Modern content - CRV gearbox issue

[keithyboy]

I know it's modern but they were suggested very recently as having potential on this very sight. Ours only appears to have potential to be a massive pain in the rear at present.

It has now developed a weird transmission fault which has me stumped. It's hard to describe but it feels as if, instead of the front wheels doing the work, all of the drive is going to the rear. This is accompanied by a lot of transmission shunt and a sort of delay before taking up drive. You can also hear the exhaust moving about on its mountings. There is a jerk when you dip the clutch and a bang as if a clutch is disengaging very suddenly.

It did it once before but sorted itself out when I jacked up the front end to have a look and gave the wheels a spin. I've tried that again but this time it hasn't worked. Even with the car in gear, there is very little resistance to the front wheels turning and the propshaft isn't turning with them.

Has anyone experienced this before? I've tried google and turned up nothing.

It's a 5-speed manual and the the dual pump diff fluid was changed last year if that helps.

I've run out of ideas other than the 'box being buggered, but this confuses me because if the 'box is buggered, last time it healed itself. The Honda forums have failed me so I'm pinning my hopes on you.

[rwdrules]

the silicon filled viscous type coupling,do fail and cause this type of behaviour, if hand with a grinder and welder you can refill them, but you must clean out the burnt on silicon off the plates, plenty of info around may be easier to get a recon one

[keithyboy]

The CRV doesn't have a viscous coupling. It has Honda's dual pump system in the rear diff instead.

[miker33]

Would get all 4 off the floor, carefully check all are spinning in gear when elevated. Also you can see if the drive to the rear is correct using the handbrake as the engine\drivetrain should be able to overcome the handbrake and force the rear wheels to turn. Should be similar with the fronts too, apply foot brake and use engine power to overcome the brake, obviously not full force braking but quite a lot. If there's any particular bit not doing it's job you should be able to spot the anomaly area of an individual wheel\axle not turning to check in more detail.

Being front drive biased the rear shouldn't ever be doing more work than the front, is the tyre wear even between front\rear?

Just a few ideas.

Good luck.

Cheers,
Mike

[keithyboy]

I had thought about tyre wear but they aren't known for being particularly fickle about it. In any case, they are all pretty similar.

Getting all four wheels up in the air is a good plan I think. From there I'm going to change the oil, I suspect it's never been done and I can see if there's anything in it that shouldn't be. If that doesn't get me an answer, I'm going to remove the propshaft. It spins all the time on a CRV so if the problem goes away, it's a rear diff problem. If there's no drive at all it's a gearbox problem.

[mk2cossie]

Is this a mk1 CRV?

As we had one at work a few years ago that felt like it was winding itself up when maneuvering at low speed.
That was cured by getting a couple of litres of Honda oil for the rear diff clutch unit and draining it out and refilling a couple of times. Was as good as gold after that

[keithyboy]

It is a MK1 CRV. The diff oil was done as a preventative measure in 2015. Winding itself up is a good description, it feels like its pulling itself to pieces but it's doing it up to 25-30 mph, which is as fast as I dare go at present.

[davidpallister]

not a broken engine/gearbox mount is it? letting the engine/box move around excessively?

[keithyboy]

Nov 5, 2016 9:16:03 GMT davidpallister said:

not a broken engine/gearbox mount is it? letting the engine/box move around excessively?

It feels like it should be something like that but they all look ok and the last time it did this, it healed itself. I was about to drop the propshaft but my wife has gone out in my car and I've discovered that the bolts have 12 point star heads for which i do not have a socket.

[keithyboy]

I am now the proud owner of a set of multi fit sockets that will undo torx, square, hex, 12 point and star bolts. I am also the proud owner of a broken gearbox. With the prop off and the engine running, you can select all the gears. You can also hear a whirring noise where a gear or spline has stripped.

I did wonder if it was a CV joint spline but the driveshafts aren't spinning.

[mk2cossie]

Is it not just because the rear axle is disconnected? Seem to recall the viscous diff part is on the rear diff extension casing and not in the transfer box up front

[keithyboy]

Nov 6, 2016 8:01:03 GMT mk2cossie said:

Is it not just because the rear axle is disconnected? Seem to recall the viscous diff part is on the rear diff extension casing and not in the transfer box up front

No. The prop spins all the time on a CRV, even when the rear diff isn't doing anything. The Americans have a habit of removing it in the hope of getting marginally better fuel economy. People also remove them when the rear diff starts making weird noises. It's making a fairly unpleasant noise too.

[keithyboy]

I must now announce to the world that I am an idiot.

I was struggling to accept that the gearbox was knackered as they just don't seem to get knackered. A much closer inspection revealed that the non-OE driveshaft had worked its way out of the box by 3/4" or so leaving maybe 1/2" or so engaged with the box. Eventually this has cried enough and rounded off. Thankfully the splines in the 'box are undamaged so we're back up and running.

My wife isn't as pleased as she might be as she's been using my Jag all week and now has to give it back.

[vitesseefi]

Well, at least a happy idiot with a healthier bank balance than might have been

Looks like a result and a happy ending to me!

Nick