Pros-Cons of "manual valving" an Automatic

[cmilliron]

Folks, I am interested in hearing opinions on which way to go when building an automatic transmission for a Land Cruiser...

If I understand this automatic thing (Th350 specifically), it can be built to function fully automatically (like my mother's Delta 88) or the valving can be changed to make it manually shift only...

The FJ40 that I'm building will have to be truely "dual purpose" (highway speeds and granite speeds)...


I intend to teach my wife to climb rocks, thus the auto tranny (she is very hard on clutches even around town)... I'm having Marlin build me a 4.7 Toybox to slow the whole show down.... ARB's and Longfields in the mix.

Would love to better understand the pro's and con's of each method of automatic tranny setup...

Cliff
Lodi, CA

 

[PHAT MAX]

actually i am thinking about doing the same thing...any opinions?

 

[Halo3]

Okay, took me some digging & some head scratching, but I finally figured out where I had just seen an article about this--in the February 2003 issue of Peterson's 4-Wheel & Off-road.

Now, the article revolves around turning a TH700R4 into a manual shifter, but, if nothing else, it may give you some ideas of what needs to be done....i.e. a gated shifter, cooling, how to cope with transmission slippage on steep grades, and changing the shift pattern from P-R-N-4-3-2-1 to P-R-N-1-2-3-4.

Hope that helps some...

 

[PHAT MAX]

yes i read that too. you dont need a gated shifter tho. and slippage on steep grades is nil if you have a 700r4 with lockup. i think it would be cool to have but i think it might get old after a while.

 

[Halo3]

Guess I shouldn't have said, "some ideas of what needs to be done...". I should have said that these were some ideas/things to take into consideration.

I've entertained the thought of an "auto-stick" for a little while...dating back to the days when I was busy building Project: J**p in my mind.

In defense of the gated shifter, I think this really solved some potential problems that could be found/experienced while 4-wheeling with an auto. The article outright admits that its cable-based linkage eliminates potential problems with all the known factors which can cause a solid shift linkage to bind.

The other side to that is from my own personal experience. In my Dakota, I've found that it is REALLY easy to bounce a knee up into a column-shifted auto, and knock it from granny gear into 2nd, Drive, or, worst yet, Neutral. On the flip side, in spending ~7 years behind the wheel of HMMWVs, I've found that the "console" mounted shifter is subject to other things in the cab. I've had a cooler, that had been ratchet-strapped to the tailgate, break free & knock the shifter into a higher gear on a steep descent. I've also caught a couple of hard bumps & accidentally knocked the shifter forward with a hand or an elbow.

IMO, the gated shifter would give one decent insurance against the Murphy-factor that seems to follow all of us on our 4-wheeling endeavors.

 

[PHAT MAX]

ok you're right

and another possibility would be a lokar shifter with the safety lock button doo-dad.

 

[Niner]

IMO you will hate the manual auto on the road. having to shift your auto on the HWY would be a PITA. or accidentally starting in a higher gear. A friend of mine had that in his fj40 and it was great for down hill because it wouldn't shift up even if the govenor wanted to. but going up hill I didn't notice a differance. another advantage of the manual was in the snow while trying to stay on top of it he could start in a higher gear so the stall converter wouldn't dig holes. The biggest problem I saw was heat, it could make a lot of it.

 

[Halo3]

I don't think the highway shifting would be that bad.  Let's face it, how often do you shift on the highway to begin with?

The way I look at it, the worst part about having an "auto-stick" would be if you used it in a daily driver that sees a fair amount of stop-and-go traffic.  But, even at that, you are eliminating the hassle of having to suck in the clutch all the time...so in comparison to our manual transmissions, it really does seem to be a good concession between a full-on automatic & a manual tranny.

Keeping it cool would be a concern, but with the number of aftermarket coolers, aluminum tranny pans (deep w/fins), and electric fans on the market these days, I don't see how it would be too much of a hassle to fab up a solution.

As for snow & sand, I would think that with a good torque/stall convertor setup & solid valve body work, one could actually get an "auto-stick" that could comfortable start in a higher gear...without stalling.  You would just have to work on getting the torque/stall convertor tuned to duplicate what a person would do if they were driving a manual in that situation, and that is simply a matter of forcing the vehicle to a higher than normal starting gear...which is done with the valve body work.  The next piece to this feat would be to feather the clutch while feeding a bare minimum amount of throttle.  With the torque convertor providing your clutch-like slippage & the stall convertor disengaging things if the RPMs get too low...you get almost the same effect. I think the main trick would be in getting a stall converter tuned down to the low RPMs that the F-engines can operate at.

Who knows?  Maybe this is one of those things that looks feasible on paper, but just does not pan out in real life.  :-/

 

[cruiserrg]

I just got this reply back from Petersons on the Autocrawler article mentioned above in the feb 2003 mag.  Thought I would share, I think I may do some of the same mods when I get there on my project.

Autocrawler
Latest Web Update
by David Kennedy
Photography: David Kennedy

(Photos are the same as in the magazine story)

We’d like to apologies to those of you who came here to the website looking for this update weeks ago. We ran late and didn’t get this update online as quick as we’d promised. We screwed up and we’re sorry. We won’t let it happen again!

Since the February issue went on sale we’ve come further with the Autocrawler's development. Unfortunately the engine in our test vehicle has had a terminal failure that will delay further testing for at least a few months but we wanted to share what we’ve learned so far. If you have questions about anything we’ve done here, or are interested in bouncing your transmission ideas off the author e-mail david.kennedy@primeida.com.

Captions:
131-0302-TRAN-02
The 30,000-pound GVW cooler from Flex-a-lite’s (PN 45951) has proved to be more than what our Blazer has needed. But it’s still winter in LA and we haven’t hit the dunes yet so for now we’ll just enjoy the extra capacity this cooler has. In our application the electric fan on the back of the cooler has never had to come on so now we know we didn’t have to put the transmission cooler where it restricts airflow through the radiator. There’s no harm done, and we may just restrict airflow through the cooler with some tape until it gets warmer outside.
One thing we don’t like about our installation is the way we’ve plumbed the fittings on the bottom of the cooler. Our configuration may be trapping air pockets at the loops in the top of the cooler and causing less than peak performance. There’s no way for us to know for sure- and we don’t even know if it matters-but next time we’ll flip the cooler around 180 degrees to put the fitting on top and make sure there’s noting in the system but ATF.  

131-0302-TRAN-03
This was the author’s first experience with making braided stainless steel lines but now he’s sold on it. Orme Brothers in Northridge, CA hooked us up with the Goodrige hose and aluminum fittings. We installed the fittings and measured the length of hose required to connect the cooler, pressure gauge, and Accusump. When you’re routing your own lines you’ll want to make sure to support them every few inches with some rubber clamps. The lines will stand up to a lot of abuse, but can wear through whatever they rub against so keep that in mind.

131-0302-TRAN-04
Our shifter is still mounted to floor, but we’ve since positioned it further from the firewall. We still intended to make a mount that will locate the shifter up high to the right of the steering wheel like the versions we’ve seen in some professional rally racing cars. But until we do we’ve moved it to a more conventional floor mounted location. The beauty of the Art Carr cable actuated shifter is that it will work well in any position as long as you don’t kink the cable.  

131-0302-TRAN-05
The 72-inch braided Kevlar hose from Auto Meter turned out to be too short to connect the pressure gauge to the transmission if we mounted it on the dash. We moved the 2 5/8 inch Pro-Comp temperature and pressure gauges to the bottom of the dash where they are less visible, but don’t restrict our line of sight out the windshield either. It’s just as well because we don’t need to monitor transmission pressure/temperature too often- but if the TH700R4 were to start acting up the gauges will give us a better idea of what is going on inside before any damage is done. We also learned we could have gotten away with a 300psi transmission pressure gauge instead of the 600psi version we’re running. We’ve never seen our Autocrawler get close to 300 psi.

131-0302-TRAN-06
Due to engine problems with our Autocralwer-equiped Blazer we didn’t get to wheel in any situations extreme enough to starve the 700R4’s pump and test the Accusump to see if it could maintain line pressure in the transmission. What we have done since last time is refine our installation by removing the Accusump’s pressure gauge and release valve and plugging them so we don’t find out the hard way if they can handle over 200 psi of ATF. For now we’ve basically overfilled the transmission with 3 quarts of ATF and supplied 12-volts to the electric valve on Accusump the to keep the valve “open” or automatic mode to feed pressure to the transmission if the 10-vane pump in the transmission should suck air. We’ve also wired a toggle switch into the valve so we can store 200 psi of ATF in the Accusump to give the transmission line pressure without the engine running. We know we can use the pressure inside the Accusump to apply the first gear clutch pack but we don’t yet know for how long.  We believe the 3 quart ATF supply provides enough fluid to keep the first gear clutch pack applied (as determined by our Pro-Comp pressure gauge) for about 60 seconds but that’s still a guess because it’s hard to know for sure as we can’t turn the transmission’s pump on and off to test our theory. Even without knowing how long the 3-quart supply will last we feel confident in saying that it will be enough to keep you driving until transmission’s pump can take back over. If you plan to park your rig at an extreme angle and want to have ATF pressure when you start wheeling again we recommend you cut power to the electric valve to store the pressure inside the Accusump until you start driving again.

131-0302-TRAN-07
As you read this there are at least three TCI Autocrawler full reverse manual valve bodies with compression braking undergoing off-road testing. Ours has the hardest shift you can get out of a 700R4 valve body but a softer shifting version is possible. To build your own Autocrawler talk to Lowell or Will at TCI and they’ll be more than happy to sell you the valve body they developed for this article. This trick valve body will also route ATF fluid pressure to the torque converter clutch solenoid while in first gear (something that the stock valve can’t do) so that you can activate the converter clutch via a 12-volt switch whenever you choose. This makes for hill descent control that matches any manual transmission, and when combined with the artificial line pressure provided from the Accusump it is theoretically possible to turn your engine over without using the starter. Just like guys with manual transmissions can do.


Sources:

Art Carr
888/526-5868
www.artcarr.com
690

TCI
662/224-8972
www.tciauto.com

Flex-a-lite
800/851-1510
www.flex-a-lite.com

Auto Meter
815/895-8141
www.autometer.com

Orme Brothers
877/ORMEBRS
www.ormebros.com

Canton Racing Products
203/481-9460
www.accusump.com

Daystar Products
623/907-0081
www.daystarproducts.com