chevrev

iTrader: (2)

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?

Magic Man

Just push it up and bolt it down.It is ok.

CarsandWomen

iTrader: (19)

totally normal, bolt em up and let us know how she runs. PS I cant say for other than chevys but theyve been like that on every motor/trans combo since the 50's, cars and trucks

chevyz2801

iTrader: (20)

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.

12secSS

iTrader: (30)

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.

cals400ex

iTrader: (27)

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.

chevrev

iTrader: (2)

I calculate .20 inch space...that ought to be close enough to bolt right up to?

01ssreda4

iTrader: (96)

exactly. i believe about 1/4 is what you are looking for so you sound just right to me.

chevyz2801

iTrader: (20)

.187 is the max you want and if you got .20 just put a washer between the converter and flexplate.

cals400ex

iTrader: (27)

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.

Circle-D

iTrader: (21)

SAE washers are usually a perfect shim. About .060 in thickness and all equal.

Chris

PBA

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.

Chrome355z

iTrader: (1)

Yep, I was around .18-.20ish; added a 0.060 washer (standard SAE washer). I grabbed a bunch and mic'd them to get three that were very close together.

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!

chevyz2801

iTrader: (20)

I had to use the stock bolts and grind them to.

01ssreda4

iTrader: (96)

hmmm, good info. is there an actual accepted spec or is this from experience. i would like to check mine next time its out and going back in.

calongo_SS

iTrader: (7)

If you've got over 1/8" shim it is pretty standard. I had to shim my PI up to my 80E.

pmbmax

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.

Char Kirk

If this is true then why does mine pour fluid out the front seal when running even with a new seal I did a transmission swap the only difference between the two transmissions is the number on the rear of the casing my old one is a 10 and -1 is a 16 not sure if that means anything if anyone can please shed some light on this would be greatly appreciated

ironmikektm525

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

mrvedit

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.