Why converter clearance is important…..
04-18-2024, 12:22 PM
#22
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One of the most common questions we get is about converter spacing/clearance, not well understood and can be confusing. I wanted to try and explain why we want 1/8” spacing and hope that will help you guys understand it better when you are installing a converter.
When installing any converter, measuring and setting the proper converter clearance is critical for proper operation of the converter and transmission. It can get a little confusing and reading on the internet all you see is you want an 1/8” clearance. What does this mean and why does it matter? The goal is to have 1/8” space between the converter hub and the transmission stator support once you pull the converter forward and bolt it up. You do not want to bottom the converter out or even worse, have negative clearance forcing it into the stator support or pump gears on start up, that will damage your converter and transmission. The converter does move in and out of the transmission, which is why the 1/8” is there to ensure the converter can move some and not bottom out in the transmission. But you do not want to have too much spacing where the converter might pull out of the pump gears and cause a major failure. I am sure you have read a thread about a 4L60 pump rotor breaking costing lots of money. Probably happened because spacing was over the 1/8” and the converter pulled out of the rotor. This is why you might need shims if the spacing is over an 1/8”, to move the converter a little closer to the trans for proper pump gear engagement. Another interesting factoid - That is why the flexplate is called a flexplate, it will flex absorbing the thrust from the converter moving in and out of the transmission.
Chris
When installing any converter, measuring and setting the proper converter clearance is critical for proper operation of the converter and transmission. It can get a little confusing and reading on the internet all you see is you want an 1/8” clearance. What does this mean and why does it matter? The goal is to have 1/8” space between the converter hub and the transmission stator support once you pull the converter forward and bolt it up. You do not want to bottom the converter out or even worse, have negative clearance forcing it into the stator support or pump gears on start up, that will damage your converter and transmission. The converter does move in and out of the transmission, which is why the 1/8” is there to ensure the converter can move some and not bottom out in the transmission. But you do not want to have too much spacing where the converter might pull out of the pump gears and cause a major failure. I am sure you have read a thread about a 4L60 pump rotor breaking costing lots of money. Probably happened because spacing was over the 1/8” and the converter pulled out of the rotor. This is why you might need shims if the spacing is over an 1/8”, to move the converter a little closer to the trans for proper pump gear engagement. Another interesting factoid - That is why the flexplate is called a flexplate, it will flex absorbing the thrust from the converter moving in and out of the transmission.
Chris
This is on a 02 trailblazer I was wondering if This look like too big of a gap I’d say it slightly bigger than 3/16
04-18-2024, 03:10 PM
#24
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thread should be STICKY !
04-20-2024, 10:16 AM
#26
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04-20-2024, 11:20 PM
#27
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Add shims until you get a gap between 1/16" and 3/16". As I said before you can use drill bits to measure the clearance. You can use flat washers of equal size as shims. It is not uncommon to need 2 washers stacked together.
Yesterday, 02:16 PM
#28
I found it best to use a feeler gauge. Before installing the torque converter. Make sure the three pads on the converter are flat (no high spots). If there are, take a file to the high spots. Make sure to do the same on the flex plate. New flex plates should be checked to make sure there are no flaws in the surface area where the converter pads make contact. Used flex plates will almost always have areas around the hole that need to be addressed. When adding shims, (all three corners) must have the same thickness of shim or shims in total. Use calipers or a micrometer to accomplish this. There should not be anymore than a .001" variation at any corner. If there is more than that. You could wear the pump bushing more than necessary, and could cause a front seal leak.
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