Whats it worth?

I finally bit the bullet and purchased a 5 speed for my 150, so my fully operational non original 4 speed Moss with O/D # JLS 45005 JS is up for sale. It comes with prop shaft, wiring and dash switch ,and speedo cable, the complete package. No bell housing
It came out of a Oct 59 FHC. and will fit 140 /150 So what’s it worth ???

I could say given you thought it necessary to pull it out and replace it - not much!

That’s too bad you think that way Terry, it’s my car and I can do what I want ,I rescued this transmission from a 150 write-off 25 years ago, it’s had a good life in my car and now its time to move on.
My original C.Ratio 4 Speed Moss box is still with me and would probably cost the same money to rebuild and you still end up with a very slow archaic bunch of gears. Someone else can now pick up the baton and continue the life of the O/D gearbox.
Respectfully Morris Barnett

Morris with the rest of the info an entirely different answer.
Given you have retained the original gearbox from your car, the gearbox you are selling is just a spare.
The close ratio box is a beautiful gearbox and I have one in my own XK150 FHC matched to the factory fitted 3.31 diff technically capable of 144mph at redline in top.
I must admit I totally dislike all forms of aftermarket 5 speed boxes and have owned and driven an XK140 with one fitted and a MKII the boxes in these cases both Toyota gearboxes (neither fitted by me) I can also say I don’t mind driving the old crash box and have had XK’s now just on 40 years
I do like and have fitted and driven XK’s and S type Jags etc with the later all synchromesh gearbox and given the look almost identical to the old moss box, they can be fitted using old original bellhousing therefore retaining all original clutch mechanisms etc and they drive very nicely I personally recommend to friends to go for this option and here in Western Australia I guess there are 30 plus cars done this way.
As to the value of the removed gearbox you will see them on EBAY anywhere from $500 to $2000
regards terry
PS what is the chassis number of your XK150FHC?

Refer back to cars in movies, I have already stated chassis number for my red 150 ots.


See the eBay auction link for a 150 transmission for sale: http://www.ebay.com/itm/like/122367803115?lgeo=1&vectorid=229466&item=122367803115&rmvSB=true

Can your 150 gearbox be readily refitted to a 120? I live near you and am restoring a 1951 FHC that came with an apparently rebuilt drive train. After spending a fair chunk of change to fix corrosion in the head, I’m not holding my breath for the condition of the gearbox. Contact me at rcarne09@gmail.com if you still have the unit for sale.


An overdrive gearbox will NOT fit in an XK120 without cutting away a large part of the center cross member of the chassis. I would not recommend it.
If you have the original type gearbox and it turns out to be no good, you can look for a standard Mark VII box, which is the same but lacks the rear mount, and swap the aluminum tail cases.

Hi Rob,

Thanks for the reply. I recall now the subject of major mods to the cross member as required for transmission upgrade was discussed on some detail in the past on the Forum. I’ll do some serious due diligence before I attempt any “cut and paste”.


if you are looking for less revs at 100km per hour in top gear change the diff ratio probably currently 3.77 maybe 3.54
go to a 3.31 and you may find 3.07 still OK a bit slow off the line