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Posted (edited)

Morning guys, I’m wondering what I will need to have my trans hold 350 hp and reliably tow? I have a deep pan on the way and planning to do a lockup switch. I’m thinking I will do a set of rv275s and a small tuner of choice. So that’s about all I’ll be doing for power. Also what do I need to know about monitoring trans temps? What is to high and what is safe? 

Edited by JAG1

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With IBMobile following me to show him how to get to the highway he got out and beat me over the head at 180 degrees. :punish:

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Here is a pretty good chart of operating temperature vs life.  There is no perfect answer.  But the hotter you let it get, the more quickly you should change the fluid.

image.png.e834d43974159bb3dd1e1cd22aa2012f.png

 

HTH

Hag

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12 minutes ago, JAG1 said:

he got out and beat me over the head at 180 degrees.

It was when the temp went over 250°F

  I have the temp sender on the out flow line from the transmission to the trans cooler.  The trans temp will normally very from 155° cruising down the freeway to 210° in stop and go traffic when towing.   The fluid heat up quickly when under load but is slow to cool after. 

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I bump pressure to 120psi and run tractor transmission fluid in it.

 

If tools and ability to learn is high put shift kit in. But can bump oressuwith out a kit.

 

Put borge Warner solenoid sensor on to.

 

Couple hundred bucks counting 5 gallons of fluid.

 

That's what I'd do since I'm broke

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Posted (edited)

Depends on your definition of 'hold'. Running around town empty maybe but not towing or playing. At least not with the stock converter. Even with a billet upgrade you'd be on the edge IMHO.

Edited by dave110

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I agree all depends on driving habits.

My stock trany held stock power well running around towing 22k regularly to 250k mikes then I put in 7x09 injectors it would then slip but I still towed nit as heavy 16k max and ran it to 280k. New how much throttle and I rarely got on it.

 

It now makes better use of the same 100hp injectors woth a 65horse programmer that boost fooling. Makes alot ov power. How much I have no idea.

 

My tranny has most all the upgrades , added clutches. I did a billet single disc and billett flexplate. However much power she makes it holds it just fine towing or empty shifting through the gears with tires broke loose. Though I haven't done that in a while.

 

 

I think if tranny is healthy a shift kit to increase lockup and crisp shifts up across the board will only help it last longer and hold more power. Pressure will also be raised with stiffer springs that are included in the kit.

It takes alittle trial and error adjusting TV cable but it has alot to do with how it shifts aswell as holding capacity. 

 

350 is alot of power 120horse over stock and what the tranny was built to hold. I'd sure try it and did and ended up  building my granny but would have had to eventually build it if it was still at stock power

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11 hours ago, dave110 said:

Depends on your definition of 'hold'. Running around town empty maybe but not towing or playing. At least not with the stock converter. Even with a billet upgrade you'd be on the edge IMHO.

I want to be able to do to all three without worry. 

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dont concern your self with HP...pay attention to Torque.

 

the 47re is a 700lb ft torque number...in my case, i am right at that point, hence why I feel it has lived so long. 

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Remember the amount of torque trapped in the transmission depends on the final gear ratio also. Its very possible to have 700 foot/pounds of torque but destroy the transmission because your running oversized inch tires. I know 285's isn't huge but just placing the point out there. 

 

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Posted (edited)

Your transmission in stock form should handle an edge ez or quad XZT and some RV 275 or equivalent if you use it wisely. 

 

Very important to keep the trans temps under control under heavy use, a lock up switch and a drive to @Dynamic to install a full lock up valve body would be my first Choice

 

I had my trans rebuilt at 200k, went mostly stock with the exception of a billet single disc, been holding up for the last 100k, but I am having cooling issues with the heavy pulls, The ability to control lock up should help that situation 

 

@Marcus2000monster for better understanding of torque vs. horse power, A general calculation

350 hp x 5252 ( torque calculation formula) diveded by given RPM @2700 = 680 ft. lbs. of torque

 

more for your reading enjoyment, you might need a couple of beers and a shot after but it dont hurt to know to much :smart:

http://www.epi-eng.com/piston_engine_technology/power_and_torque.htm
 

Edited by 01cummins4ever
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Lock up switch will not cure heat issues if transmission is already working correctly in both 3rd and 4th. Only benefit is ability to lock second when towing in second to keep from heating transmission that's only fluid coupled in second.

 

If transmission is running hot locked in 3rd and 4th adding a switch will do nothing. Tourqe converter and clutched are are slipping creating excess heat.

 

I guess theres small chance to be unlocked towing in 3rd. But youd probly be under 35mph. In that case the switch will make it lock sooner at lower speed and rpms. 

 

In my opion the switch is un needed and definitely not a cure all. 

 

Locking second pulling loads of fire wood off the mtn for me would be the only benefit. I quit using the switch because for me its un needed. And I tow 16k regular. 

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@Evan  you are correct not a cure all, but in my situation I dont have any issues towing my 12k 5ver on flat or rolling hills and can keep sustained temps of around 175 to 180 and sometime creeps up to around 190, but nothing out of ordinary. Its the steep 6 percent and greater hills that are 4 miles or longer and have switch backs and make it hard to keep a speed greater than 35mph. and it seems that a torque converter to stay in lock up in first and seconded would be most beneficial in controlling the temps.

 

just wondering why you dont use yours, I haven't installed mine yet still trying to get parts lined up and funds for an upgraded valve body to make it useful in all gears

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I dont use it because I dont tow at 35mph.  But I think I'd downshift to second because rpms would be very low at 35 in 3rd

 

I played with the switch pulling hills tunning om freeway way used it as a smoke switch to real coal at 15rpm in 3rd.

 

I do have a use for it. But I'll have to modify the valve body someday to make it lock second. Every so often 2nd OS nice towing the excavator in city traffic. Where speeds never get over 35.

 

Stubborn I guess. I just never found it useful I did try it because everyone else does. 

It's a  heap mod si everyone should try just hopefully not at the cost of a input shaft

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I'm away for the weekend in the Peak District of Derbyshire. No mountains. Just very tiny roads that go up and down VERY quick so I bought a large vehicle sat nav as a lot of our roads are not 9k american trailer friendly, plugged the size of truck and trailer in and weight. Stupid sat nav does not do elevation. At one point I heard squealing like a fan belt slipping it was the rear tyres spinning as not enough traction for the weight, this was in 1st gear flat out,I had no choice but to do as we were too far in and no way of turning around,engine temps at 204 and just got over the top,in all maybe 1.5 miles but 1st gear steep and no chance of speed due to tight road and twisting corners. 53 block.... no leaks.... 47re not gone bang.... came up the same road today again but just the truck and videoed it.... truck sounded great on its own but 9k it was howling yesterday. When I get home its trans oil change and pan down for a look and engine oil change. I'll post vid of road with truck empty tomorrow. I was worried about the trans before.... not now. If it dies i'll fix it, I'll say there is no other vehicle available here to buy that would have got over the top towing 9k other than another american truck

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I know the angst you had.  After following Jag1 up and down the cow paths of Oregon my trans fluid was dark in color and it was only a couple of thousand miles old.  I use Valvoline synthetic.

 

@wil440 if you keep using your old transmission pan put a drain in it. It makes changing the fluid and dropping the pan a lot easier and cleaner.

You can drill a 13mm hole in the front left corner of the pan then tack weld a 12mmX1.25 nut on the inside and don't weld all the way around the nut; it's thin sheet metal.   Install an engine drain plug with plastic, fiber, or rubber washer.  I tighten to 25 Nm. 

IMG_6503.JPG.57a05248f6a9fcbe839688987ce81cde.JPG

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If fluid is changing colors with only a couple thousand miles it might be slipping.

 

Cow paths that keep you out of 3rd could be causing it to slip because torque converter is unable to lock in second 

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My fluid changed colour after about 3 miles straight up a valley, I'm actually glad I haven't got gauges as I'd have bottled it and still there blocking the road 

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8 hours ago, Evan said:

Cow paths that keep you out of 3rd could be causing it to slip because torque converter is unable to lock in second 

That's exactly what happened.  Truck was towing and going to slow for a 2-3 shift up; torque convertor working like there's no tomorrow for 20 minuets; trans fluid temp went over 250°F (121°C).. 

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Run in 4 low.

 

Youd need to reduce speeds and take advantage of the hidden gearing your truck has. Unless it's a 2wd in that case your fffffed. 

 

With tcase engaged theres less strain on motor and transmission. You then could get the converter locked in 3rd at the cost of reduced speeds. I'd rather go slower and make my transmission happy then to roast it with only fluid coupling going on.

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