Gear Swap Info

[AlaskaVX]

I have no idea how I got 4.11's in my head? 4.30 it is

will edit other posts so noone gets confused

[SPAZZ]

477's came rare in Trooper's with Wide Tire OPtion... and yes there are 488's... I would be in for a group buy for the 488's if price was decent...will that be for new or used ring and pinions???

and yes..even with slow crawling 538's, larger tires, and a front locker will break the stock week cv's. better to replace cv's with high angle drivelines or just change out front axle for a way beefier one or SAS.

[kpaske]

From the looks of that chart, putting 33" tires on without changing the gears should give you better gas mileage. Why does this not seem to be the case? I believe my gas mileage has gone down (accounting for the 10% change in speedo/odo readings).

It seems that the 4.88 gears with 33" tires would be the combination closest to stock. I only occassionally offroad, so I'm mostly interested in on road characteristics, though I don't want to do anything to decrease the VX's stock offroading capabilities.

I would also consider mods that would make my VX peppier. I'm planning to purchase a supercharger within the next 6 months or so. Would the 4.88's be the best option for a SC VX with 33's?

[AlaskaVX]

I am just seeing if anyone is interested, because if we come up with a buch of people (20+) we can see if we could organize another group buy like the one for 5.38's on the 4x4wire board.

Is there 4.88's out there for the 12 bolt? or the 10 bolt? If not then this could get spendy ($500) But I really want them and am definately willing to throw that much cash at it.

kpaske, Yes I have 33" tires and am SCed

[kpaske]

I'm interested, but we'll have to see the final price tag. What would this include, and what else would need to be purchased?

[SPAZZ]

gear ratio means what Ring and Pinions you have. Usually when you buy gears it means you just get a front Ring and Pinion and a rear Ring and Pinion. Then you have to get the bearings, races, seals, and shims, pinion nuts, pinion seals, etc...necessary to set up your Ring and Pinions with your ratio choice up in your 3rd members. Yes, 488's are out there. each 3rd member costs around $250 for the parts to set up and then on top of that whatever $ the gear shop charges to set them up.

it is less expensive for you if you already have the 3rd members removed and you just drop them off at the gear shop, then pick them up and install them yourself. rear axle takes about an hour if every thing goes smooth...meaning no problems unforseen, such as in my case where your pinion welds itself to the outer bearing and race and will not come out

[Nazrat]

Originally posted by SPAZZ
gear ratio means what Ring and Pinions you have. Usually when you buy gears it means you just get a front Ring and Pinion and a rear Ring and Pinion. Then you have to get the bearings, races, seals, and shims, pinion nuts, pinion seals, etc...necessary to set up your Ring and Pinions with your ratio choice up in your 3rd members. Yes, 488's are out there. each 3rd member costs around $250 for the parts to set up and then on top of that whatever $ the gear shop charges to set them up.

it is less expensive for you if you already have the 3rd members removed and you just drop them off at the gear shop, then pick them up and install them yourself. rear axle takes about an hour if every thing goes smooth...meaning no problems unforseen, such as in my case where your pinion welds itself to the outer bearing and race and will not come out

You can't keep is in suspense here Spazz. What axles are you planning on swapping in for the 4.88s? Personally on my Trooper (My offroad vehicle) I'd like a low SAS with coil springs and a Toyota axle. That would let me run 4.88s up front. Then probably a matching rear Toy axle, or a Dana 44 or 9".

-Tad

[kpaske]

So should I consider an axle swap also, if I don't plan on doing much off roading? Would it give any advantages for street driving?

[t2p]

Absolutely not.
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The gearing - 4.30 ratio - is already *very* low.
.
Oops ...... forget that .......
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You did install large tires .... not sure why you installed the large tires if you don't plan on going off roading frequently .......... but that is just me ....... I'm a conservative one ........ and my opinion is about as high on the scale as plankton .....
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33's ? - OUCH ....... you may need lower gears to compensate for those monsters .... your acceleration - on the road/wherever - will suffer with 33's installed ....... lower gearing will help to reduce this .....
.
some might actually prefer the effect of the taller tires ....... I would rather cruise on the highway at 2000 rpm than 2700 ...

[MrCrowley]

I just towed a trailer twice this weekend and have an interesting observation. I had a chance to get firewood from a buddy's farm from a HUGE oak tree that fell over. The first trip was the VX pulling about 3000 lbs (trailer towing capacity). It was on a backwoods Tennessee state hwy with plenty of long grades- same route for both trucks. Of course it pulled fine. On the second trip, I needed the Trooper due to the carrying of passengers and just to balance out the miles between the two. Knowing now that the troop has 4.56 diff gears now, and the VX 4.30, I have to say that even though the troop has more weight, it did seem to maintain the edge when towing uphill. Not that it toted it uphill faster, but the tranny seemed to not have to downshift as soon and seemed to be "easier" on the vehicle. I did play around in both with the power mode on and off. The only thing I could think was what the VX would have been like with 4.56 AND lower vehicle weight. Now I know why there wasnt as much acceleration difference between the two as I expected when I first test drove the VX. Of course I was blown away by the handling! Hell, I ought to just use the diff gears between the two because it sure wold be cheap. Maybe Ill buy 4.88 for the troop, and put my troop's 4.56 in the VX. Cheap mod! If someone wants to do a 4.56 swap the advantage is that every salvaged trooper has the 3rd member and gears already in it! If you want a minor change and want it cheap thats probably the way to go.

[Maugan_VX]

Maybe Ill buy 4.88 for the troop, and put my troop's 4.56 in the VX. Cheap mod!

Theoretically, if 4.88 gears existed for our vehicles, this would be possible. It would hardly be cheap though.

4.88 gearing does not exist for our rigs, and even if it did, that little difference in ratio is not worth the cost of buying and installing a whole new gearset.

[kpaske]

Originally posted by SPAZZ
part numbers are RD44 and RD94

SPAZZ - What are these the part numbers to?

I'm seriously considering doing a gear swap in the near future, along with a supercharger in the next 6-12 months. I'm currently running 33's with stock gears and want some more power and pep, but don't want to lose too much fuel efficiency or top end power (or break my CV's) so I don't think the 5.38's are the way to go. According to the chart posted elsewhere in this thread, it seems that the 4.88 ratio would compensate for my larger tires, and possibly give me a hair more power. At least it would return the ratio back to near stock.

From my research, the 4.88's look ideal. Some say they exist, others think they don't. If they DO exist, what did they come off of and/or where could I get them from?

[lttlbddy]

1) Those are ARB Locker part numbers.

2) 4.88 gear do NOT exist for Isuzu differentials. Your choices are 4.30, 4.55, 4.77, 5.38

Steve G

[kpaske]

Well, it seems the 4.77's are extremely rare. Even if I could find them, would it be a noticable improvement over the stock 4.30? Maybe I just need to go with 5.38's and 35" tires.

Any thoughts on what else would need to be upgraded to make this combination possible?

[CIATexan]

Well if 4 30 gears is the highest gear ratio, is there anything greater (or less than that) Say like a 4:10. I need to suck some more gas milage outa this thing. What kinda milage are people getting around town and on the highway with their VX?