Diff Gears for 100 series (2 Viewers)

[sleeoffroad]

I hear ya, though I think I side on my locker installer's opinion (no offense) combined with the fact the 100's powertrain is notably upsized in torque compared to the 80. My installer said that because the gear was thicker (more area and mass the better) and it had more splines (another plus), and the fact they had 80 gears there to compare, that their opinion was the 100 gear was notably stronger. Who's correct? Who knows.

Uhm, the gears do not have splines (OK the pinion does) So that is irrlevant. Both Carl and me used the Toyota axles with 32 splines. So no loss there. Also Carl works for Randy's so I figure he pretty much knows what he is talking about as well.

I have no problems running the 80 gears in the rear. Carl's way is pretty elegant and good thing he got to it. I think the way he did it for the E-locker axle is well worth doing, since you only need some additional parts. Just think about the "install kit" costing a little more.

The tickness of the gear is not going to matter much since it also gains strength bolted to the carrier. Also 80 gears uses a bolt and nut to secure and 100 gears use a bolt into the gear. So, what is stronger there? It is all speculation at this point. Bottom line the benefit of regearing far outweighs the possible introduction of a slight weakness.

Is it better to have more wheelspin and have more stress on the whole drivetrain, then to crawl over the same obstacle. I will take the gears anytime.

I have never seen a 80 rear diff broken. Not even with 40" tires etc etc. We have broken just about any other part, including rear 80 series 30 spline axles shafts, but never the diff (in particular the ring and pinion). Also you are more likely to snap the pinion shaft and maybe Carl did measure both to compare.

 

[ShottsUZJ100]

I have never seen a 80 rear diff broken. Not even with 40" tires etc etc. We have broken just about any other part, including rear 80 series 30 spline axles shafts, but never the diff (in particular the ring and pinion). Also you are more likely to snap the pinion shaft and maybe Carl did measure both to compare.

Wow, I've never read that. I know you've stood behind the swap and you know 80's better than maybe anyone. Of course I hesitate because of the huge investment I have in my truck. Your above paragraph has me doubting my stance on being conservative. Perhaps I'll contact you...again, about this. Hmmm, never seen an 80 rear diff/R&P fail. wow.

 

[montocr]

100 gear

My theory for the design change in the gear does not involve strength. The ring gear is thicker to allow the bolt holes to be tapped in below the teeth. A through bolt is stronger (like an 80), but more costly to manufacture as well as assemble. The only splines on the gearset are on the pinion, and they are the same on both. They use all the same bearings, crush sleeve, seal, etc. The only difference is a thicker gear to allow a threaded ring gear, rather than a through bolt. I have personally built about 4000 differentials and work with this stuff everyday, and these areas are not to be of any concern.
Carl

 

[ShottsUZJ100]

My theory for the design change in the gear does not involve strength. The ring gear is thicker to allow the bolt holes to be tapped in below the teeth. A through bolt is stronger (like an 80), but more costly to manufacture as well as assemble. The only splines on the gearset are on the pinion, and they are the same on both. They use all the same bearings, crush sleeve, seal, etc. The only difference is a thicker gear to allow a threaded ring gear, rather than a through bolt. I have personally built about 4000 differentials and work with this stuff everyday, and these areas are not to be of any concern.
Carl

Wow. I'm CONVINCED! I hated adding lockers because it opened up my 100 to the outside world. The thought of changing the rear end freaks me more. Sounds like an option though based on you and Mr. Slees experience. Cost? Considering I already have the ARB lockers in?

 

[ShottsUZJ100]

Oh, and one last thing to Slee and Carl: Thanks for not staying silent, but rather responding to my objections in a head-on matter. It's through your knowledge and persistance that I'm now convinced and it looks like I'll benefit from that down the road.

 

[cruiser99]

Guys,

Thanks for the interesting discussion (I was afraid for a moment it would turn into another 100 vs. 80 pissing match), at any rate John, right now I am interested in the facts.

Carl, back to my questions. What are the additional parts (80's or otherwise) above and beyond the usual re-gear hardware? And also, what gears did you use?

This info will be greatly appreciated,
Thanks, Doron.

BTW Just came back from Broken Arrow, Sedona – the killed the trail. I guess they did a lot of repair work due to the recent rains and over did it. I would rank it 1 (1-5 scale) now. Still pretty as ever, though. Just thought you might like to know

 

[ShottsUZJ100]

Guys,

Thanks for the interesting discussion (I was afraid for a moment it would turn into another 100 vs. 80 pissing match), at any rate John, right now I am interested in the facts.

Carl, back to my questions. What are the additional parts (80's or otherwise) above and beyond the usual re-gear hardware? And also, what gears did you use?

This info will be greatly appreciated,
Thanks, Doron.

BTW Just came back from Broken Arrow, Sedona – the killed the trail. I guess they did a lot of repair work due to the recent rains and over did it. I would rank it 1 (1-5 scale) now. Still pretty as ever, though. Just thought you might like to know

I spoke to Brad today during our run down FH42 about the 80 swap into the 100. He himself doesn't see it a big deal either, just added expense. He figures that even though the 100 rear gears might be stronger than the 80 gear (he did say the 100 rear end (axles, etc) are stronger than the 80s...so who knows on the gear?) he said the rear gears in the 80 are very strong and should hold up OK. So, he is in aggreement pretty much with Cristo. Sounds like all good news for you.
(OK, here come the 80 vs 100 hate comments because Brad said the 100 rear end is stronger )

 

[sleeoffroad]

Cost? Considering I already have the ARB lockers in?

Carl's method is for e-lockered rear axles. If you have ARB's then you need to do the Slee LX470 method. Kinda same thing, just with ARB parts and not Toyota parts. Also some machining involved.

 

[i4c4lo]

Hey guys,

So what are the parts needed for this job? I would like to do it as well, hopefully before Moab. I guess the front is straight forward. I am basically looking for the rear parts that are needed. I do have the factory lockers in the rear. Thanks!

Amando