Changing lower bearings on 4.3 Blazer 4x4

Reply

  #1  
Old 05-14-03, 11:41 AM
Negoshe8n
Visiting Guest
Posts: n/a
Changing lower bearings on 4.3 Blazer 4x4

I have a not so bad but bad enough rod or main knock. I want to change out the bearings before it ruins the rods or mains. No blow-by and the motor has great pick-up. SO Can I just pull the motor and the then the pan and be able to change all the lower bearings. Mains and rod bearings. What is the best way to do the change? All at the same time? Rods first? Upper bearings and then lower part? I have to remove the flywheel also I guess? Pretty straight forward....right? Where should I remove the exhaust at. Manifolds or Y-pipe? Thanks for any help.
 
Sponsored Links
  #2  
Old 05-14-03, 12:30 PM
Joe_F
Visiting Guest
Posts: n/a
If the bottom end is wasted the top end usually isn't far behind.

Best bet is to buy a GM Goodwrench engine and swap over what doesn't come with the new engine. Barring that, ATK or Jasper have decent engines with a warranty.

For the R&R of the engine, you should consult a good service manual such as a GM one or an Alldata.com subscription.
 
  #3  
Old 05-14-03, 01:15 PM
Join Date: Jun 2002
Location: Long Island, NY
Posts: 1,531
If you have a knock replacing just the bearings without measuring the clearances is a waste of time. The shaft has to checked for being round, taper,finish, oil clearances etc. The rods need to measured and checked for being straight.

Not DIY job

Joe's right about entire engine replacement

Larry
 
  #4  
Old 05-14-03, 01:22 PM
redneck
Visiting Guest
Posts: n/a
LOL!, yep once the bearings are gone your crank is not far behind--it maybe able to be saved by machining. Price pulling the motor and rebuilding vs a crate motor--I think the crate is the way to go--and alot less down time--with a warrenty! Ain't no machine shop gonna give you a warrenty!
 
  #5  
Old 05-15-03, 06:49 PM
Negoshe8n
Visiting Guest
Posts: n/a
motor

I have been looking into just picking up a TPI 350. Not going to waste my time. What do you guys think about the 4.3 V8 motors?
 
  #6  
Old 05-15-03, 09:52 PM
knuckles
Visiting Guest
Posts: n/a
You might want to pull the pan and check the oil pump screen.

These engines were well known for plugging the screen with sludge, especially if they've not had regular maintenance.

You can clean or replace (recommended) the oil pump screen and replace both the rod & main bearings for less than $100. IMHO it's time and money well spent.

You have about a 50/50 chance the screen will be clogged & the original bearings will have minimal wear. If the bearings are worn to the copper, you can pretty much assume the crank is worn and you need a new engine (or a crankshaft & bearings at a minimum).

Save yourself some time and pull the #1 main bearing and the #1 rod bearing caps first. These bearings are farthest from the oil pump and most likely to see the worst wear.

A new or reman engine is very expensive and will probably take you a weekend or 2 to install.

Replacing the oil pump, oil pump screen, connecting rod bearings & main bearings will probably take you the better part of a day.
 
  #7  
Old 05-16-03, 05:55 AM
Joe_F
Visiting Guest
Posts: n/a
I'd agree, but I'd hazard a guess you've got wasted valve stem seals on the upper end, so it will be futile doing the bottom and then finding out it's a puffer anyhow .

You'd be money ahead with a new engine. These S/T Blazers keep their value, even in poor shape. I've seen ones with rust and dents going for $3000 bucks or more in the local papers!
 
  #8  
Old 05-17-03, 01:02 AM
msargent's Avatar
Member
Join Date: Jan 2003
Location: Arkansas
Posts: 469
Just for info- I've installed 10-12 Jasper engines in the last year or so. We also purchased what they (Jasper) calls an installation kit.. SOO sweet.. It came with EVERYTHING..Filters, clamps, hoses, belts, plugs, ect.. All the stuff that "nickel and dimes" a person to death..So far, no "come backs" on these engines for any reason..No leaks, no drips, just oil changes.. VERY happy customers..VERY happy mechanic!
 
  #9  
Old 05-17-03, 07:05 AM
Joe_F
Visiting Guest
Posts: n/a
What brand of parts are in this kit?
 
  #10  
Old 05-17-03, 08:16 AM
msargent's Avatar
Member
Join Date: Jan 2003
Location: Arkansas
Posts: 469
The last one I did was an S-10 pick up, the filters were AC-Delco, the plugs AC-Delco, belts and hoses were Gates.. Basically the same parts GM would have recommended for an S-10.. If memory serves correct, the kit was an extra $290 or so.. But we totaled up the kit versus having to buy the stuff part by part, and it came out ahead having it all right there and OE stuff.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes