So i've been searching everywhere for some help on this and cant find a thing!
about the beginning of last december (2013) the front differential went out (i did check everything i could to make sure that that was the actual problem) so i got a front differential from a salvage yard, pulled out the old one (which was a pain in the a**!) and began installing the one i just got (an even bigger pain) i got it installed (bolts all tight, wiring checked and plugged in right, vacuum line checked and installed, drive axles put in and bolted back into the hubs, and the front drive shaft installed) and then i took it out for a test run, when i did so and engaged the 4HI the front end started yanking the steering around about every 10-15 feet or so, or it might have been that the tires were pulling wrong or rotating wrong somehow at least thats kind of how it felt from inside the vehicle. so i pulled that one out took it back thinking that they sold me a bad front diff and got another with even less miles on it, now that i have that installed its doing the same exact thing!! if someone could please help me out and tell me what exactly im doing wrong i would be extremely grateful as i am about 30 second from filling the truck with tannerite and taking it out to and empty field and shooting it till it explodes!

thanks TX

 

Simple. You failed to match the gearing found in your truck. You need to verify the gear ratio in the rear axle and ensure that the front axle you purchase next has the exact same ratio.

 

I did give them the option codes for the front diff so it would be properly matched and supposedly they gave me the one to match my truck.

 

Codes can only go so far. If you have gotten the wrong gearing twice, then it may not be the right codes and you should pull the rear axle cover and check the numbers on the ring gear.

 

ill check that out and get back to you!
Thanks!

(would it by chance have any marks i could identify the gearing from the old one i still have?)

 

You could try pulling it apart and reading the numbers from the ring gear of the front axle, but it is more difficult than popping the cover on the rear axle.

If you have never opened up the rear axle, it likely could use a good service. I wrote a tech article a LONG time ago that runs through that process.

 

Well I checked the gearing and they did give me the right diff, I don't get it!!! Grrr

 

I talked to someone today that says it's probably the transfer case,

 

I know my dad had a similar problem in his dodge the chain in the transfer case was jumping because it was so worn out. I haven't had a blazer one apart but I'm guessing they use a chain too any maybe its jumping

 

Can I ask how long it took to get the front diff out. I'm thinking of swapping gears in my 97 blazer from 3:42s to possibly 3:73 or 4:10s I'm putting 31" tires on it next month and do I some mild towing just a thought