Outer Limits 4x4 Board

Ok just after some advice I am looking to use the Hilux T case I have,( I know this means the front diff will need to be flipped ) in my lux with the mog diffs 1uz and the 1uz auto.

My question is in relation to crawl ratios, the Lexus auto is apparently an a341e searching has found that it has a 1st drive ratio of 2.804, the T case has TG gears 4.7:1 reduction and the 404s have a reduction of 7.56:1

When I put all this into this site http://www.offroadreport.com/crawl_rati ... lator.html

I get a crawl ratio of 99.63172 now I have been told I need to add to this for an auto due to the torque converter is this true? Also I know diddly squat other than what I have read about crawl ratios. I understand like wheelbase there is no magic number but given Ill be running 40s is this ratio too low/high?

Basically I dont want to go to all the effort to flip the diffs and find its geared too low and unuseable. Its trailered so highway speed isnt really a concern. Cheers for any advice

Does this help you boof ??
http://www.high-impact.net/transmission ... raking.htm

Generally considered that an auto wil "add" 50-100% to your gearing with no lockup torque convertor activated. With the lockup TC activated it brings it down to the real numbers (your 99:1). The amount the TC adds is variable as there is only a fluid connection between the engine and gearbox. TC stall revs will have an oimpact on the revs-speed equation too.

booflux wrote:Ok just after some advice I am looking to use the Hilux T case I have,( I know this means the front diff will need to be flipped ) in my lux with the mog diffs 1uz and the 1uz auto.

My question is in relation to crawl ratios, the Lexus auto is apparently an a341e searching has found that it has a 1st drive ratio of 2.804, the T case has TG gears 4.7:1 reduction and the 404s have a reduction of 7.56:1

When I put all this into this site http://www.offroadreport.com/crawl_rati ... lator.html

I get a crawl ratio of 99.63172 now I have been told I need to add to this for an auto due to the torque converter is this true? Also I know diddly squat other than what I have read about crawl ratios. I understand like wheelbase there is no magic number but given Ill be running 40s is this ratio too low/high?

Basically I dont want to go to all the effort to flip the diffs and find its geared too low and unuseable. Its trailered so highway speed isnt really a concern. Cheers for any advice

I would just run stock transfer gears (2.28:1 I think)...this gets you close to 50:1 which is close ideal for a V8. If you leave the transfer gears in then you will need to fully manualise the auto cause if you try to launce up something it will go absolutely nowhere with 100:1 gearing. At 50:1 it will launch and crawl and do anything in the rocks and 2nd gear will be good for the longer or looser climbs.

Sam

Sam