99 4.3 4x4 won't go into 4wd any

I have a 99 4x4 blazer that won't engage into any of the 4wds. I push the button and the lights just flash for about a min or two then goes back to 2wd. The tranny was rebuilt last year and there is also some grinding noise comming from underneath the truck. It is especially noticable during accleration. It sounds like some gears are grinding possibly in the Tcase. Don't know what to do. Will it cause further damage if 4wd not repaired? And is it worth the time and money to fix with 136,000 mi on it?

Thanks

136,000 miles isn't that many miles. I bought my 96 blazer with 131,000 miles and it's still running strong at 167,000 miles.

If it's making grinding noises that can't be good.

ever changed the Tcase fluid? If not, its worth a try. Its easy and cheap (although can be messy).



136,000 miles isn't that many miles. I bought my 96 blazer with 131,000 miles and it's still running strong at 167,000 miles.

If it's making grinding noises that can't be good.

Once again, I haven't had my Blazer long enough to know from personal experiance but my brother has a 4X4 S-10 truck and his made that same grinding noice with the same problem. His front drive axel was broken which kept it from going into 4 wheel drive. When he tried to engage it all he heard was a noisy grinding sound. He heard the same sound when he turned his wheels to far. As for 136,000 miles the vortec engine is one of the best built. I have seen 2 trucks with the 4.3 with over 230,000 miles each on them and neither of them leak oil or have any kind of power loss. Rob drives his S-10 to ohio every month and up hills and all over these mountians and his truck runs just as smooth as the day he bought it with only 68,000 miles on it. My little brother just sold his GMC truck that used the same 4.3 and his was fast as hell never had any problems on it at all. The only thing he did was change the oil and put gas in it. One thing is for sure though, it all depends on how often the oil is changed. If you had some teen girl own it before you and she went 15,000 miles between changes its going to give out much sooner.

Check the vacuum line and the vacuum switch for the T-case.

Upon one of my many 4x4 issues i encounterd a similar problem, it ended up being a series of failed components, first it was the little three prong vacuum switch on top of the transfer case, which somehow caused the actuator under the battery tray to lock up and keep the front axle engaged, hence the grinding, however without being there with you, it is impossible to tell if this is the same problem. AND now that my 4x4 system is good from the vacuum and front axle, the 4HI light refuses to shut off, even tho the truck isnt in 4x4. Its kinda like a perpetual nitemare, to say the least. One part and one day at a time and my 4x4 will be brand new.