BigCountryx

iTrader: (3)

Guess I should have started a damn build thread, haha. I got the 4l80 swap 90% done today, but ran into a couple of oddball road blocks during the swap. First of all, the Neapco Yoke that I ordered to be a direct swap and use the standard U-joint doesnt fit. It requires a u-joint that is smaller than the factory size. As pissed as I was about the fact that it was smaller pales in comparison to the fact that no one makes a bastard joint to fit the combo. So for that I'm down until Tuesday when the our local driveline shop opens up. But that was half way expected.

What confuses the crap out of me is what happened when I stabbed the trans. and snugged the bellhousing bolts the TC was putting pressure on the flywheel.... enough that it was causing it to flex toward the engine slightly. I'm using a standard GM spacer and Flywheel for a 2500HD with a LQ4 and a 4L80 so it should have just bolted up. First thought was that the TC wasn't seated properly so I dropped the trans and pulled the TC to re seat it.. clunk, clunk all is good. Put it back up, same thing. So I called my buddy over. he's our local tranny guy so I figured an expert would have me staightened out in no time. Well he looked at it, dropped it, pulled the TC, reseated it and said that I had it all right, just that the clearance wasn't there. We took a few measurements, checked the starter clearance and he decided the only answer was to space the trans back 1/4". He had a TCI ford to GM adapter plate at his shop so we chopped it up and knocked out the studs to just use it as a spacer. Worked like a charm and gave us a perfect gap between the TC and Flywheel. This trans and converter is out of an 07 classic 2500HD. Never would have thought that I would have run into this issue, but I did. Guess I'll see how it works on Tues.

rossp

iTrader: (3)

If i remember correctly you only have to use the flexplate spacer if your using the 4.8/5.3 flexplate. If you have a flexplate from a 6.0 then you should be good to go without the spacer in there.

BigCountryx

iTrader: (3)

Correct me if I'm wrong, but the spacer on the 4l80 fp goes on the engine side... without it the starter wouldn't align.

GMCtrk

iTrader: (27)

The neapco yoke and universal U joint were supposed to be diredct bolt ins for the 2 peice steel driveshaft. I would imagine your SS had something different.

Also, that's very odd about the trans not lining up.

BigCountryx

iTrader: (3)

I've got a 2 piece shaft, really don't know what the deal is there. All I can think is that something may have changed in 07 being a cluster **** year with both bodystyles being made, but I have no idea.

GMCtrk

iTrader: (27)

steel or aluminum? I'm guessing it's aluminum and it has different specs than the steel

BigCountryx

iTrader: (3)

It's a steel 2 piece with carrier bearing

Coban

iTrader: (14)

14 bolt rear end right? They must have put bigger yokes on the drive-shaft from the factory.

FLT

iTrader: (1)

The spacer is used for the converter pilot. The spacer goes on the flywheel between the flexplate and the converter. If you have a converter that has a ls1 pilot you should not need a spacer is what my understanding is. If you have the spacer between the crank and the flexplate that is your issue. I would remove what you have done and try again. Vince B

hirdlej

iTrader: (31)

I don't know if this helps but my 6L came with a 2wd 4L80 - it had a spacer with it as well that went between the crank and the flexplate.......