4 x 4 Lo bang wnen starting out.
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Senior User
Joined: Feb 2004
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From: Omaha, Nebraska USA
4 x 4 Lo bang wnen starting out.
Have a question on the 4 wheel drive. When ever we get some snow here in Omaha I lik to run my expy in 4 x 4 Lo in the sub for a little distance just to get some running time on it and to make sure those gears are getting lubed.
It shifted just fine but when I went to take off it wnet about 5 feet then a very hard bang. It kept moving afterwards and ran just fine, When I stopped and take it out of 4 x 4 Lo it did the same thing in 4 x 4 Hi. I don't recall this ever happening before. What do you think?
It shifted just fine but when I went to take off it wnet about 5 feet then a very hard bang. It kept moving afterwards and ran just fine, When I stopped and take it out of 4 x 4 Lo it did the same thing in 4 x 4 Hi. I don't recall this ever happening before. What do you think?
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The gears are all in the same transfer case so it is not necessary to go into 4WDL to lube them. They are getting lubed no matter if you're in high or low. As far as the bang, the TC fluid could be old and thick, shift motor could be a little lazy or just stiff from the cold. Because of this, it might not have been fully engaged in low then high until you started rolling. You're first step to avoid this happening again could be as simple as replacing the TC fluid with new synthetic fluid.
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From: Omaha, Nebraska USA
TC fluid is 3 months old and is M1. My gues is like you said that the gears were not meshed totally. The shift motor could be getting weak, but when I leave it in Auto mode it kicks in as it always did. I don't really ever use 4x4 Lo so maybe the best thing is to not use it unless I need it as you say it is getting lubed all of the time any way. It just is like the old saying" don't use it loose it".
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That's because in auto mode the TC is already shifted into 4WD, there are clutches that are disengaged and preventing power from reaching the wheels. Once a rear wheel slip is detected the clutch engages to supply power to the front axle. The TC would blow apart if the gears were jambed together during A4WD operation, that's why they're already engaged.
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That is why the fluid was burned after 30,000 miles makes sense. I ran regular Mercon 5 in it for 500 miles then changed and went with M1. Maybe the shift motor is getting weak. Does it have to turn further to shift into 4 Lo vs 4 Hi or is it 4 Hi done inside with the clutches. Sorry to ask so many questions it is just me trying to learn. What you are saying makes sense as to what I have seen when I have changed the fluid. I was wondering if there were clutches in there as to why the fluid was burnt. Thanks for your input. I might start looking for a shift motor instead of waiting for it to go out.
