MC9 Steering Gear Info...

[Ross]

My 1980 MC9 has non-integral steering but my MC9 manual only covers the integral steering.  I have a leak on the steering gear which I think is coming from around the large nut facing the spare tire bay.  Looks like a lock nut of some sort.  Not real sure where exactly it's leaking.  The help didn't show up today so all I could do is locate the wet spot. 

Anyway, I was going through the manual to study up on the steering gear and could only find info on integral steering.

Thank....Ross

[Devin & Amy]

Ross,
Which manual do you have? The "89" or the "79".

devin

[Ross]

Ross,
Which manual do you have? The "89" or the "79".

devin

January 89...That's the problem.  I got the manual from Coachinfo and this is what they sent me for a 1980 MC9.

So here's another thing.  I talked to Luke and he said that they used AFT in thier non-integral MC9's.  Not realizing my manual was the wrong year, I put 10W40 in the power steering, which is what the manual called for.  Evidently 10W40 is used for intergral steering.  When I added oil there was none showing in the resevor, the oil leaking out didn't smell like ATF and the manual said 10W40, so I used 10W40.  I've got maybe 300 miles on the bus since adding 10W40, which was actually a year ago.  It has a pretty decent leak, so I've added 2 quarts of 10W40 in that time.  The bus drives great and other than having that leak, doesn't show any other signs of any problems.


So the big question is.....shouldn't I be seeing big problems from mixing ATF and motor oil, assuming I had ATF to begin with?  At this point, I'll try to seal up the leak around the big nut, but I don't know what to do about the oil.  I can open the return, run the engine and cycle the steering while keeping the resevoir topped off with ATF.  That should purge the system, but I'm not sure that's nessessary.

Does anyone know what will happen if you put motor oil in place of ATF in one these systems?  Just trying to figure out if that is infact what I did.  I've heard mention here that AFT and motor oil just won't mix.  If that's the case, I think I'd have some serious power steering issues.

Thanks...Ross 

[Ross]

Have I stumped the panel on this one? 

[Devin & Amy]

Ross,
i am now pretty worried. i hope someone can help. I have been putting in the 10w40 as well. I just had cause to suspect the "89" book due to a wiring diagram. it is wrong for the rear junction box. I suggest that you get in touch with Gumpydog to see what the 1979 book says. I am currently searching for this book as well. if I find it soon I'll let you know.

i too have e leak in the same spot.
What oil are we supposed to be using?   Anybody?

Devin

[Ross]

Ross,
i am now pretty worried. i hope someone can help. I have been putting in the 10w40 as well. I just had cause to suspect the "89" book due to a wiring diagram. it is wrong for the rear junction box. I suggest that you get in touch with Gumpydog to see what the 1979 book says. I am currently searching for this book as well. if I find it soon I'll let you know.

i too have e leak in the same spot.
What oil are we supposed to be using?   Anybody?

Devin

You have a 1980 MC9 as well I see which should also have the non-integral steering.  IE: Should have the slave cylinder.  How is it running on 10W40?  Mine seems to do fine, which is why I'm reluctant to flush it out with ATF.

I suspect the leak around the big nut on the steering box is not PS oil but gear oil.  I cleaned the box the other day and drove it and did not see any leakage.  I also saw some RTV around that nut, which means someone had gone after that leak before.

Ross

[tekebird]

GUys, Integral was an option as early as 1975 as per my final delivery record on my MC-8 which came new with Integral

[RJ]

Ross -

On non-integral power assist steering, the p/s fluid is supplied only to the hydraylic ram, not to the steering gearbox.

HTH. . .

[gumpy]

Ok, I just saw this thread....

Here's the scoop from 1982 manual...

Hydraulic System: Use SAE no. 10W motor oil (Service MS).

Fill the reservoir to the recommended level as indicated on the reservour. If the level is higher, overflow will occur during operation. If the level gets too low, air will be dawn into the system.

Talks about proper refilling and bleeding procedure and raising the front end and turning wheels to get all the air out.

Then, there's a section that says:

Lubrication: Use SAE 90 Gear Lubricant. Fill the steering gear housing with lubricant. Fill the housing from the uppermost filler plug. The housing should be full to ensure adequate lubrication of all internal parts. Capacity of the gear housing is 7 U.S. pints (3.3 liters).


So, it looks like the hydraulic system is separate from the gear housing lubrication.

craig