Is It The Diff?

[ROBBO48]

RAV4 06 XR-R D4D

Hi can anyone please help? Rav has been making a whirring noise and loses it slightly on acceleration, Then suddenly feels like all the back end is seized and car wont move. On revving and persevering it reluctantly moves with smoke and burning smell, probably tires maybe oil?

limped to a garage and they advised after a test drive that it was more than definitely the Diff.

limped home and removed the Diff and had a look inside. Expecting to see a tangle of broken cogs or bearings, everything "looks" OK .I don't think the drive shafts would cause this,would they?

Do I replace the Diff?

Any help greatly appreciated thanks, Julie

[gjnorthall]

Presumably this is a late 4.2 Rav not the newer 4.3 shape? Is it an auto or manual? Can you be a bit more specific about exactly what happens when you pull away. With the back end jacked up - if you rotate one rear wheel - does the opposite wheel turn in the opposite direction? Was the garage specific that they thought it was the rear diff - could they have meant the front diff / transfer box?

[ROBBO48]

Hi gjnorthall, firstly THANKS for your speedy reply. Yes I think its the old shape Rav, it is manual, and yes wheels turn opposite way when turned. The mechanic who advised me thought it was the rear Diff because in his words "I THOUGHT THE **** WAS GOING TO COME OFF". My partner took the Diff off and inspecting it, but finding nothing he could see that was untoward. Everything spins nice inside, nothing visually wrong, plenty of oil in there. Unless it needs to be under strain? he has not undone the bearing shims and inspected closely the bearings yet as he feels they look OK..

We have had knocking noises and grinding noises for a while now. Just had one side of the handbrake done as this had fell apart and was dragging and clanking in the drum.

The whirring grinding type noise became constant just before it packed up. When pulling up at a junction and trying to pull of the grinding stiff noise gets louder and holds the car back and it will not move. breaking down at a dangerous place I revved and revved and let the clutch out to try and pull off to a safer place but it feels as though the rear (possibly front} but feels like the rear has the brakes on firmly and that the wheels are locked.

The mechanic is as perplexed as me as he really thought it was the rear Diff.

I am desperate for help as finding and fitting a replacement Diff is costly although worth it but to do all this, then to find it is not this after all but something else would be more than annoying.

Is there any tests or things I can do to the Diff or bearings?

could it be the drive shafts? my mechanic friend thinks not,. You mention the front Diff? could it be anything to do with a sensor or ABS?

If I can see whats broke, I can fix it, but its always a detective job which we are all in debt to you brilliant Gurus like Anchorman and your self.

Thanks Julie

[Parts-King]

I'm thinking it may actually be a DMF and nothing to do with the diff at all..............

[gjnorthall]

Diffs are pretty robust but can give problems by being filled with non-hypoid oil. Clunks due to excessive backlash or whines due to damaged bearings are common but they tend to go on and on with these faults. Your diff seems to have normal diff action and I guess that your mechanic has checked the backlash (lack of backlash can give problems). The diff has been inspected and all in all it's hard to believe that this is a rear diff issue.

I'm unsure from your description if the problem is present all the time or whether it arises under certain conditions. It would be useful to get the car on stands or a centre lift to enable the 4 wheels to be driven such as to identify exactly what seems to be locking up. Is the car on it's original DMF and was the clutch action normal before the problem arose? These cars are pretty bombproof but do suffer DMF failures though the symptoms are not entirely consistent with the normal failure mode of a DMF.

[ROBBO48]

Hi, and thanks again. The clutch has been fine, no problems at all. The Diff is on my partners work bench while he ponders, and stares, ponders and inspects but nothing he can see looks wrong. there has been something slowly going wrong for a while but it now seems its knackered somewhere, something drastically wrong. I cant believe we cant see what it is, so the condition is pretty much present all the time now. So it looks like another day of my partner cursing the car,and cursing everything he can think of, as he lies on the floor for another day to put it all back again. Hope the neighbours don't hear him.

Regards Julie

[Parts-King]

The clutch "has" been fine does not mean it is now. When the DMF is about to go, it generally gets noisy, it knocks and clangs a bit. When it lets go, it can be catastrophic and jam the gearbox. I think you need to pay more attention to that, rather than looking at the diff, which IF it looks OK probably is. It may not be anything to do with the DMF but this is one of the only weak points on the car and deserves attention

Kingo

[ROBBO48]

OK thanks very much for that Kingo, I will get the cursing one on it as soon as poss. One other thing I forgot to mention is, the rear Diff hanger (bushes) look shot, could of been responsible for some early knocking before whatever has gone, went. The rubber is cracked and broke, I would say needs replacing or, as others recommendput some brand of gunk in (what brand?)

Regards

Julie.

[gjnorthall]

Has the centre bearing on the prop shaft been checked? I'd avoid dismantling anything else at this stage - at least until I'd got the car off the ground and attempted to replicate the problem.

This is a decent price for a new diff mount:

http://www.ebay.co.uk/itm/RAV4-2-0-VVTi-D4D-REAR-DIFF-DIFFERENTIAL-ARM-MOUNT-MOUNTING-BRACKET-BUSH-RAV-4-/171085794812?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item27d5820dfc

[ROBBO48]

Thanks gjnorthall, your a star! All help very much appreciated indeed. The cursing one with dirty hands will be under it asap and weather permitting. Does he need to put everything back before a thorough check can be done on centre bearing and other things?

Regards Julie.

[gjnorthall]

Yes the diff needs refitting to allow the system to be tested. However the propshaft will now be disconnected to remove the diff so it's a good time to inspect the centre bearing before re-connecting the propshaft. It goes without saying that all this work under the car needs to be done safely, on firm level ground with the car supported properly on axle stands.

[pgp001]

Just a thought. You mentioned some work has been done on the handbrake recently.

Have you checked the adjustment of the handbrake, mine was causing a problem because the garage had fitted new rear discs and not adjuted the handbrake properly, the handbrake shoes were binding ever so slightly even when released, when it was all cold everything was fine, but after a few miles it all got very hot and the car was holding back because the handbrake shoes had expanded with the heat, it also had an ominous burning smell and some very alarming noises.

Once it had all cooled down it went fine for a few miles until it happened all over again, the shoes were re-adjusted properly and it has been no problem since.

Phil

[ROBBO48]

Thanks gjnorthall & Phil.

Phil, I too have just had new discs fitted and I wasn't best pleased with this particular garage that I wont be using again. They fitted rear discs for the MOT, but patched up the handbrake, it was then taken to a good garage and the shot handbrake fixed and they mentioned the other side handbrake cable was sticking slightly.

On inspection and testing, hand brake seemed fine.I haven't checked the hand brake adjustment and didn't really think I had to, nor do I have the first idea on how to do this. This to me Phil, seems a likely avenue to check and sounds very similar to your problem, thanks.

Regards Julie

[gjnorthall]

It's a quick job to back off the handbrake adjustment at both rear wheels so that you can confirm / eliminate this as a problem. Check that the handbrake isn't binding because of a cable issue by releasing the handbrake and checking that the car rolls easily on a slight gradient. See:

http://www.toyotaownersclub.com/forums/topic/77297-maintenanceimprovement-tips-42/

[ROBBO48]

Thanks gjnorthall, that's very helpful. Thanks again to all you Gurus who spend time doing these "how to do links" , they are invaluable to us mere mortals. We would be all stumped and a fair bit poorer only for you guys. I will get the cursing one on it as soon as poss, when the rain stops and report back.

Regards Julie

[ROBBO48]

Well, the air has been " BLUE " all day.

The Diff has been put back, filled with gear oil, hangers fixed back, drive shafts put back. Prop shaft centre bearing checked, all seem fine, however, on inspecting the rear brakes, the one that recently packed up and cost £70 to fix because it had no springs in the drum for the handbrake, we noticed that one of the springs and the top clip were rubbing against the back of the hub also rendering this shoe loose and wobbly.

It seems this has been caused by the nail type pin the spring and clips sit on has stretched and is a totally different shape to the other pin and, the pins on offer on eBay in the fitting kit.

So. the garage charged me £70 for fitting a few springs and by the look of it, used the old pins and not fitted new.

The spring has been refitted a few times but when trying to adjust the brakes or pulling the hand brake it comes away again.

On test driving it is OK for a very short distance then can hear a binding type rubbing noise and it seems to get worse.

I sense it is this troublesome pin,spring and clip.

Are all the pins supposed to be straight?

How much brake shoe should be there? There doesn't look much, only a few millimeters

Should I replace them? Why didn't the garage change the pins to new instead of leaving old?

So one garage changes rear discs but not the shoes, or springs or adjust the brakes.

T`other changes a few springs but not pins and does not adjust brakes, We are at the mercy of these clowns.

Everything is now pointing towards the brakes..

[ROBBO48]

SORRY First photo is wrong and shouldn't be there. It should be this one, the bad spring, worn top clip and bent inner pin

[gjnorthall]

First of all I'd suggest replacing the shoes - they're worn and grooved and there's chunks of friction material chipped off the inner edge. At the same time, it's wise to replace the hold-down springs and pins - these can be purchased as a set - Girling for one list them and they do appear on eBay. The attached diagram should help you with the relative position of the parts - note that the shaped pins are positioned nearest the back of the car both sides. The job method is given in an earlier post but note that the diagram isn't for the 4.2 - but the basic job method is correct. Check the inside of the disc/ drum - they need to be free from scoring and wear (should be no wear lip). Assemble using Ceratec grease on relevant rubbing points and before assembly - check that the brake cable pulls and releases freely and smoothly. The new shoes will need to be bedded-in and there is quite a brutal procedure for this - please ask if you don't have it. If the procedure isn't followed - it takes forever for the shoes to bed in and maximum handbrake efficiency to be achieved.

Sounds as if the rear shoes might be the source of your problems - but in any event they need sorting after the woeful attempt by your garage!

[ROBBO48]

Thanks very much again gjnorhall for your rapid and detailed reply. I only wish the local garages were as efficient!

No I haven't got any details of how to bed in the brakes. I don't think my man has changed shoes before I hope its not too difficult.

On my recent MOT it mentions rear drivers side handbrake cable sticking slightly, not the problem passenger side however we cant see evidence of this. The cable seems to be covered and seems to pull.

Regards Julie

[ROBBO48]

Sorry, I forgot to ask, I noticed there wasn't much room to work on the brake shoes because of the hub. Does this need to be removed? I cant really understand the Haynes manual because of the different models and years covered. It looks quite difficult to remove and I don't think ours has in a very long while. Rusty and dust covered and split pin rusted and rotted. The large bolt nut holding the hub will not budge It does say that you can change the brake shoes and associated springs and bits while hub is in place but don't know if this will encourage more swearing from my reluctant mechanic.

Any pointers on this would be great.

Thanks again

Julie.

[gjnorthall]

It's not an easy job and Toyota made access much better on the 4.3 model. There's no need to remove the hub -though it would simplify the job. However you may well damage the bearing if you attempt to extract the hub - the hub is an interference fit in the bearing.

[pgp001]

Hi Julie

I am glad my advice about checking the handbrake has proved to be correct, I would hate to hear you had replaced the diff when the problem was actually the brakes.

I would think thrice before ever using the mechanic that told you it was the diff again.

It is probably the fact that it is an awkward job that they did not do it properly first time. That was certainly the case with mine.

They replaced the rear disc/drums and fitted new calipers and pads, but bizzarely left the old pins and clips in the calipers, and the old handbrake shoes.

It went back three times before they admitted this fact and replaced the knackered bits as well.

Phil

[ROBBO48]

Thanks Phil, looks like your bad experience has helped me.

I have Bought the parts and I am just waiting for my man to get time off to try and fit them. Not looking forward to it one bit.

parts cost me set of X4 handbrake shoes £31.50 & Fixing kit £11.30 from G & T motor spares Buxton.

It looks like he will have to attempt to fit them with the hub still on. Whether he can manage that, I don't know.

If anyone could send me that brutal Bedding in process,that would help, if he fits them, something else for him to curse.

So the hub removal with our very rusty looking what size nut? I don\t know? and then the possibility of the bearing being damaged isn't looking good to make the job any easier. I also suspect this is one of the reasons the garage bodged the job.

Regards

Julie

[pgp001]

You have a personal message.

[gjnorthall]

It's not a nice job but not that bad! A couple of tips:

- Clean everything off with brake cleaner before you start - apply Ceratec after fitting the shoes by levering the shoes so you can get at the various rubbing points - otherwise if you apply grease as you're trying to fit things - it will get everywhere and make things hard to handle..

- Cover the friction material on the new shoes in duct tape or similar. Prevents grease and dirt getting ingrained in the linings as you manoeuvre the shoes.

- Use a cable tie to keep the pivoted handbrake lever in place - this can be snipped and pulled out later.

- Fit the shoe adjuster last but before fitting the shoe retaining pins and springs.

- Note that there is a semicircular cutout on the rim of the hub. Turn the hub so that the cutout is over the shoe retaining pin - makes fitting the clip to the pin much easier.

Don't worry too much about adjusting the shoes or the handbrake cable at the end of the job - just ensure that the shoes aren't binding. To bed in the shoes drive the car on a quiet flat road at around 30MPH. Pull the handbrake on with the button pressed and bring the car to a stop. The idea is to stop fairly quickly without locking the wheels and the ratchet button always pressed whilst the handbrake lever is being pulled Repeat then drive the car to allow the brakes to cool. When cool repeat twice more. Adjust the shoe adjusters first then the handbrake cable at the handbrake lever if needs be.