forcd ind

iTrader: (7)

still working on this 4l80e, kind of rebuilding the parts as i put them in the trans-the direct clutches and forward have the bonded pistons-no problem on the direct, got the piston, and just replaced the inner lip seal
the forward drum has the same deal, but the inner seal is not like the direct, it looks more like the inner seal is bonded to the drum, although it has a stamped look like the piston-transtar only shows the piston, and a lip seal for the drum?
i hope you dont have to replace the whole drum just to get the seal-wish they would of left the pistons like the older ones, lol

tptransmission

You don't your transmission parts supplier should be able to get that for you. If the seal is not damaged or hard you don't need to worry about it. In forward you actually don't really want it in there.

performabuilt

iTrader: (25)

As TP said the molded seal pressed in the center of the drum can be omitted in the forward clutch the only affect may be a more aggressive apply into gear when moving from neutral to drive

forcd ind

iTrader: (7)

cool, thanks guys-im gonna owe a lot of beers by the time i get this built, lol

Randy WS6

iTrader: (69)

There pretty easy to change, I used a piece of pipe the same size and drove the seal on.

jakeshoe

iTrader: (14)

You can leave the center seal out of the direct too
On the TransGo -3 kit, it is dual feed anyway so it's redundant, but the TransGo kit would be way less complex if they weren't saddled with the requirement that it can be installed without trans disassembly.

Drill a bleed hole in the direct drum about .050" and leave the center seal out. It will save you some trouble later on....

Randy WS6

iTrader: (69)

Does this haft to be done? I just finished rebuilding my 4l80 with the transgo MVB 3. But if it does ill take it back down and remove the seal and drill the .050" hole.

jakeshoe

iTrader: (14)

Not mandatory but if you decide to use a transbrake later, or use another VB, it will save you some trouble.

It works fine with the TransGo kit.

Firechikn

iTrader: (15)

Sweet. I'm learning something new. I'll be rebuilding mine real soon. I'll do these mods too.

382ssz28

iTrader: (24)

Basically, the seal removal creates a firmer apply as it is an accumulator and the .050" hole compensates the firmness by releasing fluid at lower pressures, such as cruising. At full throttle this will not be noticed, it will be firm. Hey Jim, if you don't like a firm engagement into gear, leave the seal in the forward drum, especially if your not using a wave steel in the forward drum. Brian.

FLT

iTrader: (1)

I personally do not think that the firmer apply going into forward on a 4l80e is worth the added holding power for the forward clutch. My thoughts here concern the OD roller. This is a weak point in this unit to begin with and it slamming into gear can not be good for this component. Besides the forward clutch usually only fails when it is run low on oil or when the ring surface in the forward drum is damaged because of worn bushings. Just a thought. Vince

jakeshoe

iTrader: (14)

I don't recommend drilling a bleed in the forward drum. I am speaking of the direct drum, there are several reasons for a bleed on this drum.

You won't gain firmer shifts by leaving the center seal out of the forward drum except on initial forward clutch apply when you shift from park, reverse, or neutral to any forward gear and drive oil goes to the forward clutches. The fwds are not a shifting clutch pack.

If you have reasonable line pressure at idle, stock levels are fine here, then the seal isn't mandatory in the center of the fwd drum.
You can go either way on this.

382ssz28

iTrader: (24)

I agree. I was refering to the direct drum. The forward clutch is the holding clutch and does't require a firm engagement, for clarity. All the harsh engagement will do is brinell parts.

Gearhead115

Ok I'm new to this site, I hate to bring back a dead thread but, I have an 02 4l80e that fried the forward clutch, just was wondering if its ok to leave out that center seal using the molded piston. The seal was pressed or appeared to be, I had a doubly hard time removing it because when the clutches burned up it really fried that rubber. I'm not using any shift kits or anything else I'm just going for a stock rebuild. Any help would be greatly appreciated.