Modded 4L65E question/issue - trans guru's in here
Here is a picture of a BW dual-cage sprag (on the left) and a SKF on the right:

Notice that the dual cage has two cages and a thin spring plate between them. Also notice the shape of the individual sprags - the BW has nearly rectangular ones while the SKF has very curvy ones.
Looking at your picture, there is no evidence of the inner cage; all the little pieces are from the spring plate. Also the individual sprags look curvy to me.
I visited my local trans shop and the long-time mechanic there also thought it looked like a SKF, or at least a single cage.
(Thanks to Damon and Dennis at Haas Transmission in Dexter, MI for often helping me out, teaching me a lot, lending me parts for study and taking the time to look at this thread.)

Notice that the dual cage has two cages and a thin spring plate between them. Also notice the shape of the individual sprags - the BW has nearly rectangular ones while the SKF has very curvy ones.
Looking at your picture, there is no evidence of the inner cage; all the little pieces are from the spring plate. Also the individual sprags look curvy to me.
I visited my local trans shop and the long-time mechanic there also thought it looked like a SKF, or at least a single cage.
(Thanks to Damon and Dennis at Haas Transmission in Dexter, MI for often helping me out, teaching me a lot, lending me parts for study and taking the time to look at this thread.)
Thread Starter
Joined: Apr 2005
Posts: 1,065
Likes: 233
From: N.E Missouri
I clearly know the difference in the sprags. The one I pictured is a BW sprag with a cage broke off making it look like an SKF or single cage.
Here is the first sprag. As you can see this is a dual cage BW

Here is the second one. Again, dual cage BW

and the one pictured before is a dual cage BW with a cage broken off of it. I know because I installed it
I am thinking there is a feed issue somehow as stated previously.
Either way, I believe he has convinced his customer for an 80E swap and is going to repair the trans and sell it.
Here is the first sprag. As you can see this is a dual cage BW

Here is the second one. Again, dual cage BW

and the one pictured before is a dual cage BW with a cage broken off of it. I know because I installed it
I am thinking there is a feed issue somehow as stated previously.
Either way, I believe he has convinced his customer for an 80E swap and is going to repair the trans and sell it.
2BFAST: My detailed pictures were mostly to document the different available sprags for the many people (500+ by now) that have read this thread and might be wondering what the differences are. Obviously you know your sprags <grin> and know how to build a very strong 4L60E.
I have researched, asked various trans builders and learned a lot about sprags due to your thread. Even bought a brand new sprag assembly to study. Sorry to say, but I learned a lot from your misfortune.
Clearly, a 4L80E is the right choice for that power level (+700HP?) in a truck.
I have researched, asked various trans builders and learned a lot about sprags due to your thread. Even bought a brand new sprag assembly to study. Sorry to say, but I learned a lot from your misfortune.
Clearly, a 4L80E is the right choice for that power level (+700HP?) in a truck.
Last edited by mrvedit; May 14, 2013 at 08:36 AM.









