Real World Results of Towing in D vs. 3

[99Yuk]

So a week or so ago, I drove down to Barrie for the Annual fall Automotive Flea Market in Burl's Creek.

I was towing my Tritan alluminum 7x10 single axle trailer. I brought home a new Chineese import Dune buggy/Go kart for my kids.
While towing it home, I was using Android's Torque app to monitor temps.

I was noticing that my tranny temp was climbing to over 115c(240f) after a MCdonalds break.. I looked and found that I was in 'D'. I dropped it to '3' and watched. Over the next 5 minutes the tranny temp dropped to 95c(203f).

If ever you needed proof that towing in 3 vs D was better for your tranny, then look at a 20c(40f) temp difference. I was surprised at that.

I will always ensure that I'm in 3 when I do any kind of towing ever again. Even if the trailer is empty.


Hope this helps someone who may be undecided....

 

[Donnie Yukonie]

tourqe app?

 

[SunlitComet]

Uh, it says not to use overdrive when towing in the owners manual. For anybody who does not have one.

 

[Gzes]

Really? I always tow in D but I always have a 4x4 when towing

 

[SunlitComet]

 

[phillydog07]

Really? I always tow in D but I always have a 4x4 when towing

You tow in 4WD? Unless you are in adverse conditions, sounds like a very bad idea. Not supposed to be in 4WD on dry pavement.

 

[SunlitComet]

Really? I always tow in D but I always have a 4x4 when towing

http://www.extendedgmwarranty.com/owners-manual/chevrolet/1994-Chevrolet-Suburban.pdf

---------- Post added at 03:09 PM ---------- Previous post was at 03:08 PM ----------

or wet pavement either for long periods.

 

[Gzes]

No I never use 4x4 on road. I jus said that I tow with a 4x4. I have used 4x4 maybe once jus to play around in some mud before the drought I've here

 

[gpracer1]

Uh, it says not to use overdrive when towing in the owners manual. For anybody who does not have one.

It depends on how heavy the trailer or wind resistance, your gearing and the terrain. If on a flat at 65 mph, OD is fine. In the mountains it will constatly downshift and upshift, so better to leave in D.
What you really need to worry about is whether your TC is in lockup or not, because that is also a "shift" that can get damaged.....ask me how I know.

When it is not in lockup, your temps skyrocket since the TC is basically one fan blowing fluid onto another creating friction heat.

When in lockup, you dont have that, its like a manual trans as far as a clutch.

From my 99 owners manual:
You should tow in OVERDRIVE. You may want to shift the trans to THIRD or, if necessary, a lower gear selection if the transmission shifts too often (e.g., under heavy loads and/or hilly conditions)

 

[SunlitComet]

I see that in a 99 manual but something is wrong with that and your suggestions.

Gzes has A 94 model and that does not apply to him. Read page 2.23 of manual I posted above. Also in third gear the PCM commands lock-up when going faster the 75mph.

Also what you just said contradicts what 99yuk has posted about temperature.

Am I missing something?