4L60E Autopsy: Comeback-No 3rd/4th Gear Shortly After Rebuild!
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- čas přidán 14. 02. 2024
- In this video, I do an autopsy on a 4L60E that I recently built for a customer which lost 3rd gear within only 200 miles! Unfortunately, these things occasionally happen to all builders however the cause of this one mystified me. So after receiving the transmission back from the customer, I elected to film and document the tear down for both transparency's sake as well as to determine what went wrong and why so that learnings can be applied to all my 700R4 and 4L60E rebuilds going forward.
Note: Valve Body will be tested in a separate video featuring the Sonnax test plate for 4L60Es (it was previously tested prior to letting the trans go out the door - nothing remarkable was observed in testing).
Viewer's Note: There will be a follow up video on this transmission once I complete my investigation, which is expected to wrap within a week or so of this video's publication date (2.15.24).
You are a great mechanic and I love your work and videos. Carry out transmissions were always a scary experience for me. Had an e4od that I built and was a carry out. Customer stated that it would not work at all, no forward or reverse. Went to the customer to investigate and found that he had not put any fluid in the unit. Ruined the pump and some bushings. Yes I did make some mistakes while learning, and I am still learning. The first transmission that I built was a cast iron power glide. I’m 74 years old now and I really enjoy watching your work and videos. You should be very proud of your achievements.
Videos like this are invaluable to us backyard DIY guys. There's a methodical procedure going on to investigate the root cause of the problem. Looking forward to seeing the diagnosis and repair.
Ever find the problem? Had a comeback similar to this one, no obvious cause
My car is spot your problem. When you leave the load springs out for three four clutch. Every single time it will cause those clutches to burn up. Due to them not being released quick enough when the direct clutch and overdrive clutch band applies and the clutch for three four does not release quick enough that is due to leaving the load springs out and happens every single time to me. And of course depends on how he drives
I got a laugh from your saying that some mechanics hammer steel shaft into the 4L60 forward drums. One 200-4R guru giving overhaul tips on that unit that the stator shaft often wears, and to replace it as needed, but DO NOT BEAT IT IN WITH A HAMMER! That would do wonders on the aluminum 200-4R pump covers . ;) I'm also amazed that some mechanics will use impact wrenches to assemble aluminum pumps & valve bodies, then wonder why a rebuild has weird shifting.
The only thing I don't like about ur build is the fact that you left ur load springs out. I would have blocked the case servo with 2 pistons n put a updated roller bearing where you still had the thrust washer.
Had the exact same thing happen to me a few months back and it was in the 2/4 servo one of the teflon rings tour and held open the check ball in the case
Hi Nick, I've always have said, If you don't have comebacks you ain't doin much! That said, you do Transmissions and carry outs, You have no control over what goes on after your perfect rebuild goes out the door! There are so many things today like garbage parts, improper install, moron drivers and other things that have nothing to do with your work. We know you ain't trying to hide anything and vehicles will always try to make you look bad, all you can do is your best! Shit happens!👍👍
🎉Failure was the 3-4 load springs. That drum spins very fast and creates centrifuge. The clutch pack was applying while high in the rpms.
What can I do after I rebuilt one the tcc cylankid is stuck on, only thing might be is a shòt in avalanche that I 2s working on but couldn't find short so I'm asking if tcc cylankid is stuck open your opinion thanks great video
Hope to see an update soon, have this exact same concern on my truck after rebuild but I’m sure my 3-4 is smoked so, will be keeping an eye out for the update, great video!
Hi again Nick. You Sir are a stand up Guy! Please when you find the problem let us know! Thanks Nick!👍👍👍
I always use release springs in 3/4
Enjoyed it. It all looked good to me too. Mismatched vendor frictions of varying widths should not have caused it.
I had come back on a 2007 4l60e about a year ago that had a lot of friction material in the pan and it turned out it was the converter lining coming apart. I always check converter bolt length because Ive seen more than once where a bolt dimpled the converter ever so slightly and caused converter failure. I would say that this would/could cause issues in the afl and/or 3-4 circuit. Just a thought
Hey Nick did you ever put the drum back together and check that orifice? I doubt that was the issue.. Something was causing a pressure issue. I seen no reason that trans shouldnt have been ok.. A gauge on that would've told the story but they may not have been an option to you or the customer.. Thanks for the video man!
Awesome Man!!
I know you said the reverse input drum had nothing to do with the 3-4 clutch, does the difference between the drums from the 4L60 to the 4L60E have different hole sizes, there's a square hole drum and a round hole drum, I'm not a transmission builder but am a mechanic and watched a fair few videos, do have my own transmission to build so I watch as much as I can before attempting to tackle my own. You have great knowledge on the workings of the transmissions. My comment was a stab from what I've watched online. Watched a lot from a channel called precision transmission.
My 4l65e doesnt have 3rd gear after rebuilt. If i put the indicator in drive it slips in 3rd gear. If i put the indicator in 3rd gear it stays in 2nd gear. I replaced the vss and it finally shifted into 3rd gear and i thought i had it fixed but after driving it a few more times it went back to doing the same thing. I unplugged the harness and it still moves in forward and reverse
Do you have vacuum checking tools for the valving?