Talk me into (out of?) 4.88's

[mgolden]

hmmm 35's??? ok... maybe not yet lol Anyways, looks like I reached a decision: I will be going 4.88's and Detroit and 33's now l just gotta find me a bank and a driver LOL

Plus if the gears are too high (numerically) then you have a good excuse to go to 35s! :firedevil

-Mike

 

[woody]

As stated, you ran 235's with 4.10:1 for a year, you probably are used to that (good) throttle response. I had a hella fun throttle honeymoon going from 3.55 & fat 33" to a spooled 4.56 & skinny 31" Once I calmed down, the MPGs were essentially the same, maybe a tad better with the low gears. No tach in this rig, so impossible to nail an exact RPM@_x_speed

FWIW my 5 speed doorless MJ with 4.56 & BFGMT 33 x 12.5" (IIRC approx 31.5" using the working radius X 2) would run 80 mph at 3000 RPM. I verified the speedo accuracy using 10 miles of relatively flat/straight interstate mile-posts. Also on same interstate, 'chased' a buddy in his pickup up to approx 100 mph... things were getting a tad unstable up there & I was NOT watching the tach. 80/3000 was a comfortable 'all day long' cruising speed/RPM though.

My 'decisions' for my DD involve 4.10 or 4.56 for 30" or 31" (I got both R&Ps for the 4.10s, so that ratio is just an install kit & some downtime away)

 

[chino85]

The highest gears you can get with your 8.25 is 4.56. So unless you switch axles I think you should go with that.

 

[ChuckD]

Well, that's waht I'm saying. If you make you weakest link the shafts and joints, they can be replaced. I'm all for not having carnage on the trail, but some have gotten away with the weaker 260's. Will they last, definitely not. Will they got before the R&P very likely. Just remember to add a D30 truss to your project list.

That's what I'm thinking actually. Or rather I'm thinking what's the big difference from 4.11 to 4.56? When I went from 3.07 to 4.11 I saw the difference.

After replying, I didn't realize all the other responses. :banghead:

 

[Nay]

I'd do 4.88 with a manual transmission. Choosing gears with an auto is a different beast, because you have "dead spots" that get shifted around where the tranny will hunt between gears and drive you nuts. Keeping near stock ratios, such as 4.56 with 35's, can work out nicely, with a focus on crawling coming from t-case reductions.

Plus, just be real. You spend a crap load of time on this board. I don't know why you are even wasting money on 33's. You want 35's, you know it, but you just haven't fully admitted it, or you think you can just live with a D30 and 33's while everybody else is moving up to D44's and 37's. Do 4.88 and put on the 35's. Either set of tires is going to absolutely destroy D30 ball joints with driving 120 miles every day. You won't ever drive 80 mph again, because the ball joints will be constantly loose, and ball joint wobble at speeds over 60 mph is no treat.

You'll have a D44 up front in a year. Better get that daily driver soon. Stick with 31's until you get there.

Nay

 

[Kejtar]

Plus, just be real. You spend a crap load of time on this board. I don't know why you are even wasting money on 33's. You want 35's, you know it, but you just haven't fully admitted it, or you think you can just live with a D30 and 33's while everybody else is moving up to D44's and 37's. Do 4.88 and put on the 35's. Either set of tires is going to absolutely destroy D30 ball joints with driving 120 miles every day. You won't ever drive 80 mph again, because the ball joints will be constantly loose, and ball joint wobble at speeds over 60 mph is no treat.

hmmm you might be right that the inner me wants 35's but.... the concious me realizes that it would require a bit of work to make everything reliable/strong enough for them (steering work and so on). So for now I wil stick with 33's and keep looking for that DD

 

[Kejtar]

i was just looking at your sig, are you keeping the 8.25? can you get 4.88s for it? i thought i remember hearing of frequent problems with putting low gears in those...

I got a D44 in my garage waiting for me to get cracking on it

 

[Safari Ary]

I'd do 4.88 with a manual transmission. Choosing gears with an auto is a different beast, because you have "dead spots" that get shifted around where the tranny will hunt between gears and drive you nuts. Keeping near stock ratios, such as 4.56 with 35's, can work out nicely, with a focus on crawling coming from t-case reductions.

Plus, just be real. You spend a crap load of time on this board. I don't know why you are even wasting money on 33's. You want 35's, you know it, but you just haven't fully admitted it, or you think you can just live with a D30 and 33's while everybody else is moving up to D44's and 37's. Do 4.88 and put on the 35's. Either set of tires is going to absolutely destroy D30 ball joints with driving 120 miles every day. You won't ever drive 80 mph again, because the ball joints will be constantly loose, and ball joint wobble at speeds over 60 mph is no treat.

You'll have a D44 up front in a year. Better get that daily driver soon. Stick with 31's until you get there.

Nay

For all those reading, this man speaks the truth!! I've finally succumb to my inner wants and am stepping up to 35s

 

[Neil]

I would go with the 4:88's. If you don't you'll be kicking yourself later. I have an auto with 35's and 4:88's and I love it (if I could have gone lower I would have). I have ridden with Chuck (stick 33's and 4:88's) and have not noticed any drastic change in RPM's between his and mine. We were on the freeway for a little over an hour at 70-80 and it was very comfortable. RPM's were just fine.

Neil

 

[ChuckD]

Remi, how long do you plan to keep your D30? My plan is to keep mine at least two years, by that time I'll have the money time and all that to do a D44. 35's will come someday, 33's are much better than 31's even at 4.10!

 

[Kejtar]

Remi, how long do you plan to keep your D30? My plan is to keep mine at least two years, by that time I'll have the money time and all that to do a D44. 35's will come someday, 33's are much better than 31's even at 4.10!

Very good point. The D30 will not be there forever

 

[Big Red]

33 go 4.56
35 go 4.88

33s, 4.88, auto, ~80 = 3000 rpm to high for my 120 mile daily commute.

I have 33" tsl radials on my 94' wrangler with a 95' 4.3L Chevy vortec & 4l60e auto trans and run around 3,000 rps at 80 mph or so. It isn't that bad, but I have a 31% reduction I believe with my chevy trans where a ax-15 only has about a 15% reduction I believe in od so I would stick with the 4.56 gears if you don't see yourself going up to 35's. 4.56 gears would be o.k. for 35's as I have them with my 91' cherokee auto trans, but I would have liked 4.88 gears but the 8.25 only goes to 4.56 gears. 4.88 on 32's with alot of highway miles is not the best so get those big meats on their quick.

 

[Nay]

hmmm you might be right that the inner me wants 35's but.... the concious me realizes that it would require a bit of work to make everything reliable/strong enough for them (steering work and so on). So for now I wil stick with 33's and keep looking for that DD

If you don't think your junk will be reliable enough for 35's...120 miles a day on 33's is just gonna trash it. Listen to me: do not daily drive an XJ over long distances with 33"+ tires if reliabiilty is your issue, unless you swap in an axle that can handle it.

This is just my experience, YMMV: the D30 ball joints hold up terribly to heavy daily mileage when you have tires over 31" on rims with rims less than 4.5" backspace. I never had any problem with the D30 offroad with 33" tires and never worried about it. But that wobble hitting about every 3 months signaling yet another ball joint failure was too much.

This is the snag that so many of us hit: the desire for an offroad performance biased vehicle that still does the daily driving duties nicely. We've all been convinced that this will work, and we all end up realizing it sucks. You sound to me like you are smack in the middle of this little personal deception :gag: .

So listen to me :lecture: :

you are going to retire your XJ from daily driving usage if you run 33"+ tires over a lot of miles.

You want 35's.

Stop making decisions to balance on and offroad.

Just make it safe enough to get to the trail and take the trips you may take

Stop worrying about selectable lockers and other expensive road biased crap.

Cut sheet metal.

It's over.

Buy a Honda.

Do the 4.88's.

Nay

 

[Safari Ary]

So listen to me :lecture: :

you are going to retire your XJ from daily driving usage if you run 33"+ tires over a lot of miles.

You want 35's.

Stop making decisions to balance on and offroad.

Just make it safe enough to get to the trail and take the trips you may take

Stop worrying about selectable lockers and other expensive road biased crap.

Cut sheet metal.

It's over.

Buy a Honda.

Do the 4.88's.

Nay

Nay, we need to have an "introduction to XJ's" written by you that anyone who wants to get into modding an XJ has to read. You've been spot on with what I've been going through in the past few months 'cept I'm lookin for a BMW, not a Honda

 

[BrettM]

If you don't think your junk will be reliable enough for 35's...120 miles a day on 33's is just gonna trash it. Listen to me: do not daily drive an XJ over long distances with 33"+ tires if reliabiilty is your issue, unless you swap in an axle that can handle it.

This is just my experience, YMMV: the D30 ball joints hold up terribly to heavy daily mileage when you have tires over 31" on rims with rims less than 4.5" backspace. I never had any problem with the D30 offroad with 33" tires and never worried about it. But that wobble hitting about every 3 months signaling yet another ball joint failure was too much.

I had 33x12.50s on 15x8s with 3.25" backspacing, and drove thousands of street miles (10,000?) with the D30 and 15 year old ball-joints. never had a problem... sure it's added wear, but you make it sound like they're going to go the week after you put the 33s on.

regardless, I now have a D44 and 35s on 2.5" backspaced wheels for DD duties

 

[Nay]

I had 33x12.50s on 15x8s with 3.25" backspacing, and drove thousands of street miles (10,000?) with the D30 and 15 year old ball-joints. never had a problem... sure it's added wear, but you make it sound like they're going to go the week after you put the 33s on.

regardless, I now have a D44 and 35s on 2.5" backspaced wheels for DD duties

Yep, just my experience. My ball joints lasted 6 months, and then every three months after that.

My point is this: don't count on running 33's for 30,000 miles a year reliably. I was doing about 25,000 miles per year back then.

Nay

 

[ChuckD]

I know Maximus has put double that mileage on his D30, with 35's. He doesn't wheel much or hardly at all. He has not had any trouble with ball joints or any other major issues. Does that count? I think he has a 97'.

 

[Loose_Nuts_Enterprises]

I think the small ring and pinion argument is weak....I have had, and have a friend that runs LP D30's in CJs with 5.38s. One in particular is one running 37 inch Boggers, has a vortec V6, SM420 trans. Lots of torque going throug that front end with all that gear reduction. Regular trips to the hammers have only claimed one axle shaft, but they were upgraded to cro-moly ones, and haven't been a problem since. Granted this is probably lighter than an XJ, but it is a low pinion, but has lots more power, and more gear reduction than Remi will ever have.

Besides, how many of you guys have seen gears fail because of size alone? Most I have seen fail are because of housing flex, but there are remedies for that too.

Dan

 

[Beezil]

Besides, how many of you guys have seen gears fail because of size alone? Most I have seen fail are because of housing flex, but there are remedies for that too.

Dan

exactly!

 

[BrettM]

hang out on a Toyota forum for a while (i have been on Pirate's Toyota boad for about a year since i have a rear Toyota axle now) and you will see the difference guys have experienced between 5.29s and 4.10s.

i agree however that on D30s the biggest problem for r&ps is housing flex, and that for 33s r&p probably will never be an issue.