You can combine a 4.571 FD and a 0.82 4th gear to give an overall 3.748 ratio. It makes a huge difference in revs, and therefore noise, on the motorway.
If it got rid of the flatspot I'd get one but for the money and having had my van for 4 years I'm not running out to get one.
Hi Owen, excuse my denseness how do you work out that ratio ^^ Looking at the stats my 5 rib had a 4.318 final drive and I've had the 0.82 4th put in.
Stupid question alert: is it a mirror image on both top and bottom of the box? In other words if I look under the van will I see whats being shown on top of the box as per your pics?
http://thelatebay.com/index.php?threads/22509/ I started the thread I've linked to a couple of years ago. It has my experiences before and after changing gearboxes. It has some info on ratios, plus impact on running temperature etc. I got the same ratios as a 6 rib but in a normal gear box rebuilt by bears motorsport, much better than dropping 600+ squid on a gear box that may be knackered
Does anyone know if there's Someone out there that can fit a longer 4th? Mine is a 2ltr and although it'll do 70 it certainly won't be happy "all day long" more 50 / 60 for a few hours and a nice long cup of tea
Hard to tell if it is a 6 or not Edit : well if the 5 rib looks the same underneath i.e. the ribs dont quite go all the way round then it must be a 6 rib on mine
if somebody need, my 091 6-rib gearbox is still for sale, £ 500 - http://thelatebay.com/index.php?threads/091-6-rib-cp-gearbox-for-sale.52602/
Ah right you confused me(not hard) with the above 4.571 isn't the final drive it's the r&p So multiply the ring and pinion by the 4th gear gives you the final drive.
You can see the ribs have sharp corner on the 5 rib and rounded on the 6. I don't remember what it looks like underneath.