Differential Ratio

[Bob Tucker]

Dont forget your speedo will be way out, reading very high.

 

It wont be a genuine 150 mph!!!

[Guest docter fox]

It wont be a genuine 150 mph!!!

borrow a GPS thingy just to check

 

salty,

at 60 mph in 5th, what rpm are you at?

[Guest salty_monk]

60 in 5th?? If you're doing that then you're not driving it properly!!

 

90 is about 4000 rpm in 5th if that helps... (think 60 is about 2500 but not sure..)

 

Acceleration through the gears is much better with the 3.92 & you get a higher top speed too. 5th gear becomes a gear for using not just an overdrive.

[Guest docter fox]

im not driving it at all yet :boohoo:

60 in 2nd is around 6k and 90 in 3rd is about the same

got a dodgy earth on the tacho so im remembering what i can, but i remember 2500rpm in 5th is 60 as thats what we used when the sierra speedo broke...

plus i pay less attention to the tacho when we're going quicker

 

as the plate isnt on the diff what should i look for on the actual casing to find the ratio?

[Guest salty_monk]

Easiest way is to jack up the rear on one side to lift one wheel.

Mark the prop flange at the back of the diff with tippex.

Release handbrake!!

Turn the wheel that's in the air twice (2 full revolutions) & count the number of turns on the flange.

You can tell the difference between a 3.62 & 3.92 quite easily this way, it's fairly obvious (the 3.6 will finish up with the mark on the opposite side, the 3.9 will end up with the mark in approxmate same place...)

[niduncan]

Dont forget your speedo will be way out, reading very high.

 

It won't be a genuine 150 mph!!!

 

No problem, I have a VDO electronic speedo which I can easily re-calibrate by driving a measured mile.