Transmission and/or other issues from bigger tires?

[bradh8]

Hi everybody, I drive a stock 94 Explorer XLT that had 225/70R15 tires on when I got her, when I replace them this summer I want to go bigger, but don't want to (pay for, lol) lift/rims etc.... after much research, I understand lots of folks have stuffed as big as 265/75R15 underneath with no rub or scrub ... but I also have read a bunch of stuff about transmission issues and other stuff that I admit is beyond my current understanding.... I've seen that the 94 XLT came stock with my current tire size and also a 235/75R15 option, on the same rim (?) .... if possible I would like to go a little bigger than that, but I don't wanna risk any issues with the tranny or truck in general, especially since she's only got 47,000 miles on her ... aiming for a lil more trail capability and a "cooler" stance, but wanna keep her kind of original... sorry bout the long-winded revisit to a topic much discussed...but I'm a lil out of my element and wanna protect my baby! Lol... likewise anyone with a strong opinion of the General "Grabber AT" vs Hankook, Goodyear "Wrangler" or similar offerings? Thanks!!!

 

[natenkiki2004]

What's your axle code on the door sticker? Most issues with going on bigger tires stem from improper gearing. Lower numbers like 3.27 and 3.53(?) require more torque from the engine and trans and with bigger tires, that issue is made worse. Add in offroading that usually happens with bigger tires and you can smoke a trans pretty good. I've seen a Ranger on Craigslist with this issue. If you've got 3.73 gears then you should be alright. Just make sure to stick the transfer case in low range when offroading, it will greatly help the trans.

 

[2stroke]

I wouldn't put too much thought into it with the tire sizes you are talking. Even 31" tires are not the end of the world with 3.27 gear ratio, especially if you have the manual transmission. Not too long ago I saw a picture of an explorer with 35" tires with no lift. I'm sure it would rub with nearly any good bump, but point being you can fit some good size tires without much worry. Rim backspacing is a bigger concern, and that's why you see 31" listed as the max with stock rims. I did have some rubbing at full lock with mine on 31's, but never worried about it. My opinion is to either run 235/75r15 tires, which is what came on these trucks. Plenty of good choices in this size. The cheap Wrangler Radials have always been good to me. They really outshine their $75 a tire price tag. The Wrangler Duratrac or Authority are more aggressive, and with a higher price to match. Or if you want just a little more in a great tire, I would get BF Goodrich T/A KO2's in 30x9.5r15. By the way, the 235/75 tires are about 29" tires. There are a ton of 31x10.5r15 tire choices, but they are significantly more expensive than their 235/75 counterparts.

 

[bradh8]

Ah, that helps alot! Thanks for your wisdom guys!! Appreciate ya!
I'll check my gear ratio ... probly end up going with the 235/75R15 which I think will be "beefy" enough for my needs off-road. Just gonna be driving the dog I to the woods for camping and such, no serious rocks or bogs or nothin.... anyhow, thanks again!

 

[Jason94sport]

Even 31" tires are not the end of the world with 3.27 gear ratio

Yes it is! Worst thing I ever did in my past X.
235/75R15 are fine unless you need bigger.

 

[trashtruck]

i know that the tire manufacturers state you can't mix tires on a 4wd or awd without adding undue stress to the transfer gears. you have to buy them as a set of 4 up here.

 

[bradh8]

So, having looked up gear ratio info I found the following info (& realized I don't really know what I'm looking at LOL) .... I think 3.27 is the number I'm looking at... but here's all the stuff:
1st - 2.474 (8.09)
2nd - 1.474 (4.82)
3rd - 1 (3.27)
4th - .75 (2.45)
R - 2.111
Final Drive Ratio Standard: 3.27
Optional: 3.73

So, again I have to admit I'm not 100% certain what this means to me and my tire quest, haha! Any thoughts, comments advice and explanations r totally welcome!! I think it all means I'll stick with the 235/75R15 . Anyways, thanks y'all!

 

[larrydd999]

There should be a sticker on the back of the driver's door - or on the frame, I forget which. The axle code is the ratio. I have L73 (1:3.73 with locking differential) on both of our Gen1 vehicles. I run the 235/75R15 on both.

43 Open 3200 3.08
41 Open 3200 3.27
42 Open 4.10
46 Open 3.73
45 Open 3200 3.55
D4 Limited Slip 3200 3.73
D2 Limited Slip 4.10
L73 Limited Slip 3.73

 

[2stroke]

31" tires with 3.27 gear ratio is just about equivalent to stock 29" (235/75r15) with 3.08 gears. Not fun by any means, but certainly drivable. To change the gears is $500+ if you do it yourself. By the way I have a full front and rear 4.10 gear set for sale if anyone is interested. The fronts are brand new, the rear set is used, but would be perfect for 31-33" tires.

 

[bradh8]

There should be a sticker on the back of the driver's door - or on the frame, I forget which. The axle code is the ratio. I have L73 (1:3.73 with locking differential) on both of our Gen1 vehicles. I run the 235/75R15 on both.

43 Open 3200 3.08
41 Open 3200 3.27
42 Open 4.10
46 Open 3.73
45 Open 3200 3.55
D4 Limited Slip 3200 3.73
D2 Limited Slip 4.10
L73 Limited Slip 3.73

So door sticker says D4.... so with 3.73 ratio does that mean something in the 30 inch size would be OK?

 

[Rhett]

So door sticker says D4.... so with 3.73 ratio does that mean something in the 30 inch size would be OK?

Yes 30 inch tire size would be just fine with 3.73.

 

[bradh8]

Yes 30 inch tire size would be just fine with 3.73.

Sweet, thanks!

 

[Jason94sport]

what he said could go even 31's with that. Most times if your springs are decent they will not rub anything

 

[bradh8]

what he said could go even 31's with that. Most times if your springs are decent they will not rub anything

Thanks! Appreciate ya

 

[natenkiki2004]

Since it wasn't mentioned, being you have D4 means you have limited slip. Lay some tracks!

 

[larrydd999]

Just don't forget that your speedometer will be off proportionally.

 

[Rhett]

Just don't forget that your speedometer will be off proportionally.

Larrydd do you know if you can still buy the speedo gears? Used to be able to source them but now I'm not sure?

 

[timtimtimajim]

Larrydd do you know if you can still buy the speedo gears? Used to be able to source them but now I'm not sure?

Yep! You can still get speedo gears. I got one back in November when I put bigger tires on. Got it on Amazon. I have the part numbers if you want them...

 

[bradh8]

Yep! You can still get speedo gears. I got one back in November when I put bigger tires on. Got it on Amazon. I have the part numbers if you want them...

I think I'll just keep in mind the speedo will be off a bit and make appropriate mental corrections..haha ... thanks for all the input and stuff guys!

 

[bradh8]

Pretty much figuring on going with 30"x9.5" or 255/75 seems to be equivalent ... and looking around at people's trucks/tires round town, I think they'll be plenty big enough ...but not too big. Still can't decide in which tire to go with... based on looks and very positive experience with the brands (snow tires on passenger cars) I like the General Grabber AT or the Hankook Dynapro AT ... but there are lots to choose from! Lol.. anyone with further thoughts/opinions on these or other tires? 2Stroke has a point about the Wrangler...seems a good tire for the money...but am I being a nerd that I don't want that J**P word on my rig? Haha...