Topic: Need Help Auto or power???????

[surfindave]

Hey Guys i need help
I have a 2.4 turbo diesel with a auto transmission its a A343F auto almost same as the new tacomas auto.The power output is same as a 22r petrol motor approx.
I run 35s with 5.71 gears i know no1 likes 5.71 but i couldnt get any better crawl and have had them in the truck for 18mths now and no probs.
Went for a run Yesterday after just geting my SAS back after 7mths have driven it a few times but this time was a hard day.
Aird down the Xterains to 18 psi put her in 4wd and man she was a slug in both 4hi 4low i could hardly get her moving .
She seemd sluggish onroad but man offroad was shite.
Could not get wheels to spin in Low 4 with brakes on or at all .
Took her home messed around with it the engine has a code error so we tried to fix but couldnt rid the code.
The code said switch sign (not in park or neutal or A/C on )
But all where fine ??
Anyway at home today i did some tests maybe you can help
1 2wd hi tyres 35psi foot on brake hammer down and she spins rear so good
2 4wd hi hubs unlocked at front hammer down and same as above.
3 2wd low hubs unlocked handbrake tight as and foot flat on brake and she spun the tryes spitting gravel all over i thought good stuff.
4 4wd hi hubs lockd just couldnt get to spin or overide brakes not as good as No 2
5 4wd low hubs locked brake and hand brake just overpowerd brakes but not impressive .
6 Let tyres down to 12psi 4wd hi hubs locked no spin just couldnt get past brakes 
7 same as 6 only 4 low not much better than in hi range  
Blew up tyres and tried 1 and 2 she did the same but not as good maybe me just getn pissed.

Thinking about it it seems i dont have the power when drive has to go to all 4 wheels and when tyre pressure is lower it is even worse do you agree??

What do you guys rekn is my problem a power problem or an auto problem or crawl prob.
Either way i need to fix .
Im getting dual cases once marlin has the new couplers but having 2.28 in both cases.
Would this help me get the tyres spinning with my current setup as in No 3 4low with hubs unlocked but with locked hubs??
The auto seems to be working fine its a 4speed with lockup torque converter.
Please Help Dave

[FIREBALL]

Dave,
The whole idea of having 4wd is so your tires don't spin. Yes it will be harder if not impossible to spin your tires in 4wd. You do lose/use more power when in 4wd because you are turning so much more, and you will use more power when your tires are aired down, because there is more drag.
The auto robs large amounts of power from these smaller motors.To get the full potential from your motor switching to a five speed would be beneficial. The crawler will give you better wheelin ability, but it's not going to make it so you can spin the tires.
Finally check your front wheel bearings to make sure they aren't too tight, or worn. Jack up the front end, and make sure the wheels turn easily by hand. If they feal tight, then you could have a prob in front that is robbing extra power when you're in 4wd.
Good luck

[surfindave [OP]]

Thanks Fireball
Heres a pic of me new solid and bar not fully flexd in the pic but enuff for u to see thanks
Dave

[Ferg]

Another issue with an auto is heat.  Heat will kill an auto fast.  It will cause wear of the bands and result in slipping.  Make sure you have a quality trans cooler.  The factory set up is ment for the average joe drining on the street.

[surfindave [OP]]

Hey Ferg
Cooling realy isnt an issue i have a cooler fitted after the 1 in the radiator and have a temp gauge reading the temp of the oil returning to the tranny around town while in lockup she doesnt get hotter than 50deg celcius thats at 35deg C outside temp thats on return tho.
While the converter is in slippage the most she gets too is 70deg then i just hit the button and the twin fans come onto the cooler and bring it bak to 55deg i can crawl all day in low range and leave the fans on and the needle wont go past 55.
I am using an actual aironditioning condensor as the cooler with 2 fans mounted she sits up in the chassi and body right out of harms way works a treat.
The cooler is 18" long 9" wide and 1" thick with 2 9" fans.
I originaly thought it was the tranny heat but talking to a tranny guy who wheels hard told me if thats my temp goin in hed be happy with that it is even a bit of ovrkill to be so cool lol.
I think i just dont have the power to push the 4 tyres when they are all locked up i have detroit no spin front and rear so i am in full 4wd .
Do you guys rekn with a dual case fitted would i be able to turn the wheels at a lower RPM then just put her in drive and let er go thru gears when i need more speed?
I have no1 here in west aus with duals that have a auto and such a small motor so i cant see 1 in action tho i have seen suzukis with 6:1 low range and 1litre motors turning the wheels very fast.
But again thats  not auto or my truck.
When i meant spin i didnt mean as in a burnout type spin i meant turning the wheels with enough speed to pul the car.
This was my situation .
Was up a rock climb the fron wheels climbed over the ledge but i couldnt get the rear tyres up at a crawl i stopped and put the boot into her and she just couldnt get the tyres to turn and the revs of the engine wouldnt go past 1300rpm i reversed back went at the rock at 1450rpm and she went over no problems .
when i have a bit of momentum i dont have a prob but with rocks as you know momentum can be a killer so i try to idle or just over idle rocks but now with the solid maybe its heavier or having a full lokker is draining the poqwer i do not know .
Thanks for all your replies keep em coming and ill work on the motor and try fueling it up more in the lower end
Dave

[FIREBALL]

OOOOHHHHHH YYYYYYYYYYAAAAAAAAAAAAA, goin dual case will definetly help that. That's what Marlin built them for in the first place. With the Yota auto you are at a disadvantage trying to rock crawl, but if you can go duals it will make a huge improvement in your crawling ability!

[surfindave [OP]]

Hey Fireball
I found out what was wrong with my truck at last
It turned out that the torque converter has a low stall speed of 1300 rpm my engine doesnt produce enough power at those rpms to turn the wheels .
So i have a few options 1 is to get a hi stall converter at 2000rpm so my truck will develop the power to climb but comes with a risk of frying the converter and tranny
2 get approx 13% more power from my engine this will be enough to get me by with what i have but i dont think i can get that much more from the motor without it blowing .
3 and Best option is to get the ultimate dual crawler and be laffing crawlin around the hills or at least i hope lol.
Thanks for your input and help
Dave

[FIREBALL]

Yep, I think you would be very happy with the crawler. My uncle has a first gen 4runner with the auto and he would have the same prob on the big rocks, he put in 5.29's, and just that made a huge differance in how the auto worked. His still struggles here and there, but if he had duals I don't think he'd have any probs.