rabbittyj Posted March 23, 2007 Share Posted March 23, 2007 i wanted to see what was what with my awd. I put the car on jack stands in put it in first gear...the front two wheels always turn and only the drivers side rear turns until i put my foot on it then the other kicks in. My question is ...is it normal that both front wheels are always going ? i was under the impression only i in front and one in back should go until i slip....please let me know. thanks matt Link to comment Share on other sites More sharing options...
Manarius Posted March 23, 2007 Share Posted March 23, 2007 The two front wheels will turn, but only one will get power - same with the rear. When put on the ground though in low traction conditions, only one back and one front will turn with any power. Link to comment Share on other sites More sharing options...
nipper Posted March 23, 2007 Share Posted March 23, 2007 Like he said, thats normal. nipper Link to comment Share on other sites More sharing options...
ericem Posted March 23, 2007 Share Posted March 23, 2007 Ya sounds normal, but it also sounds like one wheel has a brake dragging. Might want to check the parking brake setup. Link to comment Share on other sites More sharing options...
cannonball Posted March 24, 2007 Share Posted March 24, 2007 Ya sounds normal, but it also sounds like one wheel has a brake dragging. Might want to check the parking brake setup. This or a bad bearing was what I was thinking. Theoretically on stands all wheels should turn since resistance should be equal. Link to comment Share on other sites More sharing options...
Setright Posted March 24, 2007 Share Posted March 24, 2007 One more vote for ericem Link to comment Share on other sites More sharing options...
Manarius Posted March 24, 2007 Share Posted March 24, 2007 This or a bad bearing was what I was thinking. Theoretically on stands all wheels should turn since resistance should be equal.There's too many tiny factors that go into that. Resistance of the fluid, the light dragging of the disc brake (you know disc brakes drag all the time), how well each CV joint turns, etc. In a perfect no friction world, I would agree with you - but just due to simple mechanics, there's going to be a wheel that doesn't spin even when it's off the ground. I highly doubt you have a dragging parking brake or anything that serious. If you're really that concerned, check how hot each hub unit is after driving for a little while. One that's noticeably hotter than the rest will give you a reason to investigate. Otherwise, I say it's just typical. Link to comment Share on other sites More sharing options...
subyfreak Posted March 31, 2007 Share Posted March 31, 2007 Your problem sounds like no problem at all. My 92 5mt does the same. I believe there is a clutch that sends more power to the rear wheels as needed. Link to comment Share on other sites More sharing options...
Manarius Posted March 31, 2007 Share Posted March 31, 2007 Your problem sounds like no problem at all. My 92 5mt does the same. I believe there is a clutch that sends more power to the rear wheels as needed.Actually, the Subaru 5MT uses what we call a viscous coupling to transfer power. As I recall, the 5MT is split at 50-50 pretty much all the time due to the viscous coupling being a mechanical type transfer unit. The 4EAT uses a MPT or Multi-Plate Transfer Clutch to transfer power front to rear. Link to comment Share on other sites More sharing options...
nipper Posted March 31, 2007 Share Posted March 31, 2007 Actually, the Subaru 5MT uses what we call a viscous coupling to transfer power. As I recall, the 5MT is split at 50-50 pretty much all the time due to the viscous coupling being a mechanical type transfer unit. The 4EAT uses a MPT or Multi-Plate Transfer Clutch to transfer power front to rear. Almost. The power in the manual tranny goes to the rear when its needed, otherwise the rear wheels are along for the ride. This is the huge difference between that and the 4eat, which determins when to send more power no matter the conditions. The viscous coupling needs the front and rear axle to spin at different speeds. When that happens the plates inside the coupling sheer the silicopn fluid. As the fluid sheers, it becomes hot. As it heats up it almost becomes a solid. At this stage you have a 50/50 split. When things start spinning at the same speed, the fluid cools down, becomes a liquid, and power is no longer transmitted. nipper Actually let me revise that .... i keep forgetting about the center diff. The center diff splits power all the time to all four wheels. Without the viscous coupling you can have one wheel drive. The vc in the center acts as a LSD to give you two wheel drive. (one front one rear due to open diffs front and rear). Two wheel drive is only if you get really stuck. Diffs are fasinating things, a perfect mechanical computer that constantly splits power f/r and l/r . The weakness is that the wheel with the least amount of traction gets the most power, as the diff cant tell if your slipping or going through a curve. the VC is usually designed in the neighboor hood of 6-8% speed differential between the two outputs, and thats where hook up occures. They are a bit slow to get to 50/50, but they do the job. Now if there was just a VC in the center of the car, then it would be FWD with part time AWD (only when needed). Hope i didnt confuse anyone Link to comment Share on other sites More sharing options...
Manarius Posted April 1, 2007 Share Posted April 1, 2007 Thanks nipper for clearing that up. I've always wondered how the 5MT works - I just say it's the viscous coupling with center diff :-p Link to comment Share on other sites More sharing options...
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