Griff in Fairbanks wrote:
Addendum to previous post --
While searching eBay years ago, looking for Dodge automatic transmission parts, I ran across a listing for "Chrome Dodge automatic transmission pan." The description was for a "chrome Dodge THM350 automatic transmission pan."
For those who don't know, the THM350 is a Chevy/Buick transmission ... to the best of my knowledge never used in a Mopar vehicle.
I was curious, so I dug out my transmission pan gasket chart. The pan in the listing's pictures was for a C6 transmission ... which is a Ford transmission. (Needless to say, I made note to never buy from that seller.)
In another case, a listing was selling "354 hemi valve covers." Problem was the pictures didn't show the holes in the valve covers for early Hemi spark plugs. (The spark plugs go through the valve covers into the tops of the cylinder heads on early Hemis ... not through the sides of the heads like most other Mopar engines.)
Other listings have offered used parts for two to three times what it would have cost to buy a new or reman part from the local parts store. One listing offered a used upper radiator support for a 1990 Ford E150 van ... for $150. I bought a new one from the local Ford dealer for $50. (I needed one to fix the van after my wife hit a moose ... bent everything above and in front of the water pump.)
This isn't to say I haven't found good deals on hard to find parts on eBay. Instead, it means you have to be knowledgeable and careful buying off eBay.
Addendum to previous post --
While searching eBay years ago, looking for Dodge automatic transmission parts, I ran across a listing for "Chrome Dodge automatic transmission pan." The description was for a "chrome Dodge THM350 automatic transmission pan."
For those who don't know, the THM350 is a Chevy/Buick transmission ... to the best of my knowledge never used in a Mopar vehicle.
I was curious, so I dug out my transmission pan gasket chart. The pan in the listing's pictures was for a C6 transmission ... which is a Ford transmission. (Needless to say, I made note to never buy from that seller.)
In another case, a listing was selling "354 hemi valve covers." Problem was the pictures didn't show the holes in the valve covers for early Hemi spark plugs. (The spark plugs go through the valve covers into the tops of the cylinder heads on early Hemis ... not through the sides of the heads like most other Mopar engines.)
Other listings have offered used parts for two to three times what it would have cost to buy a new or reman part from the local parts store. One listing offered a used upper radiator support for a 1990 Ford E150 van ... for $150. I bought a new one from the local Ford dealer for $50. (I needed one to fix the van after my wife hit a moose ... bent everything above and in front of the water pump.)
This isn't to say I haven't found good deals on hard to find parts on eBay. Instead, it means you have to be knowledgeable and careful buying off eBay.
Certainly a sure sign of a scammer that has searched out enough buzz words to compose a sales pitch without having true knowledge of brand specific terminology.
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Whichever comes first. If you reach 3 months without 3,000 miles on the odometer, it usually means lots of short, stop-and-go trips. These result in a buildup of hydrocarbons in the engine oil. Atmospheric humidity combines with the hydrocarbons to form acids, which eat away at engine components. (Especially crankshaft and rod bearings.)
If you pass 3,000 miles in less than 3 months, if usually means longer trips. Longer trips gives the engine time to warm up completely, causing the hydrocarbons to be evaporated and expelled through the PCV system.
Change the oil and filter before putting your motorhome into storage. Run the engine just long enough to build up oil pressure and circulate the new oil completely. It's not necessary for the engine to get up to full temperature. A few minutes run time (not more than 5 minutes) is sufficient. (This flushes the acids out of the engine's oil passages and dumps them in the pan, where they won't do any harm.)
Fresh oil means better lubrication ... and more power going to the rear wheels.
10W40 oil leads to longer engine life than lighter 5W30. However, this comes a slight expense in terms of fuel economy. Automobile manufacturers now recommend 5W30 to meet EPA standards. (This may be a case of government regulations being "penny wise and pound foolish." It may take more energy to manufacture and ship replacement automobiles -- and engines -- than is saved by the EPA standards.)
The engine life/fuel economy trade-off is up to you. It takes a slightly larger portion of the engine's power to pump the heavier 10W40 oil through the engine. Because motorhome engines often last decades before needing rebuilding or replacement, the slightly better fuel economy offered by 5W30 may be preferable.
Note: 10W40 is advisable if you plan to spend a lot of time driving in higher ambient temperatures. (90 degrees F or higher, such as in southwestern U.S. deserts.) I've always used 10W40 and the rest of the vehicle usually wears out before the engine. However, we now run 5W30 during the three winter months. 10W40 gets too thick to start the engine at the seriously subzero temperatures typical during interior Alaska winters.
1970 Explorer Class A on a 1969 Dodge M300 chassis with 318 cu. in. (split year)
1972 Executive Class A on a Dodge M375 chassis with 413 cu. in.
1973 Explorer Class A on a Dodge RM350 (R4) chassis with 318 engine & tranny from 1970 Explorer Class A
If you don't know the last time the transmission fluid and filter was changed, better do it now.
Likewise, you may want to drain and refill the differential. It's entirely possible it still has the lube that was in it when it came off the assembly line, decades ago. (Better lubrication ad nauseam.)
Up until now, we've been looking at a 'package' of inexpensive ways to improve fuel mileage. Next up is more expensive options, starting with your motorhome's exhaust system.
Postulate: More power and torque can mean less fuel used in a given vehicle under identical driving scenarios. (Assuming you don't change your driving style and vehicle load.)
If you have a single exhaust system, a dual exhaust system can improve fuel mileage. A well designed dual exhaust system allows an engine to 'breathe' easier. This means less engine power is used to push the exhaust out the tailpipe and more power is sent to the drive wheels.
There's probably not enough cost benefit in replacing an existing functional exhaust. However, exhaust systems tend to 'wear out' due to corrosion. So, if your exhaust pipes and muffler need replacing, it'd be a good time to invest a bit extra for a dual exhaust system.
First, do NOT replace your stock exhaust manifolds with headers. I've read many detailed test reports comparing various exhaust system alternatives. These reports described controlled scientific tests using engine dynamometers and other expensive test equipment. For applications like our motorhomes, stock exhaust manifolds consistently came out on top.
(I know this is going to start an argument ... save your breathe. I prefer multiple tests, using controlled scientific methods, over anecdotal reports based on limited experience.)
Readily available, inexpensive headers are frequently just ****. The manufacturers are primarily focused on making a fast buck, so these tend to be sucker bait rather than serving a useful purpose. In addition to often reducing performance and economy, these headers tend to corrode easily, often lasting only a few years. (As one friend put it, "It really sucks when your headers fall apart before the mufflers.")
With one notable exception, even well designed headers aren't suited to our motorhomes. This is because virtually all headers are made for high RPM applications, like drag strips and race tracks. These headers don't start producing significant power improvements until the engine climbs above 6,000 RPMs. Below 6,000 RPMs, they often decrease performance compared to stock manifolds.
At cruising speed, the engines in our motorhomes run at 2,500-3,500 RPMs, well below the threshold that justifies headers. Additionally, our engines 'redline' around 6,000 RPMs. Most won't go much over 6,000 and if you manage to push them past that point, you risk damaging or destroying the engine. (I know ... I've destroyed a few engines over the years by over-revving them.)
The exception is something known as Tri-Y header design. These are designed for low-RPM, high torque engines, like those in our motorhomes. Unfortunately, these are complex and difficult to manufacture, so tend to be quite expensive. Likewise, there's not a lot of demand for Tri-Y headers, so they're equally difficult to find. (Your best bet is to search the off-road, rock-climber marketplaces.)
So, assuming your exhaust system needs replacement, and you've decided to stay with the OEM manifolds, you need to find a replacement dual exhaust system. You may be able to find a ready-made system but it's more likely you'll need to find reliable shop for a custom made system. (The muffler shop I rely on uses a mix of off-the-shelf and custom components and welds everything together ... and the slightly higher price is offset by a more durable -- and safer -- exhaust system.)
Be careful. As with carburetor jets, the "bigger is better" fallacy applies. If you find a ready-made system, make sure it's suitable for lower RPM applications ... many are made with larger pipes for high RPM race applications. Likewise, make sure the shop for a custom system has the knowledge, experience, and tools (e.g., pipe benders designed to prevent kinks and constrictions). A shop that does lots of muffler replacements may be better, with broader experience than shops specializing in high performance exhaust systems.
Regardless, you want a H- or X-pipe crossover in your dual exhaust. It'll cost more but is worth the improvement in performance and efficiency. (The crossover 'balances' the two sides of the exhaust system and helps 'scavenge' the exhaust.)
Keep your tires fully inflated. We keep all our tires at the max molded into the tire sidewalls. Under-inflated tires create more rolling resistance, contributing to lower fuel economy. Under-inflation also causes less 'road grip' and reduces brake efficiency. (We also find fully inflated tires provide better traction on ice and hard-packed snow.)
Under- and over-inflation is also expensive, causing excess tire wear. Significant wear down the center of the tread indicates over-inflation and the same along the outsides of the tread (even on both sides) indicates under-inflation.
I even made a shop take my daughter's pick-up back into the shop to re-inflate the tires. They had lowered pressure in the front tires to match vehicle specifications, although they were only supposed to do an oil and filter change. They didn't have any room to argue because I'd written,"Keep tires inflated to max pressure molded in tire sidewalls," on the job ticket. (I've had problems in the past with shops reducing inflation without my approval.)
'73 Concord 20' Class A w/Dodge 440 - see profile for photo
If my impression is correct, it's creating a vacuum leak that will really mess with your engine performance.
As for vacuum hose routing, check with your state agencies. When Alaska initiated it's motor vehicle emissions testing program, the state legislature required the program provide detailed relevant maintenance diagrams and text to owners and maintenance shops.
Your state (Michigan) may have a similar resource available.
I corrected the horrendous vacuum hose mess left by a previous owner when I overhauled my 1980 Bronco, using the free information provided by the state. The information they provided was specific to the year, make, model, engine, and VIN. It eliminated the head-scratching most maintenance manuals cause when it comes to vacuum hoses.
As for LED replacements for OEM incandescent bulbs, I have concerns. Incandescent bulbs emit omni-directional light while LEDs tend to be unidirectional. So the LED replacements don't always work well in some fixtures. IIRC, the standard for various motor vehicle bulbs require a specific output, which corresponding LED replacements have to meet. However, is the LED 'aiming' its light output in the right direction?
For this reason, I prefer to replace the fixture rather than just the bulb. However, this does cost more and it may be difficult to find a suitable replacement for the OEM fixture.
Griff - I've found a couple diagrams, I think the one that is messed up controls the Idle/timing advancement, its rough when cold, but smooths out once it warms up. I haven't driven it anywhere, but before rebuilding the carb it was starting to smoke a bit... and that's gone now. I found a factory guide on the carb... but the whole thing to tuning it is measuring and bending... not much screw turning... maybe I'll take it back off this winter and play with it for a week... we'll see.
The bulbs I got were cheap off Ebay... I've been wanting to try LEDs for a while for 1) heat 2) battery draw. They were 'recommended' by another group of Vintage Holiday Rambler folks I follow.
These guys: http://www.ebay.com/itm/10x-Warm-White-RV-Camper-Trailer-1156-Ba15s-5050-18-SMD-LED-Light-Bulbs/301144033768?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
They're OK... not a cool as the LEDs we have for our house where side by side to an incandescent, you can't tell the difference in light. These are a little more blue, and don't have quit the dispersion. But, they're definitely cooler, and at night when you really need them... light things up just fine.
I have an Onan 4000K genset 1979 manual if you need a copy. However, I've never worked on it, so I can't be of any help on that.