Nissan Patrol 4x4 (Africa)

I've searched the forum for the word "ratio", ten pages later and I have not found what I was looking for.

Has anyone ever imported diff gears for a Patrol? If so, who did you buy it from?

Hi Zantus

Search for "gear ratio". You will find lots of comments.

Yes, plenty comments, but no real info on suppliers that will ship to South Africa.

Zantus, I don't have any personal experience with the company and I don't know whether they would send bits to SA, but Marks 4WD Adaptors have some interesting goodies for Patrols:

Replacement transfer case gears for lower low range ratios

Dual transfer case kits

I'm actually looking for diff gears, not transfer gears.

http://www.marks4wd.com/products/diff_g ... nissan.htm

I think they will send to SA, but they are about $200 more per diff than the ones on Ebay, but those guys don't want to ship to South Africa. When I get to that point I might ask someone in Aus to buy it on my behalf and then ship it to SA.

What ratios are u chasing? and what size Tyre you wanting to run with it?

I'm looking for 4.625:1.

Guys,

What is the deal range for a given tyre diameter?
E.g. I'm thinking 31" or 33" is probably ok with the standard ratios. But if for example one puts on 35" tyres, to what should one change the ratios to to still get the right low range speed and otherwise the right performance on-road?

Then, I would also be interested to know whether the diff ratio changes that one can make is recommended or best avoided?
Are there any reliability issues with such a change?

On the Kalahari trip the Nissan club did during Easter, one driver with a Hardbody who had a crawler gear and broke off his prop-shaft when trying to crawl over a rock. Ironically (or perhaps not), a much older Hardbody without any mods got over it and made it to the top of the mountain. It of course also may have been due to differences in driver. So is this necessarily more of a risk with a crawler gear? The links above only advertise the lower gear options, but obviously does not expand on any such possible issues...

Zantus, sorry I can't help directly.

Alex, with any modification there is always a risk. I have heard several tales of woe, particularly WRT jeeps (which are the vehicles probably most commonly modified in these ways) where changes in diff ratio have gone wrong. Firstly, the two gears per diff that are changed during a ratio change are just about the most heavily loaded components in the drivetrain. Thus the quality, hardness and accurate fitment of these are critical. There is also apparently a required running-in procedure.

Further, any change such as this (whether a re-gear in the diffs, or a lower ratio in the transfer case) can apply more torque to all the components between where the change was done and where the tire touches the ground, and thus the risk of breakages is increased. This is dependant on traction of course. Having said that though, the Patrol is quite probably the car on the market best equiped to cope with these additional forces, and particularly the later cars with the 260 rear diff.

Personally, my preferance would be for a lower low ratio. I doubt a proper crawler gear is necessary for most applications, but even for my 33"-equiped car a lower low ratio (say 2.6:1) would at times be usefull. I would say a manual car with 35" tires would probably almost need such a change, particularly if rocks are a common obstacle (wouldn't bother if sand driving was my primary application), and particularly in the case of anything with a turbo (or your Lexus).

I would only bother with a diff-ratio change if going larger than 35", but others may not agree.

Peter sums things up very well.

However if you driving a NA Diesel model you would need a diff ratio change for anything bigger than 33's in my opinion. Obviously the TB42 TB45 and the TB48 can deal with the bigger OD better than the Diesels.

Zantus, i reckon get hold of Genuine Ring and Pinion set from Australia and get a shipment. With 4.6xxx:1 you probably running 35" /36" right?

Ps: In my opinion Crawler/reduction gears in the transfer box are definitely worth considering if you go to a 35, particulalry with a Petrol motor, as you end up with "run-away" , most noticeably when reverse start recovery back down inclines, but even felt in 1st foward down inclines. Diesels less effected due to compression of course but still also worth consideration.