Club 80-90 Forums

I have aways found the 4 speed transmission on my JX a bit short am I better to get diesel 5 speed box or not? The dog leg is not an issue just would prefer more evenly spaced gears and a bit of "overdrive" options please Cheers guy

The JX diesel engine should be mated up to a 5 speed box, but there are lots of ratio variants so you need to choose the right one, the code markings for a 5 speed box that went with the JX were ASS, this gearbox had good ratios for higher speed driving, there isnt an overdrive with the 5 speed .

There are not much differences in the gearbox overall ratios on these vans.
Like 3H is 95 kph AAP is 100kph @3000 RPM and the AAP is one of the longest 4.57 diff boxes.
You can get another 10kph and have 110@3000 going custom 4.14 R&P and a bit more with custom 5th and 4th.
But that needs tdi power and torque.

There are big differences with the gearboxes fitted as standard to the T3 , some gearboxes fitted to the lower powered diesel models would not be good at motorway speeds fitted to a Jx engine van. 

what code box is fitted ? 4 speed JX was unusual, ABH is the code that should be in there, 5.43 final drive with a 0.78 4th gear, just like a TD Syncro 14", low enough 1st, quick through the gears, slight gap 3rd to 4th; 6 and a half percent slower in 4th than the 3H/ASS 5 speed turbodiesel box is in 5th gear

Thanks for the replies all, Hi Aidan will need to check my Van is in for restoration at the mo
Cheers
Nick