Space between torque converter and flywheel before bolts installed??
Space between torque converter and flywheel before bolts installed?? I am installing an LS1 and 4L60e into my 56 Chevy. I installed the 4l60e first and then mated the LS1 to it, got under the car to bolt the torque converter to the flywheel and noticed that there is a space between the torque converter and flywheel (looks to be between an 1/8 and a 1/4 of an inch). When I put a bolt in and tighten it up, the TC slides easily toward the flywheel until it makes contact.
Is this normal? Should I use spacers between the TC and the flywheel?
Is this normal? Should I use spacers between the TC and the flywheel?
I had to put washers in when i put my pro yank in with the stock flexplate. If you want more info look under the stickies under converter install.
Last edited by chevyz2801; Jan 22, 2009 at 10:02 AM.
As others said, it is absolutely normal. What happens when you install the converter, you seat the converter against the pump tabs. If left like this, when the flexplate flexes as designed, it will push the converter into the trans. If there is no cushion for movement, it will destroy the pump tabs and you will loose fluid pumping through the trans, effectively killing your trans. So yes, it is normal. 
like vince has recommended before, i found it best to push the converter all the way in the trans. then take a drill bit and see which size fits between the converter pads and the flexplate. this will tell you how much gap you have there. it should be in the .060" - .187" range according to the tranny builders. i did end up shimming mine as well.
Trending Topics
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
As others said, it is absolutely normal. What happens when you install the converter, you seat the converter against the pump tabs. If left like this, when the flexplate flexes as designed, it will push the converter into the trans. If there is no cushion for movement, it will destroy the pump tabs and you will loose fluid pumping through the trans, effectively killing your trans. So yes, it is normal.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo i was just a hair over the max and i decided to shim it. you just need to find a good quality washer that fits the size bolts you are using and put it between the flexplate and the converter tabs. i would shim it personally.
TECH Resident
Joined: May 2006
Posts: 969
Likes: 119
I have found that in the last 31 years that the ideal clearance should be .080" - .125". I have found that .187" is way to much when you finally get the transmission torn down and look at the wear pattern on the inner rotor to torque converter hub area. With .250" clearance, you stand a very good chance of breaking the rotor or gear, depending on which transmission is being installed.
Also, with the Yank converter the supplied bolts were too short (due to having to shim; I could have ordered ARP bolts but I just shortened the factory ones on a grinder.
Too much gap can cause problems as well!
8 Second Club
Joined: May 2004
Posts: 371
Likes: 0
From: Savannah, TN
are all you guys adding the crank endplay in with this If not you should . If you are going to split hairs . the reson for the clearence is to keep the convertor from bottoming out in the pump if you make big power you better put more than .020 cranks do move around alot more than you think. just from a year of convertor and tranny problems . Never had problems untile 1300hp mark was passed.
Registered User
Joined: Dec 2015
Posts: 1
Likes: 0
Mine leaks As others said, it is absolutely normal. What happens when you install the converter, you seat the converter against the pump tabs. If left like this, when the flexplate flexes as designed, it will push the converter into the trans. If there is no cushion for movement, it will destroy the pump tabs and you will loose fluid pumping through the trans, effectively killing your trans. So yes, it is normal.
TECH Enthusiast
Joined: Nov 2013
Posts: 629
Likes: 1
From: upstate ny
Good thread as i will be soon putting in my new trans/yank. So when the converters pushed all the way on the trans the measurment between the converter tabs and the flex plate should be between .080-.125? Should i rotate flexplate to check each mounting measurement? Arp bolts or factory bolts fine? Should i use loctite thx in advance
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
I don't understand that Char_Kirk is asking, but all the 2009 posts are correct and accurate.
Ironmike: Yes, there should be a minimum of 1/16" and max of 3/16" clearance between the converter tabs and flexplate. Use drill bits to confirm. Sure spin the converter to check all the tabs. If the gap is more than 3/16" reduce it with thickness-matched spacers, ideally spacers for this purpose. (I have used hardware store grade 8 washers which I match with calipers.)
Since the bolts are about 5" from the centerline, there really isn't that much shear force on them (a small fraction of those on the crankshaft bolts). So stock or even hardware store grade 9.8 is plenty good. Just make sure they are not too long (or short); you don't want them to bottom out in the converter before they are fully torqued.
Most people recommend Blue (medium) Loctite. I use Red, but even my battery impact tools easily take those bolts back out. Either a flexplate locking tool or a helper with a 24mm socket and breaker-bar on the crank will be needed to torque the bolts to about 55 ft/lbs.
Note: I highly recommend checking the converter/flexplate clearance before tightening the bell housing bolts more than finger tight. If you find the clearance is ZERO, that indicates the converter was not full installed. If you torque the bell housing bolts in that situation, you will likely damage the pump rotor in the trans.
Ironmike: Yes, there should be a minimum of 1/16" and max of 3/16" clearance between the converter tabs and flexplate. Use drill bits to confirm. Sure spin the converter to check all the tabs. If the gap is more than 3/16" reduce it with thickness-matched spacers, ideally spacers for this purpose. (I have used hardware store grade 8 washers which I match with calipers.)
Since the bolts are about 5" from the centerline, there really isn't that much shear force on them (a small fraction of those on the crankshaft bolts). So stock or even hardware store grade 9.8 is plenty good. Just make sure they are not too long (or short); you don't want them to bottom out in the converter before they are fully torqued.
Most people recommend Blue (medium) Loctite. I use Red, but even my battery impact tools easily take those bolts back out. Either a flexplate locking tool or a helper with a 24mm socket and breaker-bar on the crank will be needed to torque the bolts to about 55 ft/lbs.
Note: I highly recommend checking the converter/flexplate clearance before tightening the bell housing bolts more than finger tight. If you find the clearance is ZERO, that indicates the converter was not full installed. If you torque the bell housing bolts in that situation, you will likely damage the pump rotor in the trans.
Last edited by mrvedit; Dec 8, 2015 at 05:07 PM. Reason: Typos