Hello,
I came across a rear diff from a '85 300(2.88) but it needs the outer pinion bearing replaced. Is this something that only a trans shop could do?

I've got tools and skills(30yrs shadetree wrench turner) but I have never done a diff. Any links, info would be helpful.
Thanks

I just replaced the pininion seal. Actually, had the machinist do it. You will need a 1-12 or so inch-pound torque wrench. Mine was set at 6 inch pounds. It was worth the $50.00 bucks to have the machinist replace all the seals. If you overtighten it, then you will have real issues. I tried buying the correct torque wrench off E bay, a Snap On Torquometer, but the "correct" ones run around $75-ish and up with shipping and I doubt I will ever use it again. Plus, I do not like experimenting with projects which have major issues if I screw up the first few times. Just my .02 cents. If a boo boo is easily fixable or cheap, then I will tackle it because the risk is low. A 2:88 diff could be a high risk operation.

And you know this how?

I ask because it is highly unusual that the other bearings could have survived unscathed, given the shrapnel that is created when the first bearing fails.

There is a lot more to setting up a differential than just removing and installing parts.

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

I have not done this job before but changing the Seal is not the same as changing the outer Bearing.

Even if the Differential was sitting on a Bench and for some reasn the inner Bearing Cone was loose enough on the Pinion Shaft to come out that still leaves the Bearing Race pressed into the Housing.

There is generally not a lot of room between the Shaft and the Bearing Race to get something behind the Race to Pull it out.

That does not mean that it is impossible as there are all kinds of do-dads to attach to Slide Hammers to pull or knock stuff like that out.
It might be possible to fabricate something to do that.

Most of the time the Bearing Race is knocked with a long Punch from the inside outwards.

I think it is likely cheaper just to get a goodused differential from a Junk Yard then to pay someone to fix the old one.

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84 300D, 82 Volvo 244Gl Diesel

the owner said it needs a new bearing( its making a noise).

Yes, I am aware the expertise involved in setting up a diff. Without the unit in front of me, thought the bearing might be replaceable without taking everything apart. The item is cheap but if it needs a complete rebuild, it might be easier to buy a good one.

For the most part, changing bearings does not require loads of $ special tooling / experience.

Bearings are made much more accurately than the housing so once the factory selects shims, they can be reused.

If you are going to change one bearing, change them all. ( 2 pinion and 2 diff side ) Be sure to measure backlash with a dial indicator before taking things apart.

I'll type more later. Also, don't take too much stock in the selling owners diagnosis, knowing if the front or rear pinion bearing is failing is some pretty specific information. ( Unless they have used a bearing vibration meter since the car was new. )

Another possibility is that the drive shaft center bearing ( if your car has one ) is making noise, is so that is an easy fix.

The Pinion Bearing Preload is adjusted by way of a Crush Sleeve so there is no Shims in that area. See red Arrow.

Attached Thumbnails

 

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84 300D, 82 Volvo 244Gl Diesel

http://www.peachparts.com/shopforum/diesel-discussion/344307-w201-differential-refresh-thread.html

Similar set up - subtle differences to the W123 differentials though

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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!

Iam no expert on taking a Differential apart and making it work again.
A few years ago I was going to install a 2:47 Diff, but the Tri Flange needs to be changed to the smaller one used on the Diesels.

I asked this question about how to tighten the nut etc...and got a good answer from Arthur Dalton. this may help on setting the pre-load.

http://www.peachparts.com/shopforum/tech-help/233540-pinion-seal-replacement-how-determine-friction-load.html


Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

The shims I'm referring to are between bearing 71 and the pinion. Setting bearing pre load with a crush collar is a standard procedure for many diffs. There will be shims or adjusters on the diff side bearings.

The only critical special tool shim is the one at bearing 71, this sets pinion depth.

replacing the pinion bearing in a W123 requires a case spreader, a specific special tool. Most MB shops do not even have this tool around anymore. In my case, on my 300CD with a 2.88 rear, I found it a lot cheaper and simpler to source a low mileage used rear.

The case spreader is for the axial bearing pre-load. I have removed several crown wheels (and differential cages) from differential cases with out using a case spreader - this admittedly is not a good sign for the axial pre-load!

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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!

Some other brands of rear ends list a case spreader as required tools. I've built lots of rear ends without this tool, it is a bit difficult to slide the carrier back in but it can be done.