Maya.215 wrote:
I said the same thing on changing both sides makes no sence to do one,I'm on a search for so the oil that goes in the rear differential type and weight?
I almost missed this.I said the same thing on changing both sides makes no sence to do one,I'm on a search for so the oil that goes in the rear differential type and weight?
Synthetic 75W90 gear lube. (Might be called gear oil.)
The parts store where I have a commercial account has been bought out by a major chain and they're getting stupid with my account so I wasn't able to find the amount required. You want to fill the differential until fluid flows out the hole. IIRC, the differential fluid also lubes the wheel bearings so you'll want to make sure it stays topped off. (I've dealt with a lot of full-floating truck axles, which includes your Dana 70, so I have to look things up to make sure I'm remembering correctly.)
Some people recommend 85W140, especially if you're carrying a heavy load, pulling a large trailer, going across southwest deserts in the summer daytime, or going up and down a lot of large hills or mountain passes. However, in spite of Alaska's well-known rugged terrain, I've never had any problems using 75W90.
If you're worried about it, stop every hour or so to admire the scenery and let the gear lube cool off.
If, during routine maintenance, the gear lube smells burnt, change it and maybe consider going to 85W140. (But remember the thicker gear lube will be harder on the differential in the winter.) Otherwise, don't worry about.
What you folks on the east coast call mountains, we call hills. Even the Rockies in the lower 48 aren't that impressive compared to up here. If you want some idea as to what I'm talking about, google images of Turnagain Pass and Thompson Pass. There's not a lot of pictures of the roads up to those passes ... most people don't like to stop until they either reach the top or bottom. (And, for some people, especially truckers, reaching the bottom is sometimes a matter of circumstances rather than intent.)
By the way, 75W90 (10W30, etc.) means multi-viscosity. The first number indicates cold/winter viscosity, the W stand for winter, the other number indicates hot/summer viscosity. (The lower the number, the thinner the lube/oil and vice versa.)
In the old days, only single viscosity lubricants were available, meaning you had to change the gear lube in your differentials and manual transmission twice a year in some climates.
The same applied to engine oil, although I learned years ago that changing the oil and filter every 3 months or 3,000 miles, whichever comes first, extends engine life drastically. (That's why my van is still running strong after over a half million miles ... the body's falling apart by the engine's still chugging along.)
(Drats, I'm dating myself again.)
Here in interior Alaska, with the roughly 150 degree (F) difference between summer highs and winter lows, some people -- especially oldtimers -- still change their gear lube twice a year.
On the other hand, the 69/70 Explorer motorhome was the only vehicle that I could get started at -50 degrees (F) so I could go pick my wife who was stranded at work. Once the engine warmed up, the beast had no problems with the rear axle or any other components. (It took a few miles for the "square" tires to warm up but that's life up here.)
Bottom line: Keeping a Dana 70 full of 75W90 gear lube will make it last past your lifetime.
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
Please, please, I'm not knocking you. Not everyone has had the same educational opportunities that I have had, nor a father who was an absolute stickler on language precision and ability to express one's self.
There's a tremendous number of people in the same situation as you. Unlike some of them, I get the impression you're trying to learn and improve. That's something I want to encourage and like to help with.
I've been programming computers for almost a half century and some of the people I worked with were clearly geniuses. However, some of those geniuses weren't able to put together a coherent sentence if their life depended on it, never mind a complete paragraph.
On the other hand, you manage to get across what you're trying to say much better than some of those geniuses.
In the shops I worked in and managed, an ability to communicate with real people was a vital skill. (Computer programmers are unique beasts, living in their own little world, so I tended to call people outside that group "real people.")
As a supervisor, I always gave new people a writing test to determine their relative skill. If need be, I'd send them off to remedial English classes at the local college. (My commanders and I often got into disagreements over whether some of the college classes I signed off on were really mission-related courses that qualified for tuition assistance ... and I always won.)
So, if my attempts to help bother you, tell me to shut up. For most part, I'm only interested in helping you learn motorhome and motor vehicle terminology.
As for changing the fluid and filter in your A727 automatic transmission, you're in for a messy job unless someone replaced the OEM pan with an aftermarket pan that included a drain plug. With the OEM pan, you have to loosen the pan bolts and just let the fluid drain out everywhere. Also, be sure to drain the torque converter ... it holds a significant portion of the old fluid.
Be sure to use the correct amount and type of fluid. I burned up a newly rebuilt transmission by misreading x quarts as x pints. A good parts store should be able to tell you what type and how much. (Excuse me while I cuss and swear about what they're doing to my commercial account ... maybe I need to find a new store.)
Don't let them brush you off or give you a blank look just because you have a motorhome. (I've found it's best to not mention motorhome ... it scares them so just tell them 1978 B300 van.) The A727 automatic transmission has remained more or less the same from the early '60s right up until Mother Mopar replaced it with the A518. (A significant part of the A518 is the same as the A727 and many parts interchange.) Likewise, it doesn't matter if the A727 is in a medium duty truck, a motorhome, a pickup, or a sedan ... all of these have essentially identical A727 transmissions.
Enough for now ... the next installment of motorhome electrical systems is ready to be uploaded, as soon as I'm sure the kiddies at my ISP are done for the night with interrupting customers' Internet connections. (I also need to find the password for my domain account hosted by servers in Utah.)
Before continuing, I'd like to clarify and amplify some elements in my previous post on typical motorhome electrical systems. The following is a "top level" block diagram, reflecting the totality of most motorhome electrical systems.
![[image]](http://www.riffgan.com/motorhome/electrical/Diagram_00.jpg)
The diagram contains two "black boxes" with each representing one of the two (sub)systems typically found in recreational vehicles. The diagram also has three lines/arrows representing the connections between the (sub)systems.
For completeness, I decided to add two lines/arrows depicting two external connections for the 120/240VAC (sub)system. which were not discussed in my previous post. I chose to add these because shore power cords are usually physically attached to the motorhome and many motorhomes have onboard generators
I probably could have added an external connection line/arrow, also labelled "Battery Charger(s)." to the 12VDC (sub)system, to show that battery chargers could be plugged into external outlets, as well as internal outlets. However, I decided, in this case, external outlets (and battery chargers) aren't part of a motorhome's overall system.
You may have notice my repeated use of "(sub)system" in this text while the diagram simply uses "system." I did this to maintain a degree of continuity with my previous post. The diagram's labels are technically correct and the repeated use of "(sub)" is, at this level, superfluous. (The use of "system" and "subsystem" is a judgement call, usually related to how autonomous a component is within the overall system.)
The use of black boxes is a means of avoiding getting bogged down in details. In general, black boxes represent subsystems, circuits, and components, with each having specific characteristics and function(s). By obscuring the details existing within the black box, we're able to focus on a specific section of the overall system and how it relates to (connects to or interfaces with) other sections.
My previous post on this topic was written on-the-fly, which results in not always choosing the most appropriate terms. Specifically, I used transformers and bridge rectifiers when power supplies would have been a more appropriate term. On the other hand, I was specifically thinking about our older motorhomes and power supplies consisted of transformers and bridge rectifiers back in those days. Modern power supplies typically use electronics and are, to varying degrees, more sophisticated than old skool transformers/rectifiers.
(This is the reason I recommend upgrading to a new, more modern power supply if you're still using the power supply that originally came with your motorhome.)
As noted in my previous post, we are going to ignore the motorhome's 120/240VAC system, at least for the time being, and focus on the 12VDC system.
Just as with the typical motorhome's overall electrical system, we can break down the typical motorhome's 12VDC system into two distinct, cohesive parts: The coach system and the motor vehicle system.
![[image]](http://www.riffgan.com/motorhome/electrical/Diagram_02.jpg)
Unlike the higher level breakdown, where the dividing line between the two systems was the voltage and type of current in each system, what we're looking at now is partitioned based on function. (The criteria for dividing up a system is also a judgement call, based on a variety of factors, such as functions, locations, characteristics, etc. In complex systems, it's sometimes necessary to have multiple diagrams, each reflecting a different aspect or view of the system.)
The coach system includes the components and circuitry that supports the motorhome's living quarters role. On the other hand, the motor vehicle system includes the components and circuitry needed for the motorhome to operate as a legal motor vehicle.
Note: I prefer "coach" over "house" because house is a somewhat ambiguous term with multiple meanings and interpretation. More important to our discussion, the electrical system in most people's houses is (at least in North America) exclusively 120/240VAC systems. (If their houses have a 12VDC system, it's usually because they're living off the grid.)
(Following the same train of thought, I prefer "auxiliary battery" over "house battery" in boats.)
The only connection between the two systems is the desirable but problematic means of charging the coach battery bank and powering the coach circuits when the engine is running.
Both systems show external connections, refined and carried over from the higher level diagram.
The motor vehicle system shows a single external connection, consisting of a single battery charger for charging and maintaining the motorhome's SLI (engine) battery. (Part of the details hidden by the black box is the alternator's role as the other SLI battery charger/maintainer.)
The coach system has three external connections, which are the three connections between the 120/240VAC and 12VDC systems in the higher level diagram/breakdown. In this case, they're shown as external connections because what they're connected to is outside this diagram.
I should also note this diagram slightly modifies the definition of battery charger(s) to include both onboard chargers connected to the motorhome's 120/240VAC system and external outlets. In addition, the "(s)" indicates the possibility of more than one charger for multiple batteries/banks.
In my next post on this topic, we'll look at the coach system in more detail, largely because it's relatively simple and provides a good opportunity to address some basic concepts, such as what a circuit is and so forth.
BTW - It's raining today, which is why I managed to finish this ...
![[emoticon]](http://www.coastresorts.com/sharedcontent/cfb/images/smile.gif "smile")
Griff in Fairbanks wrote:
I postponed continuing my current discussion because I was concerned it might obscure Wolf_n_Kat's post, as well as Leeann's response. I felt it was important to make sure this thread's community had a good opportunity to read and respond to those posts.
I postponed continuing my current discussion because I was concerned it might obscure Wolf_n_Kat's post, as well as Leeann's response. I felt it was important to make sure this thread's community had a good opportunity to read and respond to those posts.
And I really appreciate that, Griff.
Update: Kat had her lobotomy... I mean, lobectomy! I'm glad the Dr. could keep those straight, I'd probably be facing a malpractice suit... Anyway, we got that over and done with - oh, and about the Explorer. A '92 Ford Explorer (not an Explorer RV, that'd be too expensive for daily trips!) with over a quarter of a million miles under her wheels. Did great, up until the day I shredded the serpentine belt. After walking to an auto store to pick up a new belt and some radiator fluid, and with a little help from a roadside-assist guy, I was back on the road.
Anyway, Mama's doing pretty good, considering she just had the upper lobe of her left lung removed. Came home Friday, and Sunday we went into the ER because she coughed and was suddenly 'leaking' from where the chest tube was. Not blood, not 'puss-ie looking', a clear fluid. Better to be safe than sorry, so I slapped a bandage (an industrial-sized abdominal bandage) over the leak and off we went. Nothing to worry about, she had just popped a stitch that wasn't particularly well-done, a couple of staples and she was good to go.
Had her post-op meeting with the surgeon yesterday, and he liked what he saw. Pulled all the staples from the thoracotemy and chest tube, 'taped her up' (Steri-Strips), and he wants to see her again in a couple of weeks. We've been having a field day cleaning tape residue off her skin (I'm thinking the hospital must have been having a sale on tape, they used so much of it!), and aside from a few twinges and a restless night last night, Kat is back at work editing the latest issue of the magazine, and has actually managed to get caught up!
We appreciate everybody's thoughts and prayers - 'community' is right! You guys ROCK!
My surgery is Sat at 7:30 eastern. Doc said 4-5 hrs, so fun. If I recover well, I'll go home. Otherwise, they'll keep me for observation.
'73 Concord 20' Class A w/Dodge 440 - see profile for photo
Leeann wrote:
That's seriously awesome news!
My surgery is Sat at 7:30 eastern. Doc said 4-5 hrs, so fun. If I recover well, I'll go home. Otherwise, they'll keep me for observation.
That's seriously awesome news!
My surgery is Sat at 7:30 eastern. Doc said 4-5 hrs, so fun. If I recover well, I'll go home. Otherwise, they'll keep me for observation.
We, of course, will be praying that all goes well (and more quickly than the estimated time!), and you get to go home right away!
Just remember to take it easy afterwards, no need for playing Superwoman (besides, Supergirl might be embarrassed!! ;-) )
Leeann wrote:
That's seriously awesome news!
My surgery is Sat at 7:30 eastern. Doc said 4-5 hrs, so fun. If I recover well, I'll go home. Otherwise, they'll keep me for observation.
That's seriously awesome news!
My surgery is Sat at 7:30 eastern. Doc said 4-5 hrs, so fun. If I recover well, I'll go home. Otherwise, they'll keep me for observation.
I PM'ed Leeann to ask, "What surgery?" I'll leave the details to Leeann ... but everyone might want to send her husband a few rolls of bubble wrap ...
To continue ...
Before diving into the Coach Electrical System, let's examine some basic electricity concepts as they apply to our discussion, starting with electrical circuits.
(Yes, we're going to shift temporarily to a bottom-up perspective to lay some groundwork before going back to our top-down examination.)
In its most basic form, an electrical circuit consists of a source, connections, and a load. The words circle and circuit are related, with both sharing common origins. So, one way of thinking about an electrical circuit is to consider the electricity following a (vaguely) circular path from the source, through the connections and the load, and back to the source.
![[image]](http://www.riffgan.com/motorhome/electrical/Basic_Electrical_Circuit_1.jpg)
All electrical circuits boil down to this basic diagram. That's it, nice and simple, just like sex.
Note: We're talking about electrical, not electronic circuits. Electrical circuits are relatively simple and straight forward, while electronic circuits can be incredibly complex, with lots of strange, counterintuitive rules and behavior. (That's why I quit studying electronics and focused on digital circuits.)