[High Pitch Sound]

Have you tried running your car on idle, then simulate pressing the gas by pulling the throttle cable and see if the noise exist? If it does, may indicate a leak in the intake system.

[Changing Gear Ratio]

Much appreciated for your write-up, JD.

I am more inclined to do the conversion as I know a trustworthy and experienced mechanic in town, also for the fact that I think even though I could find a diff with the desired gear ratio, that diff probably itself has a lot of mileage on already. Since my RV is just at around 123k miles at this time I think it still has plenty of useful life left in the original diff.

Could you kindly point me as to where I can buy (1) The gear set (2) Install kit and (3) Speedometer-correction gear-box? Please also provide me, if possible, the brand of the manufacturer of the parts mentioned and part number?

Thank you so much for all the help given.

[Changing Gear Ratio]

Thanks for the detail post again JD. Much appreciated.

For my Mexico trip, I drive all the way from Vancouver to Baja California and there are indeed steep hills, the two big ones being Siskiyou Summit (Oregon/California Border) and Tejon Pass (Just outside of Los Angeles). So yes I would like the engine to work not as hard so that it could last longer. I would also like to be able to maintain 65mph with OD on flat road if possible.

I bought my RV in 2009 and the first year I made a trip to Los Angeles/San Francisco and then I have made 5 trips to different places in Baja California. Some of the roads there are really steep as well.

You've mentioned there are two choices available: Could you tell me

(1) If I choose the Re & Re method, from what year/model Toyota can I get one that can "plug and play"?

(2) If I choose to redo my current diff, what parts should I order and what's the way to do it?

Thank you for your assistance.

[Changing Gear Ratio]

Thank you JD & Linda for your posts.

My annual Mexico trip is coming up during Christmas-New Year holidays. I will try to run a full stretch of distance in between gas stations (I usually fill up at fixed points over the years) so I will be reporting back on the MPG without OD. As long as it's ok to run at those rather high RPM continuously, I am willing to give it a try.

My experience is on those flat roads on I-5, speed usually can be maintained at the 57-60mph range with OD on. Any higher will induce the kick-down on the transmission and I will then try to ease off the accelerator to let it go back to OD.

JD, does changing the gear ratio actually helps the engine overall on highway speeds?

[Changing Gear Ratio]

Sounds to me like your RV is some sort of anomaly. I've seen road tests done of several and all showed worse fuel mileage in OD then when not. I assume because it makes the engine lug and work harder. I know my 20 foot 1988 Minicruiser got worse mileage in OD when I had the 4.10 to 1 rear. The trans also ran hotter in OD. Very noticeable whenever I was climbing even a slight incline. For most users with 22RE engines, 4.10 rear gears, and automatic transmissions - OD is pretty much not usable at high speeds so 3rd is the main travel gear. When I put the 4.56 gears in - OD became something I could use.

Thank you for your reply. I haven't been told by the previous owner (I think there were like 3 owners before me) that any modification have been done to the RV, it fact, when I bought the RV, the radiator was stock - so I don't think any modifications have been done to the gear ratio of it.

Much work have been done by me, full tune up, changing the timing chain/guides, tune up, water pump, fan clutch even fuel injectors. I have also put in a second Transmission fluid cooler, also a 3-row radiator.

I may try a full stretch of road with OD off in between gas fill ups to ascertain the MPG situation. I just worried that at about 60mph the RV is running at the high 3k RPM range constantly which could damage the engine. And, when I need to make the time and on the road I drive upwards of 600 miles per day (On a tight timetable as my time off from work are very limited).

[Changing Gear Ratio]

Well this isn't a big V8 engine. These Toyota engines are made to run at higher RPM's. Stresses the engine more to run too low and lug the engine. If you are running stock 185r14 tires, your tach is off. With 4.10 gearing your RPM's at 60mph should be around 2350. I find it hard to believe you can even keep it at 60 in overdrive. Just the wind resistance is enough to slow you down. The constant back and forth from overdrive to 3rd also heats up the trannie and can destroy it.

Linda S

Thank you for your post and advice. At long stretches of flat land, for example, driving from Albany to Roseburg in Oregon, my RV could stay at around 60mph in OD. But if I try to have it go at about 62/3mph, it starts cutting in and out of OD. One thing also concerns me is that when I tried cruising without OD at interstate speeds there things I noticed: (1) Coolant temperature rise (2) RPM high and engine noisy and (3) Significantly more fuel consumed.

I do have an external ATF Temp gauge installed also. I really didn't observe any ATF Temp change when the RV was shifting in and out of OD though.

[Changing Gear Ratio]

Most of the owners here do not us O/D ever, well maybe going down hill. So at 65, again most don't drive that fast, your turning around 3850 in 3rd.

If you went to a 4.56 or 4.88 you would be turning less rpm in a now really usable O/D. You would also do much better in the hills.

If that rpm worries you remember that there are a zillion Toyota P/U with basic 4 speed manual transmission and they have been zoom up and down I-5 at for years at 4000 rpm.

Thank you @WME for your post. I find the vehicle constantly forced to run in such a high RPM (Higher end of 3k RPM) quite worrying. Owned my Dolphin for about 6 and a half years now, and since my trips involved traveling the whole stretch of the I-5 (I go on annual trips from Vancouver Canada to Baja California) I would like my dolphin to run a bit less demanding of the engine and transmission, if anything I can do without a hefty price tag, I would do it.

[Changing Gear Ratio]

Thank you @jdemaris for your reply. I have an external tachometer installed so I can only read from there, without knowing how accurate that is.

Yes, when I am traveling on a flat road at speed slightly above 60mph the tachometer states it's at around 2700-2800 with OD. When it is without OD it's at around 3600rpm.

So from your table, using 4.56 gear ratio will actually increase the RPM of the car when it's at OD than stock. But then I guess it wouldn't run to the point that will fell the power is not enough and need to downshift in order to keep the speed?

[Changing Gear Ratio]

Hello fellow forum members may I ask what is the optimal gear ratio for my 1987 Toyota Dolpin RV (22-RE Engine)? It seems that the stock ratio may not be the best (4.10?)

And any tutorial on how to do a DIY on this project please? Thanks for all the help!

EDIT/Additional Info: I mostly travel on I-5 and would like to keep a constant speed on average in the range of 60mph. At that speed I noticed even in OD the engine is running at around 2700 rpm. Isn't that a bit high?

[RV Camshaft for 22RE]

A bigger gas engine would make it go faster and have an engine not working so hard- but also means worse fuel mileage. A diesel is inherently more fuel efficient but a diesel engine also has less power then an equal sized gas engine. That means it takes around a 3 liter diesel to make equal power to a 2.4 liter gas engine. That is unless you start making apples-to-oranges comparisons like a turbo diesel to a non-turbo gas engine. More engine means more money, more weight,etc., &c. All is a compromise so I'm not sure how to answer. A diesel is still more efficient then a gas engine - 15-25% more. But -in my state - diesel fuel costs 20% more per gallon then regular gas. That loses a lot of potential savings. Also, many "mechanics" are really just parts changers at best and very few have the know-how and tools to work on a diesel. For example - next time you're at what you think is a good repair shop - ask if they own a diesel timing light - or better yet see if they know what one is? Or, see if they have a mechanical injector tester or tools to check compression on a diesel engine. My point being that owning a diesel often is not cheaper unless you get it cheap and do your own repair work. I do - and am still shying away from diesels. My full size 1986 Chevy Blazer 4WD with a turbo-diesel 6.2 liter engine can cruise at 65 MPH and get 16 MPG. My 1992 Dodge 3/4 ton 4WD extended cab truck with a pop-up truck-camper on it gets 17 MPG with the Cummins intercooled turbo diesel. My 1994 Ford F250 with extended cab, 4WD, 7.3 IDI turbo diesel and a slide-on camper with a fixed high roof gets 15 MPG. My little 1985 Isuzu 4WD truck (Toyota sized) with a 2.2 liter diesel gets 32 MPG empty. If I had something like a Chinook camper on it I suspect it would get around 22-24 MPG and be dreadfully underpowered climbing any hills.

The Toyota sacrifices room and power but gives back with an easily handled size, ruggedness, and half-way decent fuel mileage. If money was no object, I've have a 18' Sunrader with a German Sprinter turbo diesel. It would get maybe 18 MPG at 65 MPH (note I said maybe). Years back when GM first came out with it's Detroit-Diesel designed 6.2 liter engine - several RV companies stuck the engines in some Class A motorhomes. With 350 or 454 gas engines they typically got 7-8 MPG. When the 6.2 diesels got put in, they tended to get 10-11 MPG and often blew to pieces by 40K miles. Many of those then got retrofitted with 3.9 liter turbo Cummins or isuzu DI diesel engines and got 14 MPG.

I don't know what to tell you. If you waste endless amounts of time trying to redesign things (like I do) - the answer is buy a different motorhome if you want substantially more performance. I've been trying to redesign all sorts of motorhomes and RVs for near 40 years. I've never felt I really got what I wanted yet - but I'm cheap. I've got this 1978 Toyota Chinook I'm working on right now. I couldn't bear to leave it as is - so now it has a dual-wheel full floater rear, getting a 5 speed trans with OD, bigger brakes, 150 amp alternator, 5000 watts in inverters, etc. I'm hoping I can achieve 18-20 MPG on long flat runs when I'm done. If so - I'll be very pleased (I think).

I wish you luck in your quest for economic performance. Beyond that, I really do not know what more can I say. To be honest, I don't mind to spend some money on the MH to gain more power, but I were to commit anything major into the MH, I must also calculate all related costs that could realistically keep the MH run for another 10 years or so to be economical. That will include both improvements and repairs needed both on the car part and the house part.

[RV Camshaft for 22RE]

The only reason the head was warped was that the PO had overheated it when the infamous bypass hose by the alternator broke and she didn't see the gauge skyrocket. So if you care for your Toy it will be a long time before you have head problems.

WME

Yes, quite understandable. I was thinking about the bypass hose incident I had. It sort of had a internal crack and developed a tiny hole and I saw coolant droplets started appearing on the hood when I was crossing the Golden Gate bridge in San Francisco (Long way from home in Vancouver, Canada) - I was fortunate enough to have gotten the part at a autozone store and performed my first ever roadside repair for the MH.

[RV Camshaft for 22RE]

I don't know much about what Toyota did to the 2RTE to sustain turbo use. I'd read that they used specailly coated pistions, a lower compression ratio, larger cooling system, piston-skirt oil cooling, and a completely resdesigned head. That's with a fairly low boost engine.

I would like to thank you for your answers to my questions, it's very educational. I would welcome very much on any ideas that could economically make the MH perform better, if you have, please do not hesitate to share.

[RV Camshaft for 22RE]

The only substitute for cubic inches is cubic money. Or as they also say speed cost money how fast is your wallet.

Before i supercharged a 22r, i would just install a bigger engine.

I had warped head so I did what I did to fix the problem and make a little more power. From what I figured out my engine was in the 130-135 hp range. A stock rebuild would have been in the 1000 range, so 20 hp for 200 extra was ok. 20 hp for 1200 wouldnt be such a good deal

Understood, maybe wait for my 22RE's cylinder head warp first before doing anything else.

[RV Camshaft for 22RE]

Supercharging - regardless if exhaust driven (turbo), gear or belt driven - puts tremendous stress on an engine. The idea of a charged-engine is to build a small engine with extremely heavy parts. When under boost and/or cooled condensed air and with extra fuel it can behave like an engine twice its size. When not under boost and extra fuel, it can behave like a smaller engine and get good fuel mileage. Sticking any sort of boost-amplifier on an engine not designed for it is asking for disaster - unless that engine happens to be extremely overbuilt to start with. Toyotas ARE well built, but not greatly overbuilt. A typical boosted engine that used to be very popular in the RV world was the Cummins 4BT (3.9 liter) or the Isuzu 3.9. They made near the same power as a non-turbo 6.9 Ford-IH diesel or a GM 6.2 diesel. It is a very heavy engine and I don't think suitable for a little Toyota. Besides the need for heavier parts - adding boost increases the "effective compression" ratio. If the engine is not built for boost, it will have a high mechanical compression ratio. If you add boost - that "effecitive" compression ratio gets dangerously high. For that reason, engines designed to run under boost start out with lower mechancal compression ratios then non-boosted engines. In a boosted engine, this results in less performance when not under boost then a non-boosted engine.

I can't recall if and/or how Toyota done it . . . but Isuzu took one of their non-boosted diesel engines in small trucks and Troopers and added a turbo in the 80s. That was the 2.2 liter that started life as a gas engine. Then it was converted to diesel with heavier parts. Then when a turbo was added it got further beefed up pistons and rods. Even with that they tended to blow to pieces and were not near as long lived as the non-turbo versions.

If I wanted a reliable long-term driver - I'd never consider trying to add boost to a Toyota engine not designed for it. Replacing the engine with something that is - is a different story. But - I hope you don't think adding boost will make your rig more fuel efficient. Not usually the case. Install a modern direct-injected turbo diesel and you will gain MPGs - but lose a lot of wallet. Like a German Sprinter engine maybe?

Back to your camshaft questions. With mechanical controls - it's not possible to make a camshaft the "best" for all uses and RPMs. Anything you do is a trade-off. Toyota spent a lot of time engineering a good compromise and I would not tend to mess with it. Many attempts were made years back with variable mechanical valve timing, Rhodes lifters, variable displacement engines, etc. None worked all that well. Now - with microprocessor controlled anti-detonation that allow high compression, electronic varaible valve timing, etc. - new engines CAN compromise much more.

Thanks so much for your answer. Looks like it's best to leave this one alone. You cannot actually make the 22RE a variable timing engine operation, hence I understand your point of a trade off. The reason I raised the question of boosting is because I think the 22RE and 22RTE are the same engine, just with an add on turbo, so I deduce that the baseline 22RE is designed for boosting?

[RV Camshaft for 22RE]

Thank you for your information gentlemen. It's very informative to say the least. I highly appreciate the time you put in responding to my question. I guess to sum it up:

1. In order to gain any significant improvement on performance - Just changing the camshaft will not be enough. You'll need a lot more than that.

2. I was in fact considering to buy the RV Camshaft 270/430 H/O with RV springs set from www.engbldr.com, the one WME is currently using. At least it sounds like that I'll need to buy the cylinder head assembly modified exhaust plus a lot of other stuffs to make this work. Need to rethink before committing to that.

Thanks again, but if I may impose:

3. Would supercharging be a more effective way to improve perofrmance?

[RV Camshaft for 22RE]

Hi everyone,

I would like to ask if anybody has any experience installing aftermarket performance camshafts on their Toy MH? Please let me know what make & model you used and what kind of experience you have with them on the road. Many thanks.

By the way - do you know why those camshafts are called "RV Camshaft"?

[Hot Showers On The Road]

Thanks everyone for their input. I most certainly will take Totem's advise into consideration. It's because:

1. I only need the hot shower during transit, and that amounts to less than 10 times in a year. Showering in campground at destination is usually not a problem. Unless there are times when I traveled to Mexico where those campgrounds say they have hot showers but in fact the showers are cold.

2. The wood panel in the shower room has some damage and I can see the color of the wood is dark looks like maybe water damage hence I never wanted to exacerbate the problem.

Quote from http://www.pilotflyingj.com/best-shower

RT Project5050: God Bless the Flying J and Pilot truck stops that give us a free shower with every 14 gallon fill up. @ShanePatrick50 was in need!! MuchLOVE

If that's true problem solved!

[Hot Showers On The Road]

Hello everyone, I am a Canadian living in Vancouver BC. I make quite a few trips down to the US every year. And I am wondering where I can have a hot shower while on the road - as I don't use my shower in my MH as I use it as storage place. Usually I travel with my wife and my son, and having a shower at truck stops was pretty expensive - something like 9, 10 dollars per person. Any suggestion?

[Weak alternator?]

I did the modification with the kit from trail gear.

http://www.trail-gear.com/pdf/120120-1-k.pdf

I have been using an 7294SE alternator for the past 2 years, all is well. The only problem is the charge warning light and the brake warning light comes on (albeit not in normal brightness, it was slightly dim), other than that it's good.

[Hot Rod for water heater]

Do we have a 4 gallon hot water tank system in our MH? Anyone has experience installing the hott rod system? Is it easy to do so?

[Getting the best MPG on Interstate]

Just got back from a b-day camping trip

kept my speed at 55-60 RV ran great. got 16mpg

almost all up hill.....

My first trip i had a cap & rotter miss fire (did not know tell failed smog///changed cap-rotter and spark pugs & wires runs great passed smog)

my mpg was 10mpg....just a simple tune up helped allot

How often should the distributor cap, rotor, spark plugs and wires be replaced?

[Hot Rod for water heater]

Thanks everyone for their input, very helpful info.

[Toyota won't start after sitting 2 days... help...]

Tried jump-starting yet? A weak battery won't turn the starter over.

[Hot Rod for water heater]

Probably no more than your furnace does. Both cycle on intermittently for a few minutes at a time. The furnace is only heating air, as opposed to water, but the space the water is in is much smaller (tank) than the space the air is in (coach), so it's probably about the same.

I've had my Toy for three weeks now and have used the water heater. I topped off the LP tank and for five days, ran the furnace, the water heater, the fridge and the stove on LP. After that I had them top off the tank again and I found out had gone through 2 1/2 gallons. Using all the appliances for five days cost me $8.50, and that was at an inflated LP price. If I would have gone to Tractor Supply it would have cost me $5 ($1.99/gal.).

One month of LP @ $8.50 every 5 days would be $51, and at $5 is would be $30. Seems pretty cheap to me, especially since it was cold those five days and the furnace was kicking on left and right.

When I topped off the first time, it took 6 1/2 gallons. I'm reasonably sure I have an 8gal. tank, which is probably standard for a Toy. I know that size is standard for most older Class B's, so it makes sense. Yours is probably the same as mine.

Thank you for the information. For heating needs I just use a big buddy heater. I don't usually take showers in the RV, I found that water leaks out from the faucet when I turn on the shower. And of course I worry about propane consumption. I am a Canadian and I am not familiar with propane filling in USA, my idea is that there are lots of "propane exchange program" where you swap an empty tank with a full one. Looks like most gas stations do not fill propane. And while on trip I usually get gas at Safeway where I can do the fill up while my wife does the shopping. I don't see any propane filling service at Safeway.

[Hot Rod for water heater]

Over the course of 3.5 years of ownership I never actually use the hot water furnace at all. Worrying this will use a lot of propane. Do we have a 4 gallon tank system in our MH? Anyone has experience installing the hott rod system? Is it easy to do so?