Grooved th400 rear drum.
Thread Starter
TECH Junkie
Joined: Jul 2015
Posts: 3,012
Likes: 48
TECH Junkie
Joined: Dec 2012
Posts: 3,615
Likes: 1,327
From: Iowa
I know this is a 2016 thread...and I'm usually a stickler about bumping old threads.
But I think this one is short and sweet enough to add a little info for the next guy googling some info.
The th400 and early 4l80e (pre 95) front planet band surface was roughly 15RC
The smooth 4l80e surface is around 20RC
This probably plays a good role in how long the surface lasts.
PBA is correct that the new material on the band is also much "nicer" to the surface also.
But I think this one is short and sweet enough to add a little info for the next guy googling some info.
The th400 and early 4l80e (pre 95) front planet band surface was roughly 15RC
The smooth 4l80e surface is around 20RC
This probably plays a good role in how long the surface lasts.
PBA is correct that the new material on the band is also much "nicer" to the surface also.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
Yikes, when I saw you posting on a 4 year old thread, I expected Fireworks!
But then you are the (im)poster.
Of course you, as a fantastic, knowledgeable and generous contributor, are always welcome to add to any thread.
Notice to Newbies: One reason we frown on people posting on long-dead threads is that everyone who posted or subscribed to that thread then gets an update notification by email. This is especially true for threads with many posts.
In this case as MaroonMonster pointed out, the thread was very short; plus he is a highly trusted expert contributor. So Newbies, please don't try this at home.
But then you are the (im)poster.
Of course you, as a fantastic, knowledgeable and generous contributor, are always welcome to add to any thread.
Notice to Newbies: One reason we frown on people posting on long-dead threads is that everyone who posted or subscribed to that thread then gets an update notification by email. This is especially true for threads with many posts.
In this case as MaroonMonster pointed out, the thread was very short; plus he is a highly trusted expert contributor. So Newbies, please don't try this at home.
