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Deleting lockup via valve body (AW71L)

Broke4speed said:
Honestly, the lockup SUCKS for anything other than a 13C or MAYBE a 15G.
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That's where you're wrong. They suck with a 13c as well. I can't express how much I regret putting one of them in our '93 240+T. I keep threatening to swap out the R&P to a 4.11, but that's a PITA that could have been avoided if I would have used one of my 71's.

I think a lot of the problem is they came with a torque converter better matched to an n/a engine. I've heard that the higher stall torque converter of the 72L can be used, but if I'm going to have to pull the transmission, I may as well put something in there that I know works well.
 
Up here in Canadia, we got 71Ls in our turbo models. The tranny I'm using is from a late 940 turbo, so the stall is ~2500, which is pretty good.

I'm going to disable the lockup tomorrow after work, I'll post pics if I get it to work.
 
yall are hilarious. you know you can also just roll off in it, pass whomever, and continue on, right?
 
lummert said:
Have you already tried the usual kickdown cable adjustment?
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I don't actually want it to kick down. I'd much rather be able to make a bit of part-throttle boost in 4th to facilitate keeping up with traffic. The kickdown is far too aggressive, when engaged. The car lurches forward, the boost spikes (thank you, crappy wastegate bleed valve), and the RPMs jump up to 3500+.

It would be so much better to just crack the throttle a shave, like in a manual car, and actually see boost. I can't do that with the lockup, because my cruise RPMs are too low to get the turbo to spool. Without the lockup, the stall speed of the converter would carry the RPMs to 2500+, which would start to get me the part throttle boost I want, without kicking down.
 
lower rear gear, I'm sure somebody had a set of 4:11s for ya if you rebuilt that trans you can swap them gears. 1. moar better acceleration all the way through from a standing start on up, 2 your highway bog is gone 3 more torque multiplication now happens in the rear end instead of the trans giving it a break and lenthing it's lifespan 4. faster spool up because engine accelerates faster. I would think you would have to completely block the oil flow in the convertor oil circuit to disable the function, shimming it i would think it would engage harder or maybe later? could you swap to a non- lockup t.c.? or are the input shafts different?
 
Dirty Rick said:
No electronic options? Be much better to switch it with an adjustable vacuum switch...
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that'd be tough, not a bunch of space in there, and something like a transbrake solenoid would lend to leaks and might not take the abuse
 
linuxman51 said:
yall are hilarious. you know you can also just roll off in it...
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Not sure what that means. It's not a passing issue, it's a driving down the highway issue. The way it's setup, it makes OD semi-useless.

The problem isn't that kickdown doesn't work, the problem is that it makes it so that the OD with lockup makes it so high geared that it dogs around at anything under 70. There's way too much space between 3rd and locked up OD.

This explains the issue better than I can:

coalminer said:
On my 94 Volvo N/A 940 with AW-71L, the shift points are (IMHO) too close together between shifting into OD (4th speed) and the torque converter locking (5th speed).
As it is, driving on a road with a lot of inclines, the transmission spends very little time in OD.
This is like shifting from 5th gear into 3rd gear in a standard shift transmission.
The engine is either in a strain, or revving too high.

It seems like 1st to second gear and on into 3rd gear is OK.
At that point it will shift into OD at 45MPH, and the torque converter will follow closely, locking at 50 MPH....unless the accelerator is kept depressed and the car is accelerating quickly.

If I'm climbing a long steep grade, lack of HP prevents the car from accelerating when the converter is locked. This is simply a matter of engine horsepower verses engine load.

If the throttle is increased the transmission downshift will cause the transmission to simultaneously unlock the torque converter and shift out of OD.
This in effect shifts the overall gear shift from 5th to 3rd, and totally bypasses 4th (OD).
The engine is either lugged down, or it is revving higher than is required to increase the speed of the car.
It's a big jump in engine RPM.

I would disconnect....turn off....eliminate.... the locking feature of the torque converter if I could. No, I'm not going to swap it out...., just belly aching.

If all of my driving was on a flat road, it would be OK.

Too bad that Volvo didn't design some type of adjustment on the locking function in the torque converter.
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4.10 or 4.30 rear axle if the tires are stock size helps.

Some Toyotas came with an 03-71LE with electronic valve body. Those are nice in that you can keep the converter locked in 3rd so you can tow absurdly heavy things without burning it up, or by electronic means it'll do as you describe, but to be honest it's a lot less heat for the trans for prolonged periods (grades and/or towing) to keep it locked up in 3rd than to let the ECU unlock the converter and introduce a bunch of heat and climb the grade in OD / unlocked, just noisier.

Boost (or any significant power) + OD on AW-7x trans=rebuilding/replacing the trans plenty soon anyway. :rofl:
If the car makes any decent power at all in boost, the kick down from OD +lockup to 3rd and light load/lack of OD is probably keeping the trans viable as it is, inconvenient as that might be for you.

If you want boost +OD, rebuild ZF4-22HP trans in earlier N/A cars with the land rover/jag V12/BMW ZF424HP bits and thrust washer update. Too bad those had the thrust washer screwup, they're a nice trans otherwise.
Those trans are mechanical, but have a larger converter clutch and will allow 3rd + lockup and have a much stronger OD not at the front of the trans. Good for a driver/towing car more than performance application though.
 
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i don't think he wants to boost it to death, i believe what he is wanting to do is get rid of the soft spot at cruise speed between where the engine isn't on the cam and before boost comes in, and kicking down to third is to harsh. a unlocked convertor will give you roughly, from my g.m. experience will give you another 500 r.p.m. at cruise. is that enough revs to get you where ya want?
 
freevolvos said:
i don't think he wants to boost it to death, i believe what he is wanting to do is get rid of the soft spot at cruise speed between where the engine isn't on the cam and before boost comes in, and kicking down to third is to harsh. a unlocked convertor will give you roughly, from my g.m. experience will give you another 500 r.p.m. at cruise. is that enough revs to get you where ya want?
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Sure, fine, but the guys in white lab coats weren't totally brain dead to have it kick down out of OD at really any hint of significant load and give it a little higher stall converter and 4.10 even with the original turbo. It's not an "accident" that it shifts from lockup+OD to 3rd when all they had was mechanical control.

It's not as though they had electronic control and a MAP sensor or the like, so they did what they could with what was available.

It doesn't take much boost (or horsepower rather) in OD to ruin them.
This is a long way around the block for what it accomplishes.
 
I'm not talking 15-20psi, all I want is the car to not be a dog at cruise. I'd be happy with 5psi to just bump up the forward momentum a shave if I am going up a hill or want to pass someone without going through the explosion of noise and boost spike that is called 'kickdown'.

This is a free way of eliminating the lockup, and free is always best. If it fails, I'm not going to cry.
 
Ok, so, halfway done. I dropped the lower part of the valve body, leaving the majority of it in place...and didn't lose track of any check balls.

Of course, nothing goes perfectly...sigh.

So I have this little wedge left over...

lUmcX0ge.jpg


Now, I'm 99% sure I know where it goes, but I just want to confirm. I believe it goes here...

bcE9l4La.jpg


Correct?

(all images from various Linuxman51 threads :) ).
 
did you get this too work? sorry can't help ya with that part location of you need me to i have a dead trans in the shed i could yank the pan and look
 
lol off the top of my head, I dunno. we kept that stuff stacked up as best possible when we went through that valve body(which iirc is an aw72L)
 
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