Transmission won’t go into drive or reverse

Z

Zmac14

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No codes being set
billr said:
Well, I think the inop reverse means this is not *just* and electrical problem; reverse is controlled entirely by the VB. We need one of the trans experts to confirm, before I get you headed out into the weeds. I'll ask one last time... are there any trouble codes being set???
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sorry, no codes being set at all
 
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Zmac14

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billr said:
Well, I think the inop reverse means this is not *just* and electrical problem; reverse is controlled entirely by the VB. We need one of the trans experts to confirm, before I get you headed out into the weeds. I'll ask one last time... are there any trouble codes being set???
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Also I did drive it yesterday but I had to manually shift it from 1st 2nd and 3rd
 
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billr

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Does your OBD2 scanner display live-data? If unsure, post the make and model of what you have.
 
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billr

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When you put it in reverse and try to move the truck, does the engine just rev freely (like it was in N or P)? Or does it go up to about 2500 rpm and stall, no matter how much you open the throttle?
 
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Zmac14

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billr said:
When you put it in reverse and try to move the truck, does the engine just rev freely (like it was in N or P)? Or does it go up to about 2500 rpm and stall, no matter how much you open the throttle?
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Yes when put into drive or reverse it’s just revs. No stall
 
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grcauto

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Zmac14 said:
What kind of scan tool can do that? I don’t have very many diagnostic tools really just a multimeter and OB 2 scanner.
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Scanners will give the datastream. Code readers only get codes, no live data. So, what you got?
 
nickb2

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Zmac14 said:
does the truck have to be running to check which solenoids are on in drive? I’ll have to check this next time im at The shop
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No, with a good bi directional scanner, you can activate each shift solenoid. Just key on, should be good to go. If you want line pressures, yeah truck running, and again, with good bi directional, should be golden, but I just reread this thread, you rebuilt it yourself and you have self doubt. That is a good thing, it is called intuition. Probably a reverse slash forward band or a snap ring not put back in the right way. GC also wrote something, bill r also. At some point you will find, just not as quick as usual, if you go to several sites at same time and dont take notes, weeds again.

BP is our guru, he also gets swamped sometimes, so plz forgive him.

I can only provide to you my advice as such. Once you have eliminated the possible, it must be the answer, however improbable.

You rebuilt it, yes, so go back and look at what you touched.


You wrote this
Zmac14 said:
I did myself. It’s my first one ever but I did follow a step by step Manuel I find.
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Would it help if you had a proper R and R and disassembly pdf? If so, I can provide that, cuz I lost my x ray vision goggles in fevrier right before all this corona beer thing. .
 
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billr

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I have done some searching for "4L60E no reverse", and nowhere to I find that any electrical/solenoid issues will prevent reverse. I'm still thinking that this has to be a "mechanical" problem. I am eager for BP or somebody else to confirm this, but it sure makes sense in theory. P, N, and R are all simple on-off operations, needing no sequencing or adaption to road speed vs engine speed or engine load. I see no reason to complicate the P,N,R operations with PCM control. The manual spool in the valve-body (VB) can handle all those simply and reliably.

I am also eager for the OP to get live-data. We need to find out what the PCM is seeing for "gear commanded". If the PCM is seeing R from the range switch, then I am perplexed how no codes are being set. Surely the PCM should note a problem if it thinks the trans is in gear (R) and the turbine is spinning, but the wheels are not turning; that would indicate a gross mechanical problem that the PCM should not ignore!

How about the VB, is that the untouched original, that was working when the trans was removed? Is it a rebuild, or (gasp) a JY treasure? If you opened the VB up, then there are many more possible problems. I'm thinking primarily check balls.

I urge you again to check line pressure, that can be done fairly easily from "outside" the trans, and may give valuable info. Reverse takes the highest line-pressure, so if pressure is low, then I suspect R would be the first to fail...
 
bp042665

bp042665

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ok sorry busy weekend birthday and all but ok first off the forward sprag did you take it apart in double check it to make sure its right second did you put all 7 check balls in valve body you could have cut a seal in lower / reverse piston and did you get reverse drum fully seated before you put in pump
 
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