Gear ratio: 33" and 35" tire 3-speed auto

[Sunder]

Different type of gearing question:
If I'm balancing between 2 tire sizes (33"/35", does anyone have an opinion on what the best compromise gear ratio would be?

I currently have 33" tires for winter. (I live in Canada)
I'm considering buying 35" mud tires for summer.
So splitting the time between 33" and 35" tires, depending on the season.
I just bought the 33" tires last year, so finances dictate I'm either running 2 sets of 33" tires, or 33" and 35".
(steering upgrade already taken care of, and Vanco brakes would be too - already running Blackmagicbrake pads - this is more of a gear question)

I have a 3-speed auto transmission.
The plan is to have an HP30 front, Ford 8.8 rear. (both with factory 4.10)
I partially want 35" tires due to the height loss the lower Ford 8.8 pumpkin diff will give me, plus to help avoid the deep ruts I often encounter that make me drag my diff.
I won't lie - I also like the aesthetic look of 35" tires.

I'm under the impression that 4.10 is about "optimal" for 33" tires with a 3-speed auto.
But a 4.56 or 4.88 would be better for the 35" tires.
I also do a decent amount of highway driving, and my Jeep is also my daily driver.

4.10 is the easiest/cheapest for me to run with (due to them already being installed in the axles), and I think it wouldn't be too bad with 35" tires.
(Especially because I've been tolerating 3.07 with 33" tires so far - and been saving up for this gear/axle upgrade. Currently have Dana 30/Dana 35).

If I'm balancing between the 2 tire sizes, does anyone have an opinion on what the best compromise gear ratio would be? Anyone else run different tire size combinations?

 

[GASnBRASS]

I run 4.10 with 33's and 3speed, and while I think the hwy rpm's are a tad high, I couldn't imagine running 33's with 4.56. I'd think 4.10 will be ok with 35's though. And since you do alot of hwy miles I'd say gear it for the smaller tire, or stick with 33's for both winter and summer.

 

[Jerry Bransford]

For the 3-speed automatic and 4.0L engine, you absolutely want 4.10 for 33's and 4.56 for 35's.

 

[GASnBRASS]

Yes, that's a good rule of thumb. He's asking which gears, 4.10 or 4.56, would be the best compromise if he's running both 33's and 35's (winter set and summer set).

4.10 would be a bit of power loss when you run the 35's, but 4.56 would over rev the engine with the 33's. With all the hwy miles 4.10 is the better option, plus I think it's available in a used 8.8 already.

 

[Andy5150]

4.56 with 33,s might be a little busy on the highway, but wouldn't be over reviving. You could cross the country with that combo.... and your automatic transmission would love it.

 

[Rob5589]

The compromise would be 4.56 and not driving 75+ on the hwy.

 

[Sunder]

Thank you guys! That will help my decision.

 

[CodaMan]

The compromise would be 4.56 and not driving 75+ on the hwy.

Agree!

 

[glwood]

The compromise would be 4.56 and not driving 75+ on the hwy in the winter.

 

[BlackJeep]

OP/Sunder, sorry to revive an old thread (as my first post here, no less), but I'm in exactly your situation and wondering which direction you went and what your thoughts are 2 years later. I've been running 32" tires on 3.07 gears in stock Dana 30/Dana 35 axles and a 3 speed auto for years. It's a bit awful. I'm about to upgrade to an 8.8 rear and 4.10s in both axles. My plan has been to run 33s, but there's a set of 35" BFGA ATs available locally at a price that fits in what's left of my budget. I too do mostly city and highway driving, with occasional off-road and camping trips planned.

Did you wind up going with 35s on 4.10s and the 3-speed? If so, how has it been? Will I regret that combo, in which case I should hold out until I find some decent 33s at a price I can manage? Any info would be MUCH appreciated.

 

[Jerry Bransford]

OP/Sunder, sorry to revive an old thread (as my first post here, no less), but I'm in exactly your situation and wondering which direction you went and what your thoughts are 2 years later. I've been running 32" tires on 3.07 gears in stock Dana 30/Dana 35 axles and a 3 speed auto for years. It's a bit awful. I'm about to upgrade to an 8.8 rear and 4.10s in both axles. My plan has been to run 33s, but there's a set of 35" BFGA ATs available locally at a price that fits in what's left of my budget. I too do mostly city and highway driving, with occasional off-road and camping trips planned.

Did you wind up going with 35s on 4.10s and the 3-speed? If so, how has it been? Will I regret that combo, in which case I should hold out until I find some decent 33s at a price I can manage? Any info would be MUCH appreciated.

The recommendations made in this thread for 4.56 and 35's still hold, nothing has changed as to that combination being ideal. You would be disappointed with 4.10 with 35's with your 3-speed automatic.

 

[Sunder]

OP/Sunder, sorry to revive an old thread (as my first post here, no less), but I'm in exactly your situation and wondering which direction you went and what your thoughts are 2 years later. I've been running 32" tires on 3.07 gears in stock Dana 30/Dana 35 axles and a 3 speed auto for years. It's a bit awful. I'm about to upgrade to an 8.8 rear and 4.10s in both axles. My plan has been to run 33s, but there's a set of 35" BFGA ATs available locally at a price that fits in what's left of my budget. I too do mostly city and highway driving, with occasional off-road and camping trips planned.

Did you wind up going with 35s on 4.10s and the 3-speed? If so, how has it been? Will I regret that combo, in which case I should hold out until I find some decent 33s at a price I can manage? Any info would be MUCH appreciated.

I'm glad you revived this thread, as I thought I posted an update after...but apparently not.

I currently have 4.56 gears on a HPD30/Ford 8.8, 3-speed auto. (rear Dana 44 was a lot more $$difficult for me to obtain at the time...although the Ford 8.8 ended up costing a lot more than originally budgeted for).
Jerry, above, knows his optimal gears/transmission/tire ratios. I'm very glad I listened. Kinda wishing I listened to the Dana 44 vs 8.8 story too, but hindsight is 20/20. (More to do with feeling like my installer took some liberties with his time than any actual performance complaint).
I run 33" Duratrac's in winter.
I run 35" Cooper SST Pro's in summer.
When the 33" Duratrac's wear out...I'll plan to replace with something 35".

I am very happy with this setup, infinitely better than when I ran 33" on 3.07 gears.
I have good acceleration in the city, and I felt I had an "easy" amount of torque when I climbed some rocks in the summer.

After running this setup for a while, if I could change anything...I maybe would have gotten 4.88 gears.
Why?
Well, I love the acceleration I get on my 33" tires...but I very much prefer driving on my 35" tires.
So ideally, I'd run 35" tires both summer/winter with 4.88 gears. I don't drive fast on the highways anyway.

I imagine running 33" tires on 4.88 would not be so great on the highway though...and that's the situation I was faced with. Plus I'm still running the 33" tires, because I'm not made of money

So essentially, I'm very happy with 4.56 gears running 33" and 35" tires.
I do not think I'd be nearly as happy if I tried that with 4.10 gears.
But if price was less of an object, I wouldn't have to balance between 2 tires sizes, and I'd dive into the big tires with deeper gears.

So if you're looking at 35" tires...which you are...and most likely will continue to when you have an 8.8 in the rear...I'd seriously look at going to at least 4.56 gears. Maybe even 4.88.

In my situation, I had picked up a XJ's HPD30 for $100. This is something I do recommend - if you can get one fairly cheaply.
This gave me MANY more options, for only $100 more.
I planned to replace everything in the axle anyway - chromoly axle shafts, ball joints, bearings, seals, brakes, etc. So really, just $100 more...
I now had a stronger front axle (at least when going forward).
It also gave me the chance to sandblast it, prep it, and paint in nicely too.
I now had an axle that has the pinion higher, so less chance of hitting something.
I now had extra "backup" axle shafts. (In fact, 2 sets, since I replaced the HPD30's with chromoly).
I had the ability to continue driving my Jeep with the old gears while the mechanic worked on the HPD30 and Ford 8.8. All I had to do was swap axles after vs Jeep out of commission while working on axles. This proved invaluable...because my guy took over a month to do this work due to some circumstances.
...and now I have a matched pair of axles as a "backup"...(which interestingly enough, will most likely be fitted onto a frame/body I acquired).

Considering I had 2 broken axle shafts prior in the Dana 30, and the local guy sold me each shaft - used (ASAP) - for like $150 each, which is more like double/triple what I paid for the full HPD30 with shafts...this was a no brainer for me.

My only other regret is that I took so long to re-gear.

 

[BlackJeep]

Thanks guys, really appreciate the responses. Jerry, I may be new around here, but I've been on JF and WranglerForum for enough years to take your response as the Oracle beating me over the head with the right answer. I guess I was hoping to hear that going from 3.07s to 4.10s with anything would be a big enough improvement that I wouldn't mind the 4.10/35 combo, but I realize it's foolish to spend the money on something you know is going to be wrong from the start. I'll either stick with 4.10s and 33s or 4.56 and 35s.

Sunder, unfortunately HP 30s have been hard to come by down here, and the few I've gotten close to were in such poor condition they weren't worth the paint it would've taken to cover the rust. I'm at a point now where I want to get the Jeep back into fighting form (it's been mostly a driveway ornament for more years than I care to admit), and have just enough money to do that even if I'm paying a premium on some of the used parts.

And yes... 3.07 gears is the reason I haven't driven the Jeep much since I retired it as a DD. I'm glad the time has come to trash those, and wish it had come much sooner.

 

[Chris]

3.07 is literally the worst gear ratio ever offered in the TJ, regardless of what transmission / tire size it's behind

You'll be so much happier once you re-gear. I can't even imagine life with 3.07s!

 

[Rico Suave]

For the 3-speed automatic and 4.0L engine, you absolutely want 4.10 for 33's and 4.56 for 35's.

Since I’ve used your advice before..which worked out perfectly, I have a question on gearing, which is a new phase for me. 98 TJ 2.5 3 speed auto. Obviously a turd compared to my 99 4.0 manual. However, I want to regear as opposed to engine swap. I have 31’s and hope to max out with 33’s once I wear these out. Haven’t checked my current gear, but thinking 3.07 (either way, it’s not enough). I’m thinking 4.10 gears? Wanted your option on that as well as what all do I need I order to do the regear.

 

[Jerry Bransford]

Since I’ve used your advice before..which worked out perfectly, I have a question on gearing, which is a new phase for me. 98 TJ 2.5 3 speed auto. Obviously a turd compared to my 99 4.0 manual. However, I want to regear as opposed to engine swap. I have 31’s and hope to max out with 33’s once I wear these out. Haven’t checked my current gear, but thinking 3.07 (either way, it’s not enough). I’m thinking 4.10 gears? Wanted your option on that as well as what all do I need I order to do the regear.

I just don't have enough experience with that combination to offer a reasonable recommendation. Especially with 33's. With 33's, 2.5L, and 5-speed the usual recommendation is 4.88 but with the 3-speed auto I just don't know. Typically you go one higher ratio like from 4.88 to 4.56 with the 3-speed. 4.56 is my gut recommendation for 33's/2.5/3-speed automatic but I don't have experience with that combination to really say 100% if that'd be the right choice or not.

 

[Rico Suave]

I just don't have enough experience with that combination to offer a reasonable recommendation. Especially with 33's. With 33's, 2.5L, and 5-speed the usual recommendation is 4.88 but with the 3-speed auto I just don't know. Typically you go one higher ratio like from 4.88 to 4.56 with the 3-speed. 4.56 is my gut recommendation for 33's/2.5/3-speed automatic but I don't have experience with that combination to really say 100% if that'd be the right choice or not.

Much appreciated. You have more knowledge in your guessing than I have.
thanks again.

 

[Rico Suave]

Different type of gearing question:
If I'm balancing between 2 tire sizes (33"/35", does anyone have an opinion on what the best compromise gear ratio would be?

I currently have 33" tires for winter. (I live in Canada)
I'm considering buying 35" mud tires for summer.
So splitting the time between 33" and 35" tires, depending on the season.
I just bought the 33" tires last year, so finances dictate I'm either running 2 sets of 33" tires, or 33" and 35".
(steering upgrade already taken care of, and Vanco brakes would be too - already running Blackmagicbrake pads - this is more of a gear question)

I have a 3-speed auto transmission.
The plan is to have an HP30 front, Ford 8.8 rear. (both with factory 4.10)
I partially want 35" tires due to the height loss the lower Ford 8.8 pumpkin diff will give me, plus to help avoid the deep ruts I often encounter that make me drag my diff.
I won't lie - I also like the aesthetic look of 35" tires.

I'm under the impression that 4.10 is about "optimal" for 33" tires with a 3-speed auto.
But a 4.56 or 4.88 would be better for the 35" tires.
I also do a decent amount of highway driving, and my Jeep is also my daily driver.

4.10 is the easiest/cheapest for me to run with (due to them already being installed in the axles), and I think it wouldn't be too bad with 35" tires.
(Especially because I've been tolerating 3.07 with 33" tires so far - and been saving up for this gear/axle upgrade. Currently have Dana 30/Dana 35).

If I'm balancing between the 2 tire sizes, does anyone have an opinion on what the best compromise gear ratio would be? Anyone else run different tire size combinations?

Question for the experts. Have a 98tj 2.5 3 speed auto. Done a lot of work since I got him. Can’t find the cause of the Jeep shudder on take. Today I noticed a gear oil kind is smell when I pull in the garage. Back carrier has some liquid of some sort on the bottom. Since I only have the shudder when I get on it hard from a stop and once going over 5mph it won’t shudder even when I try. Since I done I joints, trans and motor mounts, could this be the cause?

 

[Mrhp]

Most likely shudder is caused by an improper pinion angle. How much lift does your Jeep have?

 

[Rico Suave]

Ok, 2.5 3 speed auto. Running 31”. Want a 2.5” lift and regear to 4.56. Thoughts?? Besides an engine swap. Gonna run this one till she blows.