knewell Posted September 22, 2009 Share Posted September 22, 2009 I'm new to the forum, to my 1990 Dolphin, and to RVing in general. I have a question concerning the overdrive that I hope somebody with some experience can shed some light on. I recently bought a 1990 V-6 Dolphin with 23K (and some change) miles on it. Should I be driving this thing with the overdrive on all the time, just on the highways, or only downhill? I’ve seen a few other posts saying using it all the time will wreck the transmission, but is that for all Toys or just the 4 cylinder models. Your help in much appreciated, BTW we paid 5K for the DolphinJ Quote Link to comment Share on other sites More sharing options...
Maineah Posted September 23, 2009 Share Posted September 23, 2009 I'm new to the forum, to my 1990 Dolphin, and to RVing in general. I have a question concerning the overdrive that I hope somebody with some experience can shed some light on. I recently bought a 1990 V-6 Dolphin with 23K (and some change) miles on it. Should I be driving this thing with the overdrive on all the time, just on the highways, or only downhill? I’ve seen a few other posts saying using it all the time will wreck the transmission, but is that for all Toys or just the 4 cylinder models. Your help in much appreciated, BTW we paid 5K for the DolphinJ I run mine all the time only time I turn it off is when I want breaking or when it shifts up and down going up over repeated small hills. The O/D will shift down if it needs to. I know some say never use O/D but I don't like the extra noise and it's easier on fuel. I worked in a transmission shop for quite a few years and I would have to say stop and go is far harder on a transmission then using O/D. Due to the fact that the transmission works pretty hard moving a 6,ooo # little MH I would recomend a fluid flush every 30,000 miles they run pretty hot and that is hard on the fluid also if it does not have an extra cooler add one. (it looks like a tiny radiator) Quote Link to comment Share on other sites More sharing options...
nibs Posted September 23, 2009 Share Posted September 23, 2009 Maineah, I have two auto trannys that need a bit of adjusting - an Allison 740 - and a Mercedes 300D, both shift hard, and the allison shifts too early - where you at - Just kidding. Tony Quote Link to comment Share on other sites More sharing options...
bufbooth Posted September 23, 2009 Share Posted September 23, 2009 Also, using the overdrive lowers the engine's rpms, which besides gets you better gas mileage, should extend the engine life. As long as the transmission is not wanting to shift down, I keep the overdrive on. Quote Link to comment Share on other sites More sharing options...
Supurcar Posted September 23, 2009 Share Posted September 23, 2009 I think the wrecking the transmission refference is for hill climbing, it is better to keep the RPMs up as it circulates the fluid faster and it may not get as hot. So under normal conditions use the O/D, if you are hill climbing try and keep the RPMs up by turning off the O/D. I do not think it is the O/D wrecking the trans.- it is the overheating. Quote Link to comment Share on other sites More sharing options...
nibs Posted September 23, 2009 Share Posted September 23, 2009 Not to start an argument, and certainly not to diss an old pro (Maineah) buuuut I am told that the Toyota owners manual says not to use overdrive when driving a loaded truck. These motor homes are a big load for the truck. Quote Link to comment Share on other sites More sharing options...
Maineah Posted September 23, 2009 Share Posted September 23, 2009 Not to start an argument, and certainly not to diss an old pro (Maineah) buuuut I am told that the Toyota owners manual says not to use overdrive when driving a loaded truck. These motor homes are a big load for the truck. Like I said some do some don’t guess this has been a argument since they started putting the automatics in the trucks. The biggest issue is converter slip that makes heat and if a vehicle is straining in a gear that is too high the converter has to slip. The O/D will shift out if you push it and the slip will diminish, to my knowledge there has never been any hard data about longevity with out O/D or with O/D usage and if there is I would like to read it. Any way I plan to get 100+k out of mine but I do take care of it, they work hard O/D or not so fluid changes are necessary not just pull the plug but a complete change converter and all or a flush if you will every 30K. A bigger cooler and synthetic trans fluid can’t hurt either. All this is just my opinion your mileage may vary. Knewell has a “90” and I think his has a lockup converter that really does help reduce converter slip because when it is engaged the converter becomes direct drive like a clutch in a stick shift. So there is no right or wrong if you believe your transmission will last longer with out O/D go for it, me I like the quiet and a little better mileage. Quote Link to comment Share on other sites More sharing options...
nibs Posted September 24, 2009 Share Posted September 24, 2009 Got to admit, if I had an overdrive automatic, I would most likely use it. (carefully) Quote Link to comment Share on other sites More sharing options...
minicruisin eric Posted October 4, 2010 Share Posted October 4, 2010 (edited) From what I've read, the V6 tranny locks the clutches/converter when OD is used, this actually reduces the transmission temp. With the 22R/RE however, the clutches never lock and causes excess wear and heat which could reduce the life of the tranny. So IMO... V6 = use OD whenever you like, 4cyl = use sparingly if ever. Edited October 4, 2010 by minicruisin eric Quote Link to comment Share on other sites More sharing options...
Maineah Posted October 5, 2010 Share Posted October 5, 2010 From what I've read, the V6 tranny locks the clutches/converter when OD is used, this actually reduces the transmission temp. With the 22R/RE however, the clutches never lock and causes excess wear and heat which could reduce the life of the tranny. So IMO... V6 = use OD whenever you like, 4cyl = use sparingly if ever. There is a clutch inside the converter it locks the converter so that is does not slip all converters slip if they are not lock up type the 4 cylinders do not have lockup converters because they do not have enough guts to allow them to lockup it would be like leaving a standard in 5th climbing a hill so they slip if they are pushed in a higher gear and yes they will slip in 3rd also if they did not slip you would never be able to pull away from a stand still. The lockup was designed for fuel mileage not to save the transmission. The owners of the V6 will notice what seems like a different gear when they climb a hill in O/D is actually the lockup dropping out. I drive sticks and have been for nearly 50 years my Toyota is an automatic (the only auto I own) so I drive it like a stick as far as O/D is concerned to avoid the slip as much as possable. It does not matter how you cut it either 6 or 4 cylinder the converter slips because we are driving 6,ooolb MH homes that were not designed for that kind of weight the lockup does help a lot but that does not mean that they won't get hot add a cooler and change the fluid 30K or so no matter if it's lock or not. Quote Link to comment Share on other sites More sharing options...
86rader Posted October 5, 2010 Share Posted October 5, 2010 I use OD. I'm probably a little more caustious about using it than maineah, but, not as cautious as some who are of the opinion that a toyhouse should never see OD. I use throttle position as a gauge. If I am in OD and giving it much more than maybe 1/4 throttle, I will go ahead and downshift, especially if I would like a bit more speed. Toyhouses pull way better in third than OD. The jump from third to OD is a pretty big one. Quote Link to comment Share on other sites More sharing options...
teahouse Posted November 24, 2010 Share Posted November 24, 2010 (edited) Thanks to you advanced guys for taking the time to share your experience and expertise. It's really helpful! It has taken 15000 miles to get "comfortable " with the automatic transmission overdrive on our '86 22re. In the first 5000, it was all about high revs to keep that little 4 in its power range. That was the only way it could pull all that wieght, right? Overdrive was just for the long downhills. We were pumping the throttleand moving the gear stick expecting the truck to jump and skip like a passenger car. We were straining to keep up with the pace and the antics of the 4 wheeler public. The mileage was around 14. Sometimes it sounded as though the engine would jump off of it's mounts. The temp guage was wild. In the second 5000, we quit using the OD altogether. It had no "guts" anyway. We thought " what kind of morons were those Toyota engineers to install OD in a rig like this, anyway??" We got the same noise, same mileage,same temp and the same hard work driving the thing,wishing we had a 6. In the last 5000, we use OD all of the time, unless we are in city snarls. Now we are inclined to keep the accelerator at the 1/3 level... we increase our following distance so as to avoid braking/acceleration. We expect that we'll go slower up the hills and a little faster on the way down. We stay in the slow traffic lane when there is one. The 4 wheelers curse and do their best to get around. We let the transmission shift itself....it's an "automatic" afterall. At around 55 it cruises in OD turning around 2000 rpms. It is quiet, smoothe and [amazingly] does not seem to be lugging. When we hit a slight grade, it shifts itself out of OD reliably at around 50 ... returning the rpms to 2800. Then it shifts out of third to second at around 40, I think, ... returning to 2800 rpms. When we looked up the torque for the 22re, 2800 rpms was the top of the curve . Now we marvel at the cleverness of those Toyota engineers. The noise is minimal, the temp meter is more stable, the mileage is just shy of 20 and it is a pleasure to drive. Edited November 24, 2010 by teahouse Quote Link to comment Share on other sites More sharing options...
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