flexplate spacer confusion
08-20-2009, 12:02 AM
#1
flexplate spacer confusion ok, I understand that there is a .4 gap from the lsx crank when using a th350 trans and bellhousing, so a spacer is needed
I understand that on a flat flexplate(6.0 flexplate) there is a spacer that goes between the crank and the flexplate, to make up for this .4" gap
what I dont understand is why would the same spacer need to go AFTER the flexplate on a dished flexplate. what is the purpose of it if the flexplate bolts to the crankshaft like normal?
also, the 5.3s in junkyards-
a. do they come with a dished flexplate or a flat one
b. do I need a spacer?
c. does the spacer go between the crank and flexplate or AFTER the crank and flexplate?
I understand that on a flat flexplate(6.0 flexplate) there is a spacer that goes between the crank and the flexplate, to make up for this .4" gap
what I dont understand is why would the same spacer need to go AFTER the flexplate on a dished flexplate. what is the purpose of it if the flexplate bolts to the crankshaft like normal?
also, the 5.3s in junkyards-
a. do they come with a dished flexplate or a flat one
b. do I need a spacer?
c. does the spacer go between the crank and flexplate or AFTER the crank and flexplate?
08-20-2009, 04:21 AM
#2
The input shaft on all older trannies is .400 shorter than an LS1 input shaft. That's the reason for the spacer. Some of the early 6.0's had a different crank in them. I can't remember if it comes out farther at the rear or if it's shorter. These are probably the flat flexplate engines. If you get an engine with a dished flexplate bolted straight to the crank, you will still need a spacer on the outside of it so the tranny input will reach. I used the spacer made by Hughes Performance. It just pushes into the end of the crank. No bolts required. As far as the 5.3's, I can't help you there.
08-20-2009, 08:45 AM
#3
TECH Fanatic
ok, I understand that there is a .4 gap from the lsx crank when using a th350 trans and bellhousing, so a spacer is needed
I understand that on a flat flexplate(6.0 flexplate) there is a spacer that goes between the crank and the flexplate, to make up for this .4" gap
what I dont understand is why would the same spacer need to go AFTER the flexplate on a dished flexplate. what is the purpose of it if the flexplate bolts to the crankshaft like normal?
also, the 5.3s in junkyards-
a. do they come with a dished flexplate or a flat one
b. do I need a spacer?
c. does the spacer go between the crank and flexplate or AFTER the crank and flexplate?
I understand that on a flat flexplate(6.0 flexplate) there is a spacer that goes between the crank and the flexplate, to make up for this .4" gap
what I dont understand is why would the same spacer need to go AFTER the flexplate on a dished flexplate. what is the purpose of it if the flexplate bolts to the crankshaft like normal?
also, the 5.3s in junkyards-
a. do they come with a dished flexplate or a flat one
b. do I need a spacer?
c. does the spacer go between the crank and flexplate or AFTER the crank and flexplate?
The 5.3ls should all have a dished flex plate. If your using a ealier trans. 700r, th350.th400 or the 4l80 you need the spacer after the flexplate to support the tq converter nose.
The flat flex plate is used on the 6.0l with the 4l60. The early 6.0l and 4.8l 99-2000 had a longer crank flange thats was the same as the SBC position.
More info https://ls1tech.com/forums/automatic...0r4-4l60e.html
Last edited by Bo185; 08-20-2009 at 10:37 AM.
08-20-2009, 11:01 AM
#4
Pardon the slight highjack, but thought I'd ask while the flexplate experts are here.
On a '01 LS1, will a flat flex plate without spacer bolt to the crank an still clear that rear block cover plate bolt? I realize the starter would be an issue, but at the moment I'd just like to know if it'll clear that one bolt head and everything else on the block.
Thanks,
Andy1
On a '01 LS1, will a flat flex plate without spacer bolt to the crank an still clear that rear block cover plate bolt? I realize the starter would be an issue, but at the moment I'd just like to know if it'll clear that one bolt head and everything else on the block.
Thanks,
Andy1
08-20-2009, 07:36 PM
#6
thanks guys.
I did not realize that there was a snout on the converter that had to fit to the crank
DUH
I went back and looked at my current converter and of course its there. so now I understand why both types of flexplates require a spacer.
I did not realize that there was a snout on the converter that had to fit to the crank
DUH
I went back and looked at my current converter and of course its there. so now I understand why both types of flexplates require a spacer.
08-22-2009, 07:25 AM
#7
to kind of answer Andy1's question, i have my chevelle on my lift now, so i measured the flexplate to the block best i could
distance from the back of the ring to the oil pan was .380, so rem the .400 spacer would put the flexplate dead against the oilpan-also if looked like there would only be about .020 clear to the back of the block, could not tell
if it would hit any bolts, but prob would-either way, its gonna hit something,
and as stated, the starter wouldnt work
distance from the back of the ring to the oil pan was .380, so rem the .400 spacer would put the flexplate dead against the oilpan-also if looked like there would only be about .020 clear to the back of the block, could not tell
if it would hit any bolts, but prob would-either way, its gonna hit something,
and as stated, the starter wouldnt work
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08-22-2009, 08:12 PM
#8
TECH Fanatic
The LQ9 6.0l's and some LQ4 used with the 4l60/65/70 used the regular dish flexplate. Which were used in the vortec max half tons and H2's.
