92 Explorer under geards or under powered?

[the_intimidator03]

So after getting my 92 Explorer 4x4 up and running. It seems a bit underpowered to me. It has a 5 speed with 3.73 gears running 31x10.50x15 tires On the freeway in 5th gear i can maintain speed but any slight rise i must downshift.

I am trying to figure out if its just undergeared, underpowered, or if I need to look into some engine work. I have yet to do a tune up, will do plugs, wires this weekend.


P.S. If this is normal, when I replace the tires would it be best to drop down to a 30x9.50x15 or 235/75/15 tire?

 

[alwaysFlOoReD]

I had a 4.0 in a b-2. It had 4.10 gears with 31" tires and was peppy. My race truck has 3.73 with 31" tires and is peppy. It may be that a tune up will fix things, other wise I would go to a smaller tire. I'd go 29" [235/75-15] with the 3.73 just for cost of tires.

 

[Blown]

It could be both, in need of a tune-up and those tires are a little bit big for 373's. Those 31.5's are like running 3.43 gearing and then you got to add the fact that it takes more power to start and stop them with the additional rolling mass.

I would double check timing and plan on running a smaller tire when you can.

 

[85_Ranger4x4]

3.73 isn't that undergeared for 31's I wouldn't think... but I have never been that impressed by a 4.0.

Mom had a '94 with 3.27's and stock 235/75-15's... it had a hard time staying ahead of the exhaust fumes.

My Ranger has 3.73's and 31's and gets around fine with a mostly stock V8.

 

[Blown]

I looked for and got the tow package for the gearing in a 91 X after driving several of them. The difference was noted and we wouldn't have less.


The difference in tire size from a 29 to 31.5
31.5-29=2.5
2.5/29=.862 or 8.62%

3.73 gears = 3.41 That's higher gearing than stock and the tires are heavier to move with more rolling resistance.

 

[85_Ranger4x4]

I looked for and got the tow package for the gearing in a 91 X after driving several of them. The difference was noted and we wouldn't have less.


The difference in tire size from a 29 to 31.5
31.5-29=2.5
2.5/29=.862 or 8.62%

3.73 gears = 3.41 That's higher gearing than stock and the tires are heavier to move with more rolling resistance.

Ford put higher gearing in them than that.

 

[Andy D]

The Rat has 3.27 diffs. I think this is the no frills diff for the 4.0.

 

[adsm08]

I have a 4.0, 5-speed, 3.73, 31" setup on my Ranger. Compared to my 4.0 engine, 2.9 trans, 3.73 gears and 29" tires it feels sluggish. Overall I am happy with it. Probably putting the 2.9 trans in the Ranger this summer, but still it's not bad. I can hold speed and even accelerate up a hill in 5th gear just fine.

 

[the_intimidator03]

Thanks guys, Adsm08 it seems from your post of accelerating up hills in 5th means I have some powerloss. Good to know it isnt just me lol. I planned on getting BFGoodrich all terrain KO2, just debating 235/75/15 or the 30x9.50x15 I guess once I get a better idea what is going on with the motor, if it needs a yanking for some repairs... ill just stick my 302 in its place. power issue solved lol

 

[adsm08]

Throw some plugs and wires at it, a fuel filter, and some Lucas fuel treatment and see what happens. My engine is fairly fresh, but it is still getting pulled for a SOHC here soon.

 

[Blown]

I noticed a difference going from 265/75's to 255/70's, a change of 5%, but I am coming at this from a performance perspective, wanted the lower gearing, so I am running 4.10's.

I didn't add that I thought our 91 with stock tires and 3.73's was peppy enough, I agree that the OP's X probably needs a tune-up and/or a compression test would tell you a bunch about the engine condition..........How many miles?

 

[the_intimidator03]

I Just got my plugs and wires. Also changing thermostat. I think the previous owner changed the fuel filter on the rail... now it is wiretied together? I will have to snap a picture of it. As for the milelage its probably more towards 230 rather than 130k. I need to find my compression Tester. Just moved so everything is everywhere lol

 

[AllanD]

My daily driver is a '87 Supercab with a '93 4.0 with 4.10's riding on 235/75-15 KO2's

I've often thought about re-gearing to 3.73's, but I've been driving the truck this way since '07 and haven't done anything about it yet...

But then again I have Lock-Right's for both axles sitting behind the monitor on my desk and haven't swapped them in either...

Have you checked the air fliter?

 

[the_intimidator03]

Air Filter looked decent, Could see light thru it. Plan on picking up a new one this friday. Trying to figure out what fuel system cleaner I should run through. Also will try to get specs on coil to test that

 

[AllanD]

If you want a pour into the tank fuel injector cleaner I personally recommend "Techron"
this stuff was the "magic bullet" for the older Saabs, VW , Volvo and Mercedes vehicles with Bosch K-jetronic