I'm trying to figure out how much my TB (04 L6 EXT) can tow. The owners manual gives me three options from 4800 to 5800 lbs, depending on the axle ratio. How do I find out what the axle ratio is? I can't find it on any placard (the one in the glove box is a long string of indecipherable codes).

Also, is it the total dry weight of the trailer that must fall within the towing limit (assuming I haul it dry), or the trailer's GVWR?

I presume I'll need to add a transmission cooler? Is this a DIY capable project? Any good sources for kits? Or is it a dealer only thing?

Finally, there's a sticker on the receiver that says max 4000 lbs. Is this for the truck or the hitch? Does this mean there's a 4K limit, no matter what the axle ratio is?

Thanks.

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The reciever max weight is the total weight of your trailer loaded.
Tounge weight is the weight on the tounge loaded.
Also remember no towing in overdrive.
That can be found in your owners manual.
Most rear ends have a ID tag on the inspection plate with gear ratio.
Or have your dealer run your vin no.
You can find transmission oil coolers at your local parts places with the instructions on how to install them. Always go a little bigger if you can.
Also if you are going to be doing a lot of heavey towing you might consider a bigger radiator to.
Good luck MT

OK, a tranny cooler can be had for ~$50 plus install for a B&M racing one off summitracing.com. It is a fairly easy DIY, but it isnt required for towing unless you are really pushing the limits of your capacity, but for 50 bucks its cheap insurance IMO.

The hitch says 4K lbs for weight carrying, not weight distributing which is always higher on all vehicles. If the weight is spread out like in distrubiting, then you can tow more as not as much stress is placed on the tow vehicle.

The weight of the trailer should fall within the capacity of the TB to make sure it can safely start and stop the trailer (many people dont realize the brakes play a part in determining the towing capacity). I tow 2 boats, a 3400lbs dry outboard and a ~4000lbs dry inboard. Loaded, I figure adds about 500-800lbs to be generous, but my TB has never skipped a beat, ever. Granted I have the SWB model which weighs less than the EXTs and has a higher towing capacity for the I6 engine due to the less weight.

The rear axle ratio is located in the glovebox in the codes, the codes are listed below:
G80- Locking Rear Differential, heavy duty
GU6- 3.42 gears
GT4- 3.73 gears
GT5- 4.10 gears

For mild to heavy towing, you should probably have at least the 3.73s, otherwise you will be working to get up to speed but it will still manage. I have the 3.73s in my TB, and Im really glad I didnt get the 4.10s as they have great acceleration and better towing capacity but the trade off is crappy mileage.

Erik- excellent info on the diffs & option codes. Any idea if they are dana rears on the TB's?

Joel

OK, a tranny cooler can be had for ~$50 plus install for a B&M racing one off summitracing.com. It is a fairly easy DIY, but it isnt required for towing unless you are really pushing the limits of your capacity, but for 50 bucks its cheap insurance IMO.

The hitch says 4K lbs for weight carrying, not weight distributing which is always higher on all vehicles. If the weight is spread out like in distrubiting, then you can tow more as not as much stress is placed on the tow vehicle.

The weight of the trailer should fall within the capacity of the TB to make sure it can safely start and stop the trailer (many people dont realize the brakes play a part in determining the towing capacity). I tow 2 boats, a 3400lbs dry outboard and a ~4000lbs dry inboard. Loaded, I figure adds about 500-800lbs to be generous, but my TB has never skipped a beat, ever. Granted I have the SWB model which weighs less than the EXTs and has a higher towing capacity for the I6 engine due to the less weight.

The rear axle ratio is located in the glovebox in the codes, the codes are listed below:
G80- Locking Rear Differential, heavy duty
GU6- 3.42 gears
GT4- 3.73 gears
GT5- 4.10 gears

For mild to heavy towing, you should probably have at least the 3.73s, otherwise you will be working to get up to speed but it will still manage. I have the 3.73s in my TB, and Im really glad I didnt get the 4.10s as they have great acceleration and better towing capacity but the trade off is crappy mileage.


Max trailer hitch weight is the total weight you are pulling.
Max Tongue weight is the total tongue load weight that is on the trailer tongue or hitch.
MT
MT

Erik- excellent info on the diffs & option codes. Any idea if they are dana rears on the TB's?

Joel
From what I have heard, they are not Dana rears, but somthing different. If you look at the VIN number on the rear end, I want to say it is something like American Axles or something like that.

Yep, good call. From what I can tell from poking around the net, the rears are from AAM, as is the "Integrated Oil Pan" (IOP) front axle. Good stuff either way. :iceslolan

G/luck
Joel