Which ratio gears are considered the strongest? the weakest?
Ring and Pinion Strength between ratios
- Thread starter thetoyotaman
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The strongest ratios have pinion gears w/ the most teeth, i.e. numerically smaller.
Downey
SILVER Star
I.E. as the ratio goes lower, there becomes more teeth on the ring gear and fewer on the pinion shaft. This in turn makes the ring gear stronger and the pinion shaft weaker (base root below the teeth). I'm not sure what the relation is between % of lower ratio vs % of weakness, but I've always thought of it in these terms:
(a) I install 20% larger tire.
(b) I then install 20% lower gears.
(c) my power and correct spedo reading have now been
restored.
(d) My truck in now 40% weaker than a stock truck because
20% weaker gear with 20% more work load equals 40%.
(a) I install 20% larger tire.
(b) I then install 20% lower gears.
(c) my power and correct spedo reading have now been
restored.
(d) My truck in now 40% weaker than a stock truck because
20% weaker gear with 20% more work load equals 40%.
Last edited:
- Thread starter
- #4
So, what are most people running with 36's? The ratio charts seems to say to go with 4.88's to keep the same RPM as my 3.73's. But, I'm wondering if going with 5.29's is better?
You will be fine with 4.88's.
5.29's are not something that I would want to install into a semi-float rear axle because of the amount of ring gear tooth that would need to be removed in order to get the spider gear pinion shaft removed from the differential housing, to permit the removal of the c-clips that retain the axle shafts into the axle housing.
5.29's are not something that I would want to install into a semi-float rear axle because of the amount of ring gear tooth that would need to be removed in order to get the spider gear pinion shaft removed from the differential housing, to permit the removal of the c-clips that retain the axle shafts into the axle housing.
- Thread starter
- #6
Do 4.88's require grinding?
Yes, but not nearly as much as a 5.29 would.
Any gear set beyond 4.11 will require some of a ring gear tooth removed to get at the spider gear pinion shaft.
- Thread starter
- #8
Thanks. This is great help. Do lower ratio transfer case gears offer a better option for strength?
- Thread starter
- #10
What I mean is that if I stick with OEM 3.73's or 4.11's and opt to put in new t/f case gears, is that a better option for drivetrain strength. I would keep the axle strength. Would the t/f case strength be less or better than going with 4:88's. I've seen some gears with something like a 3:1 better low range and at the same time you can get an 8% underdrive in the high range.
Yes those Marks gear sets from Australia can offer that gearing to a split-case Land Cruiser. I would suggest installing a non-USA H41 transmission at the same time of the re-gear of the transfer case so as to save yourself the labor/parts expense of tearing down the transfer case to swap it over to an H41 when you decide that you just do not have low enough gearing.
However, it really depends on what you want your tire size to be, and what you intend on using your truck for.
- Thread starter
- #12
I wonder if the Mark's gears being a different ratio are weaker than stock t/f case gears?
What are you looking to do with your Land Cruiser?
If you are going to pound the hell out of it, then those gears are not going to be money well spent, as better gearing can be had in a new, significantly stronger transfer case, but at the cost of a new rear axle and transmission.
If you are going to be trail riding your truck, those gears will last you a long time.
