So my truck is at the trans shop having the new 4l80e intalled. But the two dont seem to want to work together. First the convertor didnt want to work with the crank. Keith at the trans shop made that match up and work. Now the flexplate does not fit. We tried using a 6.0 flexplate, but there is not enough room for the bolts to clear the block. So we are now using the 4.8 flexplate and having it machined to make it fit.

Then there is the issue with dealing with a trans crossmember, driveshaft and anyother little thing that give us trouble.

So for anyone else that is ever going to think about doing this swap: it is NOT a simple bolt in, load the computer software and drive deal. I just cain't wait till its done.

 

Arent the 4.8 and 6.0 blocks the same outer dimensions?? I know that the trans mount has to be modified a bit, but its nothing difficult. I think you rcsb guys can get away with a new yolk, I will need a new driveshaft

 

Is your flexplate dished in the center or flat? You can buy a crank spacer to compensate for the different flexplates. Just make sure that it is in the proper position for the starter to engage. I can't see a reason why you would have to machine it - there have been several members here who have done the 4L80E swap, including myself, and I have never heard of having to machine the flexplate before.

 

Ya, I had no problem bolting mine to my 2000 5.3L or my 2003 6.0L (with 5.3 flex plate)

 

It sounds like you were originally trying to use a dished flexplate without a spacer and bolt it up to the 4L80E. That won't work. Was the 6.0 flexplate flat? If so, you also need the spacer to make it clear the block correctly. If you are using a dished flexplate the spacer would go between the flexplate and converter, if you are using a flat flexplate it would go between the crank and flexplate. I ended up using a flat flexplate and put the spacer between the crank and flexplate and it fit perfectly. Once the trans and engine were bolted together there was just barely enough clearance between the converter and flexplate to spin the converter without touching the flexplate, which I was told is perfect.

Two things to watch out for: make sure the converter is not being jammed into the tranny, or you will break the pump, and make sure that the flexplate is in the correct position for the starter to engage it.

 

Thanks for the imput thrunder. I will have to ask Keith about the flexplate. I know that Keith knows what he is doing and he will not put it in there if there is a problem with teh convertor being pushed back or anything like that.

I just want the truck back and have it running great. Is that too much to ask

 

Haha nope not too much to ask - I'm waiting for mine to come back from the driveline shop now. I did as much of the work as I possibly could on my own, but I can't make driveshafts

I hope you get it figured out soon!

 

Yep, the dished style flexplate won't work. You need to use a 6.0L flexplate with the crank spacer. The bolts wouldn't clear the block because you need the crank spacer on there first to space the flexplate out. Then you may have to ream out the converter holes on the flexplate depending on the bolt pattern your converter uses.

If you want a bolt in affair for the crossmember and driveshaft give Speed Engineering a call. They can hook you up with both items and actually any others that you might need.

Oh, and lay the dipstick tube in place before putting the trans up. If not you'll have a hell of a time getting it in there.....it'll go but won't be fun. You'll have to get a 4L80E trans dipstick also.

The biggest issue I had when I put a 80E in my 2000 was the converter/flexplate deal but, that was because I was trying to find a flexplate that does not exist instead of just reaming out the holes for the converter to bolt up. Everything else was cake but, I just ordered the stuff from Sean at Speed Eng so there was no issues.

Keep us updated.

 

****UPDATE*****

As of Friday the trans was in the truck. I guess they had a spacer made to fit the flexplate. We used the 4.8 plate because when the engine was built they had to put weights in it to help balance it. I will have the truck back this coming friday if all goes well. I just hope that Don loaded the right program in for the trans.

 

I cant wait to see what your truck will do with the 4l80 and new intake... Sounds like a nice setup.