Ok heres the deal. I just had a rebuilt 4l80e proffesionaly installed in my 99 t/a along with a vig 3600. The guy who rebuilt it had to open it up again because he put the wrong center support in it and when he did he said all the clutches and everything looked good and were not burned. He also said he put raybestos clutches in it along with a shift kit. Ive only put a few miles on it since ive gotten it back and its making some strange noises at certain times. It is making a grinding/whining noise in first at low rpms...like driving through a parking lot. It is also making similar noise during regular driving but not all the time. When i give it more gas it doesnt make the noise. What i was wondering is....is there a break in period for a tranny like this or should i be worried about the noise. Any help would be appreciated. Thanks. Oh yeah i forgot..it is shifting fine.
__________________ 99 Trans am NBM-Volant CAI, Pace lt's, ORY, Magnaflow catback, ngk,msd,umi lca-torque arm-panhard,4l80e swap w/vig 3600,ls6 intake
I'm running a 4L80E that I built. It might whine in first, never any other time, and never any grinding noise.
If I were to guess, the guy doesn't know much about the center support differences, sungear drive tube differences and the shim under the sungear bearing. Probably still has mismatched parts.
ok cause at first he said he had the wrong center support. Something about one having a shim and one not having it and mine is the one without the shim. What are the differences between the sungear tube and bearing and how hard would that be for a mildly mechanically inclined guy to do....also this morning there was a slight noise going in reverse....yay me.
I didn't find it very difficult, I even bought an ATSG manual.
The manual I have is a few years old now, it has diagrams of all the different combinations of those parts.
If you're thinking of doing it on your own, I'd take the pan off and look in it, and break the filter open and unfold the material. If you find nothing it might not be worth tearing the whole thing down. If it's full of metal or other debris then you know there's definatley a problem.
I've yet to see a set of straight cut gears.
The 4L80E I have came out of a 1 1/2 ton 3500HD.
I've been into a lot of th475's with HD stamped on the bellhousing.
None had straight cut gears.
I've even had access to an abandoned transmission hardparts shop where all the inventory seemed to be 60% th400 parts. I've seen at least 12 different styles of output shafts. Found boxes of rebuilt planetaries, boxes of new sungears, all helical cut. Shelfs of planetary sets, hundreds. Even some rare sets made for a 36 element low sprag.
ok...well ive only put maybe 30 or so miles on it so im gonna give it some more time since its shifting fine and not slipping and then check the filter and pan for debris....thanks for all the help guys.
4l80e questions 
