Suzuki Gr.Vitara.Front wheels dont engage when reversing in 4WD
The short answer is "no", but working out why could be a little bit difficult. Any further diagnosis should be performed on a hoist or with all 4 wheels off the ground and the transfer box in 4H. Be aware that any of the following checks where front and rear wheels may turn at different speeds will generate an ABS error code and a light on the dash that may need a Dealer to turn off - if you have ABS. You'll also need a couple of hydraulic brake line locking clamps. The first check would be to make sure the front prop shaft turns in reverse as it does in forwards 4WD. Why it wouldn't, I couldn't tell you!
Stop the engine, and while someone is holding their foot on the brake, clamp off both front hydraulic lines to each of the front calipers. Release the hand brake (park brake) and release the foot from the brake pedal (keep foot off brakes from now on) and restart the engine (in nuetral or N), and whilst the engine is idling, select 1st and slowly let the clutch out (if it's a manual), or select D (if it's an auto). If the line locks are holding the pressure in the front brakes, then the manual should stall, and the auto's back wheels shouldn't be turning (but the engine would feel like it's in gear). That would confirm that the front wheels are driving when in forwards 4WD.
Then we do the same test but going backwards, so select reverse and let the clutch out (or R if auto), and if what you say is true, then the back wheels should be spinning away at idle. If the engine stalled, or the back wheels aren't turning, then everything is OK.
Remember to remove the line locking clamps after this test.
I would think that you may have only seen the wheel that wasn't turning when going backwards. These cars have open diffs - so the wheel with the most resistance to rotating won't turn, but the one on the other side will. This is the same for both the front axle and rear axle for most Grand Vitaras. Very few have a factory rear LSD, and I don't think any got a front LSD.
I've just had inspiration - if the front wheels don't drive ONLY in reverse 4WD, the only thing wrong would have to be the front diff engaging mechanism or its related wiring/switching controls. If the relays that control the pump that supplies air pressure to the diff engaging diaphragm in the front diff housing don't get the "I'm in 4WD" signal from the transfer box, the pressure is relieved to the diff and you're back into 2WD. My next check would be to see if your reverse lights are working when in reverse. See if your reverse lights come on when in 4WD or 2WD. If they aren't working, or coming on at the wrong time, then SOMEHOW, the wiring/plugs on the gearbox/transfer case may have been mixed up (during a clutch replacement?) or the wiring somewhere else is wrong. I would probably do the checking of reverse lights before the first test above. Good luck. Let me know how you go.
Jan 14, 2010 |
2002 Suzuki Grand Vitara