The front seal of my 1982 240d is leaking.
I pull the differential and need to remove the metal cap/bolt?
I've see these before on other vehicle but this one seems to be thicker metal than most.

Is there a trick to bend the metal that was crimped in order to unscrew this cap?

I assume there's a bolt underneath that I have to remove before pulling the seal.

I attached a pic.

Thanks,

pete

Attached Thumbnails

 

Use a punch or a screwdriver to straighten the lip out. That is the way the nut is locked on to the shaft. Once you straighten it out, you should be able to unbolt it. I don't believe that it has a cap.

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Milan Brown 1979 240D, rebuilt OM617.952 turbo diesel, rebuilt 722.315 transmission (my only daily driver)

Instagram: @maximed93

If it has a hole in the center and threads on the inside, the fastener would be a nut, not a bolt.

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

Don't forget before you remove the nut you need to measure the bearing running torque so you can set it back to the same value

(If you need a link to the FSM let me know)

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

The part that is dented/bent in is the nut that needs to be removed, there isn't a bolt behind it. The nut is threaded directly onto the pinion gear.

If you are only changing the seal, put the nut back in the exact same position by counting the number of pinion shaft threads exposed before removal and tightening it back so that the bent in tab lines up perfectly. Bend in the tab on both sides when done. There are two indents in the pinion shaft, mark which indent the nut is bent into before disassembly to prevent being too loose or too tight by 1/2 turn.

If the new seal has a spring on the back/inside, pack it lightly with grease to prevent the spring from coming out while installing.

Polish the surface on the yoke that the seal rides on with emery or crocus cloth and put gear oil on the seal lip so it does not start dry.

As Stretch stated measuring the torque required to turn it before and after is a good idea.

Good luck!!!

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Thanks for the quick replies. I'm about to tackle the bolt again. I did try a punch and a screwdriver but it was very tight and the screwdriver tip started to bend.

It's difficult to get a punch at the angle needed to straighten the crimp. Luckily only 1 side is crimped.

I will measure the torque when removing and count the threads. Thanks for the tips on installing the new seal. Hopefully the spring doesn't pop out. I only have 1 seal so I need to be careful.

pete

Just for clarity, we aren't talking about the torque to remove the nut. We are referring to the torque required to continuously rotate the pinion as a complete assembly so that all of the gears are rotating. Torque required to turn the assembly should be very similar before and after.

Don't over tighten the nut, put it back exactly where it was without over tightening. Don't tighten it past where it is and then loosen it, tighten it to where it should be, no tighter and stop.

The chances of the spring jumping out are very very low especially if you put some grease in the recess where the spring sits.

Good luck!!!

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Ok. I will put my torque wrench on the nut and see how much torque is needed for the gears to rotate.

Also, any idea what size socket I'll need to remove the nut?
I only have 6 point impact sockets. Looks like I'll need to purchase a large 12 point socket.

Thanks,

pete

The nut should be 30mm 12pt.
Also, IIRC, the minimum torque should be 185 Nm for the pinion nut.

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Sam

84 300SD 350K+ miles ( Blue Belle )

If I remember correctly for the larger W114/5/6 W123/6 differentials it is a 30mm 12 point - but please check first I'd hate for you to buy something only to find it doesn't fit.

You could also get an impact socket and whizz it off in one go.

If you have a large vice it is possible to clamp the yoke to help hold whilst undoing the nut.

You can also replicate the MB special tool for the job. I've done it with plywood before (!)

Your torque wrench (unless it is a dial with pointer type) probably isn't going to cut the mustard. You can get a pretty good idea of the turning torque by making your own balance as shown in this thread I did measuring the torque on steering boxes =>
What a feeling it will be! A properly adjusted W123 / W116 / W126 power steering box

Again - I stress - the importance of looking at the FSM for this job =>

Nut too tight == knackered small pinion bearing => sloppy whining and uneven wear on pinion and crown cogs - will never come right again

Nut too loose == sloppy whining and uneven wear on pinion and crown cogs - will never come right again

Every time you accelerate and remove your foot from the accelerator you'll be reminded of that pesky nut...

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Wow, that steering box write up was serious. That is something I will tackle in the spring as mine is leaking.

I think I will notch the nut and the shaft and tighten the nut to that exact point.

pete