Transmission story - good & bad

[kjohn73]

My old 97 GMC 1500 4x4 Sub was just over 300,000 km, or about 200,000 miles. I pulled my little 197 only about 800 miles with it. My wife left her 01 Sub at home to get some work done on it, and took the old one back up North. She got about 46 km north of North Battleford and the tranny blew, good and proper. Oil all over and no go

Okay, we get it towed back to Canadian Tire at NB, I talk to the service manager, he says there is a good tranny shop there. I ask him to get the tranny rebuilt.

Done. $2800 bill. My wife gets her grandson to drive it to Saskatoon and leave it at her daughter's. Wife has the keys, so no one used it. We went to get it one evening. I get back to just north of Davidson. Tranny blows. Oil all over. I bought a bunch of oil at Davidson and nursed it back to Regina. Many phone calls later, CT says the transmission shop will ship another trans to Regina.

Guy at the shop in Regina phones me and says it needs a rad, big time. He figures that the trans cooler that is built in to the rad was plugged after the first trans blew and it was not flushed. He said it was toast, plugged good and proper. Okay. New rad put in and the old Sub is back on the road.

One thing the fellow from Regina made really clear - he said I should take those &$!(&% stupid aftermarket grille covers off. He said they restrict the airflow a way too much if you are towing in the summer. Tranny will overheat and kaboom. He said they are fine in the winter, not towing.

The oil comes from the trans to the cooler built in to the rad first, then to the exterior cooler, and the built in one will plug with crap when the trans blows. He showed me the converter from the second trans. It was almost the same color as the old Sub - a dark maroon!!

I didn't mind the first trans blowing, or even the second one, as %$#& happens. Lesson - take those blankety-blank grille covers off! Oh yes, and he cautioned me about pulling a trailer in overdrive - DON'T.

[clutch]

Sorry to read about your troubles. Good advise about covers in the summer and leaving most trannys out of OD. An auxillary cooler would probably be a good idea. From your post I assume you were just using the factory cooler in the radiator.

[Spike99]

I agree those non-factory front grill covers reduce "cooling" air flow in the front of the vehicle. When towing during warm/hot climate months, every bit of air flow (to keep ATF fluid cooler) does matter. Front grill winter cover like: http://cdn.autoanything.com/images/p...winter_new.jpg

My local transmission rebuilt my GM transmisison as well. I towed a properly weighted trailer one weekend but its extreme frontal wind made my trailer feel 2,000 lbs heavier (from its own wind drag). My transmision blew and it needed a rebuild as well. And, my local transmission specialist installed "next size up" Aux ATF LPD (Low Pressure Drop design) cooler - for next time I had to pull a "Wind Drag" trailer against a strong head wind again.

For my replacement GM Tow Vehicle, I called my local transmission for proactive advice. He told me that many GM transmissions run hot (from factory) and told me to install the "next size up" aux ATF LPD cooler within my new GM Tow Vehicle as well. And, he told me to install with vertical support bars to create 1" gap between the rear of the aux ATF cooler and its AC rad. During cold winter months, I manually install a thick plastic sheet around the aux ATF cooler. Thus, keeping its fluid contents warm during the cold winter months. Unknown to many, "too cold" of ATF fluid makes it too thick. And, too thick of oil is as hard on a transmission as "too hot" burning temp oil condition. During cold winter months, I simply wrap my GM's aux ATF cooler (like a winter coat on a human body). re: http://i178.photobucket.com/albums/w...interRAD-2.jpg & http://i178.photobucket.com/albums/w...rSupport-1.jpg

Long mumblings short... Remember to re-install the front grill cover or wrap your aux ATF cooler during harsh cold winter months as well. Keeping it warm during -20 winter months is a good protection trick as well... But, remember to "leating it breath" during hot summer months as well... Best of both worlds....

[AMC_Jeep]

Part of a trans rebuild or replacement is to flush the trans coolers out. If you ask a trans shop about this and they look at you funny RUN.

You should be able to tow in OD as long as it's not hunting in and out of OD. Especially running a 4L60E.

[kjohn73]

The old Sub does have an auxiliary cooler. I will re-install the covers now. We have snow. I do have to tow my trailer back home about 250 km, but I don't foresee any really hot weather any time soon!!