Performance 4EAT

[presslab]

I've got my '98 4EAT trans apart and I'm about to order some parts to rebuild it.  Does anyone have recommendations?  I've done the TCU mods to increase cruising line pressure, a shift kit, and a high stall torque converter.  I put that into a JDM trans with low miles and the high clutch is shot a year later.

It looks like maybe Alto offers a 1.75" carbonite band, and they have some high energy frictions.  What does it take to fit another friction/steel in the high clutch?  Some machining I guess, and a different pressure plate.
 

Edited April 3, 2014 by presslab

[Fairtax4me]

Pull it apart and measure the clutches. Maybe you can match them up to a stronger set.

 

With the higher line pressure would you need to re-calibrate one of the spool valves to prevent early engagement of the high clutch?

(Maybe that's part of the shift kit?)

[presslab]

Maybe there are some thinner steels/frictions too, so I can cram more in there.  A lot of Nissans use the same trans internals so there's a fair amount of stuff out there but it's hard to know what works with what.

 

The TCU controls the high clutch, so the higher line pressure only makes for firmer shifts.

 

I'll post some photos later of the tear-down.

[presslab]

Here's some pics.  The last one is the smoked high clutch.

 

 

[Fairtax4me]

Yeah that's lookin kinda toasty.

Are those single side friction plates or double side?

[CNY_Dave]

Don't know if it'll swap into a 98 (parts or whole trans) but the Gen 2 H6 4EATs have more clutch plates for at least one of the stages.

[presslab]

If you look close at the photo you'll see most of the frictions are worn down to the metal.  Yes, the friction is on both sides.  Alto offers thinner Kolene steels, but it requires the older high clutch drum, so I need to find one of these.  I actually had one but the girlfriend made me throw my old parts away.  I have already 5 frictions of the stronger Outback trans, but with the thinner steels I should be able to get 6 frictions.  I would also be upgrading to the Red Eagle high energy frictions.

 

I know some phase 2 parts work, for example I have a phase 2 torque converter and input shaft.  But without a phase 2 trans here to compare I can't figure it out, unless someone has done it before.

[ivans imports]

Replace the forward drum its stator and its clutch pack for the one from 95-99 outback uses bigger wider clutches and has more holes for oil flow and is a harder steel stator if you haven't already got that

[presslab]

My forward clutch frictions are 36T, 1.6mm, qty 5.  The catalog shows that it's for 96-98 Legacy, I'm not sure if it's Outback or not, I'm guessing it is as the trans was mated to an EJ25.  To add more frictions I would need to machine the apply piston.  Does the forward clutch have problems?  My frictions looked fine, and hardly worn.

[presslab]

I got my high drum (from a Nissan) from eBay and it looks like it will work.  I can use the special Alto frictions and fit one extra pair in there.

 

The only downside is that I need to use the older reverse frictions/steels, which are not as wide.  Oh well.  I think reverse goes out not because the frictions just wear out but more so because the seals on the reverse drum support go bad and let the reverse clutch engage while going forward.  I have the special steel sealing rings here that came with the shift kit.

[Fairtax4me]

Is that reverse clutch also used to engage any other gear?

[presslab]

The reverse clutch is only used for reverse.  There is also the low/reverse clutch which is used in reverse, and when the shifter is in "low".  This provides engine braking in 1st gear, otherwise there isn't any.

 

I tried to order the parts from Alto this morning.  They won't sell direct.  Luckily I know a couple shops that will order it for me, but it's a pain.