Have owned a pair of 5 speeds. One was the Mini Spares Center offering and the other a JKD unit. I have also built several JKD SC / CR dog boxes. I sold the 5 speeds, felt I could not justify the cost for my personal use. My current experiment is a French Rover ultra wide ratio rod change with two over drive drop gears and a 2.76 CWP. Works out to roughly 2.56 finial drive. I'll know in a week or so how this is going to work out. I can remove the OD primary gear in car if need be. Takes me 6 min. to get to work. I have to run 70 plus or risk getting run over on the outer loop. If I end up with a 4 speed O/D tranny 1-3 around town and 4th for the highway I'll be good with that. I still have O/D drop gears and 2.95 cwp if I'm not happy.

As for JKM or what ever name they are going under now beware. We sent them a couple of thousand and got a box of MGB gears. To date they have not replied to calls emails or letters. I do just happen to have a complete JKD (not the seven spline one) Ultra close ratio dog box gear set new on hand. This was a replacement for a seven spline failure before they went underground. We run a couple of Swift trannys and a couple of JKD dogs so these are the only spare JKD parts I have been able to locate.

Steve

The only JK 5-speed I opened from the original packaging and placed in a mini had an overdrive 5th.  It sits in a very nice road-tripping mini that sees excellent trips no and again, making good use of that 5th gear.

The early JK box was very different from the later ones, it had a non-standard shift pattern.  When I was trying to get more info about my early gearset, the people on the Mk1Performance forum were very helpful.  Randy McConnell at S&M Minis sent me copies of late 60s magazine articles which had drawings, tech info, and road tests of the JK gearset, I posted copies in the Mk1 forum here.  You probably have the later type gearset, but I recommend you post on that forum for more info.

As far as ratios, those early 5-spds did have an overdrive 5th. There was a street version (0.88 ratio 5th) and a race version (0.83 ratio 5th).

I have had a couple of these apart. Which gears is it getting stuck jumping out of? If it's any of the lower gears all of the base components and function are the same as in a 4 speed rod change box. A modifided end cover supports the longer main shaft and 5th gear is actuated thru the reverse shift fork shaft. Never understood why anyone wasted their money on the 5spd anyway?  I drove a Sport 5 with John Cooper in England when they first came out and the final gear ratio was still 1:1. So the main advantage of wanting a 5spd as I explained to JC would be for us to be able to cruise down the highway at 70MPH at like 2500RPM. Apparently the later offerings had a .85 5th. Ratios arent that much closer, where you are going to notice it in any kind of street driving.  Let me know what exactly it is doing? WHen it is popping out of gear, which gear it is popping out of.

Be forewarned doing business with this version of Jack Knight Developements now called Jack Knight Motorsport Ltd and wiring their bank funds!  I am over 3 months into an adventure to have a 5 speed main shaft repaired (key part to gear box and without gear box useless) and their bank despite paper trail refusing to acknowledge receipt of wire transfer of funds taken from my account 3 months ago. My bank insists that their bank has received the money and had provided the paper trail.  At this point I am out the money for overpriced spares ( some parts that can be bought at any Mini parts supplies at substantially less ) for the gear box and the mainshaft in any condition, the pilot bearing burst taking out the 1st motion shaft and severely damaging the spigot / pilot bearing  surface on the main shaft which they offered to repair for a price of 150 pounds. I have asked them repeatedly for a parts diagram to help in choosing spare parts but nothing so far.  There appears to have been a significant turnover in people there the last few years, I had some very reliable people there a number of years ago I wonder what happened. Has anyone found an alternate source for parts new old stock or good used parts?  Is there anyone in the UK that can go knock on their door? They apparently no longer take credit cards only wire transfers to their bank - be warned it hasn't worked for me so far!!!!

Yes that's the email address I sent my request to. They say they are going to post the info on their site but have yet to do so.

If anyone can help............

if you manage to get any exploded diags or rebuild info can you let me knwo too please?

Hi Bill

I just got a reply to a question, I don’t think they are out of business at all.  Are you emailing [email protected]?

Sadly, yes I've sent two requests to them in the last months.

Thanks Again.

//www.jackknight.co.uk/

Parts listed in this download from site...

//www.jackknight.co.uk/pricelist/Mini%20Price%20List%202011%20com.pdf

Thanks, I did a search before I posted, It must be out of range.  

My Jack Knight 5 speed is acting up (sticking in gear jumping out etc)

Does anyone have drawings/exploded view parts diagram to assist in the rebuild?

Thanks