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2002 gmc envoy_slt
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2002 Envoy, 4WD, 3.42 diff. Inline, 4.2 Liter. I tow a couple of times a year, through the S.California Desert to Lake Havasu. There are a few long hills which might be tough on the transmission. Trans cooler necessary? Any other towing suggestions? Thanks, C good
 

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Western Canada Chapter
2003
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I would say if you kept it in 3 then no but it was be a very good idea to still get one; it would just be good piece of mind through those hills because the last thing you want is for your tranny to go out:no:
I'm thinking that if he lives where its hot it may be best to cool it with those nasty 3.42 gears. :undecided Cooling is never a bad idea :thumbsup:
 

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Basic Vendor- Skid Plates
2007 chevy trailblazer_ls
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Necessary? probably not... A good idea, given your climate and terrain? Yes...

If you were in AK, then over-cooling in the winter would be a concern, but it never really gets COLD where you are, but it does get REALLY HOT, so I'd say you'd be better off with a cooler...

Mike
 

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Not necessary but can't hurt, especially in the hot conditions that you tow in. Other tips? Tow in 3rd rather than Drive. Do you have brakes on your trailer? Not sure about your state's rules but many require brakes at that weight.
 

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2003 chevy trailblazer_ls
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For less than $100.00 and a little work it does help save the tranny. Even if you do not tow a lot.
 

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2007 gmc
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Always a good idea. Get a cooler with an integral bypass so the colder fluid bypasses the cooler till it warms up. Also helps the save the tranny fluid and therefore the transmission (not axles and axle gears) in stop and go traffic. I was seeing over 200F on the tranny fluid till I intalled my cooler. Now it typically stays at 180 or below.



I have a B&M which has an integral bypass and is cheap thru summit racing. Tru-cool also has coolers with the integral bypass.

What is cheaper, $50-$100 now or a new transmission later?
 

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I'd say yes... Hands down, unless you live in a REALLY cold climate a transmission cooler is never a bad idea. Note: I've cooked one transmission on my 03. Thought that I could cheat the odds "just a couple of times." Wrong... :weird: I know better and still did it.
 

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I have a B&M which has an integral bypass and is cheap thru summit racing.
Which one is that?? I can't find one with a bypass?? They do have the ones with a fan mounted on them, with a "thermostat", but that's the thermostat to turn the fan on... Link?

Tru-cool also has coolers with the integral bypass.
Eh... I looked at those, and I can't help but think they're pretty restrictive if they say "when the fluid is thick, it can't get through the fins, so it goes around the bypass, but when it's warmed up and thin, it goes through the fins"... It seems to me that if there's enough back-pressure in the bypass to force the hot fluid through the fins, that there is a bunch of back-pressure, which can't be good at all when it's cold...

Thanks,
Mike
 

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Which one is that?? I can't find one with a bypass?? They do have the ones with a fan mounted on them, with a "thermostat", but that's the thermostat to turn the fan on... Link?



Eh... I looked at those, and I can't help but think they're pretty restrictive if they say "when the fluid is thick, it can't get through the fins, so it goes around the bypass, but when it's warmed up and thin, it goes through the fins"... It seems to me that if there's enough back-pressure in the bypass to force the hot fluid through the fins, that there is a bunch of back-pressure, which can't be good at all when it's cold...

Thanks,
Mike

B&M Automatic Transmission SuperCooler # 70264

From the B&M website:
"‘LPD’ or Low Pressure Drop feature includes two bypass channels nearest the fittings to allow fluid to flow freely especially when cold to prevent lube system failure."

Tru-cool uses the same technology. From their website:
""Tru-Cool" self regulating coolers - it's the oil that regulates the cooler. That is the principle behind the revolutionary new TRU-COOL SR series of self-regulating transmission oil coolers. Thicker oil that is below the ideal operating temperature bypasses the cooler through the upper two plates. When the temperature rises, it becomes thin enough to pass through the entire cooler and receive TRU-COOL's superior heat transfer efficiently, automatically."

Tru-cool Transmission Coolers

It's you transmission so it's your call. Like I said, I have the B&M cooler and did not see any problems with it with winter in Georgia. If anything, it may have warmed up a little faster because of the slight so called restriction. Your call.......
 

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Transmission fluid does not get "thick" anywhere south of the Great Lakes in the USA...

I've seen it pour easily at -20 F. Gear oil and motor oil get thick, hence the recommendation for Amsoil synthetic, which still pours easily at -35 F. Transmission oil is no problem.
 

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Basic Vendor- Skid Plates
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Transmission fluid does not get "thick" anywhere south of the Great Lakes in the USA...

I've seen it pour easily at -20 F. Gear oil and motor oil get thick, hence the recommendation for Amsoil synthetic, which still pours easily at -35 F. Transmission oil is no problem.
Pour point isn't as relevant as delta viscosity, because trans fluid is thinner when it's hot than motor or gear oil...

Though, they do call it their "low pressure drop" system, so it may be OK... Knowing nothing about it other than the explanation on the product page made/makes me wonder...

Mike
 

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Pour point isn't as relevant as delta viscosity, because trans fluid is thinner when it's hot than motor or gear oil...

Though, they do call it their "low pressure drop" system, so it may be OK... Knowing nothing about it other than the explanation on the product page made/makes me wonder...

Mike
OK, even without the cooler your transmission is going to experience increased resistance from just the fluid being cold....unless you personally warm it up or have some kind of after market tranny heater......do you? So if these coolers are designed to have very similar characteristics as the fluid lines themselves, I guess you are saying adding ~2-3 foot of additional tubing will absolutely kill the transmission because of the additional friction the pump has to overcome because the fluid is still cold. Wow! Guess you could say adding skid plates will also add too much weight to the truck and add too much resistance to the transmission and cause it to fail. But you are right, you have to be comfortable and accept the decisions you make and the accessories you add to you truck. There is another inline bypass that will completely bypass the extra cooler but will still add some resistance to the tranny and probably kill it anyway. For me, all my trucks have AMSoil synthetics and axillary transmission coolers.
 

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OK, even without the cooler your transmission is going to experience increased resistance from just the fluid being cold....unless you personally warm it up or have some kind of after market tranny heater......do you? So if these coolers are designed to have very similar characteristics as the fluid lines themselves, I guess you are saying adding ~2-3 foot of additional tubing will absolutely kill the transmission because of the additional friction the pump has to overcome because the fluid is still cold. Wow! Guess you could say adding skid plates will also add too much weight to the truck and add too much resistance to the transmission and cause it to fail. But you are right, you have to be comfortable and accept the decisions you make and the accessories you add to you truck. There is another inline bypass that will completely bypass the extra cooler but will still add some resistance to the tranny and probably kill it anyway. For me, all my trucks have AMSoil synthetics and axillary transmission coolers.
Ever totally, completely, jump the gun and go straight out into left field without passing GO or collecting $200?? Answer: yes... you just did... I really didn't even imply any of that... In fact, in the post you quoted, I basically said it was fine...

My response was to GLF, referring to the fact that trans fluid is ~7wt, so it will pour about any time, but it does act differently warm compared to cold, so it would make use of this system.

Note that anything I tow with has a cooler on it (except the TB, for warranty purposes). The issue I've had in the past is when I am commuting on the highway in the winter (not towing), the trans doesn't ever get up to 160F, and doesn't bake the water out of the system, and things start to act funny when it gets down in the 0F and below range (TCC clutch freezing, SES light, etc), then acts fine for a few weeks after I drive hard in town, and get it good and hot... Because of this over-cooling, I have been looking for a thermostatically controlled cooler.

The only POSSIBLE issue I had with these particular coolers is not knowing how they work the bypass/plate arrangement... From the way it was worded in the limited material I saw on a sales page (not the page you linked to), it seems as if there is SOME extra resistance built into the bypass to get it the fluid to go through the plates once it warms up... Upon looking at good pictures of the coolers and the company's website, though, it looks like the lines are pointed in such a way as to point the fluid flow at the plates, but when the fluid is cold, it just back-flows through the bypass. If this is the only way that this works, that's just fine... Not as good as a real thermostatically controlled system, but better than no temp. control...

Gosh, I really didn't think I was going to have to go all "over, under, around, and through" (this is how we tie our shoe) on this, but hopefully you understand, now...

Mike
 

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Ever totally, completely, jump the gun and go straight out into left field without passing GO or collecting $200?? Answer: yes... you just did... I really didn't even imply any of that... In fact, in the post you quoted, I basically said it was fine...

My response was to GLF, referring to the fact that trans fluid is ~7wt, so it will pour about any time, but it does act differently warm compared to cold, so it would make use of this system.

Note that anything I tow with has a cooler on it (except the TB, for warranty purposes). The issue I've had in the past is when I am commuting on the highway in the winter (not towing), the trans doesn't ever get up to 160F, and doesn't bake the water out of the system, and things start to act funny when it gets down in the 0F and below range (TCC clutch freezing, SES light, etc), then acts fine for a few weeks after I drive hard in town, and get it good and hot... Because of this over-cooling, I have been looking for a thermostatically controlled cooler.

The only POSSIBLE issue I had with these particular coolers is not knowing how they work the bypass/plate arrangement... From the way it was worded in the limited material I saw on a sales page (not the page you linked to), it seems as if there is SOME extra resistance built into the bypass to get it the fluid to go through the plates once it warms up... Upon looking at good pictures of the coolers and the company's website, though, it looks like the lines are pointed in such a way as to point the fluid flow at the plates, but when the fluid is cold, it just back-flows through the bypass. If this is the only way that this works, that's just fine... Not as good as a real thermostatically controlled system, but better than no temp. control...

Gosh, I really didn't think I was going to have to go all "over, under, around, and through" (this is how we tie our shoe) on this, but hopefully you understand, now...

Mike
Sorry for passing go without collecting $200. Guess I did misread you intentions. Completely understand and agree with your last post. Sounds like you experience much colder weather than I do and have a much greater need for more expensive but better thermostatic and bypass capabilities in your cooler. Please accept my apologies for going ballistic and falling off the deep end. I just strongly belief anyone doing lot of towing, carrying much wait or lot of stop and go traffic in warmer climates should have a fluid cooler. I was also inspired by an envoy and added a power steering fluid cooler to my truck.
 

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2007 chevy trailblazer_ls
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Sorry for passing go without collecting $200. Guess I did misread you intentions. Completely understand and agree with your last post. Sounds like you experience much colder weather than I do and have a much greater need for more expensive but better thermostatic and bypass capabilities in your cooler. Please accept my apologies for going ballistic and falling off the deep end. I just strongly belief anyone doing lot of towing, carrying much wait or lot of stop and go traffic in warmer climates should have a fluid cooler. I was also inspired by an envoy and added a power steering fluid cooler to my truck.
It's no big deal...

Canyons don't come with a PS cooler??

I don't get really cold temps, but I usually am motorcycling to work if it's above 15F and no snow, so when I drive, it is either really cold, or moist, or both...

Mike
 

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It's no big deal...

Canyons don't come with a PS cooler??

I don't get really cold temps, but I usually am motorcycling to work if it's above 15F and no snow, so when I drive, it is either really cold, or moist, or both...

Mike
Nope. No PS cooler at all. Added a 24" rail (no bypass at all) mounted very similar to the envoy. Ugh,,.....wish I had a motorcycle again.
 

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I lived a big part of my life in Central Wisconsin. I've seen motor oil that acted like honey and gear oil that you could slice with a knife. It is not unusual in that part of the country to see temps in the -25 F or lower range. It gets difficult to move in the morning unless you take special precautions. Synthetic oils are the answer there, as their pour point is much lower than regular oils. Amsoil 75W90 gear oil pours like 30W in the summer, even when at -25 F.

I now live in Louisville, KY. People here THINK it gets cold in the winter... :weird: :hahano: :hopeless :suicide:

Anywhere south of Chicago, like Indy or especially Georgia, coolers year-round are really no big deal, and with the summer heat, probably a great idea even if one doesn't tow.
 

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Basic Vendor- Skid Plates
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I lived a big part of my life in Central Wisconsin. I've seen motor oil that acted like honey and gear oil that you could slice with a knife. It is not unusual in that part of the country to see temps in the -25 F or lower range. It gets difficult to move in the morning unless you take special precautions. Synthetic oils are the answer there, as their pour point is much lower than regular oils. Amsoil 75W90 gear oil pours like 30W in the summer, even when at -25 F.

I now live in Louisville, KY. People here THINK it gets cold in the winter... :weird: :hahano: :hopeless :suicide:

Anywhere south of Chicago, like Indy or especially Georgia, coolers year-round are really no big deal, and with the summer heat, probably a great idea even if one doesn't tow.
While this is true, you've got to watch how big a cooler you get... My Caprice (with 2.56 gears) with a 10x14 (or 12x16?? It was the biggest one the local parts store carried... figured I needed it because of the 2.56 gears) tube and fin cooler on it would stay below 160F in the winter (20F or below), unless I was TRYING to get it to go above that, or towing... It also only got to 210F once when going WOT for 10 minutes up a mountain, towing 3000# in second, without lockup... Towing on level ground on the interstate, the temp would stay around 160F in 85F ambient. I really had too large a cooler on it, which contributed to the over-cooling that I was seeing... I even had the aux cooler before the radiator cooler, in an effort to pick up heat from the radiator, to not over-cool as badly.

Mike
 

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Anywhere south of Chicago, like Indy or especially Georgia, coolers year-round are really no big deal, and with the summer heat, probably a great idea even if one doesn't tow.
Would still recommend a bypass of some sort to help the transmission warm up faster. Atlanta is nothing but stop & go traffic from 7-9am and 4-7pm. Takes be 20 minutes to get to work off peak and without traffic but nearly an hour on a good day in those time frames above during the week. The hot weather and stop & go traffic really cause temps to rise. Pre coolers and pre synthetics I was seeing oil and tranny fluids over 200 and intake temps in the 140s.
 
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