Turbo 400 Intermediate Clutch Clearance

[bluchev]

What would you say a minimum/ maximum clearance would be acceptable for a Turbo 400 Intermediate clutch Pack running 4 smooth 4L80e High Energy frictions?

I know .010 per clutch seems to be the norm, but im not sure how to get that much clearance in there even using ..076 steels. Are you guys machining the pressure plate?

 

[turbobitt]

I think they typically use TF 727 direct snap rings and are available in selective sizes.

AG

 

[bluchev]

Yea, im using the Trans go HD oversized snap ring now. I wasn't aware of that they came in different thicknesses. Wouldn't it be better to have the pressure plate machined to gain the clearance? I would think youd want a beefy snap ring there.

 

[Mike E]

I read somewhere that the early 4L80e pressure plate is thinner. Stock th400 was .438 and I think the early 4l80e was .375. You could pick up an easy .0625 there and maybe throw in a thick steel.

 

[turbobitt]

Yea, im using the Trans go HD oversized snap ring now. I wasn't aware of that they came in different thicknesses. Wouldn't it be better to have the pressure plate machined to gain the clearance? I would think youd want a beefy snap ring there.

I have machinged the snap ring side before. Be careful to machine the drum clearance area as well.
BTW - I'm using the thinner .375 pressure plate with 4 clutches and I think it's about .030 clearance with no issues. It's only dissengaged in 1st gear only.
Allan G.

 

[bluchev]

Well I had it set up like turbobitt last season but i just tore it down because 2nd felt like shit at the end of the season and theres signs of heat on the int. steels. i used (4) .076 clutches, (4) .070 steels and stock int pressure plate

So im thinking it was just too tight, which i had figured before hand as well but i wanted to try it out.

obviously it didnt work out too well lol

Im gonna try to get my hand on one of the 4l80e pressure plates and see what i can come up with

 

[turbobitt]

Well I had it set up like turbobitt last season but i just tore it down because 2nd felt like shit at the end of the season and theres signs of heat on the int. steels. i used (4) .076 clutches, (4) .070 steels and stock int pressure plate

So im thinking it was just too tight, which i had figured before hand as well but i wanted to try it out.

obviously it didnt work out too well lol

Im gonna try to get my hand on one of the 4l80e pressure plates and see what i can come up with

I would need to double check since I just set it up but used actual TH400 clutches instead of the Caddy high statics. The high statics took the abuse with no issues so I got to believe a shifting cluch would be better.
What clutches did you use before ? Were they the same high energy clutches ? This clutch pack is usually forgiving with regards to wear.
AG

 

[chris718]

Big sprag use the 400 radial grooved clutches to put oil over the face and reduce laminar film in first gear from lube oil..045 TO .085 is fine for clearance.

 

[bluchev]

I used 4-4l80e smooth high energy clutches. i use high energy clutches in the direct and forward as well

 

[turbobitt]

I used 4-4l80e smooth high energy clutches. i use high energy clutches in the direct and forward as well

I personally think the smooth cluthes are good and/or almost prefered for intermediate due to softening the clutch apply. I don't like running a smooth cluch for direct for the same reason. A grooved clutch will have some reduction is area contact but will help move the oil out of the way during a shift.
Allan G.

 

[bluchev]

I picked up the 4l80e pressure plate which is .366 and used two .100 steels and 2-.070 steels and it looks like im right at about .055 clearance.

 

[bluchev]

Ok so i just checked my direct drum because i heard that you're supposed to have a check ball in the drum and the piston and i found that i only have the check ball in the piston and there isn't one in the drum.

The drum has been drilled for the bleed hole 1/16" I believe.

Is not having the check ball in the drum going to cause any problems? It has a forward manual valve body, no transbrake. Not sure on power yet but the new combo should make around 900 hp

 

[turbobitt]

I picked up the 4l80e pressure plate which is .366 and used two .100 steels and 2-.070 steels and it looks like im right at about .055 clearance.

I checked mine last night and have about the same clearance (.055) with all .070 steels.
Allan G.

 

[turbobitt]

Ok so i just checked my direct drum because i heard that you're supposed to have a check ball in the drum and the piston and i found that i only have the check ball in the piston and there isn't one in the drum.

The drum has been drilled for the bleed hole 1/16" I believe.

Is not having the check ball in the drum going to cause any problems? It has a forward manual valve body, no transbrake. Not sure on power yet but the new combo should make around 900 hp

You need to have the check ball in one or the other, but as long as it's there your OK.

I would debate if you need a check ball at all if there is a hole drilled in the drum.
Allan G.

 

[bluchev]

Ok that's what i thought but i remember reading somewhere that you needed both.

That's kind of odd that you have the same clearance with the thinner steels, are you running 400 clutches or the 4l80e's?

 

[turbobitt]

Ok that's what i thought but i remember reading somewhere that you needed both.

That's kind of odd that you have the same clearance with the thinner steels, are you running 400 clutches or the 4l80e's?

I was going to use .080 smooth 4L80 clutches but Chris (CK) talked me into .080 waffle clutches. Don't know the application of the clutches but must be hard to get since I don't see listings anywhere for these cluches in this thickness.
Allan G.