Boiling transmission

[vegas39]

This is regarding our motorhome, not my trucks but I trust the opinions here more than the rv site I belong to.
We have an 08 Winnebago 31 foot, on an E450 chassis with v10. Today, we were driving home from Arizona and on the last steep hill before Hoover dam, I looked in the mirror and saw a white haze behind me. I pulled over and popped the hood and there was trans fluid all over the place, guess it was boiling out of the dipstick.

I'm going to service the trans, as the coach has 58,000 miles and I dont know when it was done last. The chassis has a factory cooler but I'm not sure if its large enough. The fan clutch is working as should and the outdoor temp today is 102 degrees.

I'm definitely going to add a trans temp gauge but can you guys give me some suggestions as what else to do to help this issue? I would like to tow the car on our next trip and thats going to add more weight. Thanks.

 

[chris142]

needs a better trans cooler and keep the fluid at the add mark

 

[Desert Diesel Dog]

I had a very similar situation. It was with a '73 454 Chevy and a cab over camper.

This started unexpectedly after having this rig a real long time. [bought it new in '74] It Got Very Bad. Maybe something was failing in the transmission... I don't know.

Long story short... I put a nice big [external] transmission oil cooler on it and never had another problem with it. It cost me a hundred bucks in 1989 but it was WELL worth it.

 

[gandalf]

I'm not sure whether you mentioned it, but I'm assuming your motor-home has an automatic transmission. There are two things I would suggest.

Service the transmission. Make sure it's in absolutely top condition. I might even consider synthetic ATF.

Put the largest transmission cooler you can find on your motor-home. I have a Long Tru-Cool Max LPD 4739 on my truck carrying the cabover camper. My camper is high and wide, just like driving a big sail down the road. I have yet to come even close to overheating the transmission. Get a GOOD transmission temp gauge and install it asap. My gauge is an Isspro. Contact Mel (AGNEM) at Conestoga Diesel.

You can buy the cooler online at Amazon, TRU-COOL MAX, or I'm sure various other sites. Google is your friend on that.

I bought mine from Dieselsite, which is/was an advertiser here on our site. If they're still in business I'd suggest supporting them.

I've heard that the transmission coolers from the Ford 6.0 diesel trucks is also pretty good. That might be easier to find at a wrecking yard.

 

[HS108]

Get a LARGE Cooler like everyone has said on here, also I would add an inline filter with a magnet something like a magnefine in it to help prolong the life of the tranny

also run the cooler in series with your factory cooler, I see people make that mistake all the time

 

[chris142]

anothet thing you can do is to buy 2 trans coolers and plum them parallel. basically you need 2 "t"'s,hoses etc.those will really slow the fluid down in the coolers which makes it lose much more heat.

 

[vegas39]

I'm not sure whether you mentioned it, but I'm assuming your motor-home has an automatic transmission. There are two things I would suggest.

Service the transmission. Make sure it's in absolutely top condition. I might even consider synthetic ATF.

Put the largest transmission cooler you can find on your motor-home. I have a Long Tru-Cool Max LPD 4739 on my truck carrying the cabover camper. My camper is high and wide, just like driving a big sail down the road. I have yet to come even close to overheating the transmission. Get a GOOD transmission temp gauge and install it asap. My gauge is an Isspro. Contact Mel (AGNEM) at Conestoga Diesel.

You can buy the cooler online at Amazon, TRU-COOL MAX, or I'm sure various other sites. Google is your friend on that.

I bought mine from Dieselsite, which is/was an advertiser here on our site. If they're still in business I'd suggest supporting them.

I've heard that the transmission coolers from the Ford 6.0 diesel trucks is also pretty good. That might be easier to find at a wrecking yard.

I thought about synthetic, how good is it when compared to standard fluid?
Sounds like bigger cooler is the way to go also.

 

[vegas39]

Thanks for the reply's, guess I'll order the biggest cooler I can get and go from there. I know this poor thing is under a strain, especially all the crap we carry along. Diesel pusher will be the next RV but that wont be for a few years yet.

 

[idiabuse]

I thought about synthetic, how good is it when compared to standard fluid?
Sounds like bigger cooler is the way to go also.

! standard ATF turns to varnish and smoke around 350F Real deal Synthetic handles 500F like normal.
There is a reason they made synthetic fluid, it last longer holds up better.

All I use is AMSOIL last 17 years.

Holds up for me and worth every penny.

Over sized cooler and large diameter cooler
lines help control heat buildup.

you can upgrade cooler and lines
or switch to synthetic and be done...

 

[towcat]

spend lotsa $$$$ on a HD cooler with a built in thermostat controled fan. it will keep things under control. be prepared to leave $700 on the counter for the kit.


http://www.xtremediesel.com/BD-Powe...0606-DS.aspx?gclid=CKTg--ney74CFQpgfgodEaUA7g

 

[vegas39]

spend lotsa $$$$ on a HD cooler with a built in thermostat controled fan. it will keep things under control. be prepared to leave $700 on the counter for the kit.


http://www.xtremediesel.com/BD-Powe...0606-DS.aspx?gclid=CKTg--ney74CFQpgfgodEaUA7g

That is pricey but much cheaper than a trans rebuild and the peace of mind of not worrying every time I climb a grade. Most of our driving we do in this thing is in the hot desert.

 

[OLDBULL8]

I don't believe you have an E4OD, but possibly a 4R100 or even a 5R100 transmission.
How many gears does it shift into, 4 or 5?

Before changing the trans. cooler, it would be nice to see a pic of what you have now.

There is a possibilty that you may have a stuck open bypass on the trans., if the cooler is restricted in any way, the bypass will open and non or very little circulation thru the cooler.

You want to make damn sure the trans. dip stick is pushed in all the way, that forces any pressure build up to go out the trans. pressure relief valve. When it pukes out the dip stick there is a good possibilty of an engine fire.

In the environment you travel in, a trans. temp gauge is a necessity. Install it in the pressure test port.

Synthetic ATF is best to use, as long as it complies with Mercon V.

 

[vegas39]

I don't believe you have an E4OD, but possibly a 4R100 or even a 5R100 transmission.
How many gears does it shift into, 4 or 5?

Before changing the trans. cooler, it would be nice to see a pic of what you have now.

There is a possibilty that you may have a stuck open bypass on the trans., if the cooler is restricted in any way, the bypass will open and non or very little circulation thru the cooler.

You want to make damn sure the trans. dip stick is pushed in all the way, that forces any pressure build up to go out the trans. pressure relief valve. When it pukes out the dip stick there is a good possibilty of an engine fire.

In the environment you travel in, a trans. temp gauge is a necessity. Install it in the pressure test port.

Synthetic ATF is best to use, as long as it complies with Mercon V.

I believe its a 5 speed. One thing that really annoys me, is driving on anything but completely flat ground, the trans is always downshifting to a lower gear and I end up running in the 4,000 rpm range.

I'll take a pic of the cooler. One thing I do know, it has large hoses connecting to it, they look like 5/8 size.

 

[hotshotidi]

you need a bigger trans cooler and fan. make sure you duesch out the lines with trans line cleaner you have to get it from online. then use low psi blow gun it dry

 

[FordGuy100]

IIRC the van chassis got a smaller cooler than what came on trucks. Thats why they had more failures with the 5R100/6.0 in vans than in trucks (transmission wise). I will have to go out and measure my excursions cooler, perhaps you can fit one up front on your rig. Mine has a factory 31 row cooler (the largest one).

If your RV has a 4R100, I would be tempted to throw a torque converter lock up switch in the cab. You would have to put it into 3rd and 2nd on your own, but that should help a lot (if your pulling grades with the converter unlocked). The V10 should have enough umph to get you up the hills in a lower gear with the converter locked.

Is your shift indicator PRND21 or PRND321?