GreazyDaMonsta

this my first swap and im almost done but i want to know what is the purpose of the crankshaft spacer

darren roar

iTrader: (1)

If its used on a 6.0 it goes spacer then flywheel. On a 4.8/5.3 it is the opposite flywheel then spacer. Its used to support the converter nose and keep everything running true. The flywheels are also different a 4.8/5.3 is dished a 6.0 is flat.

Adam253

To add what roar said. The 4.8/5.3 TCI flywheel is also flat so it will go spacer then flywheel.

gofastwclass

iTrader: (2)

You don't always need the spacer. The spacer is application specific and may not be needed depending on the year of transmission, what transmission you have and which crankshaft your engine has.

Bilster

iTrader: (21)

This is good information. Thanks for starting this thread. It's confusing reading the postings when you do a search.

donnie_19

You need the spacer if you are using a 350 turbo trans or in my case a 2004R. It supports the nose of the torque converter.

LS1MCSS

iTrader: (18)

You wouldn't need it if the engine was an early 6.0 with the longer crank.

agentruley

Also, to add, I needed a spacer with a 4.8 mated to a nv3500 BUT, I found one of the rare 4.8 specific flywheels that had the spacer 'built' in.
Also, if using the spacer, good luck finger longer flywheel bolts (For a manuel transmission application)

GreazyDaMonsta

so what you're saying is since i'm using a 4.8/5.3 on a 200r4 and the flywheel is dished i need a spacer? so what will happen if i dont use one?

1981TA

iTrader: (7)

GM sells a complete Flywheel, space and bolt combo for this kind of conversion (LSx to TH350/400). look for that, as it is much cheaper as a kit than getting the parts separately.

darren roar

iTrader: (1)

Its only going to help. With a sbc the crank still supports the converter nose.

S10xGN

iTrader: (11)

Picture a 40# weight full of trans fluid flinging around at 6,000 RPM with the front nose completely unsupported. If you're lucky, the only damage will be to the trans pump. But I would bet the bell and case (and possibly the floorboards and your feet) would suffer as well...

darren roar

iTrader: (1)

Exactly

gofastwclass

iTrader: (2)

You will get really good at pulling the transmissions in your ride.

There are two types of spacer. In your application you can choose to use either. I have used both, but prefer the bolt on type because I have access to a GMPP dealer where I can get them cheaper than most websites, same day and no shipping. You could use the type that slides on after the flexplate and doesn't require bolts if you can wait for (and pay for) it to be shipped.

The GM part is more expensive but more flexible, while the slip on will suit your needs perfectly.

The GM part (requires longer bolts): GM Spacer Longer Bolt (requires six)



One of the slip on versions: Aftermarket spacer

ijimmy

Now thats just funny , and true , you must use the spacer , I just did a ly6 with 200 4r , its the same with turbo 350 or 400 or 700 4R

There several variables , probably the least expensive and easiest way is the dished 4.8 flexplate and the slip on version , transdapt , and speedway have these available

GreazyDaMonsta

so im gonna pull the trans anyway since its in already. thanx for the info guys.

GreazyDaMonsta

trying to put trans in w/o pulling engine. its very tight at the top of the trans i tried to pull the trans down some to get some clearance. i ended up pulling the engine out half way to get top and the 2 second from the bottom bolts out now its time to put it back in im just looking for a easier way

GreazyDaMonsta

hello

darren roar

iTrader: (1)

What kinda vehicle r u working on? R u able to get to the top bolt from under the hood, is firewall clearance that tight?.

GreazyDaMonsta

a 1978 monte carlo. Its super tight back there. So i pulled the eng/trans and put the spacer on after the flywheel and bolted it back together and put it in. Hopefully i dont have to do it again anytime soon.
Now im trying to figure out how to fit a detent cable on the tb?