Re gear to 4.88's or not?

[Sixgunz]

Being new to Land Cruisers, but very familiar with lifts and large tires...it comes down to a few things..

Do you have the money burning a hole in your pocket and don't mind your rig getting less mileage? Then go for it! Is this money you'd be spending on an ARB bumper? Then forget it...

Maybe others can help out, but don't 4.88's take a different carrier? I didn't think the 4.30 carrier would work for those..

Your stock tires are, in inches, 31.2 tall by 10.8 tread width.

Going to 33's and re-gearing from 4.30's to 4.88's doesn't make sense to me, unless, like I said, you have money burning a hole in your pocket. Even then, IMHO, it's way overkill for 33's and your gas mileage will tank.

If you are going with 35's...on a 4 spd tranny...I'd bite the bullet and go for it.

just my .02 worth

 

[sonk76]

You think regear even on 33s? I know you are but I don't know if I would if I had 33s and the 5spd here. The 33s and 4spd kinda sucked over the passes but when I went to 35s it had to be done.

I found 4.88's to be overkill for the 33's on my 5spd... not to mention having the speedo off by 10% wasn't my favorite either.

 

[Letsgomoreplaces]

Your already into it a bunch of $$$, I'd re-gear. For me 4.88 is worth it even with 33's. That said, everyone has a budget, and If you have no plans of going bigger than 33 most tend to tolerate it with stock gears.

Well, my birthday and christmas arrived today

I want to install now but I am also seriously considering regearing to 4.88's and I know it doesn't make sense to put on the lockers and then tear down to regear later.

I will have to save up until about March 2012 to buy gears.
I plan to also run 33" tires with my 4spd tranny.

Question for the seasoned wheelers on here, would you regear or not?

Towing 3-5k lb camper is in my 3-5yr horizon.

 

[Letsgomoreplaces]

gears

And your one of us few old schools that can run 5.29 because of the hybrid rear carrier we had to do years ago. I've considered too, but S/C makes the 4.88 / 33's or 35's perfect. Still wish I had a 5 speed though.

35" + 4.88's with the A750F would be perfect IMO. As my rig is set-up now, weight wise, I am curious how 5.29's with the A343F would feel. Methinks mucho betta. Especially when the KK is in my rear view mirror .

Sea level makes up for a lot! But at our ~5,000' and up a regear is a must for 35's and armor. I ran the stock 4.30's and 33's for a year+ and I didn't like it either from a tranny shift point perspective; it made an already bad condition worse...

 

[ShottsUZJ100]

I tried to re-gear back in 2002 though that's how we found out the 100's rear-end was all new.

I've survived with stock gearing for 9 more years and could live with it for ANOTHER 9. That's with 35-inchers. If the plan was to stick to 33's for sure I'd never regear ESPECIALLY up to 4.88's. Mileage sucks...more RPM's...poo poo except for a dedicated trail rig. Not a DD fro sure...not for me.

That said...since I run 35's, the second my pumpkins need to be opened up the 4.88's will go in. 4.88 and 35" on a 2001 are a true match.

 

[jgray]

And your one of us few old schools that can run 5.29 because of the hybrid rear carrier we had to do years ago. I've considered too, but S/C makes the 4.88 / 33's or 35's perfect. Still wish I had a 5 speed though.

Carl - Are you saying 5.29's are available now? In my case they would be going in a 99 LC100 with the 4-speed A343F tranny. I have the rear factory e-locker as well. I thought the only option on the market for 100's was 4.88's?

 

[Nottajeep]

And your one of us few old schools that can run 5.29 because of the hybrid rear carrier we had to do years ago. I've considered too, but S/C makes the 4.88 / 33's or 35's perfect. Still wish I had a 5 speed though.

Is there a MPG difference between a 33" tire/4.88 gear combo compared to 33" tire/4.3 gear ?

 

[ShottsUZJ100]

Is there a MPG difference between a 33" tire/4.88 gear combo compared to 33" tire/4.3 gear ?

Oh hell yes! 33-inch = 4.56 to hit stock. 4.88 = 35-inch to match stock. When you turn higher RPM's all the time (4.88-33 inch) you use more gas. Better off-the-line power but a bit more noise and worse mileage. Better crawl downhill.

My 80-series is that way as well. 11MPG maximum...no matter how or where you drive.

 

[jonharis]

Is there a MPG difference between a 33" tire/4.88 gear combo compared to 33" tire/4.3 gear ?

Some have stated that it is the same, some have stated that it is worse, some state it is better. Yes you are at higher RPMs but your engine is working less hard at slower speeds. I know with 35s your gas mileage should theoretically improve.

I have not truly calculated it since re-gear because you can not use the speedo/computer as a reference but I know I get a similar total range. either way, mileage will suck. With regards to the speedo reading, It is waaay of at interstate speeds, like 12-14mph high on mine. I use a Escort Passport 9500 which has a spot on accurate GPS speed readout so I don't really care. I find it easier to look at the detector than the speedo anyways. I can see how it would annoy people and I don't like that my odometer is probably not accurate anymore, but there are ways to fix that with a calibrator.

 

[Nottajeep]

C-Dan has really tee'd this answer off over on the 80's thread https://forum.ih8mud.com/80-series-tech/516724-gear-down-not.html


I can now do a math equation to put this in perspective and see the answer in my simple mind... (tire revs per mile* X gear ratio = drive shaft RPM @ ~60mph)

* KM2 used as a model tire that most would consider buying if they are in question to regear.

4.3 stock gear x stock tire: 666 x 4.3= 2864
4.3 stock gear x 33" KM2 tire: 628 x 4.3= 2700 [-5.72%]
4.56 gear x 33" KM2 tire: 628 x 4.56= 2863 [-0-%]
4.88 gear x 33" KM2 tire: 628 x 4.88= 3064 [6.98%]
4.88 gear x 34+" KM2 tire: 598 x 4.88= 2918 [1.89%]
4.88 gear x 36+" KM2 tire: 572 x 4.88= 2791 [-2.55%]


I now understand the mpg concerns earlier. Also, regearing for a 33" tire doesn't make sense IMHO. On to the ARB's F/R!!!

 

[hoser]

Jason, I think that formula is missing the top gear transmission ratio.

Edit: nevermind, I didn't catch you said "driveshaft RPM" not engine RPM.

 

[Letsgomoreplaces]

gearing

Don't forget other factors. When re-gearing you also need to take into consideration added weight of accessories, rolling resistance, etc. Typically it is best to shoot for as low of a gear ratio as you can tolerate with highway driving.

 

[Nottajeep]

Don't forget other factors. When re-gearing you also need to take into consideration added weight of accessories, rolling resistance, etc. Typically it is best to shoot for as low of a gear ratio as you can tolerate with highway driving.

Ideal would be fitting that 34" KM2 tire under my wheel wells, but I don't want to cut, rip, or change my current suspension setup.

 

[nakman]

Carl - Are you saying 5.29's are available now? In my case they would be going in a 99 LC100 with the 4-speed A343F tranny. I have the rear factory e-locker as well. I thought the only option on the market for 100's was 4.88's?

Interested in this answer as well. For now I'm happy with 33's (285's) and stock gears, but I could see doing 5.29's and 35's some day and being even happier.



I almost regret not doing 5.29's in the 80, and running 4.88's instead.. though have to admit I've still been happy with that decision. Though it's kept me from looking at 36-37" tires, which to 80 lovers are the new 35's.

 

[bamabrock]

Why spend the money just to go from a 4.30 to a 4.88? Not worth it IMO.

 

[nakman]

Why spend the money just to go from a 4.30 to a 4.88? Not worth it IMO.

I agree that's why I'm more interested in the 5.29 option.

 

[sonk76]

Why spend the money just to go from a 4.30 to a 4.88? Not worth it IMO.

I believe with the 5-speed the difference to 4.88's is a bit bigger than that...

 

[1loudLX]

Why spend the money just to go from a 4.30 to a 4.88? Not worth it IMO.

because I was doing lockers already, and wanted the gearing to be back to stock. Now the speedo is spot on without correction. Plus I drive thousands of highway miles, probably 35k already on the new gears.


With the 5spd you're going from 4.10s to 4.88, so you're getting a little more gearing than stock even with 35s. Cant wait for the day I swap them into the 05

 

[bamabrock]

I believe with the 5-speed the difference to 4.88's is a bit bigger than that...

the OP doesn't have a 5 speed nor do 5-speeds have stock 4.30 gears

 

[OGBeno]

There is no reason to not go to 5.29's if you are going to go to any tire bigger than a 33".

IMHO, it's a waste of money to go to 4.88's when you still have gearing available.

Go all the way, or don't go at all.