I'm looking for experience on just how bad the combination of 35" tires and stock (4.10) gears are w/ a 5 spd (W56).
I know it's not ideal by any means, probably warrants 5.29s...

But it won't be used for rock crawling, rather fast trail riding and racing (and streeting), so I'm not seeing the need for high RPMs at slow speed.

I know 5th gear will basically vanish. But if my math is right, the change in relative ratios (between 28 and 35" radius) should be about right to balance the gears so it is effectively just a 4 speed transmission - 4th gear now where 5th was, etc - close to matching the auto A340 even.
(I can't find the gearing specs from the L45 to confirm though). So to some extent,thsi is better than like 31s or 33s.
Is this logic right? Who's run this combo? Biggest problem I see is getting going from a start.

i ran 35" BFG ATs with 456s and a v6 and it wasnt too bad, better than my 33x13.5 swampers. probably not too helpful, but thats all i have to say about that.... <img src="/forums/images/graemlins/cheers.gif" alt="" />

Hard on clutches!!!!

I run 33's on stock gears with a v6... and i wouldnt want it any slower.
Cousin ran 37's with stock gears and a v6 and it was a dog... 3rd gear was crusing... 4th gear on downhills...
with a 22re... wow it's going to be slow... good luck...

For an idea of what it would be like, pull a plug wire and take your truck for a spin. The performance should be about the same, given that 35's are 25% bigger than 28's and have a lot more rolling resistance.

OK thanks for the input guys.

Now I have a few questions, though.

All of these comments "seem" related to the added rotational weight, higher inertial resistance etc. big tires = more work. You're hosed on that regardless.
But isn't that irrelevant (independent) of the gearing? All the gearing does is change where in that rotational speed you put the RPMs, and have to shift... right? I can see how once you are moving, the gearing sets where you are in the power band at a certain speed. E.g. you don't want to find yourself at only 1.5k when doing 35 mph... no power.
But if the relative relationships change correctly, so that you have, say, 2500 RPM at that same speed of 35mph, then why would it matter what gear you are in?

And why hard on clutches? Please explain.

i think you are right, except that you cant always be at the right rpm, because you would be going too fast, or too slow. if you are out in the desert, or riding along on forest service roads, you have a wide speed range that is acceptable for those conditions, and big tires and tall gears dont matter so much. but when you encounter hills, or rocks you cant maintain that speed and when you shift, you will be out of the sweet spot. it can be done, and lots of people do it. for slower stuff, you can drive in low range alot and just shift through the gears...ie 5th gear in low range for speeds under 45 (or whatever it happens to be).

light tires rob less hp and that helps compensate for the bad gearing....

try it and see how it goes...worst comes to worst, you buy big tires and end up shelling out more loot for gears, or you just sell the tires and go back to 32s <img src="/forums/images/graemlins/cheers.gif" alt="" />

It's bad on the clutch, because now it will be like starting out in 2nd gear all the time.
Basically, the gears compensate for the size, and somewhat, the rolling resistance, (if you get lower gear like a 5.29 instead of a 4.88 with 35's) with a bit higher rev's.
Remember that hill you used to climb in 3rd? now it's going to be second... remember you're basically cutting off first gear...
I'd do it for alittle while then get gears... but wouldnt want to drive it like that forever.

Huh? Ok now you lost me.
Why would you cut off 1st? Aren't you basically making each gear "longer" so that you don't shift until a higher rate of speed than you were before? Shouldn't you lose the use of 5th?
E.g. at 5 mph, you were at 1500 RPM. Now you will be only 1200. 10 mph = 3000, you'd be about to shift... but now its 2400, not shifting yet.
What am I missing here?

Yes I see how this would make it take longer to get to a higher rate of speed (b/c you aren't in the higher RPMs as soon) - but many vehicles had 4 spd transmissions and seem OK, that's how my auto is now.

For example, W56 vs W56- 25% vs A340h:\

--------W56-----W56-25%--A340h
1st-----3.954---2.9655---2.8
2nd-----2.141---1.60575--1.53
3rd-----1.384---1.038----1
4th-----1-------0.75-----0.71
5th-----0.85----0.6375

Still overgeared compared to the auto tranny...

I guess I don't see why it matters if you're in 2nd gear instead of 3rd- IF the RPMs are in the same place, right?
My pointis that losing a WHOLE gear is better (maybe?) than losing 1/2 of one...?

A bigger tire changes your overall gear ratio at the wheel. Say you are running 4:10 with the bigger tires the overall ratio is now higher putting more strain on the clutch on take off. That is where the damage occurs on take off; you have to slip the clutch more to take off causing the clutch to heat up. Causing hot spots on the flywheel, disc and pressure plate. Hot spots causing chattering.

I know first hand, I run 4:88 gears with a true 36" tire and if I am in the in two or four high I can feel it in how much I have to slip the clutch for a smooth take off. My only redeeming feature, my truck is a trailer queen and very rarely sees the high range

Another thing is it very rarely sees fifth gear when in the high range.

A good example is land speed cars, them push them up to a certain MPH before the let the clutch out. Reason, they are so high geared that they risk burning the clutch out if they try to take off by themselves from a standing start. The lake car I pitted on had to be up to 30 MPH before the engarged the clutch.