W108/9 rear axle parts available?

[Housecrew]

Hi, I made an engine transplantation.
W111 280se 3.5 with W126 500se engine.
Now I want to put in a W108 280se 4.5 rear differential.
I´m in germany and we can´t find mercedes part numbers
in the computer at my local dealer.
So if someone can check those numbers or
maybe if theres someone who has parted out a 4.5
maybe i would take those gears from the rear axle...

Greetz Arne

[alabbasi]

I have a complete front and rear axle from a W109. It's big and heavy so I have no idea how you would get it to Germany.

[Arthur Dalton]

Originally Posted by Housecrew

Hi, I made an engine transplantation.
W111 280se 3.5 with W126 500se engine.
Now I want to put in a W108 280se 4.5 rear differential.
I´m in germany and we can´t find mercedes part numbers
in the computer at my local dealer.
So if someone can check those numbers or
maybe if theres someone who has parted out a 4.5
maybe i would take those gears from the rear axle...

Greetz Arne

You are not gaining much with that change. The 3.5 rear you have should be a 3:46 and the 4.5/108 will be a 3:27.
Look and see if the case on the w111 has the oil flow tube to the left axle casing...........the ratio is stamped on the machined flat on the lower/left surface of the diff casing..

[Housecrew]

rear axle ratio is 3,69 at the moment.
so 3,27 or 3,23 would be much better.
i can get a 3,46 but that won´t help me that much.


@ alabbasi: can you pull the gears out of the axle and send them to me?

greetz arne

[Arthur Dalton]

OK

If you now have the 3:69, then I do not believe the 3:27 gears from a 4.5 will fit in your differential case ..the case is larger on the 4.5. to accommodate the larger ring/pinion........
That is why I mentioned the extra oil cooling return tube..if your 3.5 case has the tube, you have the larger case..if it does not, then it is the smaller case used for the 4:08, 3;92. and 3:75 gear sets. If that is the situation, then going to the 3:27 [ which I recommend] will require the whole rear end change out rather than just the gear set.

A note**

If you find the 4.5, be aware that many of them have a problem with the casing rounding out where the spider holding pin goes through the case. This is common on the 4.5 due to the engine torque and car weight. Check that before you buy.

After a diff change, you want to center align the axle to the chassis..I have
designed a homemade measure jig/tool using simple copper tubing fabrication that you can make for about $5-$10 in parts and fittings that makes centering the rear pivot pin to factory specs real simple..if you want that, I will post a jpg .
[ I think they even have a copy of that in the archieves over at 113 group somewhere, might even be one here ..try the Search Feature]

Here is a video from the 113 site that shows that yoke/pin failure complaint. These 3:27 are also a preferred mod on the 113 , but in that case , they plug the oil cooler/return line I mention due to lack of body clearance on the smaller SL chassis..[ they just eliminate the tube with plugs]

http://video.google.com/videoplay?docid=6365474313884505435&hl=en

[Housecrew]

thx for your help arthur!

[Arthur Dalton]

Originally Posted by Housecrew

thx for your help arthur!

Bitte sehr.........
..Es war ein vergnuegen........

[Tony H]

They both have the cooling tube. I installed a 3.27 in my 3.5 coupe and the axles are identical.
Tony

[w108 300d]

Originally Posted by Arthur Dalton

OK

If you now have the 3:69, then I do not believe the 3:27 gears from a 4.5 will fit in your differential case ..the case is larger on the 4.5. to accommodate the larger ring/pinion........
That is why I mentioned the extra oil cooling return tube..if your 3.5 case has the tube, you have the larger case..if it does not, then it is the smaller case used for the 4:08, 3;92. and 3:75 gear sets. If that is the situation, then going to the 3:27 [ which I recommend] will require the whole rear end change out rather than just the gear set.

A note**

If you find the 4.5, be aware that many of them have a problem with the casing rounding out where the spider holding pin goes through the case. This is common on the 4.5 due to the engine torque and car weight. Check that before you buy.

After a diff change, you want to center align the axle to the chassis..I have
designed a homemade measure jig/tool using simple copper tubing fabrication that you can make for about $5-$10 in parts and fittings that makes centering the rear pivot pin to factory specs real simple..if you want that, I will post a jpg .
[ I think they even have a copy of that in the archieves over at 113 group somewhere, might even be one here ..try the Search Feature]

Here is a video from the 113 site that shows that yoke/pin failure complaint. These 3:27 are also a preferred mod on the 113 , but in that case , they plug the oil cooler/return line I mention due to lack of body clearance on the smaller SL chassis..[ they just eliminate the tube with plugs]

http://video.google.com/videoplay?docid=6365474313884505435&hl=en

How big is the differential case from a 4.5 or 3.5 will the gears from a w109 6.3 with 2.82 ratio fit?

[Arthur Dalton]

<,4.5 or 3.5 will the gears from a w109 6.3 with 2.82 ratio fit?
>

Any gearset for the diff. case with the oil cooler tube should interchange.
As any without should interchange.
But none will interchange from cooler/no cooler tube casings.
The no cooler diff is too small for gearsets from the cooler models.

I have never done the 2:82 , but it is from a cooler case, so I do not see any problem putting them in a 4.5 case.

[w108 300d]

Do the 3.5´s have the cooler case?

[Arthur Dalton]

The ratios for cooler case are 3:46/2:82/3:27.. The 3:27 is US 4.5 version only.

I have been told that some 3.5 had the 3:69/non cooler diff., [ coupe], but I do not remember ever seeing one.
Someone here w/coupe/3.5 can verify if so..............
I have seen the 3:69 ratio w/o cooler in different IL-6 engined chassis.
But not a 3:69 in the oil cooler casing.
SLS of Germany verifies the same on their Swing Axle Specifications insert page.

You can tell by just looking under the car for the cooler pipe going from the left axle casing back to the diff case ..it is a U shaped metal tube that circulates the lube for the better cooling requirements of chassis equipped with the higher torque V8 engines.........
..and the ratio is stamped into the botton/left of the diff casing.

[Tony H]

The 111 3.5 axle 3.69 ratio does have the cooling tube,
Tony

[Arthur Dalton]

Originally Posted by Tony H

The 111 3.5 axle 3.69 ratio does have the cooling tube,
Tony

Tony

Have you verified the ratio stamping on that case ?
Thanks

[Tony H]

I don't have the original axle anymore-I sold it several years ago but the 2 axles were identical when side by side-at least from exterior observation. The axle in my coupe now came from a '73 280SEL 4.5.
Tony