auto trans and backing

[drno]

i was speaking today to the diesel mechanic who was installing my guages and mentioned that i was concerned about the temps while backing a trailer with an auto trans. he replied " you have 4 wheel drive-just put it in 4 low" not wanting to appear stupid i just said " sounds good". will someone explain what he was talking about

 

[GFrance]

By using four wheel drive low range you will be backing in a lower gear & not putting all the load on the torque converter.

You havn't filled in your signiture, so we don't know what year truck or gear ratio you have. If it is a 2001. 5 or older you can get a 2low kit that will give you 2 wheel drive low range & make backing even eaiser by not binding up the front end when turnning.

 

[Bertram65]

I would not put it in 4WD unless you are on dirt, you will bind up the driveline and possably break something being in 4 low on pavement especially if you have a trailer attached. Backing up does heat up the trans pretty quick, even with a little load like 5k lbs my temp goes up 20 to 30 degrees in a couple minutes as I backup.

 

[cwsoules]

My 2WD heats up when I back my 10,400# 5er. With 15 minutes of manuvering it can get up to 230 degrees. As I get better in backing up the time required is reduced and the number of back and forth trips are reduced. If it gets over 230 I try to shut down and let the transmission cool for 30 minutes.

 

[Chipstien]

Don't start worrying untill you get over 220 degrees. How hot do you think the ole Torqflite gets.

 

[Joe G.]

I've noticed a temp increase while backing my 8000 lb TT, but it has not been excessive. Nothing to worry about just backing into an RV campground space.

 

[Matt400]

trans temps

I developed a kit that turns on the big vistronic fan for this purpose pulling lots of air through the trans cooler, works on 03 and newer. PM me if you want more info.

 

[y-knot]

Yes, yes I wouldn't put it in 4WD unless it was on the dirt ... . but we are not talking about a stock truck. Thats the beauty of the 2WD Low kit, it allows you to use the 4WD's low gears, but the kit keeps the front end from locking up or going into 4WD.

It is very hard on automatic trucks to do long periods of heavy backing. My tri-axle 16,000lb trailer will overheat a trany in under 2 minuets, if the road surface is rough and twisty. The reason it's so hard on the automatic trucks is two fold. First, most people that by these trucks tend to be fuel tight wads, they purchase a HD truck knowing they are going to be towing and still get the 3. 55's or 3. 73 ring and pinion gears. Thinking they will gain a mile or two per gallon, the tall gears seem like the wise choice, but really the lower gears are much better and easier on the trucks. Second, the automatics have a very high reverse gear. To get reverse, they usually use the 1-2 gear set, and hold the planitary gear housing . This gives you a reverse rotation, but keeps you in the high gear of the set. The end result is a reverse that is slightly under what second gear would be. You can see that backing a trailer, especially a very heavy trailer and then factor in the added friction of being in grass, how it would be very easy to get the trany hot. You are using second gear, the TC is unlocked, and there is very high load. Normally there is not a problem, and 90-95% of the time this arrangment is fine. Automatics make 40% more torque then a manual does when the TC is un-locked, this makes up for the added strain of backing in reverse, so under normal conditions very thing is fine. Just when you through in a trailer and add some incline of soft soil, it becomes a problem.

If you do have an automatic and have to back a trailer, after the moving is done, make sure you idle the truck for several minuets and allow the coolers to cool the trany fluid. It's on the same principal as allowing the turbo to cool before shut-down. The trany has built up alot of heat, and it not allowed to cool, the heat soaking that will occure, will damage some of the components.

Bob v, sell what I consider the best 2WDLow kit. It opperates electric free, and takes into consideration the proper way to disconect the front axle. His kit does not just interrupt the vacuum going to the front axle, it re-directs it. Our transfer case has a 2:1 low gear ratio, so by useing the low gear selection, you are greatly helping the automatic out, and in turn the backing gets easier and your trany will live much longer.

 

[Snow man]

it isn the backing that heats it up. I plow for 30 hrs straight 1/2 that time in reverse,its going 1 mph, in reverse that does it, your basically sheering the fluid the whole time. I have never had any temp related trouble form backing,not even my 3310 sunnybrook. I an only in reverse about 30 sec to 1 min max backing then cool down and shut down. !5 minutes in reverse is too long,IMO, it cannot be necessary, there has to be a way to not do that,even if it means installing a front mounted receiver and going forward,the trans is going to die early from all that heat.

 

[Matt400]

We have a favorite camp spot by a secluded lake, getting the travel trailer into it requires backing through a rough windy rocky section that takes about 10 minutes to get there making sure trees clear both sides and rocks don't tear off trailer plumbing all with no air flow. Now I just flip the switch and get plenty of air going over the cooler, makes me feel better anyway rather than working it hard with no flow.

 

[rweis]

I have a 13k 5er.



I put in an aux transmission cooler with a 1k cfm fan. When I need to back with the trailer I turn the fan on in advance and it gets the pan temps to 150*. I find the hot line rarely goes more than +50* (ie T/C work done) over the pan temps, so the hot line is running 200* (I monitor both the hot line and pan temps).



This system works in stop and go traffic, and I just pulled through the Smokey's for a week and ran the aux fan full time and never went over 200* hot line pulling hills at 20 - 30 mph not locked up (I wanted to see what actual conditions were going to be not locked up).



I put the fan switch in the cab so I have total control of the fan at all times.



Adding the aux cooler (H7B as per BK) took my transmission refill to 20 quarts.



LOTS of fluid, extra cooler, extra fan. I try to "Rough it Smoothly" when RV'ing.



Bob Weis

 

[DLBurns]

I would also go with Bob V's 2 wheel low kit... simple install and works like a dream.

I had to back my fiver up hill to get into a spot at our campground in LaConner WA and it was a piece of cake with the 2 whl low kit. Put her in 4 wheel low, flip the switch and just feather the brake to get er in the spot... . never have to touch the throttle pedal! transmission temps nevr got above 190!

 

[Warwagon]

Who or what is this Bob V's? Where would one find out about it?

 

[SnoKing]

Don't shut the engine down to cool the transmission. Put it in neutral and fast idle it. If you just shut it off the heat of the medal will just heat the fluid up more. Passing the fluid thru the coolers is what cools down the transmission case and components. SNOKING

 

[DLBurns]

Who or what is this Bob V's? Where would one find out about it?

Bob Verhoef - -- email address removed --



The two wheel low kit is a great addition if you are backing a heavy fiver into tight spaces. Just flip the switch put er' in reverse and feather the brake to back the trailer right on in to your site.

 

[PatrickCampbell]

When NOT in motion to cool the transmission, put the transmission in NEUTRAL and turn the A/C or condensor on. With the trans in park or in neutral without the clutch fan running, you will heat up to 180 F in no time quickly.

 

[y-knot]

The Bob V's 2WDLow kit is a great kit designed to allow you to use the transfer case's low range, while on pavement without the driveline binding problems associtated with 4WD. His kit is easy to install and works the best. It takes into account the properway to un-connect the front axle. most kits are electrical, and use a silinoide to simply interrupt the vacuum to the front axle disconnect system. This will allow the user to use 4Low, with the axle disconnected, but does nothing to hold the axle disconnect from sliding back and forth, within the housing. This type of 2WDLow kit is un-wise to use, the disconnect can get damaged or the the axle houseing and axle can be damaged by the loose disconnet. Bob's kit, does not simply inturrupt the flow of vacuum, it re-routes it so that the disconnect is durring 4low opperation, keeping the axle from disconnect from engauging while also suppling vacuum to hold it in place. Other on this site will have his web address, I lost my address book when I experianced a bad virus attack.





Bob v's 2WDLow kit installed on my trucks transfer case gear shift lever.

#ad

 

[JPike]

I have a Us gears unger drive cost about 2500 installed, can split al my gears and select ratios. especally good when backing, put it in low and go. with my t/t boat or anything rarly see over 215, and that is on grass w/ ambient air at 90 degrees

 

[Matt400]

When NOT in motion to cool the transmission, put the transmission in NEUTRAL and turn the A/C or condenser on. With the trans in park or in neutral without the clutch fan running, you will heat up to 180 F in no time quickly.

Its hard to say if running the A/C will help much, I know it makes the fan engage to keep condenser pressures down but with the compressor running the condenser super heats and that hot air then blows over the trans cooler. I think its better to just engage the fan clutch without the A/C unless of course its hecka hot out

 

[PatrickCampbell]

Its hard to say if running the A/C will help much, I know it makes the fan engage to keep condenser pressures down but with the compressor running the condenser super heats and that hot air then blows over the trans cooler. I think its better to just engage the fan clutch without the A/C unless of course its hecka hot out

Well that is the idea, to engage the clutch fan... but how do you do that without turning on the A/C? You can I'm sure, but not by default on our trucks. I believe our 03 fans are electronically controlled.