New guy with 3D questions

[gdrill]

Good day all.
First off, I'm in Canada, in case that makes a difference in the query. I have been researching this site for info and have learned a ton so far. Thank you for sharing knowledge. I still have some unanswered questions though.
I have been looking to purchase an older rubber tired backhoe. I have seen many and then a fellow mentioned he has a 3D he would sell. Says it is a great machine. Check oil, grease the boom, add fuel and go dig holes! It appears to be a 70-72 or so with the parallel lift arms and it looks to have a white cab. It also looks to have the early smaller rear lights mounted upon the lower cab structure vs the rectangular later update. I suspect it to be a 3D Mk III, only because of the VIN. (It has a 3 at the end) Also, what is the purpose of the parallel arms? They didn't seem to stay in production for long? Does the second pin hole on the digger boom really play that much difference in strength vs speed? The pics are small but still usable. I am trying to determine the year but the serial number makes no sense to me in what I have been able to search so far. I will attach pics of the tag and the machine. Thank you for any help in confirming this machine's true identity.
George

[FOWLER MAN]

Hi and welcome,
The JCB does appear to be a 3D III. info below may help you identify it.

[gdrill]

Thank you sir.
I will have to ask him to look for another tag apparently! I wasn't sure if the one on the dash was the only one or not.

[MrF]

Not sure on a 3D, but on my 3C3 that ID tag is on the left hand side of a chassis stiffener rib behind the hoses for the front loader arms. I keep the bucket on power pivot setting perm, but I am not in a rush to get things done.
On the 3c2 I am working on, the plate is in the cab to the right of the driver and attached to the top of the main body of the machine, it also has a tractor id tag on the chassis near the motor from nuffield (stating 384 in that case).

[gdrill]

I realize this is a 4D, and most of you have seen these pics before, but damn it looks good! I love those huge front tires. Looks all business.

[MrF]

They're still 2wd, so the chunky front tyres probably dont help traction, but the parallel arms are heavier so it possibly is done for load carrying capacity with the extra weight of the arms. I thought the 3d back acter was heavier and had more reach as well but I've never owned one to comment first hand.
For the parallel lift arms themselves, its to keep the front bucket in the same plane when lifting, as the 3c's single one piece loader arms follow a arc as they move through their range, so on the 3c you have to continually adjust the bucket craw to keep the bucket/forks level. 3cx and onwards has a linkage system to achieve the same thing without the extra weight I believe.

[gdrill]

Thank you Sir for the info. I wondered if it was not just a short and then improved upon idea. That is generally how things go. I have searched and found that the 3D should dig about 15'. Plenty for my needs. If this machine comes to be in my possession, I will do the mechanicals first and make it fully dependable and then touch up the body. It does appear fairly good as is. I should see it in person next weekend.

[Jeremy Rowland]

Hi George and welcome good luck with the 3D plenty of people on here who can offer you good advice.

Jeremy