trailblazer tranny question

thecakerator

Active Member
Jul 3, 2008
242
MI
we just recently purchased an 06 traiblazer and have heard that these transmissions tend to run on the hot side all the time, but towing makes it even worse. We are thinking about installing a tranny cooler but don't know where to begin. Does anyone have any advice on what the best one out there is? Thank you.

1995 Viking 175SD
2006 Chevrolet Trailblazer
 

Raycfe

Waterford Ct.
Oct 3, 2007
18,440
Waterford, Ct
You will want a cooler that looks like a small radiator. Not one that looks like a piece of tubing bent as a "S" with fins. The location where it will be mounted in will limit the size you can use. Careful with the Transmission cooler lines, trailblazers had problems with them, and they crossover from one side to the other. I would not try to disconnect them, just cut the needed one for the hoses. There is a new Transmission fluid that GM came out with that will also help the problem. Dextron 6. Hayden is a good brand and is sold thru NAPA stores. or etrailer.com

83 JaycoJay 806, 04 Grand Cherokee, Ray and Jin
 

Keepcamping

North Central MD.
Oct 2, 2007
46
North Central, Md.
I'm not sure how much money you want to spend, but here is the one I installed on my Trailblazer http://tinyurl.com/dejfth . It works great. Keeps the fluid cooler than the stock (in the radiator) cooler. Just be sure it is hooked up correctly and there is no need to cut any present transmission cooler lines. Like Raycfe said, stay away from the cheaper "S" tubing with fins. Hope this helps.

Kevin
03 Trailblazer
08 Fleetwood Sun Valley
 

awsandlin

Super Active Member
Mar 3, 2008
1,338
If you ask, "do I need a transmission cooler" on this website, the answer is always yes. I asked if my son needed on on his bicycle to pull his wagon and got 14 yes replies in 10 minutes.

Allen
2004 Fleetwood Utah
 

Keepcamping

North Central MD.
Oct 2, 2007
46
North Central, Md.
After giving this some more thought today and seeing Allen's reply, before you add a transmission cooler, ask yourself a couple of questions first. How much weight will I be towing (camper weight plus everything in the Trailblazer including camping equipment and people)? Will I be towing in extremely hot weather in very hilly or mountainous terrain? Will I be upgrading to a heavier HW camper in a few years?

Your Trailblazer has a transmission cooler that is inside of the radiator, but it only cools the fluid to the temperature the water/anti-freeze cools. Does cool it enough? Probably if you are not towing 5000 Lbs. in 100+ degree weather in the mountains.

I haven't heard of any problems with the transmissions as far as towing. The main reason I added the cooler to my Trailblazer is some of the mountainous and very hilly areas I go camping at. And I don't know if I will take a trip to the 'Dark Side' in the future. Hope this clarifies things a little.

Kevin
03 Trailblazer
08 Fleetwood Sun Valley
 

mbopp

Active Member
Jun 25, 2004
111
I installed one in the Envoy. The preferred one is a "stacked plate" design. Most stacked plate coolers are made by Long Engineering, a division of Dana. Summit Racing sells the B&M branded version. Get one that's 3/4" thick, the center support on the TB prevents you from using a thicker one. Even so I had to use a die grinder relieve a bit from the support but mounting it lower would avoid that hassle. Cutting & splicing the cooler line isn't too bad. You can pull the clip off the cooler line at the radiator, pull the line out of the fitting, and cut & fit it as needed. Be careful you don't lose the hairpin clip.
The 4L60E used in the TB transmission doesn't have a strong OD (4th) gear so I tow in 3rd or "Drive."
Dexron VI replaces Dexron III as the factory-fill and can be used if you do a fluid flush. Mobil does not recommend their synthetic fluid for Dexron-spec'd vehicles.
Actually for a PUC I wouldn't worry about it. I only installed mine for towing the HTT. YMMV.

'04 Envoy
'05 Travel Star 21SSO
17' Wenonah Kevlar & 16' Dagger Royalex canoes
And DD's Necky kayak
 

thecakerator

Active Member
Jul 3, 2008
242
MI
Thank you for all your responses. This job seems awfully complicated, do you have to be very mechanically inclined to do this on your own? We have a towing ability of 5750lbs, I would say total with people and the pup we will be pulling and carrying close to 2500lbs. We won't be towing on hilly terrain as we live in MI and it is almost completely flat here. But it does get very hot in the summer months.

1995 Viking 175SD
2006 Chevrolet Trailblazer
 

96Rockwood

Active Member
Mar 21, 2008
654
Whitmore Lake, MI
^^In my opion, you do not need a transmission cooler for your TB. MI has not real hills nor is it 115+ degrees. Just put it in Drive and go, if it starts to hunt gears shift it into 3rd. The 4L60E in these is stronger than people give them credit for.

Camping with a PUP state of mind in a Historic '78 Class C. The PUP's TV ('99 Cherokee) has now become the "TOAD"
 

thecakerator

Active Member
Jul 3, 2008
242
MI
ok .. thank you all for your help! We will figure it all out before our trip in June.

1995 Viking 175SD
2006 Chevrolet Trailblazer
 

Storm Trooper

Home is where you park it!
Feb 14, 2008
3,544
Where my camper is parked now.
There seems to be a lot of interesting comments on this one.

No one has asked if it had a factory tow package. If it does, I'd definitely say you don't need extra cooling for the transmission.

That being said, $100 to $150 for a transmission cooler is cheap insurance against a heat related transmission failure if you don't have a tow package. At the prices to get a rebuilt or replacement transmission, it's a no brainer.

Vehicles including SUV's are not built the way they used to be for extra capacity. The manufacturers try to build for the most common use of their vehicle and the most mpg which is use the lowest weight possible. That usually means that not a lot of extra capacity is there.

Ultimately, it's your decision and responsibility. There was a recent post in the towing section about their vehicle which the manufacturer of that vehicle stated that over 1000 lbs, the trailer needed brakes. Now this was a full size truck, one I never would have suspected would have that requirement. However I will admit I don't know better than that truck manufacturer does and certainly would not recommend towing that pup without brakes.

Lou & Jan and k9 Kyleigh Wyote (fuzz ball)
32 days booked 09,<img src=../Images/icons/icon_smile_camping.gif border=0 align=middle alt="Camping">49 nights camped 08
07 Fleetwood Avalon (Great White B&B) 03 Ford Expedition (Green Monstah)

Edited by - Storm Trooper on April 27 2009 13:11:33
 

jtuc1

Northeast Alabama
Sep 3, 2007
273
I just got one from www.transmissioncoolers.us
The price was right. It is not a tube and fin cooler but instead is built like a radiator. It is a Hayden transaver plus. They come in several sizes. I got the one rated for 5000 lb towing for my GMC 1500. I will let you know how the install went after I am finished.

2003 GMC Sierra 1500 2WD ext cab
2005 Fleetwood Victory
 

cksteele

now where did i put that hot dog
Sep 3, 2008
274
bristol ct usa
I am with the trooper on this topic. If it is not equipted with a tow package then by all means put one in. It is not as complicated as it seams just take your time and read the directions. The hardest part i found was just findeing room to mount it is all. Do that first and go from there. I hope this helps

chuck

2008 palimino stampede hybrid
2005 chevy silverado
 

Tahoein Bunch

Active Member
Feb 4, 2009
116
Anytime You can cool the oil in a tranny you are money ahead, The TB trans are real good, Never Tow in OD always tow in 3rd. Some people will say it's O.K. to tow in OD but It will Burn up your OD clutchs and that ain't a cheap fix. Get the Cooler tow package you will already have an external cooler if not put one on. Bypass cooler in radiator you will not need it after you put on a Good after market Cooler.

Just my .02

1996 Rockwood 1910 98' Tahoe 4WD and 01' Wrangler,DH 64' DW '63 DS 94' DD 97' Dodot 01' and Jenny 06'
 

awsandlin

Super Active Member
Mar 3, 2008
1,338
I had a 1998 Ford F150 that I owned since new. I towed everything, boats, flat bed trailers, popups, etc. Never had a transmission cooler other than the factory one in the radiator. I pulled in overdrive all the time. I did my own service on my transmission and I can assure you, I never had any wear on the transmission. I last changed the filter and fluid at 160K and everything was still looking great. The Over Drive gear is just the next gear after the 3rd gear or the 4th gear or whatever the last gear is in your transmission. No one would ever say don’t use 3rd gear or don’t use 2nd gear. Why would you not want to use 4 gear? I have never understood this. The only issue is you don’t want your transmission to be shifting between gears constantly. So, if it is shifting between 2nd and 3rd, you have the same issue as if it was shifting between 3rd and 4th. The issue is to control the shifting. The issue is not “don’t use overdrive”. Over drive is just another gear. If you were driving up a hill at 35 mph, your transmission might be shifting between 2nd and 3rd. So, are we going to see post saying, “never tow in 3rd gear”. The real issue is control your shifting we needed. On a flat stretch of highway, you are just wasting gas not using your overdrive and you are generating more heat on your transmission and engine regardless if you have a cooler or not. There may be times when towing you want to cut off your overdrive, but I would suggest there are times when you are not towing you need to cut off your overdrive. The issue is, is the transmission shifting excessively.

Allen
2004 Fleetwood Utah
 

Storm Trooper

Home is where you park it!
Feb 14, 2008
3,544
Where my camper is parked now.
Allen,

I have done quite a bit of investigation on this and found out that Ford truck transmissions are built quite differently than almost everyone else. They actually provide more fluid flow in overdrive than they do in lower gears, thereby providing more cooling with a stock setup.

The other companies trucks are providing less fluid flow in overdrive than in lower gears, obviously providing less cooling. Chevrolet in particular has a tow/haul mode to reduce this problem. This is typical to the most autos are designed. After seeing the number of failures in Chevrolet transmissions in our fleet, because drivers are lazy to put it in the tow/haul mode even towing the smallest of utility trailers, I have been convinced of this. My prior employer bought Ford trucks and we never had the problem I have seen here.

So basically it is not just shifting more often when in OD, but cooling (killer of trannies) is the problem with other makes.

Lou & Jan and k9 Kyleigh Wyote (fuzz ball)
32 days booked 09,<img src=../Images/icons/icon_smile_camping.gif border=0 align=middle alt="Camping">49 nights camped 08
07 Fleetwood Avalon (Great White B&B) 03 Ford Expedition (Green Monstah)
 

96Rockwood

Active Member
Mar 21, 2008
654
Whitmore Lake, MI
Ok, bottom line, what does the owners manual say on towing weights, non-tow package vs. tow package. If you are under the max weight of the non-tow package you are fine. Put it in D4 and go. If it starts to hunt betwen 3rd and 4th shift it to 3rd for that condition.

I tow in overdrive all the time, no matter what the vehicle is. I tow our 13,000 lb boat in 4th with my pickup and I am 3,000 lbs over the max tow rating, haven't had a problem yet and trans temp gage has never gone above 190F which GM considers the operating temperature of their transmissions.

Bottom line, look in the manual see what it says for your configuration (vehicle) and go. If you need the cooler based on that info then add it. It took me 1 hour to put one on the Motorhome 2 weeks ago. Not a big deal. If you don't need it based on the manual, don't worry about it. Put some trust in the transmission calibration and durability engineers at GM. Their transmissions are the benchmarch for most of the industry and many companies buy transmissions from them for their vehicles because of this.

If you have any questions PM as I have more extensive information on GM transmissions and how they work that I prefer not to disclose in an open forum.

Camping with a PUP state of mind in a Historic '78 Class C. The PUP's TV ('99 Cherokee) has now become the "TOAD"
 

Storm Trooper

Home is where you park it!
Feb 14, 2008
3,544
Where my camper is parked now.
96 rockwood,

I absolutely agree with following the manual.

I just reviewed some of the older Chevrolet pickups in our fleet and they say specifically if you are towing a trailer to put it in 3, not od.

I also looked at a 2007 - 2500 Silverado and it says to use the tow/haul mode when exceeding 75% of the TV capability.

That's different from earlier tow/haul modes in the 1500 series. I am trying to get a manual now.

One important question though, are you saying that the GM transmissions provide more coolant flow in OD or less than drive (3). That would be something I was not aware of and if so when did that change?

Also, towing a 13000 lb boat is nowhere near the loads imposed on the tranny while rolling, than a 13000 lb trailer. Once that boat is rolling there is minimal wind resistance compared to a trailer.

And yes, I do put some trust in the engineers at GM and am not denegrating their product, but am following what they recommend. My comment about GM transmissions what that it was our drivers error in not following what the manual said, not about GM in any way.

Bottom line is, most people that tow don't have a transmission temp gauge. If you are in any question about the capability of your vehicle, check the manual, check with a reputable dealership repair department and find out.

One other thing, Ford and GM worked together to design their new 6 speed auto trannies and I'm not sure how close their final product is to each other and what the new recommendations are. Most important, Follow the manual......

Lou & Jan and k9 Kyleigh Wyote (fuzz ball)
32 days booked 09,<img src=../Images/icons/icon_smile_camping.gif border=0 align=middle alt="Camping">49 nights camped 08
07 Fleetwood Avalon (Great White B&B) 03 Ford Expedition (Green Monstah)
 

thecakerator

Active Member
Jul 3, 2008
242
MI
wow .. there is so much information here to consider! I don't think our truck came with the extra factory tow package, it has a hitch but that is pretty much it ... I will have to get out the owners manual and read up on towing capabilities. I know how much we are supposed to tow, but that is about it. Jtuc1, I would appreciate hearing more about the trans cooler you added and how the installation went. Thanks again for everyone's help, I will keep you updated as we figure out what to do!

1995 Viking 175SD
2006 Chevrolet Trailblazer
 

awsandlin

Super Active Member
Mar 3, 2008
1,338
I don’t know about all GM vehicles, but on my 2009 Silverado the tow haul mode does not cut out the overdrive. The tow haul mode is used to change the shift points. Basically, the tow haul mode causes shifts to occur later, or at a higher RPM. As far as the use of overdrive, the two haul mode does not prevent the overdrive from being used. It does cause the transmission to shift into overdrive at a higher RPM and also delays the shift out of overdrive so that it reduces the number of shifts into and out of overdrive. The driver could do the same thing by controlling acceleration. The owners manual does not say not to tow with the overdrive on, (as a matter of fact, there is no “button” to cut the overdrive off). One could put the shift lever in “3” to cut stop the shift into overdrive.

Allen
2004 Fleetwood Utah
 

Storm Trooper

Home is where you park it!
Feb 14, 2008
3,544
Where my camper is parked now.
Allen,

Is that the new 6 speed transmission?

The quote below makes me think the new Chevrolet and Ford trannies are closer than I thought. The Ford engineer I had spoken a few years ago told me plain and simple leave it in OD unless the trans is hunting. More cooling was available in OD.


The following is off the gm-trucks.com website and was on the half-ton forum.

"Tow haul mode changes the transmission shift points to optimize the engine power. It also locks up the torque converter sooner to prevent overheating. If you are towing, I would recommend always using tow haul mode.


--------------------
General Motors Grand Master Technician
VISIT ME AT http://www.justanswer.com/car/chevrolet?r=...orilla&bt=0
Ask for Blue Gorilla in the Chevy Category."



But all of our discussion still doesn't answer anything for thecakerator's question.

It's important to follow your vehicle manual. It can change one year to the next.

Lou & Jan and k9 Kyleigh Wyote (fuzz ball)
32 days booked 09,<img src=../Images/icons/icon_smile_camping.gif border=0 align=middle alt="Camping">49 nights camped 08
07 Fleetwood Avalon (Great White B&B) 03 Ford Expedition (Green Monstah)
 




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