Best tq converter for the 6.2?

[kingsly]

Hey all, I just picked up a really nice low miles 4L60/700R4 to go with my n/a 6.2 that'll altogether go into my Range Rover.

The trans came out of a '91 S10, 4x4 and included the tq converter.
I've read that the 4.3l converter stalls much higher than the 5.7, and that the 6.2 MUST have a converter fitted with a poppet valve, though I've not gotten a straight answer as to why.

Then other sources have said they all work fine and it's just a matter of stall preference.

Can anyone clear up what exactly I should be shooting for? The thing I'm loving about GM family is how interchangeable things are - until things are so interchangeable that there's no clear answer!

[john8662]

1500 RPM Stall is what you want.

[arveetek]

After going through a few stock GM torque converters in the 700R4 in my old project truck (the lock-up portion wouldn't hold tight behind the torque of the diesel), I finally had Phoenix Transmission custom build a converter for me:

http://www.phoenixtrans.com/

Worked great, and never had another issue. Wasn't all that expensive either, IIRC. It's been a few years....

Casey

[Robyn]

First off Welcome to TDP :):):):):)

Some questions here are needed. ?????

Is the tranny from the S10 in stock trim (As it came from the S10) ??

There are several different units, and all 4l60 trans are not the same.
The S10 vehicles have a V6 in them and the clutch pack arrangement in the trans are quite a bit different than the 4l60 used behind the 6.2

There are more friction and steel plates used in the diesel unit.
The converter is a lot heavier.

As casey mentioned, a custom unit is the way to go.

To get a 4L60 to hang together behind the diesel you need to do some serious mods to the guts of the tranny.

Is this trans an electronic controlled unit or hydraulic with a TV cable ???

Depending on the particular parts used, the main clutch drum may need to be replaced along with the roller clutch, sprag, 2-4 servo, the 2-4 band, all the clutches and steels in the packs as well.

There needs to be the maximum amount of clutches that will fit used in order to hold up.

If this is a standard hydraulic box the governor needs to be swapped to one for the diesel.

A shift kit needs to be installed and a full hydraulic controlled lockup kit installed as well.

These are small gear boxes internally and unless they are blessed well will go away behind the diesel.

To be very reliable, the panetary units should be upgraded to the HD aftermarket sets.

Another item that needs to replaced with a HD aftermarket unit is the Sun Shell, as the stock ones have a nasty habit of coming apart.

One such good part is called "The Beast" and is beefed up considerably from a stock part.

Actually there are several input drums available (clutch drum assembly) in the aftermarket that come as a KIT along with the sun shell.
These units have a steel ring pressed over the aluminum spline area to stabilize the area and stop the shaft from tearing out of the drum.

This is the first stop in upgrading this box to handle a diesel.


The last 700R or 4L60 I built cost me about $1000 out of pocket over and above the cost of the good core I had on the bench, and I did all the bench work myself.


You can end up with a very nice package that will serve you well, but it's not just a converter that's needed.

When setting up a 700/4L60, attention to detail is paramount to a successful result.

Always use a good shift kit (I prefer Transgo -2 (Dash 2) and always choose the more radical settings (Harsher rather than softer shifts)

I call it "Setting them on KILL"

Keep in mind, the 700R boxes were used behind everything from the wimpy V6 all the way to the 5.7 V8 and the 6.2 diesel and the parts inside are very different.

These trannies had more updates, changes and mods from the factory to fix issues than anyone needs to think about or that we need to cover here.


Sorry to paint a bleak picture, but I hate seeing a lot of hard work wind up for not.

Spend the $$$ and do your gear box right and you will be a happy camper.

Robyn

[kingsly]

http://www.phoenixtrans.com/

Thanks! I'll give them a shout.


1500 RPM Stall is what you want.
Cool! Heard anything about this so called poppet valve?

First off Welcome to TDP :):):):):)

Some questions here are needed. ?????

Is the tranny from the S10 in stock trim (As it came from the S10) ??

There are several different units, and all 4l60 trans are not the same.
The S10 vehicles have a V6 in them and the clutch pack arrangement in the trans are quite a bit different than the 4l60 used behind the 6.2

...

Always use a good shift kit (I prefer Transgo -2 (Dash 2) and always choose the more radical settings (Harsher rather than softer shifts)


Sorry to paint a bleak picture, but I hate seeing a lot of hard work wind up for not.

Spend the $$$ and do your gear box right and you will be a happy camper.

Robyn

Thank you for the detailed reply Robyn! I'm sure I'll be back for plenty more as we start moving forward on this swap. :)

All I know about the trans is it's a '91 K case (w/ the correct SBC bell and cast aluminum cover), with a 4x4 tail housing. It was probably one of the last batches before the transition to the -E electronically controlled models. One of my next questions was going to be about that TV cable - my 6.2J came out of an '89 GMC tow truck, and was hooked up to a Manual trans. Are the fittings present on the DB2 or do I need to source the correct TV bracket?

I plan on keeping the 6.2 n/a, since the Range Rover axles are roughly equivalent to Dana 30's and I'm more interested in reliability and simplicity (and roughly stock power at more useful rpm's) than chirping tires or hauling a giant horse trailer straight up a mountain (my wife would disagree with the latter...)

I assumed that since the hp/torque numbers were similar between the 4.3 and 6/2 that everything would be fine. :confused:


As far as shift kits go, I'll plan on installing a transgo kit and have also been looking into a corvette servo - I'm told it improves holding power?

[Robyn]

A "K" case is good :)

Just need to give it some help to make it a good box.

The K was the best case for any HD apps

The torque and where it is along the RPM range is a bunch different between the two engines.

Over the years I have shook several 700R boxes all over the street.

The input shafts are small (Later ones are beefier) the sun shells break at the hub spline area, the sprags fail, the clutches are too few and too light, the 2-4 bands either burn up or break,
The aluminum splines in the input drum rip out.

All easily fixable issues, just need to be aware of them and gitterdone the first time around.

You have a good base to start with though.
Attention to the details I lined out will keep your tranny from becoming the "fuse"

A well built 700R/4L60 can handle a 6.5 turbo IF BUILT WELL

For your app and a stock power 6.2 the little 700 box will live a long time when loved a little.



Missy