tranny guru's help me out

[yellowjacket]

got a stock th400 planning on building for this buggy. unfortunatly im not a tranny guy, so i have some questions.

definatly getting a reverse manual v/v and gated shifter from art carr.

i have no idea what guys are using as far as stall speed. s/s seems to be a term just loosely flung around. i know what s/s is, but which speed is relevent to my use is a guess. and im not a good guesser. any thoughts?

as far as a cooler, the bigger the better, and i know a lot of guys run line thru radiator and then a seconday cooler. but am i on the right track if i dont run it through rad at all? my reasoning is that doing so would instantly HEAT the fluid temp to the temp of the radiator(160-200?), and thats as cool as i could expect it to get...? and if i just run it through a secondary, though smaller, would maybe be a better starting point since it would be cooler... i am talking about a real trammy cooler with fins and a fan btw, not a pep boys ziptie special. any thoughts?

if i was to build build it, any other info? no matter where i take it, id sure like to know what i want before i send it out. im dumb enough as it is, lol

[yellowjacket]

rigs ive driven before, seemed like the stock t/c was nice and smooth when im trying to tiptoe, and the 2500+ were the cats meow when racing from stoplites.... like to have something in the middle, exept with a rmvb im throwing all that out the window...?...

application be 4.56's, 4.3 atlas, 40's, and rock crwling -rock racing. less than 400hp

[superjeep]

Ive got one of these ???

LYTRON 2,850 BTU/HR aluminium oil cooler . You will still need 12v fans for it I have pig tails for fan also.







Shawn

[gothodgie]

i have a good friend who is really good with tranny's... i have not talked to him since the spring, but i will get a hold of him and see how busy he is and what he thinks and how $ he might want to rebuild it for you...

As far as s/s i have always heard that stock is good for the kind of wheeling we do... I will get his opinion and let u know...

:beers:
chris

[yellowjacket]

shawn- link takes me to a empty online basket. did a lytron search , found only 1200-8000$ coolers. i must be missing what your describing. interested though.

hodge- yeah, ill take any info i can get. searched on pbb, lot of armchair mechanics out there. not like i know anything more(less, actually!) but after a while the opinions conflict and then it turns into a board war... you know how pirate is..

i apreciate any knowlege someone has to give me. thanx

[superjeep]

Try this : Lytron part number (1) ES0510G23 and (2) 6120G1SB

MSC part number (1) 07440753 and (2) 07440969


Shawn

[Hope Springs Hauler]

Stall speed bits I picked up from drag racing:
High stall promotes high heat
High weight pushes the rated stall higher
Low stall reduces slippage and heat
Low stall can make a rig more sensitive to throttle input

[yellowjacket]

found them now. thanx. the 0969 is def more affordible, they both look nice. i wouldent feel bad at all with that as my main cooler. are you saying you have one you wanto sell, or are you just telling me thats what you use.?

hsh- thanx. that helps out a lot. sooo... is there any reason that i wouldent just stick with the stock t/c?

[superjeep]

Yes, I have one for you .

shawn

[yellowjacket]

cant get pics on my phone. im interested in what you got though.

my tranny has a crack that cw is fixin to tig up. other than that its driver. i doo have to put a shorter output shaft in it for the atlas hes getting for me. if i have to tear it down too far id better just send it for a total revamp, but like i said, im an idiot when it comes to autos.

everyone keep the thoughts coming. learning a lot!

[Hope Springs Hauler]

My gut tells me that with the projected weight of your rig and intended purpose, a "stock" converter would be good.
I am assuming that the rig will weigh about 4k to 4500 and be used for all around wheeling. If it was going to be a dedicated racer, I might bump up the stall speed a little.
Also, don't forget that cam selection plays into this as well. If you choose a radical cam, you will need more stall speed to get into the motors powerband.

[yellowjacket]

cool. i may leave t/c alone then for now. cam is moderate duration- 1500-6000. cant go crazy cause im running pane, dont need rumpity anyhoo.

[carwash]

I ran a 2400 in the yeti and loved it. But keep in mind, you gear ratio changes that stall. The stall of a 2400 will only be 2400 when yer in 1:1. If you go 2:1, yer stall goes to 1200 rpm... that makes sense right? Well, when i was in 5:1 of my stak, it wanted to drive thru the brakes like crazy, but if i'm stopped, i just throw it in neutral or park. I could hold the brakes and keep it from moving, but you could tell it wanted to go. It was great when i wanted to creep up a rocky trail or ledge, it would just idle right up.

I will go with a 2400 in the new rig as well, cuz i got used to it and like it. I would recommend an 1800 for you Rob. But if you hate it, don't blame me, it's a huge issue of personal preference. It's not that hard to swap out of you hate it tho really.

I ran a nice derale cooler with built in fans, let me find a pic of the model i had. I ran a trans temp gauge and it never got high, even with the flogging it endured...

http://www.red9fab.com/ImageFolio4_files/gallery/Shop_Projects/Off_Road_Projects/995_The_Yeti/06buggy_517.jpg

http://www.red9fab.com/ImageFolio4_files/gallery/Shop_Projects/Off_Road_Projects/995_The_Yeti/06buggy_518.jpg

http://www.red9fab.com/ImageFolio4_files/gallery/Shop_Projects/Off_Road_Projects/995_The_Yeti/06buggy_519.jpg

http://www.red9fab.com/ImageFolio4_files/gallery/Shop_Projects/Off_Road_Projects/995_The_Yeti/06buggy_520.jpg

http://www.red9fab.com/ImageFolio4_files/gallery/Shop_Projects/Off_Road_Projects/995_The_Yeti/06buggy_521.jpg

http://www.red9fab.com/ImageFolio4_files/gallery/Shop_Projects/Off_Road_Projects/995_The_Yeti/06buggy_522.jpg

[yellowjacket]

cool. thats the style of cooler i ran on my steering on the red moon buggy. i dident know if just that alone would keep a tranny cool enough though.

yeah im a slow learner. if i understand you correctly, if i went with a 1800 stall t/c, if i shifted into 2:1, basically my vehicle would drive as if i had a 900 stall t/c....... which means that if im idleing at say 1000rpm (example), the t/c would be locked up 100% and if i put on the brakes i would either not have the brake power to stop, or my engine would die?

i must be thinking wrong, cause my case is gonna be a 4.3, and im sure in that range even, you can stop your rig...... now i have heard that its harder to stop then, but still it can be stopped.

surely im missing something...?

[Nuts]

T350,stock t/c (1100 stall i think), dual stock cases, 5:71s, and 40s. It'll barley stop in double low, but pretty much crawls over most obsticals by its self. I usually drive it like a manual and shift into neutral when I want to stop and put it in whatever gear is needed. My cooler is just an el'cheapo with a 12" fan and the tanny never gets too hot.

[Redriverranger]

I personally prefer a higher than "stock" stall. Your torque converter actual stall is a factor of rated stall and torque applied. It will change based upon the amount of power applied. Obviously gearing affects this, but it is not a true linear amount, so 2:1 gearing downstream does not affect stall by 2:1. As said before, the higher the stall, the higher temps encountered in the tranny. Mine is somewhere between 2200-2800, for actual lockup, and I had the converter modified to lower the stall last time through the tranny, as there is not hardly anything available for my setup and I was seeing a lot of heat. Stall is not the point that the tranny starts to pull, but the point that the converter won't "slip" anymore. The higher stall tends to allow more control to ease over obstacles for me. I have driven both low stall and high stall rigs. I would recommend something higher than stock, but probably only 600-1000 rpm. Anything more in a trail rig just generates too much heat, in my opinion.

[yellowjacket]

thanx for that info. sounds like carwash's recomendation of 1800 goes along with what your saying too, red ranger.... sounds like maybe what i should be looking for. speaking of heat, whats the danger zone temp? i like the idea of the temp gauge, especially if i throw some $ into the tranny.

[oklahomawelder]

thanx for that info. sounds like carwash's recomendation of 1800 goes along with what your saying too, red ranger.... sounds like maybe what i should be looking for. speaking of heat, whats the danger zone temp? i like the idea of the temp gauge, especially if i throw some $ into the tranny.


Im glad you are asking all of these questions. All I have to do is read. Only thing different I am running than you will be the LS6 engine and running 5.13 gears. Same TH400 and Atlas 4.3.
The buggy I pulled the LS6 out of was running 5.13 gears with a 3.8 atlas and a 2 speed powerglide and it had a 2500 stall T/C in it and was super responsive and worked well, but the HP of the LS trashed the inside of the T/C last time out, so I def want to get a quality T/C this time around....

[blazerbrad]

as far as a cooler, the bigger the better, and i know a lot of guys run line thru radiator and then a seconday cooler. but am i on the right track if i dont run it through rad at all? my reasoning is that doing so would instantly HEAT the fluid temp to the temp of the radiator(160-200?), and thats as cool as i could expect it to get...? and if i just run it through a secondary, though smaller, would maybe be a better starting point since it would be cooler... i am talking about a real trammy cooler with fins and a fan btw, not a pep boys ziptie special. any thoughts?



Running through a stock radiator will absolutely NOT "instantly heat the fluid temp". Most of the thermal conductivity is from the ambient (outside) air flowing over the cooling tubes, not from the engine coolant putting heat into the trans fluid. I'm not saying the engine temperature does not have some affect on the cooling ability of the trans cooler portion of the radiator, but it is not directly proportional (i.e. engine temp = trans temp). It's just another one of those theories that has turned into an "internet fact".

[carwash]

But it does reduce the radiators ability to cool either fluid as well. I choose to run a separate cooler for each just for that reason.

[blazerbrad]

But it does reduce the radiators ability to cool either fluid as well. I choose to run a separate cooler for each just for that reason.

A very small amount. Not like if your engine is always over heating that removing the trans cooler lines will solve the problem.