Hey guys,
at the moment I could get my hands onto a used differential. The vendor says it is from a 4.0, but how can I verify that?
According to this eBay offer JAGUAR XJ8 3.2 Sport (NAW,NBW) Differential Getriebe C14HU004003 | eBay there's a C14HU-004-003 embossing on the housing (likewise HERE and HERE).
BUT: THIS differential and THIS too show exact the same embossing, although they're sold for 4.0 XJ's?
Can anyone shed light on how to judge from any embossing etc which gear ratio is inside?

PS: Does the XK8 4.0 diffs fit into the XJ's out of the box (as they have the 3.06 gear ratio as well and there's a C14HU-004-003 embossing on the housing as well) - like THIS or THIS?Thanks very much for your efforts!

 

XK8 diffs are the same. You can technically even fit the X300 dif without any issues. It fits straight into the same spot...

 

Thanks Daim! Sounds not too bad. Fitting a x300 differential is indeed on my future to-do-list.

But what about the XJ differential as mentioned above? How can I tell them apart and verify, that it is a 4.0 differential?

 

It should be mentioned that it doesn't fit exactly- the X300 diff has an offset nose and therefore you need the front brace plate from an X300 OR you need to pierce a new hole into the X308 brace plate. Also the exhaust hangers on the X308 are at a higher location so the ones on the X300 brace plate will need to be moved some how

 

Iirc the difference should have a tag with the gearbox ratio somewhere. And if only a sticker...

Or you can simply let the seller count the rotations. I'm sure the axle has different ratio for 3.2 and 4.0l versions. So if the seller turns the input shaft and counts how many times the output shaft (s) turn, you'll have a rather usable idea of if it is the right dif.

 

The XK8 diffs have a 4 bolt pinion flange. The X300/308's have a 3 bolt pinion flange. The only thing I don't know is if the flanges are interchangeable between the 3 & 4 bolt diffs. It all depends if the splines on the pinion are identical or not.

 

Should be no problem changing the input flange... The internals are the same as is the housing...

 

Hope the following information will be helpful:
Blue = 4.09
Blue Black X = LSD
Brown = 3.77
Brown Black X = LSD
Orange = 3.27
Orange Black X = LSD
Red/Yellow = 3.58
Red/Yellow Black X = LSD

Sticker location:


X308 and XJ40/X300 differential and cover comparison:

 

Dear all,

thanks so far for the ideas and info. I have taken the risk and bought the whole rear axle since it was a steal. Will pick it up the next few weeks.
Best regards, Alexander