how much is safe to tow
 

ok so my runner now has about 160K miles on it all original and i was plannin on takin it on a trip to the beach. from northern va to myrtle beach and i might be pulling a boat thats about 21ft long and about 3 thousand pounds. i was wondering if i should worry about the tranny? should i pick up a tranny cooler for it? any input would be great, thanks guys:hillbill:

So probably all-in including trailer weight you could be as high as 5500lbs with supplies, gear and associated boatie-goodness. :) Set the fore-aft balance of the trailer to put on about 500lbs of tounge weight by moving the forward roller-stop back and forth.

In a perfect world inflate your airbags or airshocks back to level ride. Or set your load equalizer hitch to do same. Any of those will keep you off the bump-stops and have a more predictable weigh shift under panic breaking should the need arrise.

If you're not going to use trailer brakes, then double-check your front brake rotors. If they are close to thin-spec (or beyond) then I'd toss in new rotors/pads before dealing with that wieght. Things gets really ugly if your front end is overly-light due to an overloaded rear-end - and then you add in over-heated brakes and warpage into the mix.

Given the total GVW, a tranny cooler might not be bad idea if conditions will result in mulitple hill-climbs loaded with hot weather outside. I've towed many miles as heavier weights without the tranny cooler, but there was minimal elevation changes to deal with. I do also make a habit of draining filling the tranny pan every 50k miles which offers a partial fluid change.

dont use overdrive, it is not a pulling gear. if you have the ECT then turn it on also. i know people say that its not worth a hoot but i have noticed a difference (slight) when pulling my 21ft bass boat. i pull it with NO issues at all. check your atf fluid also. if its remotely dark then drain and fill or flush... you should be draining and filling every 10-15k miles anyway esp if you use dino fluids (whether dex3 or T4) and or flush every 25-40k miles pending if you pull or offroad a lot..

you wont need a tranny cooler unless you do pull, haul or offroad a lot.. if this is something you do not so often then you can skip the tranny cooler and just change the fluid a little more often

btw when is the last time you changed the gear oil in the diffys?