Drove to St. Louis for the All-Star game and had what seemed to be AWD clunking in and out while on the road. A definite whump sensation at highway speeds.... I just changed 50% of the tranny fluid last month; rear axle fluid was changed quite a few miles ago, maybe 30k, think it's time for another bottle of rear pump fluid or is it something else? Vehicle has 155k miles. Thanks!!

 

The dual pump fluid in the rear differential must be changed every 30,000 miles. It will not cause "a whump sensation at highway speeds" though; signs of worn out differential fluid are a juddering/groaning from the rear during sharp turns.

If you're getting clunking noises from the rear suspension over bumps, it's likely due to worn sway bar bushings and end links or broken rear trailing arm bushings.

 

It had the chattering/shuddering when cornering in the rear axle already, that's why I changed the rear pump fluid a couple years back. At speed it will kind of -whump- underneath which appears to be related to the AWD going in or out due to going uphill or down. It is definitely not suspension related. And it only started doing this recently. It's wifey's car, so I'm just finding out about it!

 

might want to check the drive shaft also the u joints go bad sometimes.

 

DOH! Why didn't I think of that??? I've sold a bazillion sets... That IS it! Can't be anything else!!!!

 

also a chattering while turning noise could be the cv joint going bad. like a clicking sound. and also im not 100% with these 4wd systems but i think the 4wd only comes on when it feels some slippage in the front wheels.

 

front wheels slip rear wheels grip that is the concept of the crv, but if you are hearing noises jack it up and check your bushings and the sort,,,

 

sorry the thread jack...

How do you replaced the rear diff fluid?

 

You'll need a syringe pump or a gear lube pump, something like this:



First, jack the car up and position it on jackstands so that it is level.

There are two 17mm plugs on the driver's side of the rear differential. Obviously the upper plug is for filling, and the lower plug is for draining. Always remove the filler plug first, just in case you run into a problem with it - that way you don't end up with a stuck filler plug and no oil in your diff.

Once the oil has drained, reinstall the drain plug with a new aluminum crush washer and torque to 35 lb-ft. Now pump the new fluid in through the filler plug hole until it starts running back out. It will take just slightly over 1 quart (the manual specifies 1.1qt). Replace the filler plug (with a new aluminum crush washer), torque to 35 lb-ft, and lower the car off the jackstands. You're done.