Interesting. My overland trailer is only 3500 dry, so I've been thinking 4.3 is good enough with 35s and that trailer. Been thinking about a more traditional hard sided RV in the 7k l lb range. You're happy with 4.3s pulling that weight?
DIY 4.3 Re-Gear (1 Viewer)
- Thread starter TeCKis300
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I would pick 4.3s again. Every time.
The 5.7L is a brute and doesn't need the gearing that lower end Toyota's need. IMO, the reason to do 4.88s is for a super low rock crawling ratio...maybe.
I think it's easy to get drawn into the more is better, but for gearing, it's a balance. Gears don't make HP. Once at speed, so long as the right ratio is available to put the engine in the powerband, it'll do the deed, and excess RPM isn't good for efficiency. It's also little talked about but the factory torque converter lock-up logic is programmed for the certain ratio. Deviate too far, and IMO 4.88s are too far, and the lockup strategy will be compromised causing more heat in the torque converter and lost MPGs at the pump.
4.3s work so well returning gearing with 35s just a bit better than stock. Everything is as intended and shift points are on point.
Thanks, sorry to pepper with questions but I'm confused about something in the OP. The pinion flange on the 100 series... it's smaller than ours, so it needs to be swapped from mine?
My plan would be to make everything as drop-in(and reversible) as possible. Just trying to sort all that out.
bloc
SILVER Star
No, the locating circle and bolt circle are identical, it’s the splined section of the pinion itself and presumably the small pinion bearing that are smaller on the 100-series. This has no impact on transferability, other than you needing to source 100-series pinion and bearings vs 200 if it ever needs rebuild.
Toyota must have felt some need to increase the spline count, likely having to do with increased torque levels and mass in the 200 platform. If you want to be really OCD about things you can source 200 4.3s and build the diff chunk, but until people beating the crap out of 100s start having them fail I don’t think the smaller pinion is much of a concern for us.
Short story: it’ll bolt right in, but ultimately may not be quite as strong as a 200-series chunk. But that probably doesn’t matter.
There’s an online aggregator of junk yards…it’s either car-part.com, carpart.com, or copart.com I think.
Generally, I saw that tundra front diffs were cheap ($175-$250).
Land cruiser/lx470’s were a bit more. 4.10’s will likely have fewer miles and me cheaper than 4.30’s. I think they were like $400-$500 a piece (for the 4.10’s) when I was looking.
I think the lx570’s and lc200 were like $850-$1200.
Haven’t looked lately though.
In the grand scheme of things, even if it costs like $5k-$6k…it’s still only about the price of adding front and rear lockers to a brand new vehicle when selecting the option new.
bloc
SILVER Star
A new 4.3 rear diff chunk from a 100 (41110-60880) is $2400 MSRP.. $450 or so doesn't seem too bad.
Isn't the 4.30 gear set from Toyota $700 (41201-80493 from PartSouq shipped $679.57). If you were also adding an e-locker to the rear during the swap, would it make sense to get the 4.3 gear set from Toyota and a good used Tundra front? Or am I missing some part of the equation. I guess what I'm asking is if you are doing the e-locker, does the rear end need to be reset anyways, so you aren't saving any effort by using a 100series take off lump as far as ease of install?
I'm torn between something like the above option or being lazy and taking the truck to my local cruiser shop and letting them drop Nitros in....then I have to choose between 4.88 and 4.30...
I'm torn between something like the above option or being lazy and taking the truck to my local cruiser shop and letting them drop Nitros in....then I have to choose between 4.88 and 4.30...
I already have one on the shelf, so definitely looking to use it.
But to the point of your last post, if you are only looking for the gears, if I could have 20 yr old gears out of a 100 or new ones and the price difference is only $200....Although, it's my understanding there is little to no wear on these parts, so maybe still worth saving the $200...
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- #293
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It might also help that the 3.9 gears you'll be pulling out, both for front and rear axles, have value to 2016+ cruisers. I sold my set dirt cheap to a member here which helped him and helped offset my minimal costs. 3.9s are to 2016+, what 4.3s are to pre-2016 cruisers.
bloc
SILVER Star
Way more than $200 after you factor in the cost of bearings and setup. Hell even shipping it to someone that you can actually trust to set it up will add up.
This is where my lack of understanding of all the parts that need to be replaced comes in. Off to watch the videos on OTRAMM for rebuilding 9.5" rear ends with and without E-Lockers..
bloc
SILVER Star
Zuk’s pictures and descriptions are old school but should be considered reference material for proper setup.
In short, best practice is to use all new bearings and crush spacer. Plus the installer will need enough various shims to dial in the pattern. I’ll post some pricing in a few hours.
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- #299
It's all there in the first post. The original pumpkin and parts are all applicable in the build-up with a new ring a pinion. Whether you have a complete donor pumpkin or or just new ring and pinion, doesn't really matter as replacing bearings and hardware are kind of an independent decision. If you're going to re-use hardware, it'll likely be the known condition ones coming off the cruiser anyways. Yes, there are the other minor things of shims and crush spacer.
What does this achieve? I know you have a whole gearing chart somewhere. Sorry.
