2007 Tahoe - Trans Cooler?

[{tpc}]

Having a little trouble deciding what to do on this one. Seems hard to find any kind of info, even etrailer is lacking. Most people seem to either install the GM factory kit or have it installed by the dealer. This kit seems a bit on the small side, and it involves disconnecting the trans lines at the transmission and replacing them with supplied lines from the kit.

I successfully installed one in the envoy, but there are lots more pictures and descriptions and things to read. This one, not so much.

Anyone have any ideas on what fits, how big, and how to? I'm not quite sure where the radiator cooler portion is on the tahoe, and the last time I looked it seemed I might have to start disassembling things to figure it out.

Anyone see any issues with attempting to tow about 20 miles one way with it stock this weekend? Or should I definitely wait for the cooler to be installed?

 

[Ed H]

Unless you are towing a house, you should have no issues going 20 miles. I have towed many, many miles with the TB (no additional trans cooler) and it is fine. Hell, even my wife's '99 Montana has towed by 18' fiberglass fish-n-ski for probably 1000 miles in the heat of summer without an issue. IMHO, they are added security, not a requirement. I may get blasted for saying that, but that's my opinion.

 

[{tpc}]

Thanks for the reply Ed. I guess I am just nervous, lol. The truck runs anywhere from 180-200 not towing anything. Everything about it seems to run fine in relation to the motor and trans, I just don't want to mess it up because I was in a hurry.

My tow is really just to pull the TT over to the dealer "if" I think the hitch needs to be adjusted. That and to see how this vehicle does with the trailer. I may stop at home (which is on the way to/from dealer) and then its going back into storage. Some of the drive involves the expressway but only for about 2 miles.

I would estimate the weight of the trailer to be in the 4800 lb range, which the tahoe shouldn't have an issue with.

My choices are do it and stop worrying lol, wait and research the cooler a bit more before doing anything, or ask the dealer to install a cooler while its there this weekend for a brake fluid flush.

Any other thoughts?

 

[DocBrown]

The truck runs anywhere from 180-200 not towing anything. Everything about it seems to run fine in relation to the motor and trans, I just don't want to mess it up because I was in a hurry.


Any other thoughts?

The trans temp? If that's the case I wouldn't put a cooler on it until you get to the bottom of why its running that hot. Those temps won't hurt it, but my Sierra runs at 160 or so when not towing. Towing my 4800# travel trailer on flats it runs about 180.

For the short trip you are making I wouldn't worry though.

 

[{tpc}]

The trans temp? If that's the case I wouldn't put a cooler on it until you get to the bottom of why its running that hot. Those temps won't hurt it, but my Sierra runs at 160 or so when not towing. Towing my 4800# travel trailer on flats it runs about 180.

For the short trip you are making I wouldn't worry though.

Thanks doc. The manual states 180-200 is normal. It really just depends on ambient temp of the day. I mean when its 60-70f outside, its about 170-180 most of the time. When it is 70-90F its about 180-200. Saturday is supposed to be mid 80's, hence why I chose that number.

From what I have read on some other forums scanning the web, the trans temp doesn't seem outrageous. What year is your sierra? I think in 2008 they switched to the 6-speed transmissions, at least in the tahoe, so I am guessing the temps may not be comparable?

As for problems with the trans, I haven't noticed any, and the trans fluid, transfer case, and front and rear diff fluid were all just changed. Maybe I need to change the coolant as well? I can also inquire about it at the dealer when they do the brake fluid flush on sat, but not sure what type of answer I will get.

 

[{tpc}]

Ok so on the way home today I hooked up my torque app to the truck. Temps were identical between the app and the display in the truck.

This drive home was about an hour with stop and go 50mph to start, followed by about 25 min of 70 mph on the xway, finishing with more 45mph stop and go. Outside temp varied between 77 and 81F.

Once the trans temp "stabilized" as best as I can tell it was solid at 185. I saw one spike to 187, which also corresponded to an increase in coolant temp from a pretty steady 192 that had jumped to 195.

I wonder, would it make sense that the temp would be higher on longer higher mph drives like cruising at 70 on the xway? I spend quite a bit of time xway driving so a lot of my "data" relates to that..

 

[DocBrown]

What year is your sierra? I think in 2008 they switched to the 6-speed transmissions, at least in the tahoe, so I am guessing the temps may not be comparable?

Mine is a 4 speed, 4L60E. The full size PUs didn't get the 6 speed until '09 or '10. Mine also has the tow package which adds a factory trans cooler in addition to the one in the radiator. That might be the difference in temps. There aren't really many huge differences in the drive trains between the Sierra/Silverado 1500s and Tahoe/Suburbans 1500s.

 

[Ghoster]

There aren't really many huge differences in the drive trains between the Sierra/Silverado 1500s and Tahoe/Suburbans 1500s.

Agreed. My 2011 Tahoe drivetrain was virtually identical to my 2013 Silverado. Both have the external tranny cooler. A lot of people have the extra cooler and don't even realize it. Even my wifes 2012 silverado, with NO tow package, had the external tranny cooler.

 

[{tpc}]

Its odd then, because I know mine doesn't. It doesn't list it in the RPO codes nor do I see it in the grill. It does appear to have the avalanche style radiator, which maybe the silverados and sierras are the same, where the built in trans cooler...or warmer as it may be, is located vertically on the left hand side if facing the grill.

It looks like I can buy the factory kit pretty cheap online, and it comes with trans lines and everything. I'd like that for a more "finished" approach. I just think I'm going to have a hell of a time getting the trans lines in and out where they are located above the transmission pan...not a lot of room to work with.

Should I just go with an aftermarket deal like I did on the envoy? Or get a factory cooler and plumb it in without the supplied lines?

I need to find the instructions for the factory setup. I have a hard time believing it replaces the other one altogether, so if I new how they plumb it in, I could probably use the instructions and additional fittings off of etrailer, and just install it like they do for an avalanche on there.

 

[Ghoster]

Its odd then, because I know mine doesn't. It doesn't list it in the RPO codes nor do I see it in the grill. It does appear to have the avalanche style radiator, which maybe the silverados and sierras are the same, where the built in trans cooler...or warmer as it may be, is located vertically on the left hand side if facing the grill.

It looks like I can buy the factory kit pretty cheap online, and it comes with trans lines and everything. I'd like that for a more "finished" approach. I just think I'm going to have a hell of a time getting the trans lines in and out where they are located above the transmission pan...not a lot of room to work with.

Should I just go with an aftermarket deal like I did on the envoy? Or get a factory cooler and plumb it in without the supplied lines?

I need to find the instructions for the factory setup. I have a hard time believing it replaces the other one altogether, so if I new how they plumb it in, I could probably use the instructions and additional fittings off of etrailer, and just install it like they do for an avalanche on there.

The Avalanche is the same. I had a 2013 Avalanche as well. I am pretty sure the radiators are all identical. For the factory unit they just add the lines and add the external cooler. They don't subtract the internal cooler in the process, both are used.

 

[RayVoy]

Both coolers are used when an external cooler is added. I suspect one hose is different (one run from trans to cooler and a second short hose to connect the external cooler to the rad cooler).

 

[{tpc}]

Well just to report back, I finally got the factory trans cooler installed. The first one I got came with a bent trans line. The second one wasn't. SO unless ups comes asking...I now have a spare lol.

Anyways, the cooler install...well the lines were a bit of a challenge but I got them in there. Since the install, the temps are way down while not towing. Pretty consistently in the 160-170 area.

While towing, they seem to stay in the 185-190 range, but admittedly I have not towed in the main heat of the day yet. Not sure if it will have an effect or not. We towed to nashville and back last week from detroit, and the highest I saw going down was 201, and coming back was 207. Those temps didn't stay very long, and eventually worked back down into the 185-190 area, maybe a touch higher.

I'm not sure exactly what caused the 201 while in michigan. I am fairly certain that my letting cruise control handle one the hills that had come up is what caused the 207...it also caused a spike in the engine temp, the only time it did this the entire trip, and I believe they went hand in hand. It wasn't hunting but it did rev up pretty good and held it for awhile, until I saw what was happening and I backed off. After that, no issues whatsoever.

 

[Royalwapiti]

Had a tranny shop put an aftermarket Hayden on my TB. After two years a clamp failed and it dumped all the tranny fluid on the interstate. Lucky fir me I paid a fortune for a highway robbery service shop to deliver me 5 qts. No damage to tranny. Paid $251 for service on the interstate. Included adding. 5 qts and $1.59 clamp.


You did it the right way. But to alleviate your fears. I pulled trailers all the time without the cooler. You were worried about nothing for your 20 minute trip to camper dealer.