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Front differential quit working after changing transfer case what would cause this?

I changed the transfer case on my 1997 gmc safari all wheel drive now the front differential doesn't work

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Changed the transfer case with what,a used unit?

That is something all shops do
Install a used up salvage yard piece

That's your problem

You always break yours down & repair

Posted on Jan 09, 2013


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  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

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Posted on Jan 02, 2017

  • 59 Answers

SOURCE: 4wd will not engage on 2002 gmc sierra 1500

try going into reverse for 10 feet then go to drive for 10 feet that might help if not it is to the wiring to you 4x4 engage system (wires to your wheel hub)

I’m happy to assist further over the phone at

Posted on Jul 04, 2009

  • 1 Answer

SOURCE: hummer h2 transfer case

Only way for this to happen on an H2 (AWD) is for something to break rearward of the lockup hub. Take a look at the splines between the intermediate shaft and centerdifferential or even the teeth on the forward sun gear and/or stepped pinion on the center diff.

As long as you have the t-case torn down for repair be sure to upgrade to the new aluminum mode fork (production upgrade to old plastic forks thru end of 2007 or so). You should also upgrade the rear half of the housing to the 2008 version which has a pressed-in rear prop bushing (better bushing and is also replaceable.

Posted on Sep 30, 2008

  • 19 Answers

SOURCE: 4x4 wont engage front wheels

check switch or sensor on transfer case

Posted on Mar 07, 2009

  • 81 Answers

SOURCE: Transfer and Differential oil change for RX300

your front wheel drive rx300 doesnt use gear oil, the differential is lubricated internally by transmission fluid. the trans fluid is only reccomended if its dirty. if its a dark brownish red thats normal. or if its pinkish red then its new. if its black or yellow then time to flush it out. if you decide to change the trans fluid I believe the spec is 3qts. check it with the engine running and cold. thats the most accurate way to check it.

Posted on Oct 08, 2009

Testimonial: "Your clarification is very helpful. Thanks a lot. I did not find the answer clearly anywhere. Does this transaxle unit has only one outlet?"

  • 3854 Answers

SOURCE: 1995 gmc yukon wiyh 6.5 diesel 4 wheel drive will

On the full size, the front actuator is electric, not vacuum.

When in 4wd mode, a switch on top of the transfer case conducts 12 volts out to the actuator. Wire #50 (brown) is the 12v feed, and it conducts to the light blue wire (#900) to the actuator.
When shifted out of 4wd, the switch opens up and no voltage goes to the actuator.

Check voltage at the connector for the front actuator (at the front differential - it looks like a large bullet that threads into the front diff.) If it has 12 volts, the actuator is the problem. If it does not have 12 volts, check the transfer case switch and the power feed to the transfer case.

I'll assume it is the actuator, if the plug to the actuator is getting 12 volts when in 4wd.
The way this actuator works, is it is a sealed chamber that gets heated by voltage. When it heats, the pin in the end swells and pushes a shift fork in the front differential. The shift fork engages a spline on the passenger side of the differential, and boom! you have 4WD.

GM offered an upgrade to this actuator that is a motor instead of a heated device. However, it requires a small harness addition, a spacer, and a new actuator. It is about a $150 to $200 option.

If I were you, I would buy a new heated actuator. They are available at most auto parts stores, and are about $90. They are also on eBay for about $55 plus shipping. These are very easy to change - just thread out the old one, and thread in a new one.

Good luck. The actuator is usually the problem 90% of time but recheck all of the wire harness just to maker sure there is no short before replacing any parts.

Posted on Jan 02, 2010

Testimonial: "This is exactly the info i need to troubleshoot and repair efficiently complete with wire numbers and colors thanks for the help buddy"

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The actuator will not be on the front differential or drive line, it will be on the transfer case, which is mounted behind the transmission. Follow the front drive shaft back from the front differential, and the component at the rear of the driveshaft is the transfer case. That is where four wheel drive is engaged/disengaged.
I'm not familiar with your vehicle, but if you have a separate lever to engage 4wd, there will not be a fuse for the actuator - it is a manual system. If the 4wd is selected electrically, check that all wiring and connectors on the transfer case are in good condition.

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What is the differential and does it need flushed?

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