Forced Induction Superchargers | Turbochargers | Intercoolers

5.3 on TH350. Starter jamming on flexplate

Thread Tools
 
Search this Thread
 
Old Aug 31, 2017 | 10:23 PM
  #1  
moe4541's Avatar
Thread Starter
Staging Lane
 
Joined: Apr 2017
Posts: 84
Likes: 1
From: Dallas Tx
Default 5.3 on TH350. Starter jamming on flexplate

Having issues with turning the engine over. The starter is jamming in the flywheel and is staying engaged. I originally had a mini performance starter and I changed it to a remanufacture starter. Same issue with both starters. I think its the bolst on the flywheel bringing the flywheel closer to the starter and causing it to jam. The flywheel looks too close to the starter and the converter looks too far from the tranny.

I've attached a video link. Not much to see/hear already knowing the starter teeth is getting stuck.

required spacer is on. Not sure what lengths are on. I think they are stock bolt lengths.



























Reply
Old Sep 3, 2017 | 10:36 AM
  #2  
Lsxford's Avatar
TECH Enthusiast
5 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (7)
 
Joined: Nov 2016
Posts: 663
Likes: 74
From: Winfield AL
Default

Really hard to tell, but my guess is the spacer is on the wrong side of the flywheel. Iirc on a dished flexplate like you have the flexplate goes on the crank like stock, then the spacer goes between the flexplate and torque converter.
if not did you get the converter seated to the trans all the way? I believe its 3 clunks, that could make it screwy too

Ive always found its just easier to get a 6.0 4l80e flexplate with the spacer made on. Just my .02
Reply
Old Sep 3, 2017 | 04:10 PM
  #3  
brandon6.0's Avatar
TECH Addict
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (32)
 
Joined: Dec 2009
Posts: 2,331
Likes: 29
From: Glennville, GA.
Default

this is the way it needs to be. Flexplate bolted on with dish toward trans. Thin spacer to catch the torque converter hub. I wanna say looking at the pics u have it the correct way.

Your issue looks to be the starter. I don't think that is the correct starter for a ls engine. That looks like an older small block starter. the ls starter bolt pattern is straight across from each other. Not diagonal like most older small block starters. Check the starter first.
Reply
Old Sep 3, 2017 | 08:19 PM
  #4  
kingtal0n's Avatar
Banned
iTrader: (1)
 
Joined: Nov 2011
Posts: 2,261
Likes: 19
From: florida
Default

I know this doesn't help but I have a friend with the same issue. 5.3L with a th350 and th400 both have the starter hanging up on the flywheel during cranking.

I will report back if he ever finds out why. He thinks it is a shimming issue although several attempts to re-shim have not helped.
Reply
Old Sep 3, 2017 | 09:27 PM
  #5  
Game ova's Avatar
TECH Junkie
 
Joined: Jul 2015
Posts: 3,012
Likes: 48
Default

Good thing it didn't start, would have been instant death for the transmission pump. And that starter doesn't look like an ls starter. But to keep it from hanging up, shim the starter away from the flywheel. Most any parts store will have starter shims. Really shouldn't need to do that with ls stuff though.
Reply
Old Sep 4, 2017 | 07:36 AM
  #6  
mightyquickz28's Avatar
TECH Addict
20 Year Member
iTrader: (8)
 
Joined: Feb 2003
Posts: 2,145
Likes: 133
From: East Chatham, New York
Default

I have a 5.3 and the TH350. No problems here, using a Hughes Flexplate(Part# HP4004X) and the Hughes spacer when using a Vigilante 9.5" Torque converter, nor, when I switched to the current PTC TC which doesn't need the spacer(has a built in extended hub). On both setups, I had an original starter from either a stock Fbody Ls1 or a truck 5.3/4.8. That starter went bad a few months ago and I bought another from the local Advance Auto. For some reason, where the starter that I'd been using had 'staggered' (ie: two different length) bolts, this starter I purchased had symmetrical bolt lengths. And, when I cranked it, I squalled and stayed engaged for a second after it started. The sound was like a whistle. I knew what that was from old cars I used to own and just tried a few shims till it got the proper clearance. All is well now.
Reply
Old Sep 4, 2017 | 08:46 AM
  #7  
Lsxford's Avatar
TECH Enthusiast
5 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (7)
 
Joined: Nov 2016
Posts: 663
Likes: 74
From: Winfield AL
Default

Originally Posted by brandon6.0
this is the way it needs to be. Flexplate bolted on with dish toward trans. Thin spacer to catch the torque converter hub. I wanna say looking at the pics u have it the correct way.

Your issue looks to be the starter. I don't think that is the correct starter for a ls engine. That looks like an older small block starter. the ls starter bolt pattern is straight across from each other. Not diagonal like most older small block starters. Check the starter first.
Looking at it again brandon is right. My starter isnt staggered like that and the ls starters online arent either. I bet its engaging crooked and hanging it up
Reply
Old Sep 4, 2017 | 04:23 PM
  #8  
moe4541's Avatar
Thread Starter
Staging Lane
 
Joined: Apr 2017
Posts: 84
Likes: 1
From: Dallas Tx
Default

Originally Posted by brandon6.0
this is the way it needs to be. Flexplate bolted on with dish toward trans. Thin spacer to catch the torque converter hub. I wanna say looking at the pics u have it the correct way.

Your issue looks to be the starter. I don't think that is the correct starter for a ls engine. That looks like an older small block starter. the ls starter bolt pattern is straight across from each other. Not diagonal like most older small block starters. Check the starter first.




I told the guy OEM starter I'll look it up....




When you say dish towards the started, you mean the flexplate is on how it should be originally? To be clear the flexplate dishes in towards the engine, its curving in not out. I never took the flexplate off when I got the engine.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Sep 4, 2017 | 04:25 PM
  #9  
moe4541's Avatar
Thread Starter
Staging Lane
 
Joined: Apr 2017
Posts: 84
Likes: 1
From: Dallas Tx
Default

Originally Posted by kingtal0n
I know this doesn't help but I have a friend with the same issue. 5.3L with a th350 and th400 both have the starter hanging up on the flywheel during cranking.

I will report back if he ever finds out why. He thinks it is a shimming issue although several attempts to re-shim have not helped.


See if you can get pictures of his starter bolts lined up.


I've tried two starters, both had the same lineup.
Reply
Old Sep 4, 2017 | 04:28 PM
  #10  
moe4541's Avatar
Thread Starter
Staging Lane
 
Joined: Apr 2017
Posts: 84
Likes: 1
From: Dallas Tx
Default

Originally Posted by Game ova
Good thing it didn't start, would have been instant death for the transmission pump. And that starter doesn't look like an ls starter. But to keep it from hanging up, shim the starter away from the flywheel. Most any parts store will have starter shims. Really shouldn't need to do that with ls stuff though.



I hope the pump isn't damaged. The engine was turning over but never started. I'll be unbolting the converter from the flexplate tonight to make sure its locked into the trans. I don't remember it coming out when I started bolting the converter to the flexplate. It looks like a lot of space in between there (converter and trans).
Reply
Old Sep 4, 2017 | 04:35 PM
  #11  
Game ova's Avatar
TECH Junkie
 
Joined: Jul 2015
Posts: 3,012
Likes: 48
Default

Originally Posted by moe4541
I hope the pump isn't damaged. The engine was turning over but never started. I'll be unbolting the converter from the flexplate tonight to make sure its locked into the trans. I don't remember it coming out when I started bolting the converter to the flexplate. It looks like a lot of space in between there (converter and trans).
Good call. Just looking at the pic showing the distance between the converter and pump, there's no way the converter is locked into the pumps gear tangs.
Reply
Old Sep 4, 2017 | 04:43 PM
  #12  
moe4541's Avatar
Thread Starter
Staging Lane
 
Joined: Apr 2017
Posts: 84
Likes: 1
From: Dallas Tx
Default




I looked up several ls starters they all look the same when it comes to the same size bolts.
Reply
Old Sep 4, 2017 | 04:44 PM
  #13  
moe4541's Avatar
Thread Starter
Staging Lane
 
Joined: Apr 2017
Posts: 84
Likes: 1
From: Dallas Tx
Default

Originally Posted by Game ova
Good call. Just looking at the pic showing the distance between the converter and pump, there's no way the converter is locked into the pumps gear tangs.


If its not locked in, I'll probably have to spend that extra cash to have a trans shop open it up to look. I don't mess with transmissions at all!
Reply
Old Sep 4, 2017 | 05:25 PM
  #14  
brandon6.0's Avatar
TECH Addict
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (32)
 
Joined: Dec 2009
Posts: 2,331
Likes: 29
From: Glennville, GA.
Default

when I say dish I mean the flexplate should curve out toward the transmission side. I wanna say the flexplate will not bolt up to engine the other way around. IF u left the flexplate on the engine the way it was factory it is installed be the correct way. THIN the spacer goes on after the flexplate to engage the converter hub.

If u would have used a 4l80e flat flexplate u would install it with the spacer first thin the flexplate. They are installed completely different from each other.

Did u hog out the original converter holes in the flexplate for the converter to bolt up? are u certain that that converter is the correct one for that trans? converter should install close enough to the front pump that u cant fit your fingers behind it. Or should u barely be able to see the hub or front pump seal. Looking at the pics u have a lot of room between there. What brand converter?

But as far as your starter problems just go to the junk yard and grab a used starter and install it and be done. The aftermarket parts store starters are junk these days. The original used ls starters are really tough and rarely go out.
Reply
Old Sep 4, 2017 | 05:33 PM
  #15  
Game ova's Avatar
TECH Junkie
 
Joined: Jul 2015
Posts: 3,012
Likes: 48
Default

Originally Posted by moe4541
If its not locked in, I'll probably have to spend that extra cash to have a trans shop open it up to look. I don't mess with transmissions at all!
The pump is easily serviced/changed by even a complete novice, should you even need to. Even if you TRIED to screw up changing the pump....i don't think you would succeed.
Reply
Old Sep 5, 2017 | 09:57 AM
  #16  
moe4541's Avatar
Thread Starter
Staging Lane
 
Joined: Apr 2017
Posts: 84
Likes: 1
From: Dallas Tx
Default

Update.....I removed the converter from the flexplate. There's a good amount of space in between the two once the bolts were taken off. I was able to push the converter into the trans, one click so I guess it was pulled out when it was bolted to the flexplate.

I'm not sure if there's damage to the pump with just turning the engine over while it was a click out.

I tried turning the engine while the converter wasn't connected......the starter still jammed up.










Reply
Old Sep 5, 2017 | 03:29 PM
  #17  
brandon6.0's Avatar
TECH Addict
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (32)
 
Joined: Dec 2009
Posts: 2,331
Likes: 29
From: Glennville, GA.
Default

ok yea that is not the correct starter. Change it before u break the mounting flange on the block or trans.

take and add some washers between the flexplate and converter. A lot of aftermarket converters need shimming to be installed correctly. I wanna say u need 1/4" gap. IF its anything more than that add washers to get the correct gap. I usually use a drill bit to measure with.
Reply
Old Sep 5, 2017 | 07:58 PM
  #18  
moe4541's Avatar
Thread Starter
Staging Lane
 
Joined: Apr 2017
Posts: 84
Likes: 1
From: Dallas Tx
Default

Originally Posted by brandon6.0
ok yea that is not the correct starter. Change it before u break the mounting flange on the block or trans.

take and add some washers between the flexplate and converter. A lot of aftermarket converters need shimming to be installed correctly. I wanna say u need 1/4" gap. IF its anything more than that add washers to get the correct gap. I usually use a drill bit to measure with.
Ok thanks! I'll go to a salvage yard in the morning for a starter.
Reply
Old Sep 5, 2017 | 08:02 PM
  #19  
moe4541's Avatar
Thread Starter
Staging Lane
 
Joined: Apr 2017
Posts: 84
Likes: 1
From: Dallas Tx
Default

Here's my build. First time working with a LS and turbos. This site encouraged me to try it! Hopefully I'll have it running in the next day or so.



83 Shortbed dropped 5/7



2002 5.3, LS1 instake, lots of upgraded parts, twin 68/70s

Reply
Old Sep 7, 2017 | 09:57 AM
  #20  
moe4541's Avatar
Thread Starter
Staging Lane
 
Joined: Apr 2017
Posts: 84
Likes: 1
From: Dallas Tx
Default

Ok after three starters and shimming all of them, the start still jams. Even the OEM. Only thing I can think of is the flexplate is bad. I did have one guy tell at local shop say the flexplate was backwards. I don't see how that's possible, the dish is going towards the engine, going in. Unless I'm wrong. I never removed the flexplate from engine when I got it.

The teeth on the flexplate are good.

Last edited by moe4541; Sep 7, 2017 at 01:25 PM.
Reply



All times are GMT -5. The time now is 05:11 PM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE