possible trans or t case problem

[liftedandgifted]

I recently purchased a 2002 1500 hd 6.0 4l80e 4x4which had the transmission burnt out of it. Transmission was rebuilt and also did the valve body updates. Transfercase is the 246 which when I got the truck looks like it was recently replaced before I got the truck with a remanufactured unit. Everything worked fine for about 4 days. Now intermittently when the truck shifts from first to second under a light acceleration it gets a clunk then a slight slip or hesitation, I would say hesitation cause rpm doesn't seem to go up much if any, then another clunk then goes into second. That is the only time and gear change it seems to do it. I never run truck in auto 4x4 only in 2x4 of 4x4 and it doesn't seem to make a difference. I did check the rear end and spider gears and everything seems to be ok, even the junk gov lock (never liked them). also when in 2x4 the front driveshaft turns hard like its supposed to. according to gm it shouldn't spin freely and could take up to 40lbs of force. don't think its that and all mounts are good. Talked to the trans guy and he said that it could be a sticky accumulator. I am supposed to test drive and scan tomarrow and hopefully I will know. I am just curious if anyone else has had this problem or has an idea about whats going on. I found a tsb for 03 and up trucks with 4l60e about a wire going to the alternator which needs re ran but my truck is an 2002 with a 4l80e.

[Meangreenhd]

im gonna point the finger at your tranny. autos work in mysterious ways, too much fluid and valves and junk. although i do know a wquality rebuild compared to a budget rebuild is night and day from seeing buddies stuff.

these t cases are chain belt driven, so there is less of a chance of the clunk coming from the t case. when your truck is in 2wd, the front ds is dissconnected from the internals, the force needed to rotate the shaft is due to the clutch pack for your auto 4x4 mode. but it should turn by hand or tool force in 2wd when vehicle is stopped

i am not even close to an auto guy (never owned one---never will) i will leave the shifting up to me. but i am aware of how the t case works.

[txarkitekt]

I am betting on the 2nd gear tranny stuff. Might be a solenoid...might be the 2nd accumulator piston...might be anything.

[GasGuzzler]

It's most likely in the trans. Since 80's are so rarely problematic at the dealer level I can't really offer any specific possible internal issue.

[liftedandgifted]

Gov lock. looks good but was junk. transfered up the drive line and sounded like it was up front. Trans guy also does rear ends.

[knickick]

Hi GasGuzzler . That is true. I am agree with you. I hope that someday I can find a dealer without problem in his selling products.