trivial questions for my first 240 maintenances

[resunoiz]

Hi, due to the "octopus" on the brake system leaking, I've put the car on 4 jackstands and I'm planning some basic maintenance.
Being my first time with a 240 I have some -surely- stupid doubt. If someone have a little time to reassure me, I'll be very, very grateful.

1) OCTOPUS: reading here and there, it seemed a painful job but, for me, it wasn't. Apart from one of the tubes that made a little resistance to be retighten due to the line being quite bent, didn't see that much difficult. Now I have to tighten it correctly to avoid leaks.

I've tighten it "by hand" then I gave it a tightening "by feel", not with a dynamometric because I didn't find a specific torque.
I tried not to overtighten it being soft metal. There are any suggestions about, or some guidance to properly tighten it?

2) DIFFERENTIAL



the differential care wasn't ever opened till 1981 (car is in our family from new). Car ha 108.000km so the fac that there wasn't any "metal shavings" didn't surpirse me a lot, but the good thing is that was almost full. I had little oozings on the bottom, but nothing that can think a bout the gasket so I plan to refill it. B19A engine, non limited slip diff. Any guidance on torquing the two bolts?
I was thinkg about a 75W90 because I have an half can opened 6 months ago for another car, I was planning to use it and buy another liter of the same one: https://www.ebay.it/itm/126352464383 do you think it'll be ok?

3) ENGINE OIL: there is a lot of opinions about. I'll swith to syntetic but I'm already uncertain between 5w40 or 10w40. Italy, warm climates. A 5w40 will be "comfortable" : I use Leichtlauf High Tech 5W-40 on another youngtimer and it will be ideal to have the same oil for oil changes, refills etc. But I'm afraid that a 45+ year engine could start leaking with a so "thin" oil: it passed from the 10w40 semi-syntetic when new to the 10w40 syntetic in the last years. Better to continue with that thickness?
And, always about oil change: is ok to tighten the oil filter only "by hand" as someone suggested? I've always seen mechanics tighten it with the removing tool.

4) GEARBOX OIL car is a manual, 4-speed+overdrive. Some little drops around a bolt, but nothing (still) worrying. Fot the gearbox I don't know if it was ever refilled or not, and if yes... I don't know what oil was used. Gearbox is fluid, every gear change is smooth, overdrive works as it should. I've read on the "green books" I should use a "Type F" ATF oil, but searching onlince I can't find nothing with that specs.

Can you suggest me a right one to search?
Is ok to refill or better to remove all?


As said, thanks to everyone that wants to spend a little time to help

 

[shoestring]

1) What you did should be correct, as long as everything is clean and undamaged.

2) Which two bolts are you tightening? If it's the ones in the cover, they take copper washers. Finger tight, then snug it. I'm not sure how "snug" will translate. "By feel", like the brake lines. 75W90 GL5.

3) I would use the same 5W40, if that's what you already have, so that you have only 1 oil. Seals and gaskets that leak are because the seals and gaskets aren't doing their jobs, not because the oil is thin. When warm, the viscosity is the same (40).

4) I don't think the Type F specification is correct for the gearbox: perhaps for the overdrive, you can see it's a separate unit. From what I can see, the 4-speed part of the gearbox takes the same fluid as a later 5-speed M47.

No bad questions. Tutto posto!

 

[resunoiz]

1) What you did should be correct, as long as everything is clean and undamaged.

2) Which two bolts are you tightening? If it's the ones in the cover, they take copper washers. Finger tight, then snug it. I'm not sure how "snug" will translate. "By feel", like the brake lines. 75W90 GL5.

3) I would use the same 5W40, if that's what you already have, so that you have only 1 oil. Seals and gaskets that leak are because the seals and gaskets aren't doing their jobs, not because the oil is thin. When warm, the viscosity is the same (40).

4) I don't think the Type F specification is correct for the gearbox: perhaps for the overdrive, you can see it's a separate unit. From what I can see, the 4-speed part of the gearbox takes the same fluid as a later 5-speed M47.

No bad questions. Tutto posto!

thank you, at first

2) Which two bolts are you tightening? If it's the ones in the cover, they take copper washers. Finger tight, then snug it. I'm not sure how "snug" will translate. "By feel", like the brake lines. 75W90 GL5.

in my differential the fill plug and the lower one have no copper washers. Infact, I can see part of the thread, the bolt doesn't even have a flat part where you could place a washer. Maybe the system has changed over the years?
What about a half can of 75w90 already opened. Re-usable or better to throw it away?

4) I don't think the Type F specification is correct for the gearbox: perhaps for the overdrive, you can see it's a separate unit. From what I can see, the 4-speed part of the gearbox takes the same fluid as a later 5-speed M47.

there is a separate oil circuit for overdrive?
As far as I know, my gearbox should be an M46 (4 speed+ovd), that requires ATF-F. Same says skandix with my VIN.



Am I wrong?

 

[resunoiz]

@shoestring here's my differential plugs: don't thinka copper washer can be any useful


and, about the gearbox, M46. On the picture above I understand I need a single oil type...

 

[Khrrck]

there is a separate oil circuit for overdrive?

No, the same oil is used for both overdrive and the main gears. Which is why it specifies Type F. Type F does not have friction modifiers which can cause issues with the synchros, but it still works well with the OD clutch.

Here's an old thread on it.

T

Post in thread 'M46 oil'

Apr 17, 2010

OK, I'll try to explain what oil is needed and why. Basically, the 4 first gears ie. the tranny itself could do fine with the (Api) GL-4 75-90 oil, or even motor oil. But the OD unit causes the issues, as it is a planetary gear-type, it has the hydraulic operated clutch(for the fifth gear), which is similar to the ones in automatic transmissions. It "requires" some sort of ATF oil to operate correctly. The problem is, that todays automatic trannies are made so that they slip "controlled" just a bit when it changes gear. To make this work, they make these Dexron xxx ATF, which has some...

• TVS

If you can't find ATF type F in your country, I'm a little surprised. However there are a couple of substitutes suggested in the old thread if it's unavailable.

What about a half can of 75w90 already opened.

Should still be fine. It doesn't absorb water like ethanol gasoline or brake fluid.

I'll swith to syntetic but I'm already uncertain between 5w40 or 10w40. Italy, warm climates. A 5w40 will be "comfortable" : I use Leichtlauf High Tech 5W-40 on another youngtimer and it will be ideal to have the same oil for oil changes, refills etc. But I'm afraid that a 45+ year engine could start leaking with a so "thin" oil:

5w40 should be fine. The thing with oil weights is that the 1st number and 2nd number are different scales. Basically your 5w40 oil is still significantly thicker when cold than it is when hot. And when hot it'll be just as thin as the 10w40.

here's my differential plugs: don't thinka copper washer can be any useful

I expect they're either a tapered pipe thread style or they seat against a sealing surface in the bottom of the hole.

 

[resunoiz]

No, the same oil is used for both overdrive and the main gears. Which is why it specifies Type F. Type F does not have friction modifiers which can cause issues with the synchros, but it still works well with the OD clutch.

Here's an old thread on it.

T

Post in thread 'M46 oil'

Apr 17, 2010

OK, I'll try to explain what oil is needed and why. Basically, the 4 first gears ie. the tranny itself could do fine with the (Api) GL-4 75-90 oil, or even motor oil. But the OD unit causes the issues, as it is a planetary gear-type, it has the hydraulic operated clutch(for the fifth gear), which is similar to the ones in automatic transmissions. It "requires" some sort of ATF oil to operate correctly. The problem is, that todays automatic trannies are made so that they slip "controlled" just a bit when it changes gear. To make this work, they make these Dexron xxx ATF, which has some...

• TVS

If you can't find ATF type F in your country, I'm a little surprised. However there are a couple of substitutes suggested in the old thread if it's unavailable.

thank you too this was my doubt.
I've found only ravenol ATF type F, very pricey (25€/lt). Seeing there, I need 2,3 lt so I need 3 of them.

Should still be fine. It doesn't absorb water like ethanol gasoline or brake fluid.

that's what I tought. But, in this case, being very cheap a fresh 2lt of 75W90 may not be a problem

I expect they're either a tapered pipe thread style or they seat against a sealing surface in the bottom of the hole.

yes, kind of. I saw the version with copper washer and I think is for "younger" 240, maybe polar ones. I've bought a new one for the fill plug and is essentially the same with its correct PN. I saw some guys taped them with teflon, like you would do on a water pipe. I would have liked to switch to the version with the copper washer being easier to tighten and mantain dropless but...I simply can't.

5w40 should be fine. The thing with oil weights is that the 1st number and 2nd number are different scales. Basically your 5w40 oil is still significantly thicker when cold than it is when hot. And when hot it'll be just as thin as the 10w40.

thanks. So I'll stick with my Leichtlauf High Tech that I use for my E46 too

 

[resunoiz]

last (I hope) stupid question.car is on 4 jackstands, differential is now free. To fill it and get the correct level, is it better to raise with jack it to a more horizontal position or can I leave it dangling like this? Don't know if there is that much difference but...

 

[AnthonyHardy2]

You can fill it like that as long as the car is mostly level. The axle doesn't really pivot much as the suspension moves so the fluid level will be very nearly the same whether it's at normal ride height or hanging like that.

 

[resunoiz]

thank you all!

if I change gearbox oil is better to change OD paper gasket, right? I have to find the SN and look on the web to avoid Volvo (min 2-3 weeks for old stuffs...)

 

[Khrrck]

If the gasket between OD and transmission isn't leaking I wouldn't mess with it tbh.

 

[resunoiz]

If the gasket between OD and transmission isn't leaking I wouldn't mess with it tbh.

No, surely not. I was talking about this..and I'm not sure worth removing it due that does not leak

 

[resunoiz]

thank you all!

I'm waiting for the OD gasket (still thinking about if it worth change as @Khrrck suggested...), copper oring for oil sump and new bolts for differential.

used that time for some cosmetic things like cleaning the (now again) red block, fixing some cosmetic issues:







Still in need for suggestion if it worth leve OD gasket alone or change it flushing gearbox oil.

 

[Crustacean Wagon]

If the gasket between OD and transmission isn't leaking I wouldn't mess with it tbh.

Still in need for suggestion if it worth leve OD gasket alone or change it flushing gearbox oil.

If its fine why change it

 

[resunoiz]

Well, after your precious opinions and suggestions car is back on her wheels.
Gears smooth as usual but with a oil that doesn't have 25+ years, same for differential.
I did 200+ kms this weekend and had no brake failure warning nor brake malfunctions or spongy pedal.
Let's see if next days there will be some leaks on the various plugs I removed.

If the brake fluid is ok I don't know if it would be necessary a new bleed I think

 

[resunoiz]

meanwhile cleaning the garage I dismantled the brake junction block. As seen here there are practically only 2 orings and 2 whasher that needs to be replaced to have it overhauled.

The rubber gasket on the electric connector I think doesn't need to be changed being nothing more than a dust/dirt cover for the sensor: if oil is already there the block is already non operating.

I want to mantain the car as OE as possible: the option of a upgraded Wagonmeister junction with the electrical wiring on the cap does not excite me too much to preserve originality.

so instead of throw it in the trashcan I'd like to repair it and store in garage for the future: someone ever overhauled it with success?