possible to only get "partially" into 4×4??????
Question:
on my 72 jimmy…. (note a real truck) has manual locking hubs and a lever inside. don’t need no stinkin light. you say that in the snow you can tell it is in 4wd when you pull the handle so why worry about the freakin light. the light only working sometimes could be as simplae as a bad contact somewhere,therofore not telling the light to turn on. My advise is if you know its engaging don’t worry about the little bulb. unless you think that lite makes it a real 4wd truck then to hell with it.
– Hide quoted text — Show quoted text -> My 91 Z71’s 4×4 light has been working excellent the last while, and it has > again decided not to come on when I shift to 4×4. I asked about it before, > and had many varying answers. I’m leaning towards the front axle solenoid > not fully engaging…. > In the snow, its pretty easy to tell if 4×4 is working, and mine definitely > is. But is it possible to have it only partially engaged (hence the light > not coming on)???? Would this cause damage?? > Also, I mentioned before about my drivetrain "howling" when in 4×4 high. In > snow, the noise is much less noticeable (but definitely still there), but if > in 4hi on just pavement (no turning), accelerating to about 50 km/h is > smooth, but letting the truck coast will yield a noticeable howling. Even > very slight throttle application, the howling disappears (when the > drivetrain has power), but coasting howls. I know, I know, I should never > be in 4×4 on pavement….but the howling bothers me…and I’ve got street > tires on, so its not the tires. > The truck has 260,000 KM on it. The 305 is freshly rebuilt and the tranny > has been done once, but not for the last few years. I’m not sure that the > Tcase has ever been worked on. Any ideas? Would just like to sort out > these minor problems. > b
Response:
firstly: isn’t the light supposed to "blink" while the themal do-dad is heating up but the spline hasn’t engaged? secondly: maybe you could test to see if front diff is stuck in 4×4 by jacking up the front PASSENGER side wheel with the engine off and in park. If the whee turns it is desengaged if it doesn’t then the thermal spline do-dad is stuck engaged. any comments?
– Hide quoted text — Show quoted text -> My 91 Z71’s 4×4 light has been working excellent the last while, and it has > again decided not to come on when I shift to 4×4. I asked about it before, > and had many varying answers. I’m leaning towards the front axle solenoid > not fully engaging…. > In the snow, its pretty easy to tell if 4×4 is working, and mine definitely > is. But is it possible to have it only partially engaged (hence the light > not coming on)???? Would this cause damage?? > Also, I mentioned before about my drivetrain "howling" when in 4×4 high. In > snow, the noise is much less noticeable (but definitely still there), but if > in 4hi on just pavement (no turning), accelerating to about 50 km/h is > smooth, but letting the truck coast will yield a noticeable howling. Even > very slight throttle application, the howling disappears (when the > drivetrain has power), but coasting howls. I know, I know, I should never > be in 4×4 on pavement….but the howling bothers me…and I’ve got street > tires on, so its not the tires. > The truck has 260,000 KM on it. The 305 is freshly rebuilt and the tranny > has been done once, but not for the last few years. I’m not sure that the > Tcase has ever been worked on. Any ideas? Would just like to sort out > these minor problems. > b
Response:
I’d look VERY closely at the rear u-joint on the drive shaft. I had a terrible chatter developed on a trip between NY and Atlanta. When I braked it was so bad I had the rear brakes replaced while in Atlanta to fix it. They were worn but nothing real bad. Chatter still there, DAMN now what. Tried a GMC dealer. He said one drum was bad. This didn’t fix it(put the old drum back on). He said it MUST be the posi(Auburn) differential was bad. It was under warrantee in NY but by a private shop and the dealer wouldn’t honor it. I was going to drive it home to get it fixed(remember it only chattered on braking). Somehow I noticed if I put it into Neutral on braking there was NO chatter. ???? Took it to Pep boys, dropped the drive shaft in the lot and had them replace both u-joints. The rear u-joint was totally shot in 2 cups, yet never had squeaked. No more chatter. What was happening was the pinion angle increased on braking as the rear rotated down. This small change was enough to bind the u-joint. Same thing happens when you decelerate, the loads on the angles are different too. Worth a look. Also check the fluid in the transfer case and rear.
Response:
I have the after market manual cable and when you pull it, it’s locked light or non.
– Hide quoted text — Show quoted text -> My 91 Z71’s 4×4 light has been working excellent the last while, and it has > again decided not to come on when I shift to 4×4. I asked about it before, > and had many varying answers. I’m leaning towards the front axle solenoid > not fully engaging…. > In the snow, its pretty easy to tell if 4×4 is working, and mine definitely > is. But is it possible to have it only partially engaged (hence the light > not coming on)???? Would this cause damage?? > Also, I mentioned before about my drivetrain "howling" when in 4×4 high. In > snow, the noise is much less noticeable (but definitely still there), but if > in 4hi on just pavement (no turning), accelerating to about 50 km/h is > smooth, but letting the truck coast will yield a noticeable howling. Even > very slight throttle application, the howling disappears (when the > drivetrain has power), but coasting howls. I know, I know, I should never > be in 4×4 on pavement….but the howling bothers me…and I’ve got street > tires on, so its not the tires. > The truck has 260,000 KM on it. The 305 is freshly rebuilt and the tranny > has been done once, but not for the last few years. I’m not sure that the > Tcase has ever been worked on. Any ideas? Would just like to sort out > these minor problems. > b
Response:
Mine is a standard tranny so I don’t have vacuum lines to contend with. – Hide quoted text — Show quoted text – > Hmm… The vacuum switch in my ‘91 Jimmy 4×4 is stuck in the on position, so > when I leave the vacuum line hooked up and the transfer case in 2wd mode I > also get a really nasty hum coming from the transfer case (since it is then > being driven by the front wheels) between roughly 60-80kpm. My 4wd indicator > also stays lit up regardless of the shifter position until I pull the vacuum > line from the actuator. It sure does sound like your front diff doesn’t > disengage, just like mine. As for damage, everyone I’ve asked said it > "shouldn’t" cause any damage. I just leave the vacuum line disconnected > until I need it. > My 91 Z71’s 4×4 light has been working excellent the last while, and it > has > again decided not to come on when I shift to 4×4. I asked about it > before, > and had many varying answers. I’m leaning towards the front axle > solenoid > not fully engaging…. > In the snow, its pretty easy to tell if 4×4 is working, and mine > definitely > is. But is it possible to have it only partially engaged (hence the light > not coming on)???? Would this cause damage?? > Also, I mentioned before about my drivetrain "howling" when in 4×4 high. > In > snow, the noise is much less noticeable (but definitely still there), but > if > in 4hi on just pavement (no turning), accelerating to about 50 km/h is > smooth, but letting the truck coast will yield a noticeable howling. Even > very slight throttle application, the howling disappears (when the > drivetrain has power), but coasting howls. I know, I know, I should never > be in 4×4 on pavement….but the howling bothers me…and I’ve got street > tires on, so its not the tires. > The truck has 260,000 KM on it. The 305 is freshly rebuilt and the tranny > has been done once, but not for the last few years. I’m not sure that the > Tcase has ever been worked on. Any ideas? Would just like to sort out > these minor problems. > b
Response:
Hmm… The vacuum switch in my ‘91 Jimmy 4×4 is stuck in the on position, so when I leave the vacuum line hooked up and the transfer case in 2wd mode I also get a really nasty hum coming from the transfer case (since it is then being driven by the front wheels) between roughly 60-80kpm. My 4wd indicator also stays lit up regardless of the shifter position until I pull the vacuum line from the actuator. It sure does sound like your front diff doesn’t disengage, just like mine. As for damage, everyone I’ve asked said it "shouldn’t" cause any damage. I just leave the vacuum line disconnected until I need it.
– Hide quoted text — Show quoted text -> My 91 Z71’s 4×4 light has been working excellent the last while, and it has > again decided not to come on when I shift to 4×4. I asked about it before, > and had many varying answers. I’m leaning towards the front axle solenoid > not fully engaging…. > In the snow, its pretty easy to tell if 4×4 is working, and mine definitely > is. But is it possible to have it only partially engaged (hence the light > not coming on)???? Would this cause damage?? > Also, I mentioned before about my drivetrain "howling" when in 4×4 high. In > snow, the noise is much less noticeable (but definitely still there), but if > in 4hi on just pavement (no turning), accelerating to about 50 km/h is > smooth, but letting the truck coast will yield a noticeable howling. Even > very slight throttle application, the howling disappears (when the > drivetrain has power), but coasting howls. I know, I know, I should never > be in 4×4 on pavement….but the howling bothers me…and I’ve got street > tires on, so its not the tires. > The truck has 260,000 KM on it. The 305 is freshly rebuilt and the tranny > has been done once, but not for the last few years. I’m not sure that the > Tcase has ever been worked on. Any ideas? Would just like to sort out > these minor problems. > b
Response:
My 91 Z71’s 4×4 light has been working excellent the last while, and it has again decided not to come on when I shift to 4×4. I asked about it before, and had many varying answers. I’m leaning towards the front axle solenoid not fully engaging…. In the snow, its pretty easy to tell if 4×4 is working, and mine definitely is. But is it possible to have it only partially engaged (hence the light not coming on)???? Would this cause damage?? Also, I mentioned before about my drivetrain "howling" when in 4×4 high. In snow, the noise is much less noticeable (but definitely still there), but if in 4hi on just pavement (no turning), accelerating to about 50 km/h is smooth, but letting the truck coast will yield a noticeable howling. Even very slight throttle application, the howling disappears (when the drivetrain has power), but coasting howls. I know, I know, I should never be in 4×4 on pavement….but the howling bothers me…and I’ve got street tires on, so its not the tires. The truck has 260,000 KM on it. The 305 is freshly rebuilt and the tranny has been done once, but not for the last few years. I’m not sure that the Tcase has ever been worked on. Any ideas? Would just like to sort out these minor problems. b
Response:
WOW, 260,000kms and on my ‘91 GMC I am still working on getting it over 93,000 kms. Do a circuit check. Put the truck into 4 wheel high, turn the ign. on, don’t start it and crawl underneath it. Check the thermal actuator for power. If it has power, take the actuator out and connect the power to it and see if it works. If it doesn’t, replace it. If no power is there, check the elect. switch on the transfer case and keep working backwards. If the actuator works, then you have internal diff. problems. – Hide quoted text — Show quoted text – > My 91 Z71’s 4×4 light has been working excellent the last while, and it has > again decided not to come on when I shift to 4×4. I asked about it before, > and had many varying answers. I’m leaning towards the front axle solenoid > not fully engaging…. > In the snow, its pretty easy to tell if 4×4 is working, and mine definitely > is. But is it possible to have it only partially engaged (hence the light > not coming on)???? Would this cause damage?? > Also, I mentioned before about my drivetrain "howling" when in 4×4 high. In > snow, the noise is much less noticeable (but definitely still there), but if > in 4hi on just pavement (no turning), accelerating to about 50 km/h is > smooth, but letting the truck coast will yield a noticeable howling. Even > very slight throttle application, the howling disappears (when the > drivetrain has power), but coasting howls. I know, I know, I should never > be in 4×4 on pavement….but the howling bothers me…and I’ve got street > tires on, so its not the tires. > The truck has 260,000 KM on it. The 305 is freshly rebuilt and the tranny > has been done once, but not for the last few years. I’m not sure that the > Tcase has ever been worked on. Any ideas? Would just like to sort out > these minor problems. > b
