4.88's or 5.29's

[CruiserJack]

I recently put a 3" lift and 33x12.50x15's on my rig and have noticed a need for regearing. I have found that on the highway I have to keep the pedal welded to the floor to maintain 70.

So I am asking your opinions. Which gearing ratio would be best?

4.88's or 5.29's?

Also, anything else I should take care of while I am in there would be helpful.

Thanks!

Jack

 

[Nay]

He has a 3FE. ('91)

4.88's for 33's, 5.29's for 35's and up.

 

[CruiserJack]

He has a 3FE. ('91)

4.88's for 33's, 5.29's for 35's and up.

That's what I thought but wanted to make sure.

Any suggestions on best brands to go with from anybody?

 

[pr0ject42]

Talk to iron pig offroad. I was under the impression that he was going to be selling some center diff regearing kits, so you can lower your gears in high and low all from the center differential.

Only one set of gears to buy, only one differential to open up.

Not to bog you down in choices, but I think this solution is pretty slick.

 

[Corbet]

5.29's because your next set of tires will be 35's Why do it twice?

 

[spdwaver]

5.29's because your next set of tires will be 35's Why do it twice?

Agreed.

On my '91 I started with 35's (stock gearing) then went to 33's, only to find that I missed the 35's; 5.29's would really assist that 3F-E in running those tires.

 

[jonheld]

I have found that on the highway I have to keep the pedal welded to the floor to maintain 70.

FWIW, I went from 31s to 33s to 35s all with stock gears. If you can't maintain highway speed on the flats with 33s, you should look at your 19 year old motor.

 

[CruiserJack]

FWIW, I went from 31s to 33s to 35s all with stock gears. If you can't maintain highway speed on the flats with 33s, you should look at your 19 year old motor.

The 19 year old motor has 155 compression across all 6. I dont think its the 3FE. I think its the smaller gears with the larger tires. FWIW

 

[azTony]

Hmmm... when I went through this the concensus was 4.88's for 35's and now it's 5.29's? Of course

 

[Sanchez]

I'm rolling on 315's with 488's

 

[bhmmapping]

The 19 year old motor has 155 compression across all 6. I dont think its the 3FE. I think its the smaller gears with the larger tires. FWIW

I have also had 31's, 33's and 35's with the stock gears in my 92 and agree with Jon that you should not have trouble maintaining highway speed. Just because the compression is good doesn't mean the motor is properly maintained. When was the last major tuneup done. Also fuel filter, tank sock, valve adjust, timing...

not that lower gears are a bad idea, but I would make sure you got everything in tip-top shape first. Also, why was your transmission rebuilt, that is not something you hear about very often with these?

 

[Nay]

Hmmm... when I went through this the concensus was 4.88's for 35's and now it's 5.29's? Of course

No, you are missing that he has a 1991 with the 3FE. I have seen relative consensus that 5.29's for 35's with the 3FE is an excellent fit, understanding that the rest of the '91/'92 gearing may not be identical (trans gearing) to the 93-97.

This is not a statement for the 93-97 where you would need some specific usage goals to select 5.29's for 35's (like admitting 37's are the new 35's ).

 

[CruiserJack]

FWIW, I went from 31s to 33s to 35s all with stock gears. If you can't maintain highway speed on the flats with 33s, you should look at your 19 year old motor.

Im not really interested in going to 35's, the 33's I have now are great.

The major tune up including fuel filter, fuel sock, plugs, wires, all new vac hoses, rotor, distr cap, cleaning the throttle body, cleaning the air intake housing and air filter reservoir was done last month.

The tranny was rebuilt because the previous owner was a moron and trashed it. The engine was also rebuilt by a reputabile mechanic at 60,000 miles by the PO. I was shocked when I found the receipt for this and called the mechanic who specializes in LC's to confirm it. He basically said the PO was a moron, confirming my suspicion.

 

[bhmmapping]

The major tune up including fuel filter, fuel sock, plugs, wires, all new vac hoses, rotor, distr cap, cleaning the throttle body, cleaning the air intake housing and air filter reservoir was done last month.

That should cover it, but I still don't understand the lack of power, I didn't really notice much of a loss with the 33's. 70 wasn't a comfortable speed though, the truck seemed happier cruising a little faster than that. Have you noticed if the tranny is locking up in overdrive?

edit, I just read over your list of other vehicles and think I might now understand the perceived lack of power

 

[CruiserJack]

I found this website Gear Calculator which allows for a gearing calculator.

If I am correct that the factory tire diamater is 31 inches and the original factory gearing is 4.56 then I should regear to 4.88's. Actually it says 4.8541 but I rounded up.

Correct?

 

[CruiserJack]

That should cover it, but I still don't understand the lack of power, I didn't really notice much of a loss with the 33's. 70 wasn't a comfortable speed though, the truck seemed happier cruising a little faster than that. Have you noticed if the tranny is locking up in overdrive?

edit, I just read over your list of other vehicles and think I might now understand the perceived lack of power

LOL! Nah, the perceived pack of power is in relation to the previous set up not the pony's in the garage. I do live in central TX which is hilly. I dont have problems on flat highway but on hills my foot gets tired.

 

[bhmmapping]

I found this website Gear Calculator which allows for a gearing calculator.

If I am correct that the factory tire diamater is 31 inches and the original factory gearing is 4.56 then I should regear to 4.88's. Actually it says 4.8541 but I rounded up.

Correct?

factory is 4.1 - 4.56 would put you back to stock, but people have been happy with 4.88.

 

[bhmmapping]

this is a good read:

https://forum.ih8mud.com/80-series-tech/140203-4-88s-opinion.html

 

[bpassmore]

The concensus from the 3fe owners (or previous owners) is this:

5.29's.


end thread.

 

[bhmmapping]

The concensus from the 3fe owners (or previous owners) is this:

5.29's.


end thread.

not for 33's, unless you don't want to drive it on the highway. If you read the thread I linked, he was close to 3K rpms at 70 with the 4.88s