Trans fluid exchange again , and again, ...

[Moser97]

Ok guys I've read all the old threads about the pros, and cons. I have just bought a '99 Jimmy with 80k miles that's never had any trans service. I plan to go to Jiffy Lube and have them do a fluid exchange. I will make sure the use only the trans pump to move fluid into and out of the trans. I willl make sure they use only the original recommended fluid for this trans, with no additives. I will then drive the vehicle about a week (6 - 700 miles for me) and have my local guy drop the pan and change the filter, and top off with the recommended fluid only. I tow a small boat so I want to add a trans cooler too. Here are my questions.
What would you do differently?
Anyone got a specific cooler to recommend? My brother lost 2, S-10 transmissions towing this same boat. I know that heat is the killer of all transmissions so I want the biggest cooler I can get in the thing. I have heard of guys bypassing the radiator with the trans cooler lines on the theory that the radiator coolant will add heat to the trans fluid and the cooler itself will actually keep the trans at a lower temp than the radiator and the cooler on the return line. Frankly that idea scares the crap out of me. I would think you'd want the assurance that at least you have the radiator TRYING to keep the fluid at some reasonable operating temp. Any thoughts on that whole proposition?
Lastly I'd like to monitor this trans temp with an aftermarket oil temp gauge, but don't want to take the pan to have a half-coupling welded on for the sensor. Anyone have any experience with stick on, glue on, etc. sensors? I'm going from a full sized pickup to this smaller vehicle because of the 100 mile a day commute and gas prices. The last thing I want is to try to save a few buck on gas and end up frying a trans every year going fishing. Thanks in advance for all you suggestions.

[OverBoardProject]

Very good questions.

I would add the oil cooler myself and then take it to a transmission shop for a flush. There might be some contaminants in the cooler it's self.
I don't see any reason to go to Jiffy Lube. The transmission shops do a complete flush if they do their job right.

As for Oil Coolers. I don't know what brand is in my motorhome, but it's an aftermarket monster. It should really reduce the chances of overheating.

I like the idea of running the fluid through the rad. It helps the transmission fluid warm up when it's cold.

The easiest one is the temputure gauge.

I would run it in the new transmission cooler line.
Just get a sending unit that's got a pipe fitting end, and you can either use plombing parts or better yet air compressor fittings. You'll really only require a T fitting

[old_master]

Originally Posted by OverBoardProject

Very good questions.

I would add the oil cooler myself and then take it to a transmission shop for a flush. There might be some contaminants in the cooler it's self.
I don't see any reason to go to Jiffy Lube. The transmission shops do a complete flush if they do their job right.

As for Oil Coolers. I don't know what brand is in my motorhome, but it's an aftermarket monster. It should really reduce the chances of overheating.

I like the idea of running the fluid through the rad. It helps the transmission fluid warm up when it's cold.

The easiest one is the temputure gauge.

I would run it in the new transmission cooler line.
Just get a sending unit that's got a pipe fitting end, and you can either use plombing parts or better yet air compressor fittings. You'll really only require a T fitting

Great advice! Make sure you install the sensor in the inlet side going TO the cooler. That way you will know at what temperature the transmission is running. Or better yet, install a second sensor on the outlet and see what the cooler is actually doing.

[Moser97]

Thanks, this is really good advice. You'd think I would have thought of the pipefitting since I make about 5000 of them a day at work. I'll get a 1/2 or 3/4stainless "T" and reduce it down so there is lots of room for the sensor. Sorry about the second post. I thought the first one got lost and retyped. If the moderator wants he (or she) can take it down. Thanks again, and keep that great advice coming.

[BlazerLT]

Sounds like you are going the right way.

The tranny cooler in the rad should be good enough as long as it is flushed out but mind you the new fluid should do that in short order.

Just make sure you change the filter.