SJ Diff Ratios

[ROK360]

Guys,
Since I have thrown 35's on the wagon I have been wondering exactly what my diff ratios are. Found a table over on IFSJA and my limited wagon has 3.31 diffs which apparently in the US is the tow package. I am wondering what the most common diff ratios in OZ were? As it seems most 4door wagons stateside had 2.73's fitted (would have expected a Limited wagon to have the baby gears in it), so just wondering if Jeep Aus at the time stipulated a different gear set as their standard for their AUS spec vehcles.

Anyone know the detail on this one?

Cheers,

[Richo]

Fairly sure all V8 FSJ's in Oz were 3.31. Maybe some older units (pre 77?) had different rations, and would be fairly sure the earlier 6 cylinder models would have been geared different.

They were geared that way for towing/highway use, even going up to 33's turns them into a slug and you'll be riding the brakes all the way downhills offroad.

Ratios are easily available for D44's and AMC 20's, take your pick. With 35's I'd go 4.1's for allround use, or if mainly offroad use then 4.56.

[killa]

You can work it out yourself fairly easily.
Prop up the rear axle with appropriate stands so that both tyres are able to spin freely. Mark one tyre so you can count rotations, do the same with the drive shaft. Rotate the tyre one full rotation and count how many times the drive shaft turns.
3.31 times = 3.31 ratio.

[ROK360]

Richo - yep I am thinking that is going to be the case as far as downhill. Still looking into which way I am going to go here as far as diff ratios, yet to take it off road in anger since the 35's went on - it has been off getting sexy thanks to a panel beater mate. Would love to go the underdrive, 4spd auto, splitter route as the old girl loves the 35's with the current gears in it particularly on the road. I would hate to go back to the 360 screaming it's tits off at 100km/h again. Will have to wait and see on this one. Cheers Rok

[dropbear68]

I need to know this info too, my 82 fsj has a 258 with the t18 flat out over taking at 90kph, yet i had a 82 with a 258 and t5 and she would haul arse upto 160kph no problems same wheels which are factory fitted jeeps, , reverting to fords for example if you had an old xb with a 250 auto they ran a 2.92 the same set up with a 3 man would be 3.23 and the four speed retained the 2.92, from the XE onwars the 6 cyls all ran the 2.77 ratio be they auto or manual, if you wanted a bi more go but didnt want to spend much money youd drop the 3.23 in behind your auto screem like all shit between the lights but useless on the highway, if you stuck the 2.77 into an old ford with the four speed manual in effect you added a fifth gear, so getting back to the jeep, i dont want to race of the lights at a million miles an hour im too old for that shit what i want is the performance of the t5 jeep without the piss weak t5, have I confused you all yet lol, so whats the best ratio for the T18 behind the 258

[ROK360]

Try an increase in tyre size and see how that works. If you are still running 29's going to 31's or even 33's ( little bit more work as you will need to cut the guards some) will act similar to going to a higher ratio.

My Waggie runs 35s and I have gone to 3.9s and it pulls fine, yep at 110 another gear would be nice and maybe I should have settled on 3.7s. Always wanted to opt up to a 4spd. Anyway the tyre size may well help you out. Cheer