Advice Needed - Will I regret having 37s on FJ80?? (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Jan 24, 2020
Threads
17
Messages
120
Location
Utah
Hi

I have been lurking on ih8mud for several years now trying to find my first cruiser. I just found a 1996 ‘80 series in the color that I want and in my general local vicinity. My concern about it is that it has 37s on it (it also has a Ironman 4x4 suspension and lift). While I am sure that the 37s would be great for off-road, I am curious how this would ride when 95% if its life will be spent on paved roads? Would I regret having this size of tire as a daily driver? What do I need to be aware of?

Also, can someone tell me what the process would be to put smaller tires and wheels on. Could I use the same sized wheels or would I need to get smaller ones? And what would I need to do as far as re-gearing is concerned? Any idea what the cost of doing this would be? The rig is already fairly high priced, so just need to understand how much more I may have to drop if I need to downgrade tires and wheels.

In speaking with the owner, it only has a 2” lift on it.

Any help or advice would be much appreciated

IMG_1983.png
 
Last edited:
I’ll kick it off, and I’m sure many others will have an opinion… 37s are cool if you need them, without re-gearing or tuning up the engine, you may find it to be way under powered for 37s. For a daily driver, 33s would be quite nice. The wheels are stock to the car, there’s no reason to downgrade the wheels at all. Others may disagree, but I switched back from aftermarket wheels to stock for the stance and I just love the look. They are only 16s, you could not go smaller unless you had a Pre-95 version. (15 inch wheels will not fit over the rear disc brakes.)
The is that if that truck is lifted for 37, it may look over-lifted when downgrading to a size 4 inches smaller. Downgrading the lift may be a desirable option as well, to a two or 2 1/2 inch versus a 3 1/2 to 4 inch.
 
I’ll kick it off, and I’m sure many others will have an opinion… 37s are cool if you need them, without re-gearing or tuning up the engine, you may find it to be way under powered for 37s. For a daily driver, 33s would be quite nice. The wheels are stock to the car, there’s no reason to downgrade the wheels at all. Others may disagree, but I switched back from aftermarket wheels to stock for the stance and I just love the look. They are only 16s, you could not go smaller unless you had a Pre-95 version. (15 inch wheels will not fit over the rear disc brakes.)
The is that if that truck is lifted for 37, it may look over-lifted when downgrading to a size 4 inches smaller. Downgrading the lift may be a desirable option as well, to a two or 2 1/2 inch versus a 3 1/2 to 4 inch.
Thank you. Yeah, I need to find out if it had been re-geared when the bigger tires were put on it.

It had an Ironman 4x4 lift and suspension put on it, so am guessing that means it might have a lift on it that was specific for the 37’s?

Regarding wheels, I guess I had assumed that you needed bigger wheels for 37s but it sounds like the wheels that are on there may be stock?

IMG_1982.png
 
37"s in utah with 90% pavement driving will suck. My 97 with 4:88's and 315/75/16's is a dog and I question my tire size everytime I drive up a canyon or paved mtn road in our state. Back east on the plains would be a different story.

But it sure rides nice offroad with the tire pressure at 18psi.
 
So I got some additional info. It sounds like this was not re-geared when the bigger tires were put on 5 years ago. If I downgrade tire size, what is the biggest tire that I could put on and be happy with not re-gearing? Would a 33” be OK, or would I still want to re-gear based on that size?

The current owner says that this is a 2” lift on it. If i went some to 33” (or even stock tires), would the 2” lift still look and drive ok or would I want to remove the lift?
 
Unless you’re wanting to wheel this thing on borderline buggy trails, 37s are a waste in my opinion. I drive my 80 4 days out of the week and drive it on 1500 mile road trips twice a year. It has 4.88s and it’s a DOG. Regearing it is expensive, replacing tires will expensive, and the added maintenance may not be worth it to you.
Also, if you have 37s and don’t wheel hard trails, you’re kind of a nerd🤷🏻‍♂️
 
If it was not regeared, that's good - smaller tire will bring pep back to the vehicle. 33 will be better than 35, but even 35 will improve some.

Not a ton of clearance there above the tires, so it may in fact only be a 2" lift. Measure from center of the wheel hub to the bottom surface of fender flares - a 2" lift should be somewhere in the 22.5-23" range. If you were going to off-road, doesn't look like you'll have much articulation because of the tire fitment, despite 37s providing more ground clearance - so you'll actually benefit offroad with a smaller tire, IMO.

Looks like you may be set up perfectly to go to a 33" (285/75/16) AT tire. Much better for normal driving, better MPG (but still bad), gain articulation when you do go offroad, and the size will still be able to do everything you need. That's a great reasonable setup for an all-around 80. You don't NEED 2" for 33s, but it'll still look fine.

We can probably assume they didn't correct the speedometer either. Your current speed reading will be low.. for example, a rough calculation for 37s suggests you may be going closer to 65 when your speedo says 55. Another benefit of 33s would be getting close to an accurate speedo & odometer reading.
 
Last edited:
With that lift and no re gear than 33's would be perfect and driveability would be greatly increased. It would still be a super capable rig for any hunting, fishing, camping, and exploring duties.

If your worried about clearance issues than lose the running boards, mud flaps, and get some aftermarket bumpers.
 
So I got some additional info. It sounds like this was not re-geared when the bigger tires were put on 5 years ago. If I downgrade tire size, what is the biggest tire that I could put on and be happy with not re-gearing? Would a 33” be OK, or would I still want to re-gear based on that size?

The current owner says that this is a 2” lift on it. If i went some to 33” (or even stock tires), would the 2” lift still look and drive ok or would I want to remove the lift?
5 years of driving it around with those ginormous tires without regearing hasn't done any favors to the stock drive train. Has it been just a poser rig or did he 4wheel it much? Off roading could have taken a toll on the beast too. Take care with an inspection to see if it's been thrashed or not.

Regarding the lift, determine if it's driving OK now. If it does and caster correction has been addressed I'd leave the lift on and go with 33" tires. Not sure if those are stock wheels. It appears they are and someone made the foolish move of painting them.
 
Agree on everything mentioned above......
37s will rub on 2" lift-either at full lock or over bumps.
37s need min 4.88 gears and others will say 5.29 for larger than 37s. (Others have ran 4.10 w/37 and has no issues)
285s and 35s ideally goes with 4.56 but stock 4.1 will do.
I'm running 4.88 with 315s and ok with it.

Trick is not to be afraid to mash on the thin pedal and drive in 2nd gear at 4500 RPM when up hill. And your ECT button is your friend as well as OD/off button.

37s will need 3-6" lift depends on you and $$. Cutting or trimming may be involved. Caster correction will be needed, drop brackets, extended brake lines and bump stops, rear panhard bracket recommended, rear sway bar drop......ect.

You can open your check book and get rid of the poverty Ironman lift (that lift is not meant for 37s) and get dobinson IMS or MRR (I'm bias to Dobs) and get Delta control 3L arms (to run 35+ tires). 105 sector shaft for bigger tires and to combat the lack of power-install a Turbo kit from C&C. Or just enjoy what you currently have. Looks like an ideal set up from the picture. GL-good looking fzj80
 
Last edited:
37"s in utah with 90% pavement driving will suck. My 97 with 4:88's and 315/75/16's is a dog and I question my tire size everytime I drive up a canyon or paved mtn road in our state. Back east on the plains would be a different story.

But it sure rides nice offroad with the tire pressure at 18psi.
I'm running 33" with 4:88's and while I lost top end, I gained a lot of grunt at the bottom.
I was thinking of going to a 35" tire next time they need changing, to better balance the gearing and tire size... maybe I'll re-think that. A trip out West is in the "talking about" stages.
 
Lots of great info above. Tons of MUD threads on this “debate” (including the one you started). See below for a good example.

If you already have a lift, even though not a popular one, may as well keep it. You sound like a guy who needs to go to 33’s. When you swap tires you’ll think “dang those look small”, after having 37’s. Then within a year, you’ll wish you’d just gone with 35’s. 😆

My LX had 35’s for years when I bought it and it did fine with factory gearing, but I wanted more when off road, so I overgeared the diffs to 4.88’s. I’m quite happy with it on 35’s and have the option to go to 37’s if ever inspired (doubt it). I may yet go to a lower gear in T-case.

These tires are great. Quiet good manners on asphalt and can go on pretty much any reasonable trail with them. Plus they’re triple peak snow rated. I use them in Utah.

IMG_4511.jpeg


 
Those look like BFG KM3’s to me. The largest size for a 16” wheel is 315/75r16, which is 34.6” tall.

In any case, it is a nice looking Cruiser for sure.
They do look like KM3’s and don’t appear to be 37’s to me. BFG lists no 37” KM3 for a 16” wheel, there are very few left that do.
 

Users who are viewing this thread

Back
Top Bottom