4l60e Reverse Input drum clearance using Blue Plates
4l60e Reverse Input drum clearance using Blue Plates I'm building my first '01 4l60e using the Blueplate Special clutches, and a host of other supporting mods. I'm finally to the point of reassembly, and have measured .030 clearance in the Reverse input drum...but am shooting for at least .050, as this is the recommended clearance for the Sonnax smart tech input drum using the same clutch material. I'm assuming that the clearance should be the same if not more like .060 for the Reverse pack, as it spends most of it's life freewheeling.
Thoughts?
Thoughts?
Last edited by mrvedit; Apr 8, 2015 at 11:52 AM.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
First using Blue frictions for the reverse input drum is probably overkill. Also, there is little correlation between the clearance in the reverse drum with the clearance of the 3/4 clutch. Since you (probably) are not engaging Reverse at high throttle, the clearance is less critical and can be higher.
When Blue frictions are used in the 3/4 clutch my suggested clearance is .005 to .007 per friction (e.g. .050 total). At .007 per friction times the 4 frictions in the reverse drum, I would consider the minimal clearance to be .028. But I would also aim for a bit more.
Also, congrats on doing your own rebuild.
When Blue frictions are used in the 3/4 clutch my suggested clearance is .005 to .007 per friction (e.g. .050 total). At .007 per friction times the 4 frictions in the reverse drum, I would consider the minimal clearance to be .028. But I would also aim for a bit more.
Also, congrats on doing your own rebuild.
My clearance was initially like 0.070-0.075, which is technically within spec. But I swapped out the backing plate with the thicker one and got it down to about 0.050.
If you have a micrometer, you can measure your backing plate size. It's possible you have the thickest of the three sizes. Or you can take it to a shop and they can measure it, with you saying you need to buy a thinner one.
If you have a micrometer, you can measure your backing plate size. It's possible you have the thickest of the three sizes. Or you can take it to a shop and they can measure it, with you saying you need to buy a thinner one.
First using Blue frictions for the reverse input drum is probably overkill. Also, there is little correlation between the clearance in the reverse drum with the clearance of the 3/4 clutch. Since you (probably) are not engaging Reverse at high throttle, the clearance is less critical and can be higher.
When Blue frictions are used in the 3/4 clutch my suggested clearance is .005 to .007 per friction (e.g. .050 total). At .007 per friction times the 4 frictions in the reverse drum, I would consider the minimal clearance to be .028. But I would also aim for a bit more.
Also, congrats on doing your own rebuild.
When Blue frictions are used in the 3/4 clutch my suggested clearance is .005 to .007 per friction (e.g. .050 total). At .007 per friction times the 4 frictions in the reverse drum, I would consider the minimal clearance to be .028. But I would also aim for a bit more.
Also, congrats on doing your own rebuild.
My clearance was initially like 0.070-0.075, which is technically within spec. But I swapped out the backing plate with the thicker one and got it down to about 0.050.
If you have a micrometer, you can measure your backing plate size. It's possible you have the thickest of the three sizes. Or you can take it to a shop and they can measure it, with you saying you need to buy a thinner one.
If you have a micrometer, you can measure your backing plate size. It's possible you have the thickest of the three sizes. Or you can take it to a shop and they can measure it, with you saying you need to buy a thinner one.
Teching In
Joined: May 2010
Posts: 20
Likes: 3
I would keep the reverse input drum on the loose side to prevent clutch drag (that's why they made the turbulator steels). Also, if you are using the Transgo orifice cup plugs on the reverse piston and have tight clearance, you will definitely have drag issues.
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I used two thicker steels in my 3-4 clutch pack and put them in the center of the pack. Works just fine.
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Verdad Gallardo Moderator
Joined: Aug 2010
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From: Ann Arbor, MI
I have been told by several builders not to use the Transgo reverse drum orifice cup plugs, at least not in newer ('96+) 4L60E. Perhaps they were a relic from the 700R4 and very early 4L60E days?
Last edited by mrvedit; Apr 8, 2015 at 10:01 PM. Reason: Make my post clearer.
I'm not sure. When looking for replacements, they list as "93-up"...and this unit is a 2001...appeared to be bone stock on disassembly. So, you're thinking that I should just go with conventional steels? Also, do you think that .040-ish will still be too close for this setup?
TECH Resident
Joined: May 2006
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Use the "waved" steel to replace the Belville steel. This will stop the metal contamination from the Belville eating the drum. Set the clutch clearance to .040" - .070". Always use the Turbulator steels as they get rid of the excess drag. DO NOT install the orfice plugs from TransGo, as they will cause the piston to try to apply at hi-rpm (5,500 & up) from centrifuge which will burn the clutches and gradually you will lose reverse. Leave the aluminum piston alone. The reverse apply feed hole in the separator plate should be .104".
Use the "waved" steel to replace the Belville steel. This will stop the metal contamination from the Belville eating the drum. Set the clutch clearance to .040" - .070". Always use the Turbulator steels as they get rid of the excess drag. DO NOT install the orfice plugs from TransGo, as they will cause the piston to try to apply at hi-rpm (5,500 & up) from centrifuge which will burn the clutches and gradually you will lose reverse. Leave the aluminum piston alone. The reverse apply feed hole in the separator plate should be .104".