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Welcome to the forums.
When towing a 4wd or AWD vehicle, you usually need to put the transmission and transfer case in neutral.
The problems you would experience is drive line wind up which will take a toll on the clutch packs in the differentials and transfer case.
The rear end differential would be number 1. The force of the wheels turning the ring/pinion backwards is bad. And yeh, spinning up the transmission backwards as dreamer mentioned…
Wow, didn’t expect replies this soon..
These awds are the type that only activate the rear wheels when the front wheels lose grip. No way to switch modes, it does it all on its own.Quoted From dreamer2355:
Did you look in your service manual to see how the vehicle is to be towed?
To be towed on all fours or all four wheels off the ground. Very vauge, no specific reason as to why. This post is not intended to clear up how AWD’s should be towed, rather, to understand why AWD’s need to be towed this way and what gets damaged when the rule isn’t followed.
Here’s what happens when you tow an AWD vehicle with two wheels on the ground (and therefore free to rotate) and two wheels up (and locked in place). Note, this information comes from a Subaru forum, but the same principles apply. Note, there will be some disinformation in here as I’m just giving a basic rundown of how it works. The way the AWD system works is via a viscous coupling inside what passes for a transfer case. It’s got two shafts inside of it surrounded by a fluid that I can’t currently remember the name of. One of those two shafts is attached to the front axles. The other shaft is attached to the rear driveshaft. When those two shafts are spinning at the same speed, the fluid stays cool and liquid. When the shafts spin at different speeds (like when the front wheels spin and the rears catch-up) the fluid gets hot and locks the two shafts together, which will make them spin at the same speed and the fluid then cools down.
The problem with towing that sort of drivetrain with two wheels down is that the fluid never cools off, as it’s constantly trying to make two locked wheels spin at whatever speed the tow vehicle is moving at. Something is bound to fail under those conditions, either the fluid will burn up and stop working, or the shafts will break, or something along those lines. The fix for such a problem is to replace the center coupling (which is the generally accepted term for an AWD transfer case), which may or may not require replacing the entire transmission.
For more information, you may want to look up how a viscous limited slip differential works, as it’s essentially the exact same principle.
I would recommend replacing the fluid in the rear end with the proper Honda fluid and see if the noise goes away (it may take a bit of driving for it to work in), I suspect it will. Honda uses a viscus coupling in the rear end that only engages when the wheels begin to slip, it’s this friction that heats the fluid enough to engage the rear wheels, I suspect that during the tow the fluid got overheated and you MIGHT get away with just changing it out. I’m not sure if that one takes ‘double pump’ fluid or if it just takes Honda ATF, check the casting on the outside of the unit or the service manual for the correct fluid.
Thanks guys,
I will change the not so old dual pump fluid out of my Good CR-V and recycle it into the parts car one day when I get a chance. It only takes one bottle, but I wouldn’t even want to dump that much money into this thing, hehe. Will take pics of what the fluid looks like and update this thread.Flatbed or dollies but no wheels on the ground at all.
Usually scrap yards and disposal companies will tow them regardless of damage just because the car is going to be auctioned or dismantled.
So, I had the vehicle up on jackstands to pull a tow hitch off it, decided to jack up all four corners off the ground and put it in gear to see what happens. Here is what happened.
3 Tires Spin, Left Front, Both Rears, but the Right Front remains dead still. The one front seems to be spinning faster than the others.
So what is messed up in this system?
I still cant wrap my head around what is going on in these part time 4 wheel drive systems.That’s normal and how those differentials work, here is my video on checking for wheel bearings that will demonstrate what I’m referring to.
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