They're easy to see on the Rav4 fortunately.

Thanks for the info.

In my experience, wear at the bushes is not always eveident unless the part is levered with something very long! I have grabbed hold of the diff from underneath, swung on it as much as you can under a RAV, and can feel no movement on the bushes. They are visible as small metal coffee cup-sized metal cradles to the rear of the diff, can't see the front ones. Am I right here? There is about 1mm end float on the transverse prop shafts between the UJ's diff and rear wheel bearing and about 5 or 6 mm rotational freeplay on the main gearbox to diff prop shaft. Do you think these are within limits?

Could it be in the clutch? It bites, vaguely, quite near the floor. The cars done about 52K miles.

[peterart]

Propshaft sounds fine......................that's me stumped.

[GEN6GT]

Propshaft sounds fine......................that's me stumped.

Never mind, I'll have another good swing on those diff bushes later.

[GEN6GT]

Propshaft sounds fine......................that's me stumped.

Never mind, I'll have another good swing on those diff bushes later.

No good, I have given the diff a good lever with a length of wood and the bushes seem pretty firm.

As I said the clutch is 51k miles old and needs a lot of feathering for a smooth change - could the clunk come from that?

[JITSU]

This is a common problem on the short wheel base mark 1 rav4. Actually I presume it could happen on the long wheel base just the same, but not heard of it so far

Yes the LWB suffered too,well mine did :D .

It does sound very much like the Diff Bushes,play is hard to detect but for the price of the Bushes you are better off replacing them anyway .

[GEN6GT]

This is a common problem on the short wheel base mark 1 rav4. Actually I presume it could happen on the long wheel base just the same, but not heard of it so far

Yes the LWB suffered too,well mine did :D .

It does sound very much like the Diff Bushes,play is hard to detect but for the price of the Bushes you are better off replacing them anyway .

Thanks for that, I'll put it on my 'to-do' list. I can see the bush at the back, there is one very obvious big one in a cylindrical cage plus a another beside that does not appear to be attched to very much is that a bush too or some kind of balancer weight, etc. Are there any bushes to the front of the diff as well?

[JITSU]

If I remember correctly there are 4 Bushes on the rear Diff that you'll need to replace.

[Jones~32]

Sounds like its the rear diff mount, the same has happened on my GT4 recently.

However, no matter how hard you swing on the diff, it wont perform the clunk you hear when driving.

I have had mine on a raised surface and had my Dad go under the car, put the handbrake on firmly, put it in 1st and try to pull away, it didnt clunk, so i then put it in reverse and try to move away gently, that makes it clunk, believe me!

Maybe try this one your drive? if you hear it clunking from this test then that would point directly to the mount in my opinion But be careful if you do try it!!

[GEN6GT]

Sounds like its the rear diff mount, the same has happened on my GT4 recently.

However, no matter how hard you swing on the diff, it wont perform the clunk you hear when driving.

I have had mine on a raised surface and had my Dad go under the car, put the handbrake on firmly, put it in 1st and try to pull away, it didnt clunk, so i then put it in reverse and try to move away gently, that makes it clunk, believe me!

Maybe try this one your drive? if you hear it clunking from this test then that would point directly to the mount in my opinion But be careful if you do try it!!

I have tried this now, wothout the use of anybody's Dad!. There is no clunk on going forward or back BUT if you load up the bushes by going forward and immediately go back the 'clunk' appears (but quietly - not as much energy at rest as with the inertia of the car at speed). Anyway, thanks for that, I am going to get them checked.

Incidentally, speaking as a ex-Celica Gen 6 owner, is the GT4 4-wheel drive a (close) relative of the full-time drive on the Rav do you know?

[Jones~32]

Sounds like its the rear diff mount, the same has happened on my GT4 recently.

However, no matter how hard you swing on the diff, it wont perform the clunk you hear when driving.

I have had mine on a raised surface and had my Dad go under the car, put the handbrake on firmly, put it in 1st and try to pull away, it didnt clunk, so i then put it in reverse and try to move away gently, that makes it clunk, believe me!

Maybe try this one your drive? if you hear it clunking from this test then that would point directly to the mount in my opinion But be careful if you do try it!!

I have tried this now, wothout the use of anybody's Dad!. There is no clunk on going forward or back BUT if you load up the bushes by going forward and immediately go back the 'clunk' appears (but quietly - not as much energy at rest as with the inertia of the car at speed). Anyway, thanks for that, I am going to get them checked.

Incidentally, speaking as a ex-Celica Gen 6 owner, is the GT4 4-wheel drive a (close) relative of the full-time drive on the Rav do you know?

Im told by my Dad, whos a Toyota technician, that they share a very similar/if not the same 4WD system ;)

But that doesnt necessarly mean that a GT4 diff mount will fit :!Removed!:

[GEN6GT]

Sounds like its the rear diff mount, the same has happened on my GT4 recently.

However, no matter how hard you swing on the diff, it wont perform the clunk you hear when driving.

I have had mine on a raised surface and had my Dad go under the car, put the handbrake on firmly, put it in 1st and try to pull away, it didnt clunk, so i then put it in reverse and try to move away gently, that makes it clunk, believe me!

Maybe try this one your drive? if you hear it clunking from this test then that would point directly to the mount in my opinion But be careful if you do try it!!

I have tried this now, wothout the use of anybody's Dad!. There is no clunk on going forward or back BUT if you load up the bushes by going forward and immediately go back the 'clunk' appears (but quietly - not as much energy at rest as with the inertia of the car at speed). Anyway, thanks for that, I am going to get them checked.

Incidentally, speaking as a ex-Celica Gen 6 owner, is the GT4 4-wheel drive a (close) relative of the full-time drive on the Rav do you know?

Im told by my Dad, whos a Toyota technician, that they share a very similar/if not the same 4WD system ;)

But that doesnt necessarly mean that a GT4 diff mount will fit :!Removed!:

Thanks!

[Jones~32]

Good luck solving it, hope it is just a diff mount and not something worse ;)

[GEN6GT]

Had the diff bushes checked and mechanic can see no signs of wear - but as I read it above, there could still be enough give in the bushes to make a clonk (especially on changing down from 3rd to 2nd).

Perhaps it would be wise to change them - anyone know how much they cost?

Incidentally, my mechanic did notice a small amount of free play in the universal joints, is this common @ 52K miles?

[JITSU]

I think the Bushes cost about £50 but fitting was more,go for uprated ones if you can rather than standard Toyota ones as these will last longer and tighten up the back end too.

No idea about UJ play,sorry.

[GEN6GT]

I think the Bushes cost about £50 but fitting was more,go for uprated ones if you can rather than standard Toyota ones as these will last longer and tighten up the back end too.

No idea about UJ play,sorry.

Thanks Jitsu!

Where might one get uprated bushes??