1967 250sl whining rear diff after rebuild

[sixforlife]

Hello everyone, its a bit long but bare with me as i need all your opinions about this issue.
My freind has a 1967 250sl pagoda wich is fully rebuilt from the ground up. 3 monthes ago he decided to change the gears from the original 4.1 i think to 3.75ish (i dont remember the exact number). All the bearings were replaced with new ones, and a new set of gears went in.
Job was done by a mechanic wich dont know this rear end and didnt made any adjustments or shimming - just replaced the parts and closed it. Ater that the car had a whine in mid-speeds so he asked me to step in. I did my research and read more than a few threads over here about this rear end, even got a heynes manual for it (was a stupid mistake - this one doesnt cover nothing i needed).
Iv searched the web for a proper mercedes benz manual that will cover all the diff specs, found some leads and contacted a few seller wich couldnt tell me wich manual will cover the rear end internal parts proceedures adjustments and torques so iv gathered all i could find (wich isnt much) on the web and went in. I have a vast expirience with ring and pinion and diff lockers installs so this one isnt strange to me.
Long story short the mesh between the R&P wasnt good, iv adjusted everything to a proper pattern on both sides (coast and drive). Closed the cases together and tightned the ring on the universal joint side to load the carrier bearings and than went in to the pinion nut and crush sleeve.
The info i found on the webs about this one is while axels are in place and with no brakes on - i should tightened it to 24-26 feet pound of resistance on the flange while turning it so i went ahed and tried. the socket kept popping out of the nut so iv built a retaning plate that didnt alowd it to pop out.
Iv closed the nut with big force and after checking it with the proper tool (using one just like this - https://images-na.ssl-images-amazon.com/images/I/513wapiBN0L._SL1500_.jpg) it turns when hitting 5 feet pounds wich is tight to a point i cant turn the flange with my hand but with a spanner.
Iv tried to keep on tightning it and couldnt. It felt like i might strip the nut if i kept going.
Long story short - did a test drive and i have a whine from the rear axle at 30 to 70 kph, mostly at decelation. Now, as far as i know these kind of whine will probably come from a loose/faulty pinion bearings, so is it possible that with all the force iv used and the torque valeu iv got just isnt enough?
Im asking this because from all that iv read i didnt found 1 clear answer about how much the pinion nut should go in (feet pound or something else) and im actually scared to damage the pinion or the nut itself if ill use more force.
Id allso mention that this is not my first crush sleeve im crushing in, and this one did crashed (felt it close to when i started tightning it down) but no one of the previous was that though.
Any sort of values, torques, wich manual to get, and most importantly your opinion about this issue and what should i do next will be wellcomed.

THANK YOU!

[Shvegel]

24 foot pounds is incorrect.  You are way over at 5 foot pounds.  The differential tolerances are close enough that you "should" be able to just swap bearings and use the same shims on the pinion and side bearing.  You should only need to set the pinion preload and side bearing preload by tightening the pinion nut then the side bearing big slotted nut.  As long as you are taking it apart again to change the crush sleeve(It is crushed too far) verify that both pinion bearing races are fully seated in their bores.  Sometimes they are not all they way down and will work down after the preload has been set.

You will most likely have to download the image to read it as it is quite small but the values are in inch pounds not foot pounds.  the correct setting is less than 2 foot pounds.  you will need an inch pound torque wrench to set it accurately.

If it were mine I would:
Take it apart and install the original shim under the rear pinion bearing if you changed it.

Make sure both pinion races are all the way in their bores.

Replace the crush sleeve and the grooved nut.  (I always replace the nut these days after going through what you are twice)

Tighten the nut until you have a rolling measurement of 12.2 to 13.9 inch pounds.  I use a clamp between the socket wrench and the pinion head to keep the socket in the grooves.

Put the ring gear carrier back in with the original shim under the bearing in the left side axle housing.

Tighten the big grooved nut on the right side until you get an added 6-7 inch pounds.

If the previous mechanic replaced the gears in the original housing rather than replacing the matched gears and housing forget what I said about the shims.  Unfortunately,  I have no guidance for you.  It takes very rare and expensive tools to set one up from scratch.

[sixforlife]

Ill get more specific.
As iv mentioned these arent the same gears but lowered from the previous wich means bigger pinion. The previous guy who installed everything installed the new gears set and new bearings onto the previous shims set up - pinion depth + carrier bearing as it was originally in the axle with the previous different gears.
Before i did enything iv cleaned everything and checked the pattern with the proper paint. Pattern was bad, here are 3 pics of it-





As you can see the pinion is way off creating this kind of pattern. the pinion had 1.7mm shim behind it and ive went 2 ways - one is iv added thickness to 2.0mm wich didnt improved much and locked the gears because the carrier adjusting ring was toped out and couldnt lift the carrier to give some slack of movement.
After that iv went to the other way to 1.5mm wich gave better patterns, and then to 1.4mm wich gave the best pattern of all the tries.
Here are pics of the final pattern as it is currently on the car - 




After iv finished improving the pattern iv closed the cases, preloaded them and varified a proper backlash.
Assembled the whole axle, inserted both axels in and started tightning the pinion nut while checking with the tool iv added pic of, wich eventually is to tight after what youv said.
Question is would a tight pinion bearings howl and whine at these speeds? i have no whine under 30 or over 70kph.
As for the crush sleeve- i have the old one wich was installed 100km ago in the previous installation and seems like it didnt got crushed as i compared it to a new one iv got for this job and they were about the same height.
Im not going to take the thing off the car and open it all over again, first im gonna try (a lot) to see how and if i can pull out the upper bearing from the seal side.

Thanks for the file youv added but in this size its unreadable.

[Shvegel]

It’s going to be really tough to get the bearing out you might be able to weld a tab onto it but I would worry about welding it to the shaft.

I think what you may have missed is that the carrier position is not set with what you termed the carrier adjusting ring.  The carrier position is set by using shims under the left side bearing. One you get it set up so you have your pattern and backlash with the adjusting ring just snug you tighten the ring to set the preload on the side bearings so when you measure at the pinion you get the additional 6 to 7 inch pounds.

I am curious how you measured the backlash?  Being an enclosed housing it is tough to get a proper measurement.  I ended up building the fixture below.

There is a link below the file I posted.  If you click on it and download the file you can enlarge it so you can read it.

[Shvegel]

Here is a pretty good description of the adjustments.

http://automotiverepairguides.blogspot.com/2013/07/mercedes-benz-1968-72-split-housing.html

[sixforlife]

Hello again and thanks for the answers.
Backlash was measured with a long slim rod iv got that bolts on to my dial indicators tip and went in thrue the oil fill hole to touch the crown wheel.

As for removing the upper pinion bearing to replace the crush sleeve im happy to tell you that you absolutly CAN remove it out without taking the whole axle apart quite easily and here is how, as a service for this community:

After you took the oil seal housing and the flange off, bolt the pinion nut on it again while the top of the pinion sitting inside the nut.
If you have backlash you have a few mm to push the pinion in before it meshes up completly with the crown wheel.
With a soft plastic/ rubber hammer tap it GENTLY small taps to push the pinion inside until you feel it stopped.
Now when you pull the pinion, your bearing sits a bit higher. take a flat screwdriver and catch the inner bearing race as shown in the pic-





While applying pressure on the screwdriver towards the diff case and by that pushing the bearing out towards you - you basicly lifting again the pinion out of the crown wheel and now you have another few mm of clearens to push the pinion in again wich eventually ends up pushing the bearing up more and more towards the pinion nut.
Hold your screwdriver with pressure (always pushing the bearing up towards you) as described and GENTLY tap the nut until your bearing is free.
If youll do this corectly and apply pressure as describe while gently tapping on the pinion nut with patient, it will take you about 2-3 minuts to get your bearing out :





To sum up - iv replaced the crush sleeve and the pinion nut, tightened them to the correct specs and the whine is gone.

Thank you for all the answers, and nice to meet!

[Shvegel]

Great bit of work!  Thanks for posting the outcome as I am sure there will be others who are in the same situation.

[George Des]

Good to know that sleeve can be replaced without a total teardown. Have been through that twice with some older axles and it is no fun. And yes setting the backlash is not easy with the design of this differential.