4 Speed Manual Performance with 33/10.5 BFG AT?? (1 Viewer)

[RogerThat]

Looking to get some new shoes for my 84 Fj60. I've read everything on Mud about tires and I know there is a lot of opinions here...

Running with stock rims and stock suspension Anyone have any insights around what I could expect in terms of performance degradation with a 4 speed manual with ~260k. I have the TBI conversion so it has always felt like I can get up and go pretty quickly with power. It won't be a daily driver but more an adventure rig with maybe drives around town 1-2 days a week.

I don't want to wear out the trans and I want ideal back mountain performance with good on road in town driving. Anyone have some input on what I can expect with the 33/10.5 BFG AT?

 

[OSS]

They'll work ok but the vehicle won't be as fun to drive with taller tires. Lots of guys have those tires on the 60.

The most important "mod" you can do when using oversized tires is modifying the transfer case shift linkage to allow driving in 2WD Lo when cruising offroad slow. There's a piece of metal on the linkage bracket at transfer case that prevents the transfer shifter from being shifted into Low when in 2WD. It just needs to be bent out of the way to allow the shifter to move - and bingo! 2WD low

 

[GeologistFelix]

I have pretty similar tires (Dick Cepek Extreme Country) in 33x10.5, and the stock H42 and 3.70 gears.

With a mediocre carb setup, mine does just fine except for getting started on hills on pavement (so, literally the worst situation for the wimpy 1st gear in high-range). I think I probably ate more clutch in the 3 years since I got big tires than in the 25 before I bought the truck as a result, but it does great in every other situation. Oddly, you'll use 3rd gear a lot more on highway pulls, and your TBI setup should make it even nicer at high RPMs.

That said? I'm working hard to pick up a used H55 semi-locally because I'm kind of sick of it. I had also thought about used 4.11 (or are they 4.10?) thirds from a 62, but I think the H55 is going to solve more gearing problems for the money. I do have the longer late-85 through 87 version of the H42, though, which you won't, so I won't need driveline mods (or someone's donor driveshafts) like you would have to get for your truck.

 

[Seth S]

I think if you were to swap in the 62 diffs you'd be even happier.

 

[Michael Hanson]

Hi, My 31s are fine ,33s On the other one too slow. Mike

 

[klinetime574]

I ran 33x10.5x15 with a 4 speed for a number of years. I was living in Texas then and didn’t have to worry about hills. Off road I always wanted lower gears, but I never got stuck or anything. Related or not, my 4 speed wore out. Countershaft bearings went out, rattling in 1st gear. Tried to get it rebuilt, that didn't last.

I now have a 5 speed. Still running on the same clutch disc as before. The 60 can definitely can take off from a stop easier, and just seems more peppy. I’ve debated switching to 4.11 gears, but I like the highway cruising speed, and first gear 4-Low going down an incline is definitely more controllable than with the 4 speed.

HTH

 

[Seth S]

IMO the stock 60 diffs + 4 speed + 31" tires are about as good as it gets without major mechanical or $$$ outlay. The truck still accelerates well climbs highway hills pretty well, and does just fine on trails especially with low range in the transfer case. 33's would probably be ok in low range on moderate terrain but I think you'd be happiest with 33's, a 5 speed, and the 4.11 diffs. The 62 folk seem pretty happy with that setup.

 

[onemanarmy]

BFG 33s run small, sometimes 1.5" small, so it won't be as noticable as a true 33 would.

 

[RogerThat]

All great input! I had originally meant to ask about 31's - My subconscious must want the awesome look of the 33's.

So it sounds like the benefit of 33's would be a bit better cruising speed with bigger tires - but would feel sluggish uphill and in lower gear. My gut, influenced by all the insights here, is telling me 31's with everything stock is probably going to make me happier in the long run for driving performance.

 

[Cincodemustache]

I rolled with 31s for 6 months when I moved to Texas and decided to put on 33s. While the start is slower from 1st, as long as your engine is tuned and carb secondary is working you should be able to hustle up hills. It will be a bit slower with 33s but if you want the look I would say go for it.

 

[Seth S]

31’s are like the poor mans 5 speed

 

[Gretsch]

A vote for the 33's. Slower yes, but whats that mean in a 60 series really? I read all the same opinions on 33's with the stocker 4 speed and almost got talked out of running them. Have them now and would never look back. Am in Texas flatland as well so no hills to worry about. But I think it runs better on the highway with the 33's myself. 5 Speed would prolly be better but the stocker 4 is fine IMHO. Thats just me. If you like the look of the 33's, then go for it. HTH.

 

[RogerThat]

@Robert Franzke would it have changed your mind if there were a lot more hills around? I live in Idaho and this rig will be primarily used on old mountain roads.

Thinking that I will be going with the 33's. @Seth S do you have any photos of yours on 31's? or anyone else have 33's that they want to try and convince me with?

Thanks for all the input everyone!

 

[Seth S]

@Robert Franzke would it have changed your mind if there were a lot more hills around? I live in Idaho and this rig will be primarily used on old mountain roads.

Thinking that I will be going with the 33's. @Seth S do you have any photos of yours on 31's? or anyone else have 33's that they want to try and convince me with?

Thanks for all the input everyone!

 

[brian]

it will drive just fine, but the tires might not fit as well as you would like with sagging oe springs.
performance will be just fine.
i've had 33s with 3:70/h42 combo for as long as i can recall...no problems, no burned up clutches.
i have gone so far as to swap 3:70 rears into my 40 series with the same combo. that 2f has a little more pep than the 87s engine and it drives even better.

 

[Gretsch]

@Robert Franzke would it have changed your mind if there were a lot more hills around? I live in Idaho and this rig will be primarily used on old mountain roads.

At this point its hard to say. My experience with my 60 and hills is very limited and I might not be the best person to ask about that. I took it to Colorado last year, and have to say it sucked on the hills. I am sure the 33's didn't help, but I think my experience had much more to do with the altitude than the tires. Thing was completely gutless on Raton Pass or climbing into the San Juans for example. But in its defense I was pulling a Bantam trailer as well.

I think with some tuning and timing advance it would have been much better. Mine is desmogged and was missing the HAC setup at the time so theres that. Not sure what altitude you are at there, but if your truck runs well there now, I don't think it would be an issue with the 33's. I guess at this point in my time with this truck, if I flat couldn't run the 33's with the way its set up, I would prolly move on to something else. I just accept its limitations, and love it for what it is. If its slow on the hills, then its just gonna be slow on the hills. But its gonna look great doing it. These are slow trucks, period, and they have many more flaws than anything 33's would do to them. The 31's prolly are the safer choice for hills. But I guess I would caution against going with something you really don't want. If the 33's are your thing, then they will work fine. And if they are slow, then just enjoy the extra drive time in your cruiser. HTH.

 

[HemiAlex]

1st was weak, but I never used it in low range. The highway speed was nice. I put 25k on 33x10.5 with an h42 and 3.70 gears. It worked but wasn’t ideal. I then swapped to an h55f and the same tire size. The 5 speed really improved the trucks manners. Completely worth it.

The bigger issue for me was how poor the handling was on the 10.5 with a 5” wheel. Too much sidewall slop, and horrible rolling resistance with the low pressure you have to run to make it work. Yes, I’ve wheeled mike that with the bulged tires and it worked...

But putting a 255 section width tire on a 6” 70 series wheel was the single greatest thing I could do to improve my handling and drivability. For a lot of people going to a 16” tire wasn’t an option, but there are a ton more tire sizes that are better suited these trucks in that diameter. Even my 33x10.5 was only 31.25” on its best day. 255/85 is a 33” all day.


I’ve swapped to a 5 speed and tall and narrow tires in the correct size wheel, and I won’t go back.

 

[Seth S]

Next time I do tires I’ll jump up to a 16” wheel and go with the 31” equivalent in a 16” wheel. I almost had an amazing score on some 16” steelies but someone else just beat me to it on cl

 

[Seth S]

A side note. A certain truck I like and maybe will pursue in the future has 8.9:1 diffs. It sits on 12x20 tires iirc. Those are like 44” diameter I think. But it makes engine swaps tricky to get gearing in a place that makes sense for a diesel swap.

 

[RogerThat]

1st was weak, but I never used it in low range. The highway speed was nice. I put 25k on 33x10.5 with an h42 and 3.70 gears. It worked but wasn’t ideal. I then swapped to an h55f and the same tire size. The 5 speed really improved the trucks manners. Completely worth it.

The bigger issue for me was how poor the handling was on the 10.5 with a 5” wheel. Too much sidewall slop, and horrible rolling resistance with the low pressure you have to run to make it work. Yes, I’ve wheeled mike that with the bulged tires and it worked...

But putting a 255 section width tire on a 6” 70 series wheel was the single greatest thing I could do to improve my handling and drivability. For a lot of people going to a 16” tire wasn’t an option, but there are a ton more tire sizes that are better suited these trucks in that diameter. Even my 33x10.5 was only 31.25” on its best day. 255/85 is a 33” all day.


I’ve swapped to a 5 speed and tall and narrow tires in the correct size wheel, and I won’t go back.

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Great looking rig! Love the look of those tall and skinny tires- you make some great points about drivability.

I guess I'm going to show my true noob side here.. I liked the idea of staying stock, which is why I hadn't thought to move to a 16" tire. Would this require a lift of any sort? I'm assuming your rig isn't stock suspension?

I have a full set of 2018 4-Runner tires that are 17″ diameter, 7″ width and I'm fairly certain the bolt pattern is the same. I just figured at this size I'd likely have to get a lift to make it fit. Not particularly interested in lifting it at this point.