Thinkpads Forum

I want to put a different hard drive (a higher-capacity one that I have sitting around, which happens to be 9.5mm) in my T420.

When I take out the current hard drive, it has rubber caps/guides on the edges. I think it might be a 7mm one. I can fit the 9.5mm one in (and the machine will boot into Ubuntu which I have installed on that hard drive) but it will only fit without those rubber guides. Am I doing any damage if I do this and leave it in this way?

I can't really find clear specs on what the T420 can accomodate safely - one spec sheet said 7mm SSD and 9.5mm regular HDDs, but it seemed like that might vary by very specific model. (Mine is a T420 4236.)

Admin edit: Added PIC warning and reference to 7mm drive in subject line

All T420 systems should be able to handle a 9.5mm height HD. If your existing drive is 7mm it may have rubber rails designed ONLY for 7mm. I discovered that a few weeks ago when I was playing around with my T420 systems (couldn't figure out why the rubber rails didn't fit over the HD and caddy).

The "damage" that might take place if you don't use the rubber rails is that the drive may wobble inside the bay. I would recommend using them.

If you were looking at specs for a T420s, then that system can only handle 7mm drives.

Hmm, *my* computer definitely isn't a T420S.

Maybe I'll have to try again - I was in a bit of a frenzy when I was playing around with swapping drives so maybe I missed something. It would seem strange that it wouldn't fit a 9.5mm one.

I'm juggling different drives because my Windows 7 install started having big problems and instead of fixing it I'm hoping to just stick a new (well, new to that machine) drive in and install Ubuntu instead, but getting all ready for that has been a bit of a chaotic process for various reasons.

(Note: I've edited my original post to reference my own photo of the differences between the 7mm and 9.5mm rubber rails, instead of using eBay links which will go dead in a few months.)

Here's the difference between the hard drive rubber rails for 7mm and 9.5mm drives: (click the thumbnail to get a larger image)


The top rail is the one meant for 9.5mm thick drives. It can be installed on either side of the drive/caddy without worrying if it will fit correctly inside the HD bay. The bottom rail is for 7mm drives in 9.5mm HD bays. It has an inner wall that has 10 compartments that fills up the extra 2.5mm when using a 7mm drive. It needs to be orientated properly with respect to the top and bottom sides of the HD in order to fit inside the 9.5mm HD bay.