Nbs Silverado ?

[chevyhutch]

Hey Guys, I just bought a new 2007 NBS Silverado with the 4.8 engine, 342 rearend it's the W/T edition with the LS package. well my question is it has 300 miles on it now and i smell something like hot transmission fluid after driving and getting it hot. i pulled a 14ft. box trailer empty about 15 miles tonight and when i get home you could smell that trans fluid even my wife smelled it. the computer said trans temp was 196 degrees is this normal for a new truck? is it just burning off the new ? and what's normal operating temp for the transmission ?

 

Thanks, Rodney

[MS3DALE]

Well I can tell you that when I towed my buddies Corvette from down your way (Hickory,N.C.--I came up through Fancy Gap on I-77) to up here near Pittsburgh my tranny temp showed 196 degrees as well,I never smelled any trans.fluid though.

I'd say with everything we had I was pulling around 6,500 lbs.

[chevyhutch]

Well I can tell you that when I towed my buddies Corvette from down your way (Hickory,N.C.--I came up through Fancy Gap on I-77) to up here near Pittsburgh my tranny temp showed 196 degrees as well,I never smelled any trans.fluid though.

I'd say with everything we had I was pulling around 6,500 lbs.

 

 

MS3DALE, thanks for the reply. i wonder if my truck came with trans cooler on it ? if not, would you recommend installing one, and which one ?

i'm still wondering if it's just the new burning off the truck as it gets hot ? and also i noticed the other day i let it idle for a while as i was talking to someone, and when i got in the truck my temp gauge was well past the 210 degrees mark and the fans had not come on, is this normal ? i would have thought the fans would come on just past 210 ?

[C & A s Dad]

Rodney, 196 is not too hot but it seems warm for pulling an empty trailer as you described. However, even at 196 degrees you should not be smelling anything. You likely have a small leak if you are smelling something.

 

As far as an aux cooler. You can look in your grille just behind your bowtie and if it has an aux cooler, you will see a small radiator looking device that will be approx 5" tall x 11" long. If there is not one there, I would highly recommend you add one. You can get any brand you like, I personally use and sell Hayden who is our (CARQUEST) supplier . Just be sure you get a stacked plate designed cooler and not the old tube and fin style. With where you live, you will likely want to stay with one close to the stock size or maybe one notch up. I say this because if your winter temps get low enough, you could have your fluid running too cool. If you add an aux cooler, be sure to leave the fluid running through the radiator first as it does now and then to the cooler and back to the trans.

 

The CARQUEST part # on the OE size cooler is 77421. The # for the next size up is 77422 and the 77018 universal installation kit will help with mounting it.

 

Search Transmission Coolers on this forum. If you do not find enough info, send me a PM with your e mail address and I will be happy to send you some pics of one installed.

[MS3DALE]

Just like Trey said,I would definetly add a tranny cooler if you don't have one.

If you PM me your VIN and e-mail address I can send you a copy of the build sheet,It will tell us if you have a cooler,but you should be able to tell by just looking as Trey mentioned.

You could also get a GM accessory tranny cooler,Its part #19171484 and lists for $91.00.

As Trey said just make sure you get a "stacked-plate" style cooler.

[cerbomark]

take a look at the underside, if you dont see anything wet it could just be the new smell of evrything getting hot the first few times. I sometimes notice these things when pulling into the garage after a long trip and I have no leaks or problems. The fan should come on when ideling and temp goes to 210 or so. My fan comes on at that point. Trans temp seems normal too.

[Gozer]

For the first few hundred miles I noticed weird smells off my 2007 NBS Sierra as all the stuff burned off.

 

As far as temperature go, my 6.0L engine temp has never gone above 210, even pulling my ~6500# travel trailer over grades in Northeastern PA. Transmission temp has gone as high as 215 or so, but not for long periods of time. It more typically runs in the 180-190 range when towing.

[C & A s Dad]

I am old school when it comes to the E Fans. Being an '02, my Yuk Xl still has a mech fan and fan clutch. On a upper 90s day at idle for 10 minutes or so, after towing my 6500 camper it will creep up to 202 or 203. The minute I pull off and the fan speed increases, the water temp drops to 194 to 198 and remains there. The trans temp runs low 160 range on a upper 90s day but this is due to the larger aux trans cooler that I installed.

 

I realize 210 is not too hot and the E fans do a great job, but I wonder why the OE sets the engage temp so high?

 

I like the pull of that big mechanical fan when it is needed. Shoot, I have to warn my children not to walk too close to the grille when the clutch is engaged. It will pull em in there like a bug.

[jeff1018]

200 definatly seems too hot for the trans, while pulling an empty trailer. My vmax 6.0 ran about 170-180 pulling a 32 ft camper across the pocono mts. with no smell ever. definatly need to upgrade that trans cooler if I were you.

[chevyhutch]

I ordered the Tranny cooler today. it will be at the dealership tomorrow... waiting on a call from dealership to see what they would charge to install it. i'm not much on mechanical installations

but if they are too high i'll see if i can get somebodyelse to do it.

 

Thanks, for all the advice everybody