Upgrading Gearing with 35s

[Fixedgear74]

Hey All:

I have found a few threads discussing this but wanted to get more feedback (older threads).

A little back story.
I have a 94 X that yes has the dreaded A4LD transmission, which likes to over heat when pushed hard (I have the stock trans cooler on it but also have a Mishimoto cooler with an electric fan that I plan on installing).
I am working on trying to scrape together parts for a manual swap (trans and transfer case) but am still running the A4LD for now.

I currently have a 5.5" lift with 35x12.50s tires running 4.56 gearing. I have an Eaton E-locker in the front (D35) and a Detroit Locker in the rear (8.8).

I am looking into changing my gearing because the 4.56s aren't low enough now with the 35s (seem to be working the trans to hard, they were ok when I had 33s).
My question is what do you think would be better 4.88s or 5.13s.
I understand with the 4.88s would be better on the highway, but am still interested in the 5.13s also.
I know with the 5.13s the RPMs on the highway will be high but don't mind if I can cruise at 55ish.
I also am worried that the pinion shaft maybe on the smaller side with the 5.13s.
You can see my X in my profile pic.
Interested to hear your thoughts, Thanks.

 

[Fix4Dirt]

Hey All:

I have found a few threads discussing this but wanted to get more feedback (older threads).

A little back story.
I have a 94 X that yes has the dreaded A4LD transmission, which likes to over heat when pushed hard (I have the stock trans cooler on it but also have a Mishimoto cooler with an electric fan that I plan on installing).
I am working on trying to scrape together parts for a manual swap (trans and transfer case) but am still running the A4LD for now.

I currently have a 5.5" lift with 35x12.50s tires running 4.56 gearing. I have an Eaton E-locker in the front (D35) and a Detroit Locker in the rear (8.8).

I am looking into changing my gearing because the 4.56s aren't low enough now with the 35s (seem to be working the trans to hard, they were ok when I had 33s).
My question is what do you think would be better 4.88s or 5.13s.
I understand with the 4.88s would be better on the highway, but am still interested in the 5.13s also.
I know with the 5.13s the RPMs on the highway will be high but don't mind if I can cruise at 55ish.
I also am worried that the pinion shaft maybe on the smaller side with the 5.13s.
You can see my X in my profile pic.
Interested to hear your thoughts, Thanks.

imo theres enough people running 513s and who push it hard that i think its ok to run. i men it is smaller, but people have abused rigs on 513s with no ill effect, so its probably one of those things that doesnt effect it enough?

Gear Ratio Calculator

heres a good site to know where your rpm will be at. 513s also fgive you more trail control, especially if you are worried about working the a4ld to hard

with a manual id much rather hav 513s also

 

[RangerX]

I would run 33s until you swap in a manual trans and see how that is with 35s. Regearing is a lot of time and money, you probably know that since you already have non stock gearing.
I was fine with 4.56 and 37s for 12 years of SoCal driving and wheeling. Granted my Ranger is less heavy than an Explorer, and had a manual trans…
Will this be a daily driver or mostly offroad?

 

[DintDobbs]

5.13's all day every day. I'm running a 2nd-gen so I can't be absolutely sure of how the 1st-gen transmissions are geared, but I'm running 33's on 5.13's (the RPM's game is real, I gave up driving faster than 50 MPH) and wouldn't go back.

If your rig is a dedicated off-roader, the 5.13's are the better pick. If you're even considering 5.13's, the 5.13's are a better pick, in my opinion. Those 35's have got to be heavy.

I made up a formula to give you the difference in final drive ratio before/after swap.

(Old Tire Diameter / Old Gear Ratio) / (New Tire Diameter / New Gear Ratio) - 1 = % difference in final drive ratio

In my case, (30/4.10) / (33/5.13) - 1 = 0.14 (rounded)

So, I gained roughly 14% extra torque and run my RPM's roughly 14% higher, given the same speed in top gear. Running 50 MPH I used to hold right around 2000 RPM, now I'm right around 2250, so you can see that my formula is reasonably close (given that it doesn't account for added drivetrain friction or tire weight).

In your case, if you go 5.13's, you get about 13% difference

(35/4.56) / (35/5.13) - 1 = 0.13

Or if you go 4.88's, you get about 7% difference

(35/4.56) / (35/4.88) - 1 = 0.07

So IMO, if you don't think the 4.56's are enough, go on the safe side, spend the money once, and get the gears you know you actually want.

 

[dvdswan]

5.13s. My truck came stock with 4.63s and when I SAS'd and put 35s on 5.13s brought it back close to stock ratio with stock tires.

 

[410Fortune]

The jump from 4.56 to 4.88 hardly makes it worth the time and $$$ to install

You should go with 5.13 and or consider a doubler for your t case

I hope your trans has aux cooler! The poor a4ld lol

 

[Nedwreck]

Another vote for 5.13!

"Never fear the gear" as they say, and OD in our A4LD's is pretty tall anyway.. (.75:1?)

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[dvdswan]

I hope your trans has aux cooler! The poor a4ld lol

You talk as if the A4LD has past...

 

[410Fortune]

It did, 3 of them before I finally went to transwerx in California and had a good one built… then in 05 I took it out and went v8

 

[Fixedgear74]

Thanks for the feedback.
I am leaning towards the 5.13s.
I will update this thread when I move forward.

 

[410Fortune]

If you went from 4.56 to 4.88 you would hardly even notice the change
The cost of the gears and install are huge these days

Your old 4.56 can be sold to recoupe some of the cost

Many years ago I paid a shop to re gear my bii from 3.73 to 4.10

Whoops

I swore I would never need anything more than a 33” tire hahahaha I was wrong.
Could hardly tell I hd different gears
I should have gone 4.56 I have regretted that ever since
I could make up for it by installing a doubler or atlas t case, I mean I am running 35’s with 4.1 but luckily my bii has a v8 so I get good mpg on the highway because my rpm are low. A doubler would give me good crawler gears without having to revisit the ring and pinions and I could keep my highway gears…