Thinking of changing my gearing...any thoughts?

[Robman]

Donor : 1998 Explorer XLT 4dr 4.0L SOHC Automatic trans.(5r55e) 4x4. 3.73 gear ratio.

Recipient: 2000 Explorer SPORT 4.0L OHV 5-speed manual 4x4. 4.10 gear ratio.

So, the sport has become my daily driver due to the transmission in the Donor crapping out on me, I love the sport manual trans and bulletproof OHV motor. However I am really tired of revving 2000rpm @ 80 km/h. I have a couple questions as I may plan to swap out the whole rear axle and the front diff in favour of the Donor vehicles parts.

Question #1 - Are they directly interchangeable?
Question #2- Do you suppose any adverse effects from changing the manual tranny'd 4.0L OHV sport from 4.10 to 3.73 gearing ?

I just want to be able to cruise at 90 km/h in a nice low RPM so I atleast feel like I'm not chewing through the fuel at an unreasonable rate. But I wonder if I persue this that I might render the poor OHV gutless or if I'll make the swap and wish I had never done it, as it is a fair amount of work. I would love to pick your intelligent brains on this matter. thanks - Rob.

 

[ld50]

Not sure if the parts are interchangeable but what size tires do you have on the sport? Going to a larger tire would offset the 410s a bit. I wouldn't want anything bigger than a 31 or 32 inch tire for 410s though. If you just went to 373, you would notice less oomph and/or response at low speeds but at faster speeds you could cruise at slower rpm.
I run 513s and 35 inch tires on my first gen.

 

[blueka]

my black sport 5spd had 4.10s... it was fine.. your parts are directly interchangeable... it can be done in a few hours if you know your way around a toolkit...chop chop


Si

 

[Runnin'OnEmpty]

I would not do the gear swap. Stick with the 4.10s
and go up a tire size as suggested. I have a Ranger
with 4.10s and it cruises well with a 30 inch dia. tire.

 

[MercuryMullet]

With the info given, it appears you have a 29ish tall tire and run 2k at 50 mph (80). 3.73 will get you running 1729 at 50. a 31" tire will have you running 1778 50 (80) or 1955 at 55 (90). So changing your gears or going to 31s is the same result. I'd go 31s.

 

[Robman]

Thanks very much for your input guys, my tires are 245/75 R16 Goodyear Wrangler Territories. I guess I'll just stick with the 4:10s as 300rpm isn't really a huge difference.
You made a good assumption MercuryMullet as they are 29-30ish tall tires Thanks for the speedy replies guys. Keep Explorin'!