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Old 12-05-2008, 07:28 AM
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Mr. Claret Mr. Claret is offline
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Location: Mankato, Mn
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Exclamation Rear wheels not driving correctly

Fellow SVXers,

I recently swapped out the front differential on a '92 claret. After swapping the differential the analysis was that the previous owner had changed the front CV axle seals inside the diff case. To do this he unscrewed the tensioner that helps align the ring gear side-to-side of the pinion and keeps the bearings and all that in place. When he put it back together he had failed to screw the part where the axle seal is located in all the way causing wobble in the ring gear and the entire contents of the front differential, destroying the pinion gear and chewing the ring gear up pretty well.

After having replaced the differential, all has seemed well, however I have been able to turn over the front tires on pavement without rear wheel response. Even on snow, no response. A day or two ago I put it on a hoist to diagnose a noise coming from the front-end casued by sliding into a curb (kind of a whiring sound increasing with speed and louder on decel to stops; any ideas on that?) and I noticed the rear wheels were not engaging. After so any RPMs and higher speed of the front wheels the rear would get going pretty well but I think ony from centrifical force. I had a colleauge raise the hoist and see what was going on. He ended up grabbing the drive shaft and he could stop the drive shaft with his had at speeds of 20+! With wet shoes on wet tires, he put his heel on the out side of one of the rear tires and couldn't stop it, only slow it down. Also had two guys hold both back tires no problem, and then one front and back no problem, but couldnt hold both fronts of course. This to me doesnt seem right (correct me if I am wrong). I know there is a torque distribution, but from as far as from what I read the front wheels shouldn't really lose grip and the 1st gear distribution should be 50/50.

I do have the flashing power light at start up (16 times) and have checked codes. with the check engine reads "23" MAF sensor. TCU reads "11" Solenoid A. Cleaned MAF sensor with MAF cleaner (next step is to re-solder inside) Clear codes and both still show. The power light was flashing when I bought the car with the bad diff.

I have done quite a bit of research on this and from what everyone else state, they either have no rear wheels or intermitent rear wheels, with this Claret there is SOME rear wheels. Of course this is up on a hoist and could be caused bby the centrifical force, but I am not 100%. Last night I had a knowledegable co-worker help me test the Duty Solenoid A. I recall the ohms to be around 590 (i have read ohms should be 3 at 0 volts). I believe we were reading 2.9 volts when ignition was on. I have yet to test the Hz of the "A" but with the ohms that high I don't know if its worth it. As long as he knew what he was doing and the fuse in the multimeter was good, we did jump 12v to the Solenoid "A" and got no buzzing, click or anything. He wasn't positive that the meter still had a good fuse though. Were I get confused is the failing of Solenoid "A" causes full pressure for drivability, obviously there isn't full pressure.

So this brings me to think that the trouble code is incorrect and the Duty Solenoid "C" could be the problem, which contradicts the TCU trouble code. The Duty "C" regulates power to the rear and of course in the front diff swap I did have to take off the exstention housing. Maybe some debis got in there? Maybe didn't get connecter connected properly (doubtful)?

Any other ideas or trouble shooting advice would be greatful. I'm not a pushy guy, but the sooner the better, I don't want ot stress my front end too much causing more issues. Like I mentioned other who have the same rearend issues state they have no rear wheels or they work intermittently, mine when off the ground, thats about it. I recently got new Kuhmo ASX tires and thoguht they were the culprit of bad handling. Maybe I was wrong.

Thank you in advance for all that reply

Sonny

Last edited by Mr. Claret; 12-05-2008 at 08:55 AM.
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Old 12-07-2008, 04:51 PM
oab_au oab_au is offline
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Re: Rear wheels not driving correctly

Quote:
Originally Posted by Mr. Claret View Post
Fellow SVXers,

I recently swapped out the front differential on a '92 claret. After swapping the differential the analysis was that the previous owner had changed the front CV axle seals inside the diff case. To do this he unscrewed the tensioner that helps align the ring gear side-to-side of the pinion and keeps the bearings and all that in place. When he put it back together he had failed to screw the part where the axle seal is located in all the way causing wobble in the ring gear and the entire contents of the front differential, destroying the pinion gear and chewing the ring gear up pretty well.

After having replaced the differential, all has seemed well, however I have been able to turn over the front tires on pavement without rear wheel response. Even on snow, no response. A day or two ago I put it on a hoist to diagnose a noise coming from the front-end casued by sliding into a curb (kind of a whiring sound increasing with speed and louder on decel to stops; any ideas on that?) and I noticed the rear wheels were not engaging. After so any RPMs and higher speed of the front wheels the rear would get going pretty well but I think ony from centrifical force. I had a colleauge raise the hoist and see what was going on. He ended up grabbing the drive shaft and he could stop the drive shaft with his had at speeds of 20+! With wet shoes on wet tires, he put his heel on the out side of one of the rear tires and couldn't stop it, only slow it down. Also had two guys hold both back tires no problem, and then one front and back no problem, but couldnt hold both fronts of course. This to me doesnt seem right (correct me if I am wrong). I know there is a torque distribution, but from as far as from what I read the front wheels shouldn't really lose grip and the 1st gear distribution should be 50/50.

I do have the flashing power light at start up (16 times) and have checked codes. with the check engine reads "23" MAF sensor. TCU reads "11" Solenoid A. Cleaned MAF sensor with MAF cleaner (next step is to re-solder inside) Clear codes and both still show. The power light was flashing when I bought the car with the bad diff.

I have done quite a bit of research on this and from what everyone else state, they either have no rear wheels or intermitent rear wheels, with this Claret there is SOME rear wheels. Of course this is up on a hoist and could be caused bby the centrifical force, but I am not 100%. Last night I had a knowledegable co-worker help me test the Duty Solenoid A. I recall the ohms to be around 590 (i have read ohms should be 3 at 0 volts). I believe we were reading 2.9 volts when ignition was on. I have yet to test the Hz of the "A" but with the ohms that high I don't know if its worth it. As long as he knew what he was doing and the fuse in the multimeter was good, we did jump 12v to the Solenoid "A" and got no buzzing, click or anything. He wasn't positive that the meter still had a good fuse though. Were I get confused is the failing of Solenoid "A" causes full pressure for drivability, obviously there isn't full pressure.

So this brings me to think that the trouble code is incorrect and the Duty Solenoid "C" could be the problem, which contradicts the TCU trouble code. The Duty "C" regulates power to the rear and of course in the front diff swap I did have to take off the exstention housing. Maybe some debis got in there? Maybe didn't get connecter connected properly (doubtful)?

Any other ideas or trouble shooting advice would be greatful. I'm not a pushy guy, but the sooner the better, I don't want ot stress my front end too much causing more issues. Like I mentioned other who have the same rearend issues state they have no rear wheels or they work intermittently, mine when off the ground, thats about it. I recently got new Kuhmo ASX tires and thoguht they were the culprit of bad handling. Maybe I was wrong.

Thank you in advance for all that reply

Sonny
Giday Sonny, you do have a few problems.

First off, as there is no code for a C solenoid problem, it looks like you have a mechanical problem with the AWD, probably with the transfer valve, or a lack of pressure to the transfer clutch itself. The little bit of drive you are getting is just the transfer clutch drag.

The code for the A solenoid, denotes a open or shorted circuit, or the solenoid valve is stuck. If it is an electrical problem, you will have full line pressure all the time, causing hard shifts. especially when pulling it into gear when cold.

The solenoid resistance is 3 ohms, and uses a 5V duty cycle signal. The signal before the dropping resistor is a 12V duty cycle. I would not apply 12 DC to the solenoid for too long. I don't know where you checked the resistance for the solenoid from, but the dropping resistor, (10/15 ohms), behind the battery is in the circuit, so if you checked from there it would be anywhere from, 12 to 18 ohms. I would check that the dropping resistor is the standard one, as there are some that have been modded with a much higher resistance. If you still read a high reading, I would look for a wiring problem.

You say " obviously there isn't full pressure ". If this assumption is based on the AWD problem, it is wrong as the pressure at the transfer clutch is regulated at the transfer valve. The hard shifts, with no variation to throttle position is the best clue to if the A solenoid is modulating the line press or not.

This is the circuit for the A solenoid.

[

Happy hunting.
Harvey.
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