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Measuring oil level in aut. transmission is not easy?

Started by Jan S, 28 April 2022, 04:34 PM

Jan S

Aut. transmission is an 722.004 in a 1975 US W116 450 SE.

The trans lost a bit of oil when I rehabilitated the radiator. Quantity is unknown.

Now I'm trying to refill, but it's not easy to measure the level (engine idling).

Any tips?

- visit a professional workshop?
- replace filter and all oil and refill with 7,9 liter (according to spec)?
- other?
1975-mod W116 450 SE with 6.9 engine

daantjie

Indeed this can be a challenge.  Most important is to make sure the engine is fully warmed up.  Best to take a drive to get it hot but if you cannot then a long idle for sure.
Car must be level and engine running.  You should also move the shifter to each position for a few seconds with brake on then back to P.  Let idle a bit then take multiple readings.  Add very little at a time as it's easy to overfill.
Daniel
1977 450 SEL 6.9 - Astralsilber

Jan S

Thanks, daantjie

yes, I have tried exactly what you described. Long idle + a 10 min careful drive + shifter move. Refilled approx 1,1 liter.

I'm not seeing a "fairly obvious" oil mark on the dipstick. Maybe there is too little oil, but I don't want to overfill.
1975-mod W116 450 SE with 6.9 engine

daantjie

I would slowly add with engine running in P.  It can be tricky to see it on the stick but if you tilt it under sharp light it should show.  Just make sure you observe absolute cleanliness and wipe with lint free cloth.  Chamois type cloth is best.
Daniel
1977 450 SEL 6.9 - Astralsilber

Jan S

Solved!


This is a bit embarrassing ...

I had to refill nearly 3 liters, BUT THEN there was a clear oil mark between upper and lower marks on the dipstick.
1975-mod W116 450 SE with 6.9 engine

daantjie

Quote from: Jan S on 30 April 2022, 01:32 PMSolved!


This is a bit embarrassing ...

I had to refill nearly 3 liters, BUT THEN there was a clear oil mark between upper and lower marks on the dipstick.

Haha we've all been there...
Daniel
1977 450 SEL 6.9 - Astralsilber

Jan S

1975-mod W116 450 SE with 6.9 engine

ptashek

On a warmed up engine and transmission (~80*C), with engine running, the level should be exactly at the maximum mark.
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE

raueda1

Now that it's fixed I'd suggest that you do as I did.  Get some high quality plastic bottles such as these:  250 ml bottles and fill them with ATF.  Use these to top off.  The difference between the high and low marks on the stick is not very much.  It's very easy to overfill and very hard to suck out XS fluid.  Cheers,
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

Jan S

Quote from: ptashek on 30 April 2022, 07:50 PMOn a warmed up engine and transmission (~80*C), with engine running, the level should be exactly at the maximum mark.

Thanks!

I re-measured the level yesterday after a 30 min drive. Engine idled for 5-10 min and level was exactly at the max mark.  All good now, I think.
1975-mod W116 450 SE with 6.9 engine

Jan S

Quote from: raueda1 on 02 May 2022, 03:51 PMNow that it's fixed I'd suggest that you do as I did.  Get some high quality plastic bottles such as these:  250 ml bottles and fill them with ATF.  Use these to top off.  The difference between the high and low marks on the stick is not very much.  It's very easy to overfill and very hard to suck out XS fluid.  Cheers,

Yes, good idea to keep an close eye on the oil level of these old trans ... especially when suffering from "incontinence"  ;D
1975-mod W116 450 SE with 6.9 engine