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+--- Thread: swaping the LSD part between 2.47 and 2.82? (/showthread.php?tid=5566)
swaping the LSD part between 2.47 and 2.82? - swampmonkey - 05-03-2014
Hey
got a 2.82 gen1 diff from w126 on the way, not shure if it has LSD or not, but in case it dont, i got two 2.47LSD laying around, one gen1 and one gen2.
can i swap over the LSD part from one of these 2.47 to the 2.82? get the LSD part+gear of the 2.47 out of that house, changing over the gear from the 2.82 to the LSD centerpiece, and then put it back in, in the 2.82 house?
would be awsome, and hopefully not as crazy geared as the 2.47...
RE: swaping the LSD part between 2.47 and 2.82? - Druk - 05-03-2014
Note that if you swap components between diff cases you will have to check and maybe reset the 'preload' on the diff case. This is done by measuring the 'stretch' imposed over the width of the case when the bearing housing bolts are tightened down and altering that setting by interchanging shims as required. The preload is set so that when the case expands with heat the taper roller bearings are then at the correct adjustment.
Home made tooling to hold dialgauge to measure stretch. Here 0.9mm.
![[Image: 7.jpg]](http://s62.photobucket.com/user/a10ruk/media/300TD/7.jpg.html)
![[Image: bastardpic-1.jpg]](http://s62.photobucket.com/user/a10ruk/media/300TD/bastardpic-1.jpg.html)
Also...if the settings are changed then the relationship of the pinion to the crownwheel may have altered and that WOULD NOT BE A GOOD THING.
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RE: swaping the LSD part between 2.47 and 2.82? - swampmonkey - 05-03-2014
Very interesting Druk...
see if i got it correctly, you have that homebuild stretchmeasuring thingy.
1. put the differential parts in
2. tighten one side
3. get the stretchmeasurethingy in place and set to 0.
4. tighten the other side, and see how much "wider" the casing gets?
5. adjust the stretch to the correct "size"
6. Profit?
questions:
1. how much stretch is supposed to be good?
2. where do i get those shims? partnumbers? havent seen any of those in the EPC
3. alignment left/right regarding the crown-wheel/pinion how do i set that?
RE: swaping the LSD part between 2.47 and 2.82? - Druk - 05-03-2014
In EPC look at #35 Rear Axle: #015 Housing: part #80 Spacer Washer. Available from 0.9 to 2.6mm in .05mm steps.
My very basic understanding is: set dialgauge mounted on stretchymeasurethingy at 0 with existing spacers and torque one side as you say. Torque other side bearing housing bolts down to spec. Measure deflection. If required adjust both sides spacers equal amount till correct deflection is obtained. This keeps diff central in housing or, at least, in same relationship to pinion. Deflection is created by bearing outer ring pressing in on taper roller. The less the deflection reading the slacker the bearing will be when all is hot. The more the deflection the tighter the bearing is compressed on itself and the likelihood of greater wear or early failure.
2 years since I did mine and I'll need to find where I got the settings from. I've never dealt with an LSD and know nothing about them but I'll bet the side preload adjustment is still relevant.
edit...found it. Bolt torque 20Nm. Spread for large case 0.15mm - 020mm. Manual (Factory R107) also explains use of shims to set pinion backlash at 0.08mm - 0.14mm. ie adding or subtracting shim size on whichever side of diff till backlash is correct. Once backlash set then spread checked again and both sides shims calculated to obtain correct spread whilst maintaining pinion in relation to crownwheel.
If push comes to shove I can copy relevant pages and email you them.
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RE: swaping the LSD part between 2.47 and 2.82? - DiseaselWeasel - 05-04-2014
There's a HUGE capitel about differential rebuilds in the FSM. Read it. EVERYTHING is covered.
At least on W124s crown wheel differes with LSD diffs...
RE: swaping the LSD part between 2.47 and 2.82? - swampmonkey - 05-04-2014
(05-04-2014, 03:52 AM)DiseaselWeasel There's a HUGE capitel about differential rebuilds in the FSM. Read it. EVERYTHING is covered.
At least on W124s crown wheel differes with LSD diffs...
FSM?
RE: swaping the LSD part between 2.47 and 2.82? - Purplecomputer - 05-04-2014
(05-04-2014, 06:51 AM)swampmonkey(05-04-2014, 03:52 AM)DiseaselWeasel There's a HUGE capitel about differential rebuilds in the FSM. Read it. EVERYTHING is covered.
At least on W124s crown wheel differes with LSD diffs...
FSM?
factory service manual
RE: swaping the LSD part between 2.47 and 2.82? - DiseaselWeasel - 05-04-2014
Ah I thought it was Fucking Service Manual
RE: swaping the LSD part between 2.47 and 2.82? - swampmonkey - 05-04-2014
(05-04-2014, 12:44 PM)DiseaselWeasel Ah I thought it was Fucking Service Manual
Al i could think of was the Flying spagetti monster....
Our spaghetti
Who art in the colander
Hallowed be thy sauce
Thy serving come
Thy strands be wrung
On forks as they are on spoons
Give us this day our daily meatball
And forgive us our starchiness
As we forgive those who are starchy against us
And lead us not into Kraft parmessan
But deliver us from Chef Boy Ardee
For thine is the garlic
And the onion and the bay leaves
For ever and ever.
Ramen
http://en.wikipedia.org/wiki/Flying_Spaghetti_Monster
----
Ontopic
where could i find this service manual?
and how does this work in the other type of differential, where we dont actually have any load on the bearings?
but just push the parts in by hand?
RE: swaping the LSD part between 2.47 and 2.82? - DiseaselWeasel - 05-05-2014
Look at startekinfo.com, it's all there
RE: swaping the LSD part between 2.47 and 2.82? - DeliveryValve - 05-05-2014
Hey swamp, the carriers are not a direct fit because the ring(crown) gear is situated in a different spot along the axis between the 2.47 and 2.82. You'll see the difference immediately once you have the 2.82 on hand.
However, my theory is you can still use the carrier by making a custom thick spacer to go between the 2.47 carrier and the 2.82 ring gear. You'll need longer bolts also.
Be sure to post up pictures of the differences.
.