so yesterday I put my blazer in 4 low for the first time, here is what happened.

I put it in 4 low and smashed the gas to the floor, lurched forward then the noise, and it seemed as if my motor revved way up while making this noise and no acceleration. I let off the gas and the noise stopped and got a real nice firm shift into second gear.
I stopped put it in 4 high and all was fine.... put it in 2 high and all was fine....back to low side... GRIND...

The noise I heard was LOUD mind you, and if youve ever put an auto tranny in park while moving.... thats what it sounded like... a loud tick/grind noise.

sounds like its coming from the front of the truck.

This noise does not exist in 4 high or 2 high.



does anyone have any idea what this is ? This is my first push button blazer .. and ive never heard this noise from any of my 1st gen blazers.

 

It is possible that for some reason, the vacuum supply to the front axle while in 4LO is not sufficient to pull on the actuator which engages the front axle. To test, get to the actuator. Pull out on the cable, and use a small set of vice grips to hold it in the engaged position. Engage 4LO and drive. See if that helps. If it does, then you have to determine what is really going on. It could be a sticking engagement cable or it could be a problem with the vacuum switch on the transfer case.

 

Maybe shoulda eased into the power since you were doing it for the first time..

 

haha yeah, whoops ive used 4 high before and no problems so, figured 4 low was fine too.

swartlkk :

Thanks for the info, I went out to take a look at it. Had the hood popped and e-brake on, put it in low side and gave it some gas.... turns out I must have busted the drivers side motor mount... the noise is the plastic fan hitting the plastic shroud.

odd that the motor doesnt lift enough in 4 or 2 high to make it rub

 

Well, that would do it.

The reason is that the engine has more mechanical advantage in 4LO due to the gearing. With greater mechanical advantage, the engine will move more when power is requested.

 

yeah it was almost comical watching it through the space between the hood and cowl.
It looked like my engine was going to do a somersault right out of the bay.

ehhh great, now i get to have all the fun of changing the mounts

 

And oh what fun you will have!

 

Just do a 350 swap

 

Maybe sometime in the future. I put a 4 bolt 350 stroked to a 383 in a 91 sonoma a few years ago. That truck was dangerous. I could just imagine that in 4 low BUAHAHAHA !!!