Synthetic lube in a Honda?

I'd love to get synthetic lube swapped into my 98 Honda. I have a favorite I'm going to try in the crankcase, but would like some input on the rest of the drivetrain. I'm not familiar with the "Real Time" drive set-up. Anybody have experience to share? Thanks

 

Real Time 4wd Info

Hayseed, I would wait until one of the Japanese based users can confirm what the Real Time system uses for fluid before changing out.

I have been doing some reading on the Honda Real Time system
here ---->>>> http://translate.google.com/transla...d&start=30&hl=en&rls=com.microsoft:en-us&sa=N

It seems according to that info that the Acty operates normally as a Front Wheel Drive, kicking in power to rear as required.

I have seen a post where a Acty owner says there is a switch located underneath on the actual transmission were you can lock it in 2wd, which I would think is for towing purposes.

So my question to any Acty owner out there - If you lock the switch in 2wd underneath does the power go to the front or back wheels?

Just curious and wanting to add to my knowledge base

 

Synthetic in an Acty

I asked my parts mgr in Japan what fluid goes in the Acty transfer case and was told 75/85 gear oil. He checked with a Honda Acty in Japan and was told this.
according to this information synthetic would be fine ... Is this bad info?

 

Ok guys, thanks for the replies and links. I've had good luck swapping synthetic into diffs on american rigs in the past. Benefits in cold weather are immediate and obvious. I'm sure it's better on the hot end too. However, I had a friend try it in a Audi with bad results.

Tripper - I sprang for a shop manual last week, and hope to have some spec #s to work with when it arrives. The link you posted is saying (I think), that with all four off the ground, all will turn with same authority. (in the trivia area)

Tom, your advice may well prove to be right. If there are viscous clutches or couplers involved though, might well be some type of friction modifier involved. Just being cautious I guess.

Oldie - It looks to me like the article you posted is dealing with a new Real Time system. Seems like a much more sophisticated system than what we've got, and looks to me like it strictly uses an auto trans. Think what we've got is likely more like their 90s system.

If I make any headway tracking spec #s down, I'll post. Seems like if any vehicle would benefit from freeing up the drivetrain, ours would be it.

 

My 2 cents on syn. oils. My rule of thumb, Syn. oil under 40000 mile engines, otherwise conventional oil. Syn. oils will clean out fine solids that are trapped in seals and my create a small leak or cause you to burn a little bit.. Thats why you dont want to put it in a higher mileage engine. Although a little seepage is worth the protection that syn. offer.

 

I don't think there's anyway that it uses gear oil in it. The only difference between the original Real Time system [brought out in '90] and the later system [2005] is they new & improved the pump system. There is no electronics involved with it all. It is most like a automatic transmission and you couldn't pump gear oil through any type of AT that I'm familiar with.

After re-reading the info from both links it definitely drives the front wheels on dry pavement with the rear getting 0% - just along for the ride if you like.
Once the front start to slip it causes the Real Time system to start diverting torque to the rear drive shaft as required until the front and rear wheels sync to the same speed.

My point from my previous post was that if you go under the truck and lock it in 2wd then you will probably be locking out the rear axle from the Real Time system - making it the only front drive Kei truck.

I found Honda CRV forum link here --->>> http://www.hondasuv.com/members/showthread.php?t=2648
That talks about DPSF [Dual Pump System Fluid] which I believe is used on the newer Real Time systems so OldMachinist could be right on with the CVT-F type fluid

 

I would think that locking out the AWD would result in just the rear tires working. CRV have the motor in the front so front wheel drive untill traction is needed. ACTY's have the engine in the rear and I find it strange they would send the power up the driveshaft to turn the front wheels. Not a very efficent method. I will put my ACTY in 2WD mode tomorrow and let you know which wheels turn.

 

I was also looking for a switch but couldn't find it. It's really not a switch. If you look were the front driveshaft enters the the transmission at the rear (right side) you will see a bolt that is painted orange. Next to what looks like a bolt there is a second bolt that locks the first bolt in place. Unscrew the second bolt then rotate the first bolt 180 degrees so that the locking groove aligns with the locking bolt. If you look close there is marks indicating 4WD and 2WD.

 

To quote from Wikipedia article on Real Time 4wd technology:

During normal operation (front wheels are driven) turn the front and rear wheels almost equally fast. This work equally with both pumps pumping and hydraulic pressure circulates between them.


If the front wheels for some reason a higher speed than the rear wheels, working with the front axle associated with a higher pump pumping than with the rear axle related.

Because this pump less than their wegpumpt hydraulic oil from the other pump is fed builds up pressure in the hydraulic system on. This pressure acts through a pressure cylinder to a clutch strips (later versions: claw clutch) and closes them. It now reaches torque to the rear wheels. The greater the speed difference between front and rear axle, the greater is attached to the rear wheels driving force transferred.

At bottom it mentions vehicles that this applies to:

There is Real Time 4WD in the following models:

Acty (Japanese market)
Civic Shuttle
Civic
CR-V
HR-V
Accord

I think you will find in general terms that "modern all wheel drive systems" be it in a Subaru Imprezza, Toyota Celica All trac or as in the Honda Real Time 4wd system being discussed here that they all pull primarily with the front wheels and kick in the rears as needed.

Toyota All-Trac: " the majority of the power is routed to the front wheels as would be in a traditional Toyota FWD automobile."

Audi quattro & VW 4motion: "The mid-1980s Mk2 Golf syncro, with its transverse engine and transmission positioning, still had most of its torque sent primarily to the front axle."

Nissan ATTESA system used in the all wheel drive Bluebird:
"In the new system, as with a normal FWD car, the gearbox contains a differential that drives the front wheels. However, an extra shaft from this differential also drives a bevel gear housed in the transfer case that permanently turns the driveshaft (i.e. there is no longer a "centre" differential). Housed in the rear differential is a viscous coupling that in normal conditions is disengaged. This means that for general driving, the system is FWD only. When the computer detects slippage of the front wheels, the viscous coupling engages and transfers up to 50% of the torque to the rear wheels."

I'll see if I can get a reply from Honda in Japan to confirm which way the system in a Acty works.

 

just a random thought here... those that typically get the torque to the front wheels are also front engine... would it stand to reason with the acty being rear engine that the primary drive would be the rear? i'm interested to know.

 

Me to that's why I'll probably e-mail Honda.jp to get it right from the horses mouth

 

I have had my Acty in 2 WD for a month, power is to the rear wheels. When in 4x4 equal power to the front and rear (thus full time all wheel drive) The diff lock will only lock the rear diff in the transaxle.

I hope this cleared up the confusion

Robert

 

I can take your word for power to the rear wheels in 2wd however it is "not" a equal power system when in "Real Time 4wd" it will power the other axle only as needed i.e. when slippage occurs in one axle resulting in different wheel speeds then the Real Time system kicks in and adds torque to the other axle then when equal axle speeds occur then it goes back to 2wd as stated in the article.

 

To my thinking that doesn't cover the "Real Time system" which is part of the rear differential. I don't think if you change the tranny fluid that it will drain the rear diff, I think it is seperate system. The reason I think this is that the tranny is vented to air - not pressurized. While the "Real Time" system is hydraulicly operated with pumps.
Also I would be careful on what "MTF" means - If they are also saying it's ok to use API SE 10w30 [which I believe because Honda has long used motor oil for there transmissions] and you put in something thicker then things good get nasty.
IMO

 

I received the service manual last week also. After reading what was listed for lube specs, I had about as many questions as before - just different ones.
Although GL-4 seems right in diff, but no weight listed... Transaxle uses MTF or API SE 10W-30 motor oil? Seems pretty vague and genaric to me.

I've been thinking of the drivetrain in these things as being similar to the original "Real Time" system brought out in the late 80s in the Civic wagon, but backwards, being rear-engine. One big disapointment of the manual is that it covers neither the trans nor differential in any detail... In the specifications chapter, trans merits one page of tolerance specs - diff, less than 1/2 page. No exploded diagrams, no theory of operation blurb, no teardown proceedure, no mention of hydraulic pump(s), no nothing - just absent. It's kind of weird, because engine and clutch are covered pretty well, servicing, rebuilding, and so forth. I guess the question of how closely related the "Real Time" systems are will go unanswered for a while yet.

On a whim, I decided to head down to the Honda dealer to see if I could get any lube info. Although this is my first imported vehicle, in the past I've had the best luck getting info from the parts counter guys. Such was not to be the case here. While this is a pretty large dealership (maybe 500 new rigs), the "parts counter" consisted of one young fella sitting at a desk, looking pensive (seems like they might be trying to foster the "Maytag repairman" image). Anyway, the database didn't seem to indicate Real Time existing before about '97, and it was clear that anything before that would have been when dinosaurs still walked the earth. Seems like lube info even for post 97 vehicles was strangely absent. After some pretty fun persistance, I finally had him abandoning the comfort of the computer and running off for the service manager. I did tag along and finally got a few answers on lube. Guy had been in the business for 25 years or so and had reccomendations on lube. Although he wasn't a synthetic lube guy, unless it was OE, He said 75-85 would be the weight range for the GL-4, and that yes indeed, 10W-30 motor oil or MTF was just fine for the trans. He also confirmed that the transaxle is a common case set-up. Ok, now I've got something to work with.

There's lots of good brands of synthetic lube out there. I've had good luck with Schaeffer's and have a stocking dealer here locally. They have the GL-4 covered, but I don't see a 5-30 or 10-30 motor oil tagged for trans use. I think Amsoil has a 5-30 listed for just that use. I've got a motor oil in mind that I use in other outfits, so looks like I'm good to go..

Sorry to run on. Dick

 

Yep, that's the way I thought it would work. Just a basic low tech with no viscous coupler.

 

So in conclusion, I would be correct in saying...

GL-4 75-85 Synthetic for the front diff
10w-30 Synthetic for the transmission (any motor oil, friction modifiers not req'd)

The rear diff is part of the transmission, so changing the oil in the transmission changes the rear diff fluid as well.

There is no transfer case oil to change.

Is this correct?