towing in od???

[kx250pilot]

my friend just bought a 26 foot wildwood tt and he pulls with a 01 chevy 1500. the salesman told him not to pull in od. does anybody know why? fwiw i tow my 26 foot baja toyhauler everywhere in od but i have a full dtt transmission with 4. 10 and at 60 mph the tach reads 2000 rpm.

 

[R-N-R]

I pulled our 28' TT in 3rd at 70mph@2800rpm, OD at 70mph@2200rpm. . OD works for me ('02 auto 4:10) btw, mileage at 70 was not good. I always heard not to use OD when towing. My understanding is that the trans will hunt between OD and 3rd, (I'm still working on understanding the "locked up" thing) creating excess wear and tear on the trans. In my old 1/2 ton gasser, I could not use OD, in this 3/4 ton CTD using OD seemed fine.



There are plenty of experts on this board (not me) that should be able to shed some light on this topic.



Bill

 

[Snow man]

The 4L60E in the chevy has a 3-4 clutch pack that has 6 discs,it is working very hard in OD towing,also the 2-4 band is applied in OD,it has been known to slip under heavy loads. On top of that towing in OD with a gas v8,the gears are usually 3. 42-3. 73,that puts the engines under 2000 rpm's at 70 mph,these gas sers do not have the torque to pull well there,so the transmission gets overcycled(shifts between 3rd,4th,and in and out of lockup often on anything other than flat ground,this is what ultimatley will kill the trans even if it doesnt slip,overcycling will kill it every time. There are mods that can be done to the trans so it will tow reliably in OD(if you have the power to pull it),Ive rebuid a few 700r4's and they are internally similar,i always upgrade the clutch packs to the 9 disc if its in a a tow truck,and there are oversized 4th gear apply pistons that hold the band tighter,eliminating the weak area,Tell your friend to tow in drive it is much better for it,unless it he's towing under 4K lbs,and it is a low load,not a lot of wind drag,and no hills.