Re-Gear for 35's

[aktundra]

Soon I will be installing a 4" kit & 35's. I seem to recall that most folks reccomend regearing the diff's to 4.88's, but I monitor the 40 series forum as well, and just want to confrim I got it right for the '80. It seems like I saw something on the 80cool list that called out a 4.56 for an FZJ80. I am a simple man, and the information super highway has me a bit overloaded.

This forum doesn't seem to be shy in sharing opinions, what say ye?

Also, has anybody put a bunch of miles on a regeared rig and can reccomend a quality vendor.? What should I expect to pay?

 

[Elijah]

I'm regearing next week to 4.88's with my 35's and that it puts the gearing just slightly over stock, but when I go to 37 inch tires it will be spot on with the original gearing from the factory.

 

[aktundra]

Where did you get your gear sets?

 

[SR.GRINGO]

4.88's have worked well for me. After some reading here on mud I went with reider racing. They have served me well

 

[Moxwell]

just got 4.88s, they are fantastic, I am running 35s and whenever I need to pass I just nudge the gas pedal a little and the truck really scoots. Much better pickup than I had with the original tire size and original gears, engine feels less forced, does not lag.

 

[Moxwell]

Sorry, forgot to mention that I got Yukons, install kit, lock right installed for 1500.00, I used to have this annoying growl emanating from somewhere beneath my driver side floorboards that usually came on around 50 mph and steadily built up to a loud roar, but with the new gears it is gone, I am now free to enjoy the mud terrains lapping the pavement.

 

[Buckru]

I think the gearing question depends on your situation. I have 35's and will eventually regear to 4.56 and not 4.88. The reason i will choose 4.56 is I live in Houston and I have to drive 5 hours to my nearest wheeling spot whhich will help fuel economy just a hair over 4.88. Also, Houston is flat as a board and we are at sea level. 4.56 just makes sense for me and is appropriate for my situation. If I lived at upper elevation and in the mountains I'm sure I'd feel differently.

Buck

 

[Beowulf]

I am a simple man, and the information super highway has me a bit overloaded.

Keeping the answer simple...

"Normal"=stock
4.10 gears w/35" tyres gives you an effective ratio higher than normal.
4.56 gears w/35" tyres gives you an effective ratio equivalent to normal.
4.88 gears w/35" tyres gives you an effective ratio lower than normal.

The reason many will recommend 4.88 gears w/35" tyres is that this lower effective gearing helps off-road and helps compensate for a heavier tyre. Your fuel economy will suffer slightly but that is to be expected with a modified trail rig. Just about everything you do to it will decrease the MPG.

-B-

 

[CreeperSleeper]

I would run 4.88's if I were you to make up for the extra wieght of the tires and wheels etc...

Personally, I will be going to 5.29, but my rig is just a toy and I need all the gear I can get!

 

[GXO]

I plan on going to 5.29s when I grenade what I have now...unless i steal TiredIron's axles!

 

[FirstToy]

anyone have a link to that chart showing RPMs at various speeds w/ different gears?

 

[Cruiser_Nut]

I have 35s and just went to 4.88s. Here is a chart showing stock, 35s with stock gearing, and 35s with 4.88s

A previous comment mentioned that the 4.88s are slightly over stock rpm, but it makes up for the heavier tire. I must agree. I have the Toyo MT and they are a bit heavier than other 35s and with the mountainous terrain where I live the 5.29s might have been a better choice.

 

[aktundra]

thanks folks

I think I understand the trade-off's a lot better. If I got this right, I think for me the 4.88 is the right place to be. I will still allow me a little room for a modest increase in tire size if i feel inclined in the future (in any case the '80 will always be a DD).

My tranny also has the PWR button, so in the occasional off-road situation where higher rpm's are called for, and a higher gear set would have provided, I can call on the r's as needed.

Does anybody still have a part number for a 4.88? In today's day & age everyhting is shipped over the internet, & I would hate to go through the time & expense of getting a gear set for the wrong application.

Thanks again to all those that contributed to my school'in

 

[speedyone]

Try here - https://forum.ih8mud.com/showthread.php?t=107231 price seems good. You can also try Randy's Ring and Pinion (just google them). All you have to do is tell them your make and model and what ratio you want and they will do the rest.

 

[Romer]

I have 4.88's and wouldn't do anything else for 35's. Loved the low torque off road and on road performance is ecellent. I bought precision gears from Slee and the rest of the parts from cruiserdan. Have a professional re-gear you, you need to have access to all the right shims to get the rear done correctly

 

[Land Speeder]

I plan on going to 5.29s when I grenade what I have now...unless i steal TiredIron's axles!

Hey Dan, go ahead and sell me the 4.88's and get your 5.29's now

I've thought about 5.29's since i will have 37's eventually, but alas, i have a semi float rear and I understand there is waaay too much grinding to get 5.29's in. 4.88's.... not so much.

 

[FirstToy]

I have 4.88's and wouldn't do anything else for 35's. Loved the low torque off road and on road performance is ecellent. I bought precision gears from Slee and the rest of the parts from cruiserdan. Have a professional re-gear you, you need to have access to all the right shims to get the rear done correctly

thx Romer, didn't realize Slee carried them. I will def. get OEM seals and stuff from Cdan

 

[Letsgomoreplaces]

4.88 w/ 35's

You wont be dissapointed w/ 4.88 and 35's. I have run our 4.88's in both my FZJ80's w/ 35's and in my uzj100 w/ 35's. 4.88 is only slightly lower than 4.56 and helps make up for the added weight on most vehicles. Many of the "namebrand" LC gears are inconsistant w/ what actual mfg's gears are in the box, and many have had complaints w/ noise. This is why we get ours directly from the best of the few mfg. source, to assure a quality set everytime. I have run these in my UZJ100 w/ 35's for about 50,000 miles of highway commuting, towing a 5500lb boat, offroading, etc, and are silent.

 

[BDA130]

Are 4.88s the most appropriate for towing a 2500# trailer on 35s? Gearing is out of my wheelhouse. It was suggested I look at it since I'm experiencing high transmission temps while towing.

 

[scottryana]

Is this with the HDJ81 in your signature? Diesel trucks will use different (higher) gearing than a similar gas truck to put the diesel in it's powerband and redline.

Are 4.88s the most appropriate for towing a 2500# trailer on 35s? Gearing is out of my wheelhouse. It was suggested I look at it since I'm experiencing high transmission temps while towing.