O/D or Not????

[ForceHeadache]

I've seen several different references on whether or not you should tow in O/D. Most of the posts say not too, but several say do it. I own a 1985 16ft Bayliner Capri with an 85hp O/B motor. References I've found say that towing weight is approx. 2,000 lbs. (Is that about right?) The owners manual for my truck (95 GMC 1500 Ext Cab - no towing package - Automatic) says you shouldn't tow in O/D, but when I take longer trips, I usually do tow in O/D with this boat. It doesn't seem to bother the truck much. Any thoughts?

 

[JB]

Re: O/D or Not????

Howdy, Headache.<br /><br />I tow about 2000lb (Boston Whaler Montauk 17, Suzuki DF70)with my '98 Mercedes ML320. I have probably towed her 40,000 miles of the 90,000 I have on the truck.<br /><br />I use OD and Cruise Control on the highway. <br /><br />The computer that controls my transmission has a towing subroutine that figures out what to do after about two miles and can keep control by selecting the best ratio for what is happening at the moment for the rest of the trip. My manual makes no mention of not towing in 5th (OD).<br /><br />Watch your rpm. If it drops, downshift.<br /><br />Good luck.

 

[JRJ]

Re: O/D or Not????

JB is correct. It's all about RPM's and how hard your rig is working. If you don't have a tach, just pay attention to your speed and don't over rev or lug your engine. OD is generally OK for sustained speeds of 50 to 55+ towing or not.

 

[Down South]

Re: O/D or Not????

Hi Forceheadache,<br /> If the owners manual says don't do it, then don't do it. You wouldn't use the wrong type of 2 cycle oil in your outboard just because it's cheaper and there aren't any apparent problems (yet) would you? Of course not...<br /> Without a towing package on that truck it makes it worse. That tranny is having to work hard under those conditions especially this time of year. <br /> What usually happens is everything seems great. You actually may never have a problem but if that tranny goes, it's usually all at once. I own a Ford Power Stroke and I don't tow in overdrive. Transmissions cost a lot. <br /><br />If I were you, I'd at least purchase a cooler for that transmission if you do much towing and turn the overdrive off when hauling a load.<br /><br />Good luck

 

[6MISFITZ]

Re: O/D or Not????

I agree strongly about adding a tranny cooler but not about using "D" unless it is a big trailer or a big hill that needs this gear.<br /><br />One thing about towing boats compared to towing a travel trailer having just completed a vacation with my new travel trailer, boats tow much better ! My travel trailer comes in 500-800 less then my boat but, it is shapped like a BRICK. <br />My little Astro van could easily maintain 60mph on a mild grade pulling the heavier boat but could not maintain 60 mph on level highway in OD towing the travel trailer. <br /><br />Your 16' boat and trailer should easily be handled in O.D. The owners manual for my 97 Astro says to tow in OD unless speed cannot be maintained in that gear and the tranny in my van is the same as your truck!

 

[snard]

Re: O/D or Not????

What the operating manuals say is that you should maintain it in OD as long as you can maintain your speed (whatever it may be) without constant shifting in and out of overdrive.

 

[Jango]

Re: O/D or Not????

I have almost the same tow as you - a 17ft Bayliner with 85 Force & Escort trailer. I tow with a 88 F150 with 302 & Auto Trans. I tow in OD with very few downshifts except in VERY hilly roads. No problem at all.<br />You didn't say what motor your truck has. If you have a V8 and Auto trans, you should have no problems, especially if you keep your speed up.

 

[crazyray]

Re: O/D or Not????

Your Truck will do alright as long as one you keep the temp of tranny down....a cooler AND a tranny temp gauge are really essential......also start off in Drive then only use od at 55+ low load conditions...ie. flat terrain..what will kill ya if that tranny doesn't have the line pressure to endure low speed gear changes into od....or hunting back n forth between direct and OD.....when in doubt use Direct...<br />you will be surprized how much the tranny temp will spike under high load

 

[Scoop]

Re: O/D or Not????

I also have had vehicles that say don't tow in overdrive. The major problem is some trannies will keep going back and forth bewteen gears because of the increased load. Different trannies are made to shift do to different conditions. This constant shifting can cause premature failure mostly due to the extreme extra heat generated then extra wear. If your manual says do not tow in over-drive, I would advise not to especially if your load is more than half of your vehicles total tow rating. A tranmission cooler is also very advisable. Tranny repairs are extremely expensive and when it goes, you are stuck wherever you are and probably are paying whatever price the locals want to charge. Rememeber the movie National Lampoon's Vacation. "How much is the bill?" "How much you got?"

 

[Bob_VT]

Re: O/D or Not????

Here is an overdrive experiment for everyone.<br /><br />Without a trailer or load drive your vehicle in OD and let off the gas....the vehicle coasts pretty easy. Now pay attention to passing and you will feel the transmission shift twice to attain good passing speed.<br /><br />Now try the same experiment without OD and you will feel the vehicle slow when you let off the gas (the engine is braking the vehicle) and a passing gear is faster to attain too.<br /><br />Stay out of OD unless you are on a road that will permit constant speed (ie. highways, straight roads with few hills). I would also suggest a transmission cooler if you are not already equipped.<br /><br />Bob