Strokinit383

iTrader: (22)

I'm swapping in a 5.3 and would like to keep the t56. Are all of the LS based engines internally balanced? Can i just replace the 5.3 flexplate with any LS flywheel and replace the the truck balancer with an f-body balancer?

Thanks

iansane

Hope so. I did exactly that and have been running it that way for about 6 months and 15k miles!

Red99TA

iTrader: (11)

I know they're all internally balanced but I read somewhere that some motors do have some weights on the flywheel to account for a little bit of imbalance in the motor that they found at the factory. I just installed a new clutch a couple weeks back and looked at my old flywheel last night and noticed it's got 2 small plugs pressed in with some green paint that the factory used to marked its location with. There's also several areas where they drilled into the flywheel to remove material during balancing (did not drill all the way through) but I believe that's just to balance the flywheel with the clutch whereas the plugs were to help balance the motor. Could be wrong though. I also found two little plug looking things on my stock pressure plate that are installed on one side of the PP only (several drilled-through holes that go all around the PP and only 2 of them had this little weight pushed into it). I'm assuming that's for the clutch/FW balance as well but not sure.

I actually had my new clutch/FW balanced together as a unit and I've got a little more vibration coming up through the pedal than the stock setup. Wondering if that's because my stock FW had that little bit of weight on one side to account for motor balance and the new FW doesnt.

Strokinit383

iTrader: (22)

That's what I was afraid of. For my 383, I had the flywheel balanced to match the flexplate at a machine shop. I had to have the balancer, crank and flywheel out of the motor. I was hoping to avoid disassembling the 5.3! Maybe I can somehow have the flywheel balanced to the flexplate without needing the remove the crank.

Red99TA

iTrader: (11)

I don't think the pulley is used to help balance these motors (just the FW on some cars). I don't see why you couldn't just have a shop balance the new FW to match the old one if the old one has any weights on it and then you just install the new flywheel in the same orientation as the old flywheel. Should be easy to do since the FW has an extra hole in it by the bolt holes where a dowel pin would go if you had one. Of course not all of them have any weights so if that's the case I would think a neutrally balanced FW would be fine.

Strokinit383

iTrader: (22)

Yeah that would be ideal, but I'm attempting to match a flexplate (automatic) to a flywheel. Not sure how the weight differential will effect the balancing process. I guess I will need to contact a machine shop.

Red99TA

iTrader: (11)

I see - I just posted a new thread with pics of my stock FW/PP and the weights in question. Hopefully some experts will chime in to verify that the factory does use weights sometimes to help balance the motor.

iansane

Wouldn't it make more sense that those weights were to neutral balance the flywheel itself? So that it could be put on any motor along the assembly line?

Red99TA

iTrader: (11)

It would make sense for LuK to neutral balance all the FW/PP combos prior to shipping them to GM. I question why there's 3 different balancing "weights" used on my stock setup - mallory slugs in the flywheel, different weights on the PP, and then areas drilled down on the FW to remove material. Makes you wonder if one or two of those methods was to zero balance the assembly and then the third used to help motor imbalance.