Where to source 4.90 diff's for my NL??

Joined: 28 Nov 2005 Location: Merimbula, NSW

Hi all,

After recently needing to swap a 2.8 Td V5M31 5 speed manual into my paj i have noticed that in comparisson to my petrol box it has a much taller 5th gear, from my searching all other ratio's are the same.

Been doing alot of towing lately so considering fitting some 4.90 diff ratio's to relieve the gearbox of a bit of strain, still running 33's on it aswell.

So where would be the best place to source some second hand diff's or would i be better off fitting some new crown wheel and pinion's? Might be pricey but.

Would there be much difference or would i see a bigger difference if i dropped the tyre size back down for towing to a 30 or a 31 inch?

Joined: 11 Jan 2004 Location: Adelaide

By my calcs, going from 4.636 to 4.90 is a little over 5% difference. Dropping from 33s to 31s would be a little over 6% difference.

Personally, I'd look for the 4.9s - new or s/h would depend on the price difference, but I'm guessing I'm too cheap for new. Very Happy

Joined: 18 Nov 2004 Location: New Zealand

HI, I did the 4.9 swap. It brought the gearing back to nearly normal bt not quite as my original 31's measured less than 30 and the BFG 33's were almost 33. As Scott said it is about 5% and I had altered tyres by 9%.

In NZ, LWB 2.8 Diesels had the 4.9's. SWB 2.8's had 4.636. (All SWB 2.8's are imports).

I'd try and get some 4.9's as well. If you are going to swap the whole front diff assembly over (which is by far the easiest as it needs to come out anyway) make sure when you buy the diff you get the Drivers side cv assembly. The 4.636 cv will not bolt up to the 4.9... Rolling Eyes

Joined: 28 Nov 2005 Location: Merimbula, NSW

Thanks for the reply's, will probally go with a second set of rims and some smaller tread for the time being and see how that goes... much cheaper and easier option if it works out.