Hello!

1961 P1800
B18B engine. It's got overdrive too.

I need to do some maintenance...the car runs a little rough, but strong.
I'm mechanically retarded so I'll start with an oil change--that's easy!

But I also need to check the oil level in the carburetors' damping cylinder. What should I top that up with?

Also I want to change the oil in my transmission. Again I need a recomendation as to what lube to use.

AND for the OVERDRIVE??? I should drain and refill that as well. What oil should I fill it with?


I use Castrol 20W50 for my engine oil.

Please send me some answers, thoughts and suggestions. Specifics are great too!

THANKS!

G

Interesting thread. Have any of you tried these new oils on the market from Castrol, Valveline, Quaker State, etc. that say they are for high mileage engines and help reduce oil burning/leaking? I tried the 10w-40 High Mileage Oil in my 93 850 and she seems to burn less oil on the highway now. My 1800 has low mileage, but it's all original so the seals are probably all dried out. 20W/50, from my experience, gives a slight hit in performance because it's so heavy. I've only used it in the past in motors that leak or burn oil. Is there any other reason to go with it?

I've got a leak in my trans that I'm going to have a closer look at this weekend. Not sure if it's the trans or O/D, but it's a slow leak. Any ideas what seals to look at first? Could it just be the seal on the O/D bottom plate?

20W-50 is fine for the engine, carb domes and tranny. The OD shares the tranny oil.

I recommend you use Mann brand oil filters, whether they say Mann or Volvo on them. They are exactly the same except for the markings. They're excellent. The engine and filter hold just over 4 quarts.

To fill the carbs, remove the air cleaners and the caps on the domes, which will come out with a plunger attached. Put in a small amount of oil, no nearly enough to fill it with the plunger out. Put plunger and cap back on, and lift the piston up all the way with your fingers. Any excess oil will squirt out the vent hole in the cap (have a rag handy). If none does, add more oil and repeat.

The thicker the oil, the richer the mix will be as you put the gas pedal down. This is what SUs do instead of having accelerator pumps. 20W-50 or 30W is about right. Lighter oil does not give better throttle response, which some people might try to tell you -- it's the other way around.

Check where the throttle shafts go through the carb bodies. This is themost common place where SUs wear out, in my experience. If you can rattle them around at all because the holes they go through have worn oval, the carbs need to be rebushed. This makes a night/day difference in performance, tunability, etc. That might be the cause of the roughness right there -- a B18B with nothing wrong with it is about the smoothest 4-cyl motor going, even at idle.

Drain the tranny from the lower of the two plugs on the right side of the case, and from the marked plug at the rear of the OD. Above the OD plug on the left is a plate held on with four bolts. Remove this after draining (and if you're very careful, you may actually not break the hard gasket behind it), and pull out the cylindrical wire mesh filter for cleaning.

After its all back together fill from the upper plug on the right of the case. Your local GenericAuto store will have a pump for oil bottles that makes this easy (inexpensive).

Oil capacity is 1.6 quarts, and you won't be able to get in quite all of it. Replace the plug and drive 5-10 miles. This will get the OD passages filled up, and then you'll have room in the gearbox for the rest. It's a pain, but if the tranny and OD are in good shape, you can go a long time without draining. Do check the level and top up at every oil change, but no need to drain and fill twice.

--Phil S.

I was always told to use 30W NON-DETERGENT motor oil in the gearbox and OD. I know lubricants is a subject comprised of many opinions but is there damage potential in using additive-laden oil in the OD? Of coure when I got my 1800 ten or eleven years ago, draining the gearbox revealed the presence of gear oil, engine oil and a little water.
--
Roy Olson

Roy,

I don't know... are modern oils even rated as detergent or non-detergent?

I don't think the ODs are nearly as picky as some suggest, although I'm no expert on seal chemistry or whatever. I'm running ATF in the M46 (JP-type OD, I believe) because that's what's stamped on it. In the M41 J-type I use 80/90 hypoid gear oil. In the M41 D-type I've used gear oil and 30W motor oil, and I can't tell the difference. I recently had some problems that could have been viscosity-related, so I tried 20W/50 oil. Problems turned out to be electrical, but it seems happy with that so I'm leaving it in there for now.

Both types of motor oil have been Valvoline racing oil, which I bought on a whim, thinking it might be more durable than "regular" motor oil, as it doesn't get changed often. After several years and many thousands of miles, both M41s have stayed spotlessly clean inside. Can't say about the M46, as I've never had occasion to take it out of the car (knock on wood).

Hey Phil,
Thanks for the reply. I bought a case of 30W "non-detergent" last year and see these oils frequently in the auto parts joints. Your point about the M46 is well taken. I had one in a 240 that I bought new and drove for 375K. The ATF was changed at the initial dealer service and never touched again. The gearbox was factory intact when I sold the car, never a problem. As for the M41s, I was told some time ago that the additives in modern oils (detergents) are not good for the ODs. I don't know. You're proof that this might be bunk. I guess I'll keep the 30W in mine since it's been absolutely no trouble.
--
Roy Olson

I recently had a lot of trouble with an overdrive in a rallying PV 544, basically because we couln't stop it from disengaging when really caning it. This on a PV with a 4.8 rear diff and LSD.

I had a long conversation with an oil expert in the technical department of Millers oil. He told me that the multigrade part of engine oil is a polymer. Whilst it copes very well with its designed use, in an engine, it does not cope well with the extreme pressures in a gearbox. We now use some really weird high viscosity Hypoid oil in the D type overdrive, and it works a treat.

I agree though that in npormal use the overdrives are not very fussy, and tend to throw in whatever comes to hand.

Regards

Pete

I agree with that. Straight cut oils last longer in gearboxes & diffs, if you use a 20w-50, it will quickly become a straight 20 all by itself.

Pete,

Do you mind telling us exactly what that weird high-viscosity product is? One of my cars does have a motor capable of exerting some ambnormal pressures -- right now I've got the J-type with 80/90 hypoid behind it.

Was also very interested in your comments about the relative strength of D vs. J the other day... nice to hear some straight talk once in a while. I may swap my trannies; the box with the D has nicer gear ratios for the sportier car. Only reason I did what I have now was fear of the D-type not handling real power.

8^)