94 suburban 4x4 will not engage

[77mesa4x4]

Brief history, bought a 94 suburban took it to Rockypoint, mexico. The 4x4 was working ok. Sometimes would grind while trying to put it in 4low, had to shut off engine put it in 4low then Start the burb back up and it was fine. Then I told the wife(soon to be ex)to put it in 4high while on the beach and take it out of 4x4 when on the street. Well it seems she put it in 4LOW was not able to dis-engage it and drove around on the streets in 4low. I had no problem taking it out of 4low. Went on the beach again, 4x4 was working fine. When my wife was ready to leave she burried the suburban. Noticed that the 4x4 was not engaging 4low or high(the indicator was not showing in 4wheel nor would the front tires move). <br>Does anyone know what the problem could be? Any help would be greatly appreciated.<p>You know the worst part..... I was pulled out by a Ford Ranger!!!

 

[CA Enterprises]

Don't know that I can help, but had to get the dig on the Ranger. I don't know that I would tell that again. lol<p>Do you think the diff. could have burned out?<br>Transfer case. I assume its manual? I would think somewhere between the tranny and the axel, because it still drives in 2x. and you said it only made a noise in 4x.<p>Hope you get it fixed easily?&gt;&gt;&gt;<p>Adam

 

[yortengel]

Check the fuse for the 4wd. The front axle is locked in by an electric acuator. I have replaced them. There are diagnostics supported for this type of problem in the service manual. You could probably check a copy out at the local library. Good luck.

 

[CA Enterprises]

yortengel,<p>Question, if there was a grinding noise would or could it still be a fuse? <p>Just curious,<p>Adam

 

[Abe]

i had a 95 z71 that i had same problem with,<br>except, i didnt have the ford ranger in my equation.... =-)<p>anyway, it is most likely that the transfer case is worn, needing a rebuild. I am assuming that you can put the man shift for 4 wheel anywhere anytime and not end up with that grind going into 4 low?? if you can move through the gears on the transfer case when vehicle is running and it does not grind like it did before for you going into 4 low your transfer case needs rebuilt. If you still get the grind going into 4low, then either your transmission has an added problem for the picture or your fuse is blown.<p>also it should not grind going into 4 low, that is a warning that your transfer case is out of adj. or low on fluid........<p>-Abe<br>

 

[Alan]

Only problem I ever had with my '89 was the &quot;Thermal Linear Actuator&quot;. Replaced that cure the slow/no engage problem. It does make me wonder where the GM engineers came up with that Rube Goldberg system though. My not a vacuum or electric solenoid instead of some sort of goo that swells when you apply heat?

 

[John DiMartino]

I would suspect the actuator assy.It is possible,but extrememly doubtful that you toasted the T-case,those actuators burn up like crazy on those GM IFS systems.<p>----------<br>John D<br>

 

[77mesa4x4]

HAVE NOT HAD MUCH TIME TO LOOK AT MY SUBURBAN.(YOU KNOW, WHEN THE WIFE DRIVES THE BURB AND YOUR NOT TALKING). ANYWAY, THE TRANSFER-CASE IS SHIFTING INTO 4LOW & 4HI. SO IT APPEARS THAT ACTUATOR IS THE CULPRIT. CHECKED THE FUSE AND IT LOOKED GOOD. HOW CAN I VERIFY IF THE ACTUATOR IS BAD? AS SOON AS I FIND MY VOLT METER I WILL VERIFY THE VOLTAGE TO THE ACTUATOR. DOES ANYONE KNOW HOW MUCH AN ACTUATOR COST? IS IT EASY TO REPLACE? THANKS FOR THE HELP. <p>HAD I TAKEN MY TRUSTY 77 CHEVY 4X4 TO ROCKYPOINT, THING WOULD HAVE BEEN WAY DIFFERENT. THE ONLY THING WAS COULDN'T AFFORD THE GAS AND I HEAR THEY LIKE OLDER CHEVYS IN MEXICO.<br>

 

[Alan]

You may have voltage but unless the actuator heats and expands properly it won't lock the from axle. Figure around $75 for a new one.

 

[77mesa4x4]

Finally got my 4 wheel working again, thanks for your help!<br>It ended up being the actuator. Dealer item, they did not have the original replacement because of the problems they have been having with them. So I got an electric one(not that goo junk that swells with heat). Cost $74, but also had to buy a wiring harnes with it(different connectors and a long wire) cost $22. <br>Oh, I found out what the grinding problem was. After reading the owners manual it say's the vehicle must be moving ~2-5 mph then put in neutral and (without stopping) shift the 4x4 lever in 4lo. If you &quot;pause&quot; while shifting it will grind.<br>WHEN ALL ELSE FAILS READ THE INSTRUCTIONS.