Diff dis-sassembly & rebuild suggestions

Wes

Wes

Moderator
Site Donor $
Messages
1,888
Reaction score
1,792
Location
Tasmania, Australia
Help me out brains trust.
Have been all over Hobart today (not that that's a big adventure) and none of the local diff shops want to take on reconditioning an E9 LSD.
I swear to god the oldest 'technician' was 12..
So my question is how involved is the tear down and rebuild, as I'm guessing this will be a Wes job. The diff has been sitting around for at least 20 years, which worries me.
Had the breather cover off and things are very clean inside other than some shadows/junk on the gears where they have been sitting either above or below the fluid for a long time. There appears minimal wear on the gears.
I'm thinking remove the flanges, side plate and take a look before deciding on going further, as it could be a simple as a good clean and replace the seals.
Plan B is I fly Don over :)
 
flying Don over would be a safe bet, and you know its fund to spend time with the maestro ... seems like there has to be a place in Sydney or somewhere in OZ that would do it. would hate to think about freight to the USA and back - expensive thought with no fun in it, but i know diffsonline.com can do it - Mario at VSR uses them ... and primarily they just do BMW diffs. option 3 - what about buying a know quality LSD - then you could have yours gone thru and keep a spare, or sell it.
 
What specifically do you need to do with it?

From what I have learned, refreshing the clutch packs and seals does not require any super special work. Just make absolutely sure the shims go in in the exact same order and location they came out from.

You will probably replace the pinion seal, which means you will need to set the preload on the pinion bearing, which may require a special low-torque torque wrench. When I did this 25 years ago, I actually just measured the distance from the center of the socket to the end of my socket bar, and hung a spring scale on it. I then tightened the nut progressively until I got the right torque on the pinion shaft (measuring the load on the bar from the scale, times the length of the bar).

If you are changing bearings or gears, then you will need a set of shims and will need to go through the process of setting the pinion depth and the ring position, which is quite involved, and requires using a paste to see the gear contact patch. You then assemble, check the contact patch, adjust the shims and repeat until it is correct (quite a process)...
 
We send to Pete- we know our limits.



I think you should Google Melbourne or Sydney diff shops!
 
Here is a pretty thorough explanation of the entire process. This is onan E30 Diff, but the process is essentially the same. I gotta say removing the pinion bearing with a grinder takes some huevos!)

 
ScottAndrews said:
What specifically do you need to do with it?

From what I have learned, refreshing the clutch packs and seals does not require any super special work. Just make absolutely sure the shims go in in the exact same order and location they came out from.

You will probably replace the pinion seal, which means you will need to set the preload on the pinion bearing, which may require a special low-torque torque wrench. When I did this 25 years ago, I actually just measured the distance from the center of the socket to the end of my socket bar, and hung a spring scale on it. I then tightened the nut progressively until I got the right torque on the pinion shaft (measuring the load on the bar from the scale, times the length of the bar).

If you are changing bearings or gears, then you will need a set of shims and will need to go through the process of setting the pinion depth and the ring position, which is quite involved, and requires using a paste to see the gear contact patch. You then assemble, check the contact patch, adjust the shims and repeat until it is correct (quite a process)...
Click to expand...
My end point is an operating diff. I can probably get away with just changing the seals and rubber ring. That means removing the nut that holds the mounting flange for the prop shaft.
 
Wes said:
My end point is an operating diff. I can probably get away with just changing the seals and rubber ring. That means removing the nut that holds the mounting flange for the prop shaft.
Click to expand...
By "operating" do you mean not leaking, or not slipping or making whining noises?

Seals seem fairly easy. Clutches also seem pretty easy, but if you are in there, then it's probably also a good idea to think about bearings.. and so the scope creep starts!
 
My cost to replace seals, bearings and o ring with the initial cleaning transportation and final paint is $1200.00

I pay it because having a leaky stinky diff burning diff fluid all over the rear muffler is not an option.
 
A full refresh of the diff isn't easy for an average diy-er for the crush sleeve that needs carefull torqueing.
Even more challenging is setting up the gears for their correct contact patch.
But if the diff isn't having issues with the main pinion bearing, and not chamging gear parts, then I think one can replace the seals and bearings of the output flanges, and the oil seal of the input flange quite easily.

The crush sleeve, being a metal spring in essence, can be re-used *if* the large nut is tightened and returned to the exact same position which it held before disassembly. Provided no parts for and after of the crusher sleeve changed position (same and untouched pinion bearing), the crush sleeve will again do it's job once retightened to it's original position.

If you go the diy route, I do not see a problem with this approach and replcing the parts listed above.

I've done it the same way (None lsd though), but haven't driven it one mile since.
So the above is just a hypothesis untill i drive the first 20K kilometers without problems. In 2030 or so :-)
 
I'd second that. I think this is a reasonable gamble for the home mechanic, and equally may not be worth the risk if you're running a business and have to deal with a disgruntled customer!

I just replaced all the seals in my diff and tried it out, which is an LSD as it happens. You've little to lose except a few hours time and the cost of the seals and it may well be fine, particularly if there are no obvious signs of damage. Mine has been performing fine so far.
 
Literally JUST got back from picking my CSL diff up from Pete not 20 mins ago.
 

Attachments

  • CSLDiff_Rebuilt.jpg
    CSLDiff_Rebuilt.jpg
    245.2 KB · Views: 31
You must log in or register to reply here.
Back
Top