thanks for the tips,
i had the u-joints replaced last week with a new pair of napa offroad. i didnt get fincanced to the new vehicle so looks like im stuck with the blazer. They only wanted to give me 3100 for it, thats dealers for you. To clairifly what the sound is exactly, from park **** to drive "no clunk" accelrate medium to light throttle clunk shifting from 1 to 2nd. or anytime the drivetrain slacks and connects. somtimes very hard vibration at highway speeds. i know for a fact alot of it is from the tires but i also hear a noise that sounds like wind but i have sealed all the windows well. so could this poss be the rear end?

 

looks like we have another case of a sagging door...

 

gotta thank you guys for all the help, when i get a few more dollars in my pocket im gonna take it to my mechanic. until then im gonna be driving the 91 s-10 beater.. and yea i have a sagging door too.

 

so got it to my mechanic, he told me that there is alot of play in the transfercase and also play in the rear end. basicly he said my entire drivetrain is in need of a major overhaul. [:@] the clunk i was hearing was in the transfer case, and the vibration in the rearend. so what now? i was thinking about a total motor swap going to the v8 would be nice since i tow stuff, but i dont know wich way to go? can you guys tell me what is the cheapest and best way to go about this. thanks, J. also remeber the truck has 106k and is a 2000 ls blazer 4x4 and to be honest i dont know how strong the motor is. i purchased it new and i think it was rode hard and put away wet.

 

U-joints.

Play in the t-case would be the chain. Replace it. Rare for these t-cases to have issues, they are pretty stout units, especially for our trucks.

If you go V8 get the book by JTR (web search). It covers everything you need to know about the swap.

As for the stock 4.3L V6. Strong as an ox. It is the standard engine on some fullsize trucks. I once did brakes on a fullsize 1/2 ton with the 4.3L V6, the guy used the truck to haul all his masonry equipment (scafolding), and a trailer full of bricks to the job sites. He never had a problem with the engine. Typically they last to about 180,000-200,000 miles before something lets go. Altough I have personally owned a 4.3L with 286,000 miles on it, strong as the day I bought it with 60,000 miles on it.

Your '00 shoudl be pushing in the neighborhood of 200hp/250ft pounds of torque. Torquey little engines. Compare it to all other V6 engines and you will see what I mean. Compare it to the V8 as well.

Couple of other things. The tranny you have behind your engine is the same one behind the fullsize truck/suv/vans. Couple of minor internal differences. Plus it will bolt up to a small block chevy V8 engine. Makes doing that V8 swap easier.

 

hmm, any ideas on if thats a easy fix or not? what about the rear end? i would like to be able to drive it if i could put it together cheap.
i just had ujoints put in a couple weeks ago. thanks for the info, ill do a search for chain replacement. and rear end swap or repair.

 

Before I replaced anything I would get the tires road force balanced. The most common cuase of vibrations is tires.

After that it could be a number of things, mostly revolving around the suspension/ steering components. Worn out shocks can cause a vibration and eat your tires.

real hard to tell you what it is without seeing the truck in person.

there are several visual inspections that can be done to find the problem. Plus a host of push pull tests wiht the truck in the air to find problems.

At this point, all we have to go on is what the mechanic said. Is he right? I have no way of knowing at this point.

Post up some more description of the issues.
For example a vibration in the seat is typically an issue int eh rear end, tires is hte first place to start.

 

ok ill swap out the tires as soon as i get the chance. i know it helped when i had my other set on but there still was a vibration in the seat and a constant howling sound but i dont think its wind. there is alot of vibration when i come to a stop but thats from the front rotors being warped right? when i bought it we had to get the gasket between the trans and transfercase and the dealer paid for it. Is that somthing that even exists? they said the fluid was leaking into the transfercase and it caused the fluid in the trans to get low enough that it would slip a little in 2nd gear. As far as the shifting noise goes it just flat out clanks when shifting into 2nd but only like a u-joint would. had them replaced and still clanks. there is some seapage at the rear end at the yoke. but looks very minor. i have been thinking for a long time that the rear end needed work, but kinda scared of opening it up and having to spend a ton in repairs. kinda driving till she breaks.