School me on 9" ratios

[Wfoyota]

Seems that the 5.43 and 6.20 9" ratios are special in some way. So what makes them special? Diving into the fab housing stuff for the first time and learning about 9s as I go. Buggy will be a fab9 and super shave 14 bolt. 14b already has 4.88 in it so it would easiest to match that in the 9 but if there is something special about the 5.43 then I could regear the 14b to 5.38. Fab axle peeps care to elborate?

For reference, talking low pinion 9.

 

[chaplinfj60]

9 inch has about every possible combo out there. it is absolutely crazy. i guess i never heard of anything special

 

[chaplinfj60]

or

 

[Wfoyota]

9 inch has about every possible combo out there. it is absolutely crazy. i guess i never heard of anything special

Matching the gears isnt a problem since I can in 5.38 down. It just seems that a lot of the comp guys are using a 5.43 or 6.20 ratio so curious if there is something special about those over others such as tooth contact or something.

 

[chaplinfj60]

my bad....

 

[FleshEater]

Matching the gears isnt a problem since I can in 5.38 down. It just seems that a lot of the comp guys are using a 5.43 or 6.20 ratio so curious if there is something special about those over others such as tooth contact or something.

It probably has more to do with the final drive ratio they want.

But this is just my uneducated guess.

 

[Sean]

5.43s are popular in the reverse cut 9" world....that's what Mega Hi 9s are made in and GearWorks has the 5.43 as the most popular one they've stocked in the past, but GW is working on 5.83s and 6.20s....all, reverse cut gears for HP applications.

 

[RunningProblem]

Who is running a 6.20 and what transmission and transfer case ratios ar why running? I’m going to agree with Fleshy and say ‘crawl ratio they want’ is the reason for 6.20s.

 

[total newb]

I would assue its because they popular ratios for circle track guys.

 

[Ghetto Fab.]

I'm guessing crawl ratio too, but I know some of the racer types complain about not having deep enough gearing also. Dirt takes a lot more power to go fast, so you don't really want to be pulling highway rpms when in the dirt. 2400 on the highway might be ok, but in the dirt its too tall. Weren't some of the racers running under drives at one point? Deeper gearing fixes that issue. No clue on the 5.43s though. That seems like an odd choice to me. With double OD transmissions now, I'm not sure deeper rear end gearing is as much of an issue as it used to be.

 

[Tydes]

I have 6.20s in my wife’s car, gives it good power in high range and takes stress off the Dana 300.

Suzuki 1.6 16v turbo, 4speed auto, kick/Dana 300, 6.20s in steering 9s, 39” krawlers

 

[Sean]

I have 6.20s in my wife’s car, gives it good power in high range and takes stress off the Dana 300.

Suzuki 1.6 16v turbo, 4speed auto, kick/Dana 300, 6.20s in steering 9s, 39” krawlers

I think that's the other big thing on lower ratios....taking stress off the parts before them in the drivetrain.

 

[AgitatedPancake]

14b was limited to a max of 5.38 at some point weren’t they? If that’s the case and you’re dead set on running a 14b for the other axle, your mind is already made up for you

I run 5.83s in my 9”s on 42s, and with the doubler the crawl ratio is fine, and it’s a nice balance for street driving (not that you’re concerned about that)

Edit - Reread the OP, this response isn't really relevant, my bad.

 

[vetteboy79]

I'm guessing crawl ratio too, but I know some of the racer types complain about not having deep enough gearing also. Dirt takes a lot more power to go fast, so you don't really want to be pulling highway rpms when in the dirt. 2400 on the highway might be ok, but in the dirt its too tall. Weren't some of the racers running under drives at one point? Deeper gearing fixes that issue. No clue on the 5.43s though. That seems like an odd choice to me. With double OD transmissions now, I'm not sure deeper rear end gearing is as much of an issue as it used to be.

I believe Randy Slawson used to race with the Atlas in 2.0:1 and an overdrive trans.

I race mine (6-speed manual and 4.88s) with the Dana 300 in 2.62:1, top speed is around 78 MPH at redline in 6th gear but there are very few places to actually hit that on any of our race courses around here, so it fits perfectly. Keeps the ratios closer with the stick shift and I don't have to mess around changing from hi to low when a crawling portion comes up.

 

[RSwenson]

Been a few years but I think the Pinion Gear Contact (Tooth Count) is greater on 5.13 than 5.38.
Seems like it was 2 tooth contact for 5.38 and 3 for 5.13???,,,, something like that.
Research that a bit.
Might matter.

 

[94toytruck]

Who is running a 6.20 and what transmission and transfer case ratios ar why running? I’m going to agree with Fleshy and say ‘crawl ratio they want’ is the reason for 6.20s.

My friend has a old comp car. It's got 60s but they are 6.17s with a 4.3/th350/D300 with stock gears. It did really well!

 

[YotaAtieToo]

I'm a fan of deep gears, less stress on tcase and driveshafts, less tq twist, more usable high range, ect. I'd bet a lot of people would really benefit from 6.xx-7.xx gears if they actually tried it.

Even some u4 guys are running 6.20s, so it's not just a underpowered toyota/suzuki thing.

I thought the op was more referring to strength though? I don't buy that ratio is the only factor in strength. Especially in 9"

Are 5.43s more aimed at offroad guys? Are most 5.43s going to actually be stronger than 5.38s in a 9"?

JR4X

 

[RunningProblem]

My friend has a old comp car. It's got 60s but they are 6.17s with a 4.3/th350/D300 with stock gears. It did really well!

So either 42:1 or 60:1. I am at 39:1 with a stock Jeep and 5.13s. I’m not good enough to use the extra 3 crawl points. If I went 4:1 in the transfe4 case I’d be at 57. Again, three crawl points.

 

[JR4X]

I'm a fan of deep gears, less stress on tcase and driveshafts, less tq twist, more usable high range, ect. I'd bet a lot of people would really benefit from 6.xx-7.xx gears if they actually tried it.

Even some u4 guys are running 6.20s, so it's not just a underpowered toyota/suzuki thing.

I thought the op was more referring to strength though? I don't buy that ratio is the only factor in strength. Especially in 9"

Are 5.43s more aimed at offroad guys? Are most 5.43s going to actually be stronger than 5.38s in a 9"?

JR4X

Hate being late to the party with all the excellent ponderings above.

MegaHi are 5.40 and Gearworks are 5.43. They are definitely stronger than 5.38’s in the same diff. Seems counterintuitive but the 5.40 and 5.43 ratios have less ring gear teeth so the teeth you do have are larger and thus stronger. The root of the tooth on the 5.40’s are yuge compared to 5.38’s. We’re actually running MegaHi gears in gearworks 3rds because the strength in tooth outweighs the minor diameter gain in the 10” GW 5.43 ratio. (Except now we’re out of mega gears so going forward will only be using GW stuff)

The reason that it seems counterintuitive to me that a coarser gear cut would be stronger. Is that we know a finer spline cut is stronger. Much stronger. But the 5.40/5.43 have proven to be stronger than the 5.38’s they replaced.

Here is a pic of 5.40’s on the left and HP9 5.38’s on the right. You can see everything about the mega stuff is bigger, compare every part of the pinion. The GW r&p have the same characteristics vs OG set.

Here is MegaHi 5.40’s next to D60 HP 5.38’s,

Another benefit to that ratio is that it matches close enough to any other axle offering. Probably because it’s so ubiquitous Gearworks went ahead and did Amboid cut high pinion 5.43’s for running in the rear. So they have two different cuts of high pinion and two different cuts of low pinion. So that no matter what you’ve got they have a gear orientation to be on the drive side of the tooth. Rear engine, flipped diffs? They got you covered. Front engine high pinion F/R? They got you covered.

Now tube works has entered the chat for real. They just debuted their true 10”+ cross tie in high pinion. Pretty sure Gomez bros racing ran one for a year to test it for Tubeworks and it must have been a successful test.

The above pictures are Tubeworks new 10 plus gears compared to a gearworks 10” r&p.

 

[Sean]

Hate being late to the party with all the excellent ponderings above.

MegaHi are 5.40

Apologies for my fuck up on the ratio and thanks for the correction. And thanks even more for the added tech info..... Too bad TubeWorks is so spendy; sure is gorgeous stuff.

 

[bdkw1]

Hate being late to the party with all the excellent ponderings above.

MegaHi are 5.40 and Gearworks are 5.43. They are definitely stronger than 5.38’s in the same diff. Seems counterintuitive but the 5.40 and 5.43 ratios have less ring gear teeth so the teeth you do have are larger and thus stronger. The root of the tooth on the 5.40’s are yuge compared to 5.38’s. We’re actually running MegaHi gears in gearworks 3rds because the strength in tooth outweighs the minor diameter gain in the 10” GW 5.43 ratio. (Except now we’re out of mega gears so going forward will only be using GW stuff)

The reason that it seems counterintuitive to me that a coarser gear cut would be stronger. Is that we know a finer spline cut is stronger. Much stronger. But the 5.40/5.43 have proven to be stronger than the 5.38’s they replaced.

Here is a pic of 5.40’s on the left and HP9 5.38’s on the right. You can see everything about the mega stuff is bigger, compare every part of the pinion. The GW r&p have the same characteristics vs OG set.

Here is MegaHi 5.40’s next to D60 HP 5.38’s,

Another benefit to that ratio is that it matches close enough to any other axle offering. Probably because it’s so ubiquitous Gearworks went ahead and did Amboid cut high pinion 5.43’s for running in the rear. So they have two different cuts of high pinion and two different cuts of low pinion. So that no matter what you’ve got they have a gear orientation to be on the drive side of the tooth. Rear engine, flipped diffs? They got you covered. Front engine high pinion F/R? They got you covered.

Now tube works has entered the chat for real. They just debuted their true 10”+ cross tie in high pinion. Pretty sure Gomez bros racing ran one for a year to test it for Tubeworks and it must have been a successful test.

The above pictures are Tubeworks new 10 plus gears compared to a gearworks 10” r&p.

Jayson is milling those on mazak integrix lathes. It allows for better tooth shape and the reinforcement ring. He even laps them in on the machines.

 

[JR4X]

Jayson is milling those on mazak integrix lathes. It allows for better tooth shape and the reinforcement ring. He even laps them in on the machines.

I like their thought process. The amount of tooth engagement is crazy. They didn’t just make the ring gear bigger OD, they also put tooth all the way to the od of the locker shrinking the ID of the ring gear. Probably a little more friction loss but the spread of contact is huge. Then they webbed the ends of the teeth together for strength. I’ll probably never be able to afford a pair of 3rds but I can appreciate all they have to offer with them. I’d call that, optimization of space.

 

[chaplinfj60]

So is this all 543 gears. The added benefits Or just GW and such

 

[JR4X]

So is this all 543 gears. The added benefits Or just GW and such

I don’t touch car low pinion stuff but I don’t think the car 9” 5.43’s you’d get from Yukon or Randy’s R&P are going to have the special sauce that gearworks does.

Yukon does have low pinion 10” diffs for racing and rock crawling and they do have the bigger pinion shanks/splines. They don’t currently have a high pinion offering in their 10”.

But to answer your question it’s going to be limited to gearworks tubeworks and megahi for the bad ass parts I think.

 

[YotaAtieToo]

I don’t touch car low pinion stuff but I don’t think the car 9” 5.43’s you’d get from Yukon or Randy’s R&P are going to have the special sauce that gearworks does.

Yukon does have low pinion 10” diffs for racing and rock crawling and they do have the bigger pinion shanks/splines. They don’t currently have a high pinion offering in their 10”.

But to answer your question it’s going to be limited to gearworks tubeworks and megahi for the bad ass parts I think.

Any idea how the peasant 9" gears compare to each other?

I feel like we had a thread on pbb about this. There seems to be a gap between standard 9" stuff and the the $1200 race gears.

 

[JR4X]

Any idea how the peasant 9" gears compare to each other?

I feel like we had a thread on pbb about this. There seems to be a gap between standard 9" stuff and the the $1200 race gears.

I’ve had good luck with Yukon peasant gears, and so have my circle track friends. I don’t know anyone running peasant gears in a crawler. I’d run them in my tracker.

 

[bdkw1]

Any idea how the peasant 9" gears compare to each other?

I feel like we had a thread on pbb about this. There seems to be a gap between standard 9" stuff and the the $1200 race gears.

Peasant gears, they 4.10 is the strongest. 4.88 is a close second. Lower gear sets the small pinion becomes more of a liability. This is why underdrives are popular. Lowers DS speed gets you into a stronger gear.

 

[Wfoyota]

Thanks for the replies everyone. High pinion and GW stuff is out of the budget for this buggy unfortunately but the want is real. So general consensus is there is nothing super special about low pinion 9 gears of different flavors except for the 35 spline pinion upgrade? I may call ECGS and see if they have a recommendation for maximum tooth contact gear ratio without getting too high.

 

[JR4X]

Thanks for the replies everyone. High pinion and GW stuff is out of the budget for this buggy unfortunately but the want is real. So general consensus is there is nothing super special about low pinion 9 gears of different flavors except for the 35 spline pinion upgrade? I may call ECGS and see if they have a recommendation for maximum tooth contact gear ratio without getting too high.

Let us know what they say. I just remembered another quality mfg worth mentioning that everyone forgets in the off-road world because they are associated with drag racing. Mark Williams enterprises has 35 spline pinion 9” gears for half of what the high pinion stuff costs. MW is starting to get into the off road market with quality American made products. We use MW billets yokes exclusively. IMO nobody else comes close to MW quality/strength on yokes.

They also make a few bling parts for 14 bolts.

 

[Wfoyota]

Let us know what they say. I just remembered another quality mfg worth mentioning that everyone forgets in the off-road world because they are associated with drag racing. Mark Williams enterprises has 35 spline pinion 9” gears for half of what the high pinion stuff costs. MW is starting to get into the off road market with quality American made products. We use MW billets yokes exclusively. IMO nobody else comes close to MW quality/strength on yokes.

They also make a few bling parts for 14 bolts.

Will do. Yea, MW stuff is solid, especially in the 14b world.