4l60e rebuild question
4l60e rebuild question Doing my first rebuild and I have a question. I have endplay on the output shaft but it does not seem to make contact with the input shaft. Is this correct? When everything is assembled the output shaft still has endplay and none on the input.
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As far as I know, the torrington bearing in the input drum assembly will ride on the output shaft, giving each one similar end play. (Correction: this is not true, see below.)
It sounds like your input drum is not fully seated; it is critical that it have some end play; .015 to .030 is the spec and I try to keep it on the low side. The selective washer will set the final end play.
I check end play with a partially assembled input drum, before installing the 3/4 clutch. You also do not need to install the reverse drum to check/set end play. This makes it trivial to install the input drum, bolt in the pump and check the end play; if necessary change the selective washer and re-check.
When fully seated and fully assembled, the top of the reverse drum will be a bit below the case lip for the pump and look like this:
You need to determine if everthing is properly seated, set the end play with the selective washer and the output shaft end play should take care of itself. If you decide that the output shaft has quite a bit more end play than the input shaft, Sonnax makes an output shaft washer/shim set to correct it, but I doubt that is often needed and would be a lot of extra work.
It sounds like your input drum is not fully seated; it is critical that it have some end play; .015 to .030 is the spec and I try to keep it on the low side. The selective washer will set the final end play.
I check end play with a partially assembled input drum, before installing the 3/4 clutch. You also do not need to install the reverse drum to check/set end play. This makes it trivial to install the input drum, bolt in the pump and check the end play; if necessary change the selective washer and re-check.
When fully seated and fully assembled, the top of the reverse drum will be a bit below the case lip for the pump and look like this:
You need to determine if everthing is properly seated, set the end play with the selective washer and the output shaft end play should take care of itself. If you decide that the output shaft has quite a bit more end play than the input shaft, Sonnax makes an output shaft washer/shim set to correct it, but I doubt that is often needed and would be a lot of extra work.
Last edited by mrvedit; Sep 3, 2014 at 07:49 PM.
If I set just the input drum(no clutches) in the case after I have the bottom of the case together should I be able to push up on the output shaft and move the input shaft? The input drum is on the bearing but the shafts are not touching Thanks.
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Joined: Aug 2010
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From: Ann Arbor, MI
First, you need to have the input drum assembled up through the forward sprag assembly and the snap ring from the forward/overrun clutch assemblies. In other words, all but the 3/4 clutch. Make sure torrington bearing was installed properly (the "input sun gear bearing"?).
I "think" when fully assembled the output shaft will touch that torrington bearing when the output shaft and input shaft are pushing together. I will be swinging by local trans shop this morning and will ask.
CORRECTION My local trans mechanic did not think the output shaft would touch that torrington bearing. He explained that the input drum's movement into the trans is limited when the sun gear (attached to the sprag)bottoms out in the outer planetary. The selective washer then determines how far the input drum can move out, which is then the total end play.
Generally when you can install the clip on the output shaft, everything up to the outer planetary is spaced correctly.
Have you experimented with different selective washers to confirm you can get input shaft end play with the correct washer?
I "think" when fully assembled the output shaft will touch that torrington bearing when the output shaft and input shaft are pushing together. I will be swinging by local trans shop this morning and will ask.
CORRECTION My local trans mechanic did not think the output shaft would touch that torrington bearing. He explained that the input drum's movement into the trans is limited when the sun gear (attached to the sprag)bottoms out in the outer planetary. The selective washer then determines how far the input drum can move out, which is then the total end play.
Generally when you can install the clip on the output shaft, everything up to the outer planetary is spaced correctly.
Have you experimented with different selective washers to confirm you can get input shaft end play with the correct washer?
Last edited by mrvedit; Sep 3, 2014 at 08:56 AM. Reason: Correction
Tried tonight with no selective washer and now I have endplay. I seem to lose endplay just as the pump seats. I did not use the gasket which is .015 so when I put that in I will have some more. I will make a new washer tomorrow at .060 and measure. I was under the impression that the input should move when I push on the output. It is close but they do not touch. Thanks for trying to help.
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Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
Did you replace any hard parts? If you have the original hard parts, then I would expect the same selective washer to give the original end play. I know it is too late now, but measuring the end play before disassembling the trans can be useful.
Sorry for my incorrect statement in the earlier post. I don't fully assemble a trans on a regular basis and therefore go partly by memory. I keep a disassembled 4L60E in my basement so that I can research details to answer questions here. Therefore I assembled the relevant parts outside of the case today. The torrington bearing in the input drum is called the "sun gear" bearing and indeed the input sun gear (snapped into the forward sprag) runs on this bearing. The end of the output shaft tappers to a smaller diameter and runs inside the bearing without touching it. The end of the input shaft does not touch the input drum and therefore has end play completely independent of the input shaft.
While the input shaft end play spec is .015 to .030, my local trans builder said that as little as .010 is fine, especially because it increases by a few thousands during early operation. I build a few at .012 and they have survived hard use. So, of all the end play you have is from the .015 gasket, that should be plenty.
Sorry for my incorrect statement in the earlier post. I don't fully assemble a trans on a regular basis and therefore go partly by memory. I keep a disassembled 4L60E in my basement so that I can research details to answer questions here. Therefore I assembled the relevant parts outside of the case today. The torrington bearing in the input drum is called the "sun gear" bearing and indeed the input sun gear (snapped into the forward sprag) runs on this bearing. The end of the output shaft tappers to a smaller diameter and runs inside the bearing without touching it. The end of the input shaft does not touch the input drum and therefore has end play completely independent of the input shaft.
While the input shaft end play spec is .015 to .030, my local trans builder said that as little as .010 is fine, especially because it increases by a few thousands during early operation. I build a few at .012 and they have survived hard use. So, of all the end play you have is from the .015 gasket, that should be plenty.
If I was to start over on another rebuild I know just what I would check for before disassembly. This is my first rebuild so it is a learning experience. I disassembled this thing enough times now that I feel like I have six rebuilds under my belt. I just wanted to be sure I was right and each time I came up the same clearance. I will go with what I have as I feel I am very close. Thanks again.
